The Solar, Hydronics and Geothermal Technical Committee Report on Proposals for Public Review and Comment

2019 Report on Proposals

Information on IAPMO Codes and Standards Development 1. Applicable Regulations. The primary rules governing the processing of the Uniform Solar, Hydronics & Geothermal Code and Uniform Swimming Pool, Spa and Hot Tub Code are the IAPMO Regulations Governing Consensus Development. Other applicable rules include the Guide for the Conduct of Participants in the IAPMO Codes and Standards Development Process. For copies of these documents, contact the Code Development Department at IAPMO World Headquarters at 4755 E. Philadelphia Street, Ontario, CA 91761-2816 USA, or at 909-472-4100. These documents are also available at the IAPMO website at www.iapmo.org. The following is general information on the IAPMO process. All participants, however, should refer to the actual rules and regulations for a full understanding of this process and for the criteria that govern participation. 2. Technical Committee Report (TCR). The Technical Committee Report is defined as “the Report of the Technical Committee, consisting of the Report on Proposals (ROP), as modified by the Report on Comments (ROC), published by the Association.” 3. Report on Proposals (ROP). The ROP is defined as “a report to the Association on the actions taken by Technical Committees, accompanied by a ballot statement and one or more proposals on text for a new Document or to amend an existing Document.” The ROP and the ROC together comprise the Technical Committee Report. Anyone who does not pursue an issue, either in person or by designated representative in accordance with Section 7.0 (Public Review and Comment of the Regulations Governing Consensus Development), as a proposed amendment of the Report on Proposals will be considered as having their objection resolved. 4. Report on Comments (ROC). The ROC is defined as “a report to the Association on the actions taken by Technical Committees, accompanied by a ballot statement and one or more comments resulting from public review of the Report on Proposals (ROP).” The ROP and the ROC together constitute the Technical Committee Report. Anyone who does not pursue an issue, either in person or by designated representative in accordance with Section 8.0 (Public Review and Comment of the Regulations Governing Consensus Development), as a proposed amendment of the Report on Comments will be considered as having their objection resolved. 5. Appeals. Anyone can appeal to the Executive Committee concerning procedural or substantive matters related to the development, content, or issuance of any Document of the Association or on matters within the purview of the authority of the Committee. Such appeals must be in written form and filed with the Secretariat (See 9.0 of the Regulations Governing Consensus Development). Time constraints for filing an appeal must be in accordance with Section 9.0. Objections are deemed to be resolved if not pursued at this level. 6. Document Issuance. The USHGC/USPSHTC Executive Committee is the issuer of the Uniform Solar, Hydronics & Geothermal Code and Uniform Swimming Pool, Spa and Hot Tub Code. The committee acts on the issuance of a Document within sixty days from the date of the recommendation from the ROC Technical Committee Meeting, unless this period is extended by the Executive Committee. Hugo Aguilar To: IAPMO Members and Other Interested Parties Recording Secretary IAPMO Executive Date: September 9, 2019 Committee

Enclosed is your 2019 Report on Proposals (ROP). Arnold Rodio Chairman These proposals were presented to the Solar, Hydronics & Geothermal Technical Committee Swimming Pool, Spa members who met in Ontario, California on June 19, 2019. & Hot Tub Code TC All comments for consideration by the Technical Committee should be submitted to IAPMO by January 13, 2020. Lance MacNevin Chairman On May 19, 2020, the Technical Committee will consider all the comments received in Solar, Hydronics & response to the actions contained within the ROP for the Uniform Solar, Hydronics & Geothermal Code TC Geothermal Code (USHGC) and will vote on whether to modify any of their previous actions.

Following the ROP is a preprint of the USHGC, as it would appear in the event that all proposals accepted by the USHGC Technical Committee in June 2019 are ultimately approved for inclusion in the final version of the 2021 edition of the Uniform Solar, Hydronics & Geothermal Code. This preprint is provided to you as a courtesy. All changes are tentative and subject to revision. This document is not to be considered the final version of the 2021 Uniform Solar, Hydronics & Geothermal Code. Specific authorization from IAPMO is required for republication or quotation. 2021 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE TECHNICAL COMMITTEE (As of 05/29/19) NAME REPRESENTATION CLASSIFICATION Plastics Pipe Institute (PPI) Lance MacNevin, Chair Special Expert (Irving, TX) SunEarth Adam Chrisman Special Expert (Fontana, CA) Plastic Pipe and Fittings Association Michael Cudahy Manufacturer (Glen Ellyn, IL) EggGeothermal Consulting Jay Egg Consumer (Kissimmee, FL) Underwriters Laboratories, (UL LLC) Research/Standards/ Jeffrey A. Fecteau (Goodyear, AZ) Testing Laboratory Watts Water Technologies Chris B. Haldiman Manufacturer (Springfield, MO) Department of Water & Power Amir Tabakh Enforcing Authority (Los Angeles, CA) American Supply Association Jim Kendzel Manufacturer (Itasca, IL) Harvey Kreitenberg & Associates Harvey Kreitenberg Installer/Maintainer (Los Angeles, CA) Caleffi North America Cody Mack Manufacturer (Milwaukee, WI) Plumbers Local 130, UA James Majerowicz Labor (Chicago, IL) Viega LLC Jeff Matson Manufacturer (Broomfield, CO) Aztec Solar Inc. Edmond Murray User (Rancho Cordova, CA) IGSHPA Research/Standards/ Roshan Revankar (Stillwater, OK) Testing Laboratory Sunrun Mark Rodriguez Installer/Maintainer (Irvine, CA) Sound Geothermal Corporation Donald Cary Smith Special Expert (Sandy, UT) Taylor Costea IAPMO Staff FORM FOR COMMENTS ON IAPMO USPSHTC/USHGC COMMITTEE DOCUMENTS-2018

NOTE: All Comments MUST be received by 5:00 PM PST on January 13, 2020 PLEASE USE SEPARATE FORM FOR EACH COMMENT Forms to be submitted electronically and accessed at the following: http://codes.iapmo.org/form_comments_ushgc_uspshtc_2021.aspx

Date Name Tel. No. Organization Email Address

Street Address City State Zip.

Please Indicate Organization Represented (if any)

Recommendation:

Check one (see instructions)

 Add new text

 Revise text

 Delete text without substitution

Section number: Code: USPSHTC USHGC

Comment on Proposal Item number:

Proposed Text [Note: Proposed text must be in legislative format i.e., using underscore to denote wording to be inserted (wording) and strike through to denote wording to be deleted (wording)].

Statement of Problem and Substantiation/Resolution:

Are you referencing standards in your comment? Check one  Yes  No

If yes, please provide two hard copies or one electronic copy with your comment. Please note that if a standard is referenced above in your comment you must submit such standard in order for your comment to be processed. If the standard is not received by the closing date, your comment is considered incomplete and will not be processed.

Where additional supplementary materials such as tests, research papers, or other documents need to be submitted, please provide supporting material electronically. Please note that if supporting material is not received by the closing date, it will not be accepted for review by the Technical Committee. Copyright Assignment (This comment is original materials and is considered to be the submitter’s own idea based on, or as a result of, research and experience, and is not copied from another source). I hereby irrevocably grant and assign IAPMO all and full rights in copyright, in this proposal. I understand and intend that I acquire no rights, including rights as a joint author, in any publication of IAPMO in which this comment in this or another similar or analogous form is used. I hereby warrant that I am the author of this comment and that I have full power and authority to enter into this copyright assignment.  By checking this box I affirm that I am, and agree to be legally bound by the above Copyright Assignment and the terms and conditions contained therein. I understand and intend that, by checking this box, I am creating an electronic signature that will, upon my submission of this form, have the same legal force and effect as a handwritten signature. Note: If you are not the author of this comment (this text is copied from another source) please do not submit. The author of the comment must give copyright assignment (which is the submitter’s own idea based on or as a result of research, experience and is not copied from another source).

Patent Policy. IAPMO’s patent policy is to adhere fully to the ANSI patent policy. Every proponent of a code change proposal should familiarize him or herself with the ANSI patent policy which is available in its entirety at www.ansi.org/essentialrequirements. Upon receipt of a notice of an essential patent claim, IAPMO will coordinate with the claimant to ensure collection of the assurance(s) required by IAPMO’s adherence to the ANSI patent policy before the proposal that includes an essential patent claim is introduced into the code development process. INSTRUCTIONS FOR SUBMITTING COMMENTS

PLEASE READ CAREFULLY

1. Check the appropriate box to indicate whether this comment recommends adding new text, revising existing text, or delete text without substitution (see examples below). 2. Enter the appropriate comment on proposal item number that the proposed text applies to. 3. In the space identified as “Proposed Text” indicate as follows: • Where making a recommendation to “Accept as Submitted”, simply state “I request to accept the code change proposal as submitted by this public comment”. • Where making a recommendation of “Accept as Modified”, indicate the exact wording you propose based on the original proposal. (Refer to Examples for applying charging statement for adding text, deleting text and revising text) • Where making a recommendation of “Reject”, simply state “I request to reject the code change proposal by this public comment. 4. In the space titled, “Statement of Problem and Substantiation/Resolution,” state the problem that will be resolved by your recommendation and give the specific reason for your comment. 5. Where referencing a standard in your comment, such standard needs to be submitted in accordance with the Guidelines for Referencing Mandatory Standards. Please provide two hard copies or one electronic copy with your comment. Please note that if the standard is not received by the closing date, your comment is considered incomplete and will not be processed. 6. Where additional supplementary materials such as tests, research papers, or other documents, need to be submitted, please provide supporting material electronically. Please note that if supporting material is not received by the closing date, it will not be accepted for review by the Technical Committee. 7. Check the box for copyright assignment. Please note if you are not the author of this comment (this text is copied from another source) please do not submit the proposed change. The author of the comment must give copyright assignment (which is the submitter’s own idea based on or as a result of research, experience and is not copied from another source).

Note: Content of Comments shall be in accordance with Section 7.4.1 of the IAPMO Regulations Governing Consensus Development of the USHGC and USPSHTC. Failure to comply with the above requirements will result in the comment not being processed. For further information on the standards process, please contact Code Development at 909-472-4111. For technical assistance, please call 909-230-5535 or 909-218-8126, or email [email protected].

Note printed copies of the above referenced documents will not be available at the hearings.

Examples for applying charging statement for adding text, deleting text and revising text

Add new text as follows (applies only when adding a new section or all new text): Water Service. Piping from the water main or source of water supply to the water distribution piping of the building or premises served irrespective of the water meter location.

Revise text as follows (applies when revising an existing section by deleting text, adding text or both as follows): Building Supply. The pipe carrying potable water from the water meter or other source of water supply to the building or other point of use or distribution on the lot. Building supply shall also mean water service. Piping from the water main or source of water supply to the water distribution piping of the building or premises served irrespective of the water meter location.

Delete text without substitution (applies when deleting an entire section, table or both as follows): 302.0 Iron Pipe Size (IPS) Pipe. Iron, steel, brass and copper pipe shall be standard weight iron pipe size (IPS) pipe. 306.1 It shall be unlawful for any person to deposit, by any means whatsoever, into any plumbing fixture, floor drain, interceptor, sump, receptor, or device, which is connected to any drainage system, public sewer, private sewer, septic tank, or cesspool, any ashes; cinders; solids; rags; inflammable, poisonous, or explosive liquids or gas; oils; grease; or any other thing whatsoever that would, or could, cause damage to the drainage system or public sewer. TABLE OF CONTENTS

Item # Code Section Page #

001 206.0 1 001.01 205.0 2 002 208.0 3 003 302.1.2 4 004 304.1, 304.2.2 5 005 308.1.1 6 006 313.2 7 007 401.3 – 401.5 8 008 402.2, Table 901.1 9 009 205.0, 403.1 11 010 403.2. Table 403.2 12 011 403.3 14 012 403.4 15 013 405.1 16 014 405.2.1 17 015 405.4 18 016 406.0 – 406.2 19 017 406.2.2 20 018 406.2, 406.3 21 019 406.5, Table 901.1 22 020 407.4 23 021 407.5 24 022 Table 408.1, Table 901.1 25 023 Table 408.1, Table 901.1, Table 901.2 26 024 408.1, Table 408.1, Table 901.1, Table 901.2 29 025 408.4 33 026 409.3 34 027 411.4 35 028 411.4, 411.5 37 029 411.8 38 030 414.2, 414.5, 414.7 40 031 414.5.3 41 032 414.8 42 033 416.2 43 034 416.1 44 035 416.1, 416.2, 416.2.4, Table 416.2.1 45 036 417.2 48 037 417.5 49 038 417.6 50 039 501.4 51 040 501.5.4 – 501.5.4.1 52 041 501.8 54 042 501.8, Table 901.1, Table 901.2 55 043 502.5.2, Table 901.1 57 044 503.2, Table 503.3(1) – Table 503.3(4) 59 045 209.0, 701.1, 701.1.1, 701.4 – 701.11 62 046 703.2 – 703.4.2.1, Table 703.2, Table 703.3, Table 901.1 64 047 703.5, 704.0 – 704.2, 715.0, 715.5 69 048 705.0 – 705.8 70 049 706.0 – 706.4 71 050 707.0 – 707.15, 715.0, 715.6 72 051 707.0, 707.16 – 707.17.8 75 052 708.1, 708.3 – 708.8, 715.0, 715.7, Table 901.1 77 053 709.0 – 709.1 79 054 710.0 – 710.6.2.4, 715.0, 715.4 80 055 711.0 – 711.4 82 056 712.0 – 712.4 83 Item # Code Section Page #

057 713.0 – 713.3 84 058 713.0, 713.4 – 713.6 86 059 714.0 – 714.7 88 060 715.0 – 715.8 90 061 Chapter 2, Chapter 8 92 062 802.2.1, Table 802.2.1, Table 901.1, Table 901.2 128 063 Table 901.1, Table 901.2 131 064 Table 901.1, Table 901.2 132 065 Table 901.1, Table 901.2 134 066 Table 901.1 137 067 Table 901.2 138 068 Table 901.2 139 069 Table 901.1 140 070 Table 901.2 141 071 Table 901.2 142 072 Table 901.2 143 073 Table 901.1, Table 901.2 144 074 Table 901.1, Table 901.2 145 075 Table 901.1, Table 901.2 146

2019 Uniform Solar, Hydronics & Geothermal Code Preprint

Proposals

Edit Proposal

Item #: 001

USHGC 2021 Section: 206.0

SUBMITTER: Mark Eatherton Advanced Hydronics

RECOMMENDATION: Delete text without substitution

206.0 - D -

Draindown. An active solar energy system in which the fluid in the solar collector is drained from the solar energy system under prescribed circumstances.

SUBSTANTIATION: The term “draindown” should be removed as it is not referenced within this code. Draindown systems are the most problematic of all freeze protection systems and commonly experience frozen vacuum breakers, malfunctions with draindown valves, and lack of proper pipe drainage. For these reasons, draindown systems are seldomly installed and are not recommended. The removal of such language prevents the code from referencing material that is not current in the industry. It is also recommended that this term be removed from the Chapter 5 description on page vii of the Preface and from the Index on page 98.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

COMMITTEE STATEMENT: The Technical Committee does not agree with the technical substantiation provided but does agree that the term "draindown" should not be listed within the code.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 15 NEGATIVE: 1

EXPLANATION OF NEGATIVE:

CHRISMAN: Removing the definition for “draindown” does not improve the code. Historical issues with equipment reliability does not equate to future issues and the applicability of this system design in certain regions where the code may be adopted. Having reference to the term “draindown” would be valuable.

1 Proposals

Edit Proposal

Item #: 001.01

USHGC 2021 Section: 205.0

SUBMITTER: USHGC Technical Committee Proposal

RECOMMENDATION: Add new text

205.0 - C -

Certified. A formally stated recognition and approval of an acceptable level of competency, acceptable to the Authority Having Jurisdiction. [NFPA 96:3.3.10]

SUBSTANTIATION: The additional definition for “certified” is necessary as it is repeatedly mentioned throughout current and proposed code language. Utilizing an NFPA extract would be ideal, and the same definition gathered from NFPA 96 is also used within the mechanical code. For these reasons, the additional language is necessary and further enhances the USHGC.

COMMITTEE ACTION: ACCEPT AS AMENDED BY THE TC Amend proposal as follows:

205.0 - C -

Certified Person. A formally stated recognition and approval of an acceptable level of competency, acceptable to the Authority Having Jurisdiction. [NFPA 96:3.3.10] A person trained and certified by the equipment manufacturer, or by a recognized organization through a formal certification program for the system to be serviced or cleaned; that is acceptable to the Authority Having Jurisdiction.

COMMITTEE STATEMENT: The term "Certified" is being amended to "Certified Person" as the intent of the submitter was to provide terminology for a certified person and not a certified manufactured part or piece of equipment.

Additionally, the terminology provided has been replaced to further support the submitter's intent. The new definition was gathered from the Uniform Mechanical Code.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

2 Proposals

Edit Proposal

Item #: 002

USHGC 2021 Section: 208.0

SUBMITTER: Christopher Jensen UL LLC

RECOMMENDATION: Add new text

208.0 - F -

Field Evaluation Body (FEB). An organization or part of an organization that performs field evaluations of electrical or other equipment. [NFPA 70:100]

Field Labeled (as applied to evaluated products). Equipment or materials to which has been attached a label, symbol, or other identifying mark of an FEB indicating the equipment or materials were evaluated and found to comply with requirements as described in an accompanying field evaluation report. [NFPA 70:100]

SUBSTANTIATION: The term "field labeled" is used several times within Chapter 8. This term is currently not defined and without a definition may be misunderstood to imply permission to affix a listed label in the field. Since the sections containing the term "field labeled" are all extracted material from NFPA 70, and this term is defined in NFPA 70, the definition of "field labeled" needs to be extracted and placed within the USHGC to ensure proper use of this term. Additionally, the term "field evaluation body (FEB)" also needs to be extracted and placed within the USHGC as the acronym, FEB, is used within the definition of "field labeled" and may not be understood by the users of this code.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

3 Proposals

Edit Proposal

Item #: 003

USHGC 2021 Section: 302.1.2

SUBMITTER: David Mann Self

RECOMMENDATION: Revise text

302.0 Standards and Alternates. 302.1 Minimum Standards. (remaining text unchanged)

302.1.2 Standards. Standards listed or referred to in this chapter or other chapters cover materials that will conform to the requirements of this code, where used in accordance with the limitations imposed in this or other chapters thereof and their listing. Where a standard covers materials of various grades, weights, quality, or configurations, the portion of the listed standard that is applicable shall be used. Design and materials for special conditions or materials not provided for herein shall be permitted to be used by special permission of the Authority Having Jurisdiction after the Authority Having Jurisdiction has been satisfied as to their adequacy. A list of standards that appear in specific sections of this code are referenced in Table 901.1. Standards referenced in Table 901.1 shall be applied as indicated in the applicable referenced section. A list of additional approved standards, publications, practices and guides that are not referenced in specific sections of this code appear in Table 901.2. The documents indicated in Table 901.2 shall be permitted in accordance with Section 302.2.

SUBSTANTIATION: Section 302.1.2 is being revised to allow the end user to use an applicable approved standard in Table 901.2 without the additional step of an alternate method and material. All standards in Table 901.2 have been vetted and have a place in the code. To prevent confusion in the field and to prevent contradictions within the USHGC, Section 302.1.2 must be revised as the standards in Table 901.2 can be used, where applicable, without additional approval in accordance with Section 302.2.

COMMITTEE ACTION: REJECT

COMMITTEE STATEMENT: The proposed change is being rejected as it negates the current provisions for alternate methods and materials. The Technical Committee agrees that the Authority Having Jurisdiction should determine when and where the standards in Table 901.2 are applicable.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

4 Proposals

Edit Proposal

Item #: 004

USHGC 2021 Section: 304.1, 304.2.2

SUBMITTER: IAPMO Staff - Update Extracts NFPA 54 - Extract Update

RECOMMENDATION: Revise text 304.0 Accessibility for Service. 304.1 General. All Aappliances shall be located with respect to building construction and other equipment so as to permit access to the appliance. Sufficient clearance shall be maintained to permit cleaning of heating surfaces; the replacement of filters, blowers, motors, burners, controls, and vent connections; the lubrication of moving parts where necessary; the adjustment and cleaning of burners and pilots; and the proper functioning of explosion vents, whereif provided. For attic installation, the passageway and servicing area adjacent to the appliance shall be floored. [NFPA 54:9.2.1] Unless otherwise specified, not less than 30 inches (762 mm) in depth, width, and height of working space shall be provided. Exception: A platform shall not be required for unit heaters or room heaters.

304.2 Access to Appliances on Roofs. (remaining text unchanged) 304.2.2 Access Type. The inside means of access shall be a permanent or foldaway inside stairway or ladder, terminating in an enclosure, scuttle, or trap door. Such scuttles or trap doors shall be at least 22 inches by 24 inches (559 mm by 610 mm) in size, shall open easily and safely under all conditions, especially snow;, and shall be constructed so as to permit access from the roof side unless deliberately locked on the inside. At least 6 feet (1829 mm) of clearance shall be available between the access opening and the edge of the roof or similar hazard, or rigidly fixed rails or guards a minimum of 42 inches (1067 mm) in height shall be provided on the exposed side. Where parapets or other building structures are utilized in lieu of guards or rails, they shall be a minimum of 42 inches (1067 mm) in height. [NFPA 54:9.4.3.3]

SUBSTANTIATION: The above section is being revised to correlate with NFPA 54-2018 (latest version) in accordance with Section 16.0 of the IAPMO Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes (Extract Guidelines).

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

5 Proposals

Edit Proposal

Item #: 005

USHGC 2021 Section: 308.1.1

SUBMITTER: Christopher Jensen UL LLC

RECOMMENDATION: Revise text

308.0 Condensate Wastes and Control. 308.1 Condensate Disposal. (remaining text unchanged) 308.1.1 Condensate Pumps. Where approved by the Authority Having Jurisdiction, condensate pumps shall be installed in accordance with the manufacturer’s installation instructions. Pump discharge shall rise vertically to a point where it is possible to connect to a gravity condensate drain and discharged to an approved disposal point. Each condensing unit shall be provided with a separate sump and interlocked with the equipment to prevent the equipment from operating during a failure. Separate pumps shall be permitted to connect to a single gravity indirect waste where equipped with check valves and approved by the Authority Having Jurisdiction. Motor operated condensate pumps rated 600 volts or less shall be listed and labeled in accordance with UL 778.

Note: UL 778 meets the requirements for a mandatory reference standard in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

SUBSTANTIATION: Section 308.1.1 is being revised to include provisions for motor operated condensate pumps by requiring such pumps to be listed and labeled in accordance with UL 778.

The addition of UL 778 is necessary as it covers component specifications, electrical and fire enclosures, internal wiring, parts in contact with potable water, mechanical assemblies, protection against corrosion, supply connections, performance, ratings, and markings for motor operated condensate pumps rated 600 volts or less.

Including UL 778 within this code provides consistency and clarity for AHJ’s, manufacturers, and testing labs as to an appropriate product standard. Adding UL 778 to Section 308.1.1 is consistent with a similar reference in Section 310.1 for circulators and pumps.

Additionally, UL has 21 manufacturers that currently have condensate pumps listed to UL 778.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

6 Proposals

Edit Proposal

Item #: 006

USHGC 2021 Section: 313.2

SUBMITTER: Lance MacNevin Plastic Pipe Institute

RECOMMENDATION: Add new text

313.0 Heat Exchangers. 313.2 Shutoff Valves. Shutoff valves shall be installed on the supply and return side of a heat exchanger. Exception: Where a heat exchanger is an integral part of a boiler or is a part of a manufactured boiler and heat exchanger packaged unit, and is capable of being isolated from the hydronic system by supply and return valves.

SUBSTANTIATION: Section 313.2 is being proposed to include provisions for shutoff valves to be installed with heat exchangers. Shutoff valves installed on both the supply and return side of heat exchangers ensures safe disconnect from any piping to allow for maintenance and repair when needed.

Heat exchangers that are integral with boilers as well as boiler heat exchanger packaged units are excluded from this provision as long as they may be isolated from the hydronic system by means of the supply and return valves.

The proposed language provides clarification for the end user and further enhances the code.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

7 Proposals

Edit Proposal

Item #: 007

USHGC 2021 Section: 401.3 - 401.5

SUBMITTER: Lance MacNevin Plastic Pipe Institute

RECOMMENDATION: Revise text

401.0 General.

401.3 Water Hammer Protection. The flow of the hydronic piping system shall be controlleddesigned to prevent water hammer. 401.4 Terminal Units. Terminal units, valves, and flow control devices shall be installed in accordance with the manufacturer’s installation instructions. 410.4401.5 Return-Water Low-Temperature Protection. (remaining text unchanged)

(renumber remaining sections)

SUBSTANTIATION: Section 401.3 is being revised to clarify that the piping system installed must be designed to prevent water hammer from occurring. Controlling the flow of the hydronic piping is not the only method of preventing water hammer. Adjusting the length of the piping as well as installing water hammer arrestors and check valves are piping design methods that effectively prevent such occurrences. For these reasons, the provisional language has been amended.

A terminal unit is a component of the hydronic system that receives heat and provides it to a room or space. Hydronic systems are composed of an energy source (boiler, water heater, or chiller), in combination with pumps and piping that connect the energy source to terminal heat-transfer units. There are multiple types of terminal units that can be selected from in relation to the application and budget of the installer/user. For this reason, the terminal units must be installed in compliance with the manufacturer’s installation instructions, and all connecting valves and flow control devices must be compatible with the terminal units.

Section 410.4 has been relocated to Section 401.5 as this language is better suited under “General” provisions rather than provisions for “System Controls”.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

8 Proposals

Edit Proposal

Item #: 008

USHGC 2021 Section: 402.2, Table 901.1

SUBMITTER: Lance MacNevin Plastic Pipe Institute

RECOMMENDATION: Add new text

402.0 Protection of Potable Water Supply.

402.2 Chemical Injection. Where systems include an additive, chemical injection or provisions for such injection, the potable water supply shall be protected by a reduced-pressure principle backflow prevention assembly listed or labeled in accordance with ASSE 1013. Such additive or chemical shall be compatible with system components.

(renumber remaining sections)

TABLE 901.1 REFERENCED STANDARDS STANDARD REFERENCED STANDARD TITLE APPLICATION NUMBER SECTIONS Reduced Pressure Principle Backflow Preventers and Reduced Backflow ASSE 1013-2011 402.2 Pressure Principle Fire Protection Backflow Preventers Prevention

(portions of table not shown remain unchanged)

Note: ASSE 1013 meets the requirements for a mandatory reference standard in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

SUBSTANTIATION: The addition of Section 402.2 is needed for further provisions on protecting the potable water supply from additives and chemical injections. Backflow prevention assemblies are necessary as they prevent contaminants from being drawn up into the potable water system when there is a higher pressure on the contaminant side in relation to the potable water supply side.

ASSE 1013 is provided as it lists performance requirements for reduced pressure principle backflow preventers. The standard also provides material requirements, compliance and hydrostatic backpressure testing procedures, and installation guidelines. The standard requires that such assemblies be equipped with two independent acting check valves separated by an intermediate chamber that is hydraulically operated to vent to the atmosphere. Such requirements ensure that the pressure on the contaminant side does not exceed that of the potable water side. For these reasons, the addition of standard ASSE 1013 is appropriate and aids in protecting the potable water supply.

Additionally, chemical compatibility is a necessary requirement to prevent damage to system components and piping.

COMMITTEE ACTION: ACCEPT AS AMENDED BY THE TC

9 Amend proposal as follows:

402.0 Protection of Potable Water Supply.

402.2 Chemical Injection. Where systems include an additive, chemical injection or provisions for such injection, the potable water supply shall be protected by an air gap, or a reduced-pressure principle backflow prevention assembly listed orand labeled in accordance with ASSE 1013. Such additive or chemical shall be compatible with system components.

(renumber remaining sections)

(portions of table not shown remain unchanged)

COMMITTEE STATEMENT: The phrase "listed or labeled" allows for the choice between the two, where manufactured equipment actually must be "listed and labeled." From a technical perspective, listing and labeling are meant to be used in conjunction.

Additional language is required to clarify that systems utilizing an air gap device do not also require a backflow prevention assembly.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

10 Proposals

Edit Proposal

Item #: 009

USHGC 2021 Section: 205.0, 403.1

SUBMITTER: Mark Eatherton Advanced Hydronics

RECOMMENDATION: Revise text

403.0 Capacity of Heat Source. 403.1 Heat Source. The heat source shall be sized to the design load or the connected load, whichever is more.

205.0 – C – Connected Load. The total amount of heat required by all heat-consuming end-uses served by a single heat source in a system.

SUBSTANTIATION: Section 403.1 is being modified to include considerations for any connected loads when sizing a heat source to be incorporated into a hydronic system. In addition to the design space heating load, other loads such as domestic hot water, may also be present within a system. Properly sizing the heat source ensures that the system works efficiently. An undersized heat source will constantly run and cause increased wear on the unit, and an over-sized heat source unit will cycle on and off too often.

Such language is necessary as it provides clarification for proper sizing of heat sources needed for system efficiency.

A definition for the term “connected load” has been added for further clarification on the proposed language added to Section 403.1. Such addition is necessary to ensure that the sizing requirements of Section 403.1 can be properly met.

The “connected load” in this case refers to the combined heat requirements of all heat consuming components connected to a single heat source.

COMMITTEE ACTION: REJECT

COMMITTEE STATEMENT: It is not always required that the heat source be sized to the connected load. Hybrid hydronic systems rarely go to the full load of the system.

Additionally, radiant heating systems may have a very high potential output, and sizing the heat source based on this would not be appropriate. For these reasons the item is being rejected.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

11 Proposals

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Item #: 010

USHGC 2021 Section: 403.2, Table 403.2

SUBMITTER: Lance MacNevin Plastic Pipe Institute

RECOMMENDATION: Revise text

403.0 Capacity of Heat Source.

403.2 Dual Purpose Water Heater. Water heaters utilized for combined space-and water-heating applications shall be listed andor labeled in accordance with the standards referenced in Table 403.2, and shall be installed in accordance with the manufacturer’s installation instructions. The total heating capacity of a dual purpose water heater shall be based on the sum of the potable hot water requirements and the space heating design requirements corrected for hot water first-hour draw recovery.

TABLE 403.2 WATER HEATERS TYPE STANDARDS Gas-Fired, 75 000 Btu/hr or less, Storage CSA Z21.10.1 Gas-Fired, aAbove 75 000 Btu/hr, CSA Z21.10.3 Storage, Circulating and Instantaneous Electric, sSpace hHeating UL 834 Solid fFuel-Fired, hydronic UL 2523 For SI units: 1000 British thermal units per hour = 0.293kW

SUBSTANTIATION: Section 403.2 is being revised to show “listed or labeled” to provide clarification that water heaters do not need to be both listed and labeled. Both listing and labeling are completed by nationally recognized laboratories that make periodic inspections, determine compliance with nationally recognized standards, and test equipment for specified use. The requirement for both would be redundant and unnecessary.

Table 403.2 is also being updated to incorporate correct titles and descriptions of the types of water heaters covered by the provided correlating standards.

COMMITTEE ACTION: ACCEPT AS AMENDED BY THE TC Amend proposal as follows:

403.0 Capacity of Heat Source.

12 TABLE 403.2 WATER HEATERS TYPE STANDARDS Gas-Fired, 75 000 Btu/h or less, Storage CSA Z21.10.1 Gas-Fired, Above 75 000 Btu/h, Storage, CSA Z21.10.3 Circulating and Instantaneous Electric, Space Heating UL 834 Solid Fuel-Fired UL 2523 For SI units: 1000 British thermal units per hour = 0.293kW

The revisions and updates made to Table 403.2 are being accepted as submitted.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

13 Proposals

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Item #: 011

USHGC 2021 Section: 403.3

SUBMITTER: Mark Eatherton Advanced Hydronics

RECOMMENDATION: Revise text

403.0 Capacity of Heat Source. 403.3 Tankless Water Heater. Tankless water heaters used in space-heating applications shall be rated by the manufacturer for space-heating applications, and the output performance shall be determined by the temperature rise and flow rate of water through the unit. The ratings shall be expressed by the water temperature rise at a given flow rate. Manufacturer's flow rates shall not be exceeded.

SUBSTANTIATION: The proposed language adds further clarification on tankless water heaters. Tankless water heaters must only be rated by the manufacturer for space heating applications when they are used to provide space heat.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

14 Proposals

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Item #: 012

USHGC 2021 Section: 403.4

SUBMITTER: Mark Eatherton Advanced Hydronics

RECOMMENDATION: Add new text

403.0 Capacity of Heat Source. 403.4 System Temperature. Where a hydronic distribution system is designed for use with a geothermal water-to-water heat pump or an air-to-water heat pump, the distribution system supply water temperature shall not exceed 120°F (49°C). Exception: Hydronic distribution systems which contain components that require the hydronic system to operate at higher temperatures.

SUBSTANTIATION: The proposed section has been added to provide a maximum supply water temperature of 120°F. This maximum temperature is within the range of what nearly all hydronic heat pumps can achieve. Lower design temperatures enhance both the heating capacity and the coefficient of performance (COP) of heat pumps. Where an existing hydronic distribution system includes heat emitters designed to operate at higher temperatures, a 120°F operating temperature may not be adequate to operate the system.

COMMITTEE ACTION: REJECT

COMMITTEE STATEMENT: The temperature provided is technically incorrect as these systems can output higher temperatures. For this reason, the item is being rejected.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

15 Proposals

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Item #: 013

USHGC 2021 Section: 405.1

SUBMITTER: Mark Eatherton Advanced Hydronics

RECOMMENDATION: Revise text

405.0 Installation, Testing, and Inspection. 405.1 Operating Instructions. Operating and maintenance information shall be provided to the building owner, shall be kept in the mechanical room, and shall be water-proof.

SUBSTANTIATION: The added language clarifies that the operation and maintenance documentation should be waterproof and should be kept in the vicinity of the equipment it addresses.

COMMITTEE ACTION: REJECT

COMMITTEE STATEMENT: The proposal is being rejected as operating and maintenance documents may not always be kept in the mechanical room. Additionally, it may be difficult to ensure that the documents are kept waterproof. Furthermore, the proposed language is overly restrictive and not enforceable.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

16 Proposals

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Item #: 014

USHGC 2021 Section: 405.2.1

SUBMITTER: Mark Eatherton Advanced Hydronics

RECOMMENDATION: Add new text

405.0 Installation, Testing, and Inspection.

405.2 Pressure Testing. (remaining text unchanged) 405.2.1 Piping Used for Combustion Venting. Where polymer-based drain, waste and vent pipe is used to vent a combustion heat source, the completed assembly shall be pressure-tested at not less than 5 psi (34 kPa).

SUBSTANTIATION: The addition of Section 405.2.1 is to include piping utilized for combustion venting. In order to prevent leakage of exhaust gasses into occupied spaces, the polymer-based DWV exhaust piping assembly must be pressure tested. The addition of this pressure test is for safety of the end user.

COMMITTEE ACTION: REJECT

COMMITTEE STATEMENT: The proposed language is being rejected as the inclusion of the term "combustion" in the title is incorrect. Additionally, no method of testing was provided for the assembly.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

17 Proposals

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Item #: 015

USHGC 2021 Section: 405.4

SUBMITTER: Mark Eatherton Advanced Hydronics

RECOMMENDATION: Revise text

405.0 Installation, Testing, and Inspection. 405.4 Oxygen Diffusion Corrosion. PEX and PE-RT tubing in closed hydronic systems shall contain an oxygen barrier. Exception: Closed hydronic systems without ferrous components in contact with the hydronic fluid.

SUBSTANTIATION: Some closed hydronic systems can have ferrous components; so PEX or PE-RT in these systems must have an oxygen barrier. Therefore, the exception should be removed.

COMMITTEE ACTION: REJECT

COMMITTEE STATEMENT: The substantiation lacks sufficient technical justification as some hydronic systems may be installed without ferrous components.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

18 Proposals

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Item #: 016

USHGC 2021 Section: 406.0 - 406.2

SUBMITTER: Lance MacNevin Plastic Pipe Institute

RECOMMENDATION: Add new text

406.0 Pressure and Safety Devices. 406.1 General. Each closed hydronic system shall be protected against pressures exceeding design limitations with not less than one pressure relief valve. Each closed section of the system containing a heat source shall have a relief valve located so that the heat source is not capable of being isolated from a relief device. Pressure relief valves shall be installed in accordance with their listing and the manufacturer’s installation instructions. 406.2 Discharge Piping. The discharge piping serving a temperature relief valve, pressure relief valve, or combination of both shall be in accordance with Section 311.3.

(renumber remaining sections)

SUBSTANTIATION: Any heated closed system is capable of developing pressures that exceed its design working pressure. Closed liquid-filled systems can develop high hydrostatic pressures with even slight temperature increases. A hydronic system is more likely to be subjected to extreme temperatures and pressures that could cause associated hazards. Pressure and temperature relief valves are necessary to prevent injury that could result from the failure of pressurized vessels and piping. Typical hydronic systems involve large complex piping circuits with valve arrangements that greatly increase the likelihood of portions of the piping system being isolated from the overpressure or over-temperature safety devices. Any portion of a system isolated from the relief valve or valves is unprotected from the danger of excessive pressures and temperatures. To ensure complete protection to all portions of a system, multiple relief valves at different locations in the system are necessary.

A safety or relief valve discharge pipe is needed to direct the discharge to a location where it cannot cause injury or property damage. The material from which the discharge pipe is constructed must be able to withstand such pressures and temperatures, as well as be able to resist the forces developed during discharge that would tend to dislocate the discharge pipe. Section 311.3 (Discharge Piping) addresses discharge piping materials as well as further provisions on discharge piping and should be referenced within Section 406.2.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

19 Proposals

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Item #: 017

USHGC 2021 Section: 406.2.2

SUBMITTER: Mark Eatherton Advanced Hydronics

RECOMMENDATION: Revise text

406.0 Heating Appliances and Equipment. 406.2 Boilers. (remaining text unchanged) 406.2.2 Noncondensing Boilers. Where the heat exchanger and venting system are not designed to operate with condensed flue gases, the boiler shall be permitted to connect directly to the panel heating system where protected from flue gas condensation. The operating temperature of the boiler shall be more than the fluid temperature in accordance with the manufacturer’s instructions. The minimum return-water temperature to the heat source shall comply with Section 410.4.

(Section 410.4 is shown for information only) 410.4 Return-Water Low-Temperature Protection. Where a minimum return-water temperature to the heat source is specified by the manufacturer, the heating system shall be designed and installed to meet or exceed the minimum return-water temperature during the normal operation of the heat source.

SUBSTANTIATION: A reference to Section 410.4 (Return-Water Low-Temperature Protection) has been added to ensure that the heating system is installed and designed to at least meet the minimum return water temperature specified by the manufacturer.

This is necessary to prevent condensation of moisture in the flue gases since noncondensing boilers are constructed of materials like carbon steel, cast iron or copper, and these materials are unable to withstand the corrosive condensate produced. This corrosive condensate will chemically eat away at the boiler’s heat exchanger as well as the inside of the vent connector. For these reasons, the additional proposed language is needed.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

20 Proposals

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Item #: 018

USHGC 2021 Section: 406.2, 406.3

SUBMITTER: Lance MacNevin Plastic Pipe Institute

RECOMMENDATION: Revise text

406.0 Heating Appliances and Equipment. 406.2 Boilers. Boilers and their controls systems shall comply with the mechanical code.

406.3 Dual-Purpose Water Heaters. Water heaters used for combined space- and water-heating applications shall be in accordance with the standards referenced in Table 403.2, and shall be installed in accordance with the manufacturer’s installation instructions. Water used as the heat transfer fluid in the hydronic heating system shall be isolated from the potable water supply and distribution in accordance with Section 313.0, Section 314.0, and Section 402.2402.0.

(Section 402.0 along with pertaining subsections are shown for information only)

402.0 Protection of Potable Water Supply. 402.1 Prohibited Sources. Hydronic systems or parts thereof, shall be constructed in such a manner that polluted, contaminated water, or substances shall not enter a portion of the potable water system either during normal use or where the system is subject to pressure that exceeds the operating pressure in the potable water system. Piping, components, and devices in contact with the potable water shall be approved for such use and where an additive is used it shall not affect the performance of the system. 402.2 Protection of Potable Water. The potable water system shall be protected from backflow in accordance with the Uniform Plumbing Code. 402.3 Compatibility. Fluids used in hydronic systems shall be compatible with all components that will contact the fluid. Where a heat exchanger is installed with a dual purpose water heater, such application shall comply with the requirements for a single wall heat exchanger in Section 313.1.

SUBSTANTIATION: Currently the mechanical code lists provisions and standards for “boilers and their control systems.” In order to correlate with such language, Section 406.2 is being revised to show “control systems” rather than “controls” as this may be confusing for the end user. Since Section 406.2 requires compliance with the mechanical code, language between the codes should be consistent to ensure that all listed provisions are clear.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

21 Proposals

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Item #: 019

USHGC 2021 Section: 406.5, Table 901.1

SUBMITTER: Lance MacNevin Plastic Pipe Institute

RECOMMENDATION: Add new text

406.0 Heating Appliances and Equipment.

406.5 Heat Pumps. Water source heat pumps shall comply with AHRI/ASHRAE/ISO 13256-1 for water-to-air heat pumps and AHRI/ASHRAE/ISO 13256-2 for water-to-water heat pumps. Air source heat pumps shall comply with AHRI 210/240. Heat pumps shall be fitted with a means to indicate that the compressor is locked out.

TABLE 901.1 REFERENCED STANDARDS STANDARD REFERENCED STANDARD TITLE APPLICATION NUMBER SECTIONS AHRI 210/240- Performance Rating of Unitary Air-conditioning & Air-Source Heat Pumps 406.5 2017 Air-source Heat Pump Equipment

(portions of table not shown remain unchanged)

Note: AHRI/ASHRAE/ISO 13256-1, AHRI/ASHRAE/ISO 13256-2, and AHRI 210/240 meet the requirements for mandatory referenced standards in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

SUBSTANTIATION: Section 406.5 has been added to provide standards to address both water and air source heat pumps. Both standards provide detailed test methods, performance requirements and marking provisions for water-source heat pumps. AHRI/ASHRAE/ISO 13256-1 specifically addresses water-to-water and brine-to-water heat pumps while AHRI/ASHRAE/ISO 13256-2 addresses water-to-air and brine-to-air heat pumps. AHRI/ASHRAE/ISO 13256-1 and AHRI/ASHRAE/ISO 13256-2 have been used in the industry since 1998 and have been reaffirmed two times without substantive changes to the requirements. AHRI 210/240 covers air source heat pumps and their classifications, markings, as well as testing and rating requirements.

The inclusion of both water and air source heat pumps is applicable to Chapter 4 (Hydronics) as these heat pumps are used in hydronic space heating applications including radiant flooring and air heating.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

COMMITTEE STATEMENT: The proposal is being accepted; however, the standards provided are only performance standards where health and safety are not addressed. Standards pertaining to health and safety must also be included. An applicable health and safety standard would be UL 60335-2-40 as mentioned by the Technical Committee.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

22 Proposals

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Item #: 020

USHGC 2021 Section: 407.4

SUBMITTER: Mark Eatherton Advanced Hydronics

RECOMMENDATION: Delete text without substitution

407.0 Expansion Tanks.

407.4 Open-Type Expansion Tanks. Open-type expansion tanks shall be located not less than 3 feet (914 mm) above the highest point of the system. An overflow with a diameter of not less than one-half the size of the supply or not less than 1 inch (25 mm) in diameter shall be installed at the top of the tank. The overflow shall discharge through an air gap into the drainage system.

SUBSTANTIATION: Open type expansion tanks are no longer installed in any new or retrofit applications. These types of tanks are not capable of reaching high operating temperatures like that of closed expansion tanks. Open tanks allow for air to migrate into the system resulting in corrosion of components. Additionally, open expansion tanks must be located above the highest heating element, in general on the top of buildings, where they may be exposed to freezing conditions.

For these reasons, open type expansion tanks and their listed provisions should be removed from the code.

COMMITTEE ACTION: ACCEPT AS AMENDED BY THE TC Amend proposal as follows: 407.0 Expansion Tanks. 407.1 General. An expansion tank shall be installed in each closed hydronic system to control system pressure due to thermal expansion and contraction. Expansion tanks shall be of the closed or open type. Expansion tanks shall be rated for the pressure of the system.

COMMITTEE STATEMENT: Open-type expansion tanks are being removed from Section 407.1 since the provisions for open-type expansion tanks are being removed in Section 407.4.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

23 Proposals

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Item #: 021

USHGC 2021 Section: 407.5

SUBMITTER: Lance MacNevin Plastic Pipe Institute

RECOMMENDATION: Add new text

407.0 Expansion Tanks.

407.5 Sizing. Expansion tanks shall be sized to accept the full expansion volume of the fluid in the system. The minimum capacity of a closed-type expansion tank shall be sized in accordance with Section 605.4.

SUBSTANTIATION: The proposed language in Section 407.5 is necessary as it addresses sizing of expansion tanks to be installed in hydronic systems. Section 407.5 also includes a reference to Section 605.4 (Minimum Capacity of Closed-Type Tank) which provides an equation for determining the minimum volume required for closed-type expansion tanks.

Sizing of expansion tanks used in hydronic systems is necessary as the tanks are utilized to accept changes in the fluid volume and density in relation to temperature gradients, maintain positive gauge pressure, and prevent cavitation at control valves.

COMMITTEE ACTION: ACCEPT AS AMENDED BY THE TC Amend proposal as follows: 407.0 Expansion Tanks.

407.5 Sizing. Expansion tanks shall be sized to accept the fulldesign expansion volume of the fluid in the system. The minimum capacity of a closed-type expansion tank shall be sized in accordance with Section 605.4.

COMMITTEE STATEMENT: The proposed text is being modified as the sizing should be based on “design” parameters rather than the full expansion volume of the fluid within the system. There is no need to size the expansion tank beyond design parameters.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

24 Proposals

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Item #: 022

USHGC 2021 Section: Table 408.1, Table 901.1

SUBMITTER: Adam Segura Self

RECOMMENDATION: Revise text

TABLE 408.1 MATERIALS FOR HYDRONICS AND SOLAR THERMAL SYSTEM, PIPING, TUBING, AND FITTINGS STANDARDS MATERIAL PIPING/TUBING FITTINGS Cross-Linked Polyethylene (PEX) ASTM F876, CSA ASSE 1061, ASTM F877, ASTM B137.5, NSF 358-3 F1807, ASTM F1960, ASTM F1961, ASTM F2080, ASTM F2098, ASTM F2159, ASTM F2735, CSA B137.5, NSF 358-3 Cross-Linked Polyethylene/ ASTM F1281, ASTM ASTM F1281, ASTM F1974, ASTM Aluminum/Cross-Linked F2262, CSA B137.10 F2434, CSA B137.10 Polyethylene (PEX-AL-PEX)

(portions of table not shown remain unchanged)

TABLE 901.1 REFERENCED STANDARDS STANDARD REFERENCED STANDARD TITLE APPLICATION NUMBER SECTIONS ASTM F1961-2009 Metal Mechanical Cold Flare Compression Fittings Fittings Table 408.1 with Disc Spring for Crosslinked Polyethylene (PEX) Tubing(WITHDRAWN) ASTM F2262-2009 Crosslinked Polyethylene/ Aluminum/ Crosslinked Piping, Plastic Table 408.1 Polyethylene Tubing OD Controlled SDR9(WITHDRAWN)

(portions of table not shown remain unchanged)

SUBSTANTIATION: The proposed modification removes reference to ASTM F1961 and ASTM F2262 as the promulgator has withdrawn the standards.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

25 Proposals

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Item #: 023

USHGC 2021 Section: Table 408.1, Table 901.1, Table 901.2

SUBMITTER: Jeff Matson Viega LLC

RECOMMENDATION: Revise text

TABLE 408.1 MATERIALS FOR HYDRONICS AND SOLAR THERMAL SYSTEM, PIPING, TUBING, AND FITTINGS

STANDARDS MATERIAL PIPING/TUBING FITTINGS ASME B16.15, ASME B16.18, ASME ASTM B42, ASTM B43, ASTM B75, B16.22, ASME B16.23, ASME B16.24, Copper/Copper Alloy ASTM B88, ASTM B135, ASTM B251*, ASME B16.26, ASME B16.29, ASME ASTM B302, ASTM B447 B16.51, ASTM F3226 ASME B16.5, ASME B16.9, ASME Steel ASTM A53, ASTM A106, ASTM A254 B16.11, ASTM A420, ASTM F3226, IAPMO PS 117 ASTM D1693, ASTM D2513, ASTM D2683, ASTM D2737, ASTM D3035, ASTM D2609, ASTM D2683, ASTM Polyethylene (PE) ASTM D3350, ASTM F714, D3261, ASTM F1055, ASTM F2165, AWWA C901, CSA B137.1, ASTM F2165, CSA B137.1, NSF 358-1 NSF 358-1 ASSE 1061, ASTM F877, ASTM F1807, ASTM F1960, ASTM F1961, ASTM F2080, ASTM F2098, ASTM ASTM F876, ASTM F2165, Cross-Linked Polyethylene (PEX) F2159, ASTM F2165, ASTM CSA B137.5, NSF 358-3 F2735, ASTM F3347, ASTM F3348, CSA B137.5, NSF 358-3 ASTM F2165, ASTM F2389, ASTM F2165, ASTM F2389, Polypropylene (PP) NSF 358-2 NSF 358-2 ASSE 1061, ASTM F1807, ASTM Raised Temperature Polyethylene (PE- ASTM F2165, ASTM F2623, ASTM F2159, ASTM F2165, ASTM F2735, RT) F2769, CSA B137.18 ASTM F2769, CSA B137.18 Cross-Linked ASTM F1281, ASTM F1974, ASTM F1281, ASTM F2165, ASTM Polyethylene/Aluminum/Cross-Linked ASTM F2165, ASTM F2434, F2262, CSA B137.10 Polyethylene (PEX-AL-PEX) CSA B137.10 Polyethylene/Aluminum/Polyethylene ASTM F1282, ASTM F1974, ASTM F1282, ASTM F2165, CSA B137.9 (PE- AL-PE) ASTM F2165, CSA B137.9 * Only Type K, L, or M shall be permitted to be installed.

26 (portions of table not shown remain unchanged)

TABLE 901.1 REFERENCED STANDARDS STANDARD REFERENCED STANDARD TITLE APPLICATION NUMBER SECTIONS Fittings, Piping and ASTM F2165-2019 Flexible Pre-Insulated Plastic Piping Table 408.1 Tubing ASTM Metallic Press-Connect Fittings for Piping and Tubing F3226/F3226M- Fittings Table 408.1 Systems 2016e1 Metal Press Insert Fittings with Factory Assembled ASTM F3347-2019 Stainless Steel Press Sleeve for SDR9 Cross-linked Fittings Table 408.1 Polyethylene (PEX) Tubing Plastic Press Insert Fittings with Factory Assembled ASTM F3348-2019 Stainless Steel Press Sleeve for SDR9 Cross-linked Fittings Table 408.1 Polyethylene (PEX) Tubing IAPMO PS 117-2018 Press and Nail Connections Fittings Table 408.1

(portions of table not shown remain unchanged)

TABLE 901.2 STANDARDS, PUBLICATIONS, PRACTICES, AND GUIDES DOCUMENT DOCUMENT TITLE APPLICATION NUMBER IAPMO PS-117-2016 Press and Nail Connections Fittings

(portions of table not shown remain unchanged)

Note: ASTM F2165, ASTM F3226, ASTM F3347, ASTM F3348 and IAPMO PS 117 meet the requirements for mandatory referenced standards in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

SUBSTANTIATION: The proposed standards are being added to further enhance Table 408.1 by providing applicable material standards for both piping and fittings to be used in hydronics and solar thermal systems.

ASTM F2165 is being added as it covers flexible, pre-insulated plastic piping systems used to convey hot and cold fluids. This includes piping systems supplied complete with plastic carrier pipe and thermal insulation. Both bonded and non-bonded insulation types are included within this standard. Carrier pipe materials covered include PEX, PE, PP, PE-RT, PEX-AL-PEX, and PE-AL-PE. The components covered are intended for both residential and commercial applications including potable water distribution systems, radiant heating and cooling systems, and hydronic distribution systems. This standard applies to both piping/tubing and fittings and should be added to both columns for PEX, PE, PP, PE-RT, PEX-AL-PEX, and PE-AL-PE.

ASTM F3226 is added to the “Fittings” column of both steel and copper/copper-alloy as it pertains to copper/copper alloy and steel press-connect fittings for use in piping and tubing systems with a maximum allowable working pressure of 300 psi. Fittings under this standard directly attach to the pipe/tubing and create a seal and restrained joint.

ASTM F3347 is added to the “Fittings” column for PEX as it covers copper alloy press insert fittings with factory assembled stainless steel press sleeves to be used with PEX tubing. Such fittings are intended for use in 100 psi systems with a maximum operating temperature of 180°F. Requirements for materials, workmanship, dimensions, and markings are also included within this standard. The components covered are intended for use in both residential and commercial applications including potable water distribution systems and under-floor heating/cooling systems.

27 ASTM F3348 covers plastic press insert fittings with factory assembled stainless steel press sleeves for use with PEX tubing. Such fittings are intended for use in 100 psi cold and hot water distribution systems with a maximum operating temperature of 180°F. The standard includes requirements for material, molded part properties, performance, workmanship, dimensions, and markings.

IAPMO PS 117 is added to the “Fittings” column for steel as it covers press and nail connections made with carbon steel fittings and Schedule 10 and 40 carbon steel pipe. The standard provides specifications for materials, physical characteristics, performance and markings.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

28 Proposals

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Item #: 024

USHGC 2021 Section: 408.1, Table 408.1, Table 901.1, Table 902.2

SUBMITTER: Lance MacNevin Plastic Pipe Institute

RECOMMENDATION: Revise text

408.0 Materials. 408.1 Pipe, Tube, Tubing, and Fittings. (remaining text unchanged)

TABLE 408.1 MATERIALS FOR HYDRONICS AND SOLAR THERMAL SYSTEM, PIPING, TUBING, AND FITTINGS STANDARDS MATERIAL PIPING/TUBING FITTINGS ASME B16.15, ASME B16.18, ASME ASTM B42, ASTM B43, ASTM B75, ASTM B16.22, ASME B16.23, ASME B16.24, Copper/Copper Alloy B88, ASTM B135, ASTM B251*, ASTM B302, ASME B16.26, ASME B16.29, ASME ASTM B447 B16.51, ASSE 1061, IAPMO PS 117 ASTM A269, ASTM A312, ASTM A554, ASTM F1476, ASTM F1548, ASTM Stainless Steel ASTM A778 F3226, IAPMO PS 117 ASSE 1061, ASTM F877, ASTM F1055, ASTM F1807, Cross-Linked ASTM F876, ASTM F3253, CSA B137.5, NSF ASTM F1960, ASTM F1961, Polyethylene (PEX) 358-3 ASTM F2080, ASTM F2098, ASTM F2159, ASTM F2735, ASTM F3253, CSA B137.5, NSF 358-3 ASTM F2389, CSA B137.11, Polypropylene (PP) ASTM F2389, CSA B137.11, NSF 358-2 NSF 358-2 ASSE 1061, ASTM F1807, Raised Temperature ASTM F2159, ASTM F2735, ASTM F2623, ASTM F2769, CSA B137.18 Polyethylene (PE-RT) ASTM F2769, ASTM D3261, ASTM F1055, CSA B137.18

(portions of table not shown remain unchanged)

29 TABLE 901.1 REFERENCED STANDARDS STANDARD REFERENCED STANDARD TITLE APPLICATION NUMBER SECTIONS ASTM A554-2016 Welded Stainless Steel Mechanical Tubing Piping Table 408.1 ASTM A778/A778M- Welded, Unannealed Austenitic Stainless Steel Piping Table 408.1 2016 Tubular Products ASTM F1476-2007 Performance of Gasketed Mechanical Couplings Fittings Table 408.1 (R2013) for Use in Piping Applications Performance of Fittings for Use with Gasketed ASTM F1548-2001 Mechanical Couplings Used in Piping Fittings Table 408.1 (R2018) Applications ASTM F3226/F3226M- Metallic Press-Connect Fittings for Piping and Fittings Table 408.1 2016e1 Tubing Systems Crosslinked Polyethylene (PEX) Tubing with ASTM F3253-2018 Oxygen Barrier for Hot- and Cold-Water HydronicPiping, Fittings Table 408.1 Distribution Systems IAPMO PS 117-2018 Press and Nail Connections Fittings Table 408.1

(portions of table not shown remain unchanged)

TABLE 901.2 STANDARDS, PUBLICATIONS, PRACTICES, AND GUIDES DOCUMENT DOCUMENT TITLE APPLICATION NUMBER IAPMO PS-117-2016 Press and Nail Connections Fittings

(portions of table not shown remain unchanged)

Note: ASSE 1061, CSA B137.11, IAPMO PS 117 and the ASTM standards meet the requirements for mandatory reference standards in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

SUBSTANTIATION: Table 408.1 is being revised to include further material standards for copper/copper alloy, stainless steel, PEX, PP, and PE-RT.

ASSE 1061 establishes minimum performance requirements for push-fit fittings and push-fit connections intended for use in hot and cold potable water distribution and hydronic heating systems in residential and commercial applications. ASSE 1061 is applicable for fittings used with PEX, copper, CPVC, and PE-RT tubing.

Stainless steel has been added due to its corrosion resistant properties, and applicable material standards have been added for piping, tubing and fittings. The listed ASTM standards for piping and tubing all address corrosion resistance, chemical composition requirements, and sizing requirements. ASTM F1476 and ASTM F3226 establish performance requirements and qualification tests required for mechanical couplings and fittings while ASTM F1548 defines classification, materials, test requirements, inspection certification, marking and packaging of fittings for use with mechanical couplings.

IAPMO PS 117 has been added to the fittings column for both copper/copper alloy and stainless steel as this standard pertains to press and nail connect fittings for both materials. This standard specifies requirements for materials, physical characteristics, performance testing, and markings.

30 ASTM F1055 covers electrofusion PE fittings and their requirements for materials, workmanship and testing performance. This standard is also applicable to PE electrofusion fittings to PEX pipe or tubing.

ASTM F3253 is a PEX standard for tubing with an oxygen diffusion barrier, including requirements for appropriate fittings. While ASTM F3253 is very similar to ASTM F876 for tubing (same dimensions) and ASTM F877 for fittings (same fitting connection performance), it also includes performance requirements for the oxygen diffusion resistance of integrated EVOH (ethylene vinyl alcohol) barrier layers, which is not part of ASTM F876. This is an important feature for those hydronic systems which need an oxygen barrier on the PEX tubing.

CSA B137.11 is the approved system standard for PP pressure pipe and fittings, which is analogous to ASTM F2389, currently listed in Table 408.1 for PP pipe and fittings. It is common to list the equivalent CSA pipe and fitting system standards with the analogous ASTM and other product standards. CSA B137.11 is currently missing from Table 408.1 and this change will improve the Table.

ASTM D3261 addresses butt heat fusion PE fittings for PE piping and tubing and includes requirements for materials, workmanship, dimensions, markings as well as sustained and burst pressures.

COMMITTEE ACTION: ACCEPT AS AMENDED BY THE TC Amend proposal as follows:

408.0 Materials. 408.1 Pipe, Tubing, and Fittings. (remaining text unchanged)

TABLE 408.1 MATERIALS FOR HYDRONIC AND SOLAR THERMAL SYSTEM, PIPING, TUBING, AND FITTINGS MATERIAL STANDARDS PIPING/TUBING FITTINGS Copper/Copper Alloy ASME B16.15, ASME B16.18, ASTM B42, ASTM B43, ASTM ASME B16.22, ASME B16.23, B75, ASTM B88, ASTM B135, ASME B16.24, ASME B16.26, ASTM B251*, ASTM B302, ASME B16.29, ASME B16.51, ASSE ASTM B447 1061, ASTM F3226, IAPMO PS 117 Steel ASME B16.5, ASME B16.9, ASME ASTM A53, ASTM A106, ASTM B16.11, ASTM A420, ASTM F3226, A254 IAPMO PS 117 Polyethylene (PE) ASTM D1693, ASTM D2513, ASTM D2683, ASTM D2737, ASTM D2609, ASTM D2683, ASTM ASTM D3035, ASTM D3350, D3261, ASTM F1055, ASTM F714, ASTM F2165, CSA B137.1, NSF 358- ASTM F2165, AWWA C901, CSA 1 B137.1, NSF 358-1 Cross-Linked Polyethylene (PEX) ASSE 1061, ASTM F877, ASTM F1055, ASTM F1807, ASTM F1960, ASTM F1961, ASTM F876, ASTM ASTM F2080, ASTM F2098, F2165, ASTM F3253, CSA ASTM F2159, ASTM F2165, ASTM B137.5, NSF 358-3 F2735, ASTM F3253, ASTM F3347, ASTM F3348, CSA B137.5, NSF 358- 3 Polypropylene (PP) ASTM F2165, ASTM ASTM F2165, ASTM F2389, F2389, CSA B137.11, NSF 358-2 CSA B137.11, NSF 358-2 Raised Temperature Polyethylene (PE-RT) ASSE 1061, ASTM F1807, ASTM F2159, ASTM F2165, ASTM ASTM F2165, ASTM F2623, F2735, ASTM F2769, CSA B137.18 ASTM F2769, ASTM D3261, ASTM F1055, CSA B137.18 Cross-Linked ASTM F1281, ASTM F2165, ASTM F1281, ASTM F1974, Polyethylene/Aluminum/Cross-Linked ASTM F2262, CSA B137.10 ASTM F2165, ASTM F2434,

31 Polyethylene (PEX-AL-PEX) CSA B137.10 Polyethylene/Aluminum/Polyethylene (PE- ASTM F1282, ASTM F2165, CSA ASTM F1282, ASTM F1974, AL-PE) B137.9 ASTM F2165, CSA B137.9 Stainless Steel ASTM A269, ASTM A312, ASTM ASTM F1476, ASTM F1548, ASTM A554, ASTM A778 F3226, IAPMO PS 117

(portions of table not shown remain unchanged)

TABLE 901.1

REFERENCED STANDARDS STANDARD REFERENCED STANDARD TITLE APPLICATION NUMBER SECTIONS ASTM A554-2016 Welded Stainless Steel Mechanical Tubing Piping Table 408.1 ASTM Welded, Unannealed Austenitic Stainless Steel Tubular Piping Table 408.1 A778/A778M-2016 Products ASTM F1476-2007 Performance of Gasketed Mechanical Couplings for Use in Fittings Table 408.1 (R2013) Piping Applications ASTM F1548-2001 Performance of Fittings for Use with Gasketed Mechanical Fittings Table 408.1 (R2018) Couplings Used in Piping Applications ASTM F1961-2009 Metal Mechanical Cold Flare Compression Fittings with Fittings Table 408.1 Disc Spring for Crosslinked Polyethylene (PEX) Tubing(WITHDRAWN) Fittings, Piping and ASTM F2165-2019 Flexible Pre-Insulated Plastic Piping Table 408.1 Tubing ASTM F2262-2009 Crosslinked Polyethylene/ Aluminum/ Crosslinked Piping, Plastic Table 408.1 Polyethylene Tubing OD Controlled SDR9(WITHDRAWN) ASTM Metallic Press-Connect Fittings for Piping and Tubing F3226/F3226M- Fittings Table 408.1 Systems 2016e1 Crosslinked Polyethylene (PEX) Tubing with Oxygen ASTM F3253-2018 Barrier for Hot- and Cold-Water Hydronic Distribution Piping, Fittings Table 408.1 Systems Metal Press Insert Fittings with Factory Assembled ASTM F3347-2019 Stainless Steel Press Sleeve for SDR9 Cross-linked Fittings Table 408.1 Polyethylene (PEX) Tubing Plastic Press Insert Fittings with Factory Assembled ASTM F3348-2019 Stainless Steel Press Sleeve for SDR9 Cross-linked Fittings Table 408.1 Polyethylene (PEX) Tubing IAPMO PS 117-2018 Press and Nail Connections Fittings Table 408.1

(portions of table not shown remain unchanged)

COMMITTEE STATEMENT: The revisions made to Table 408.1 in Items #022 and #023 are being included in addition to the changes provided in Item #024 as requested by the Technical Committee.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

32 Proposals

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Item #: 025

USHGC 2021 Section: 408.4

SUBMITTER: Lance MacNevin Plastic Pipe Institute

RECOMMENDATION: Revise text

408.0 Materials.

405.4408.4 Oxygen Diffusion Corrosion. PEX and PE-RT tubing in closed hydronic systems shall contain an oxygen barrier with an oxygen permeation rate not to exceed 4.59 E-04 grains per square feet per day (0.32 mg/m2/day) at 104 °F (40 °C). Exception: Closed hydronic systems without ferrous components in contact with the hydronic fluid.

SUBSTANTIATION: PEX and PE-RT tubing used for hydronic applications requires an oxygen barrier to prevent diffusion of oxygen molecules into the water through the piping walls. An oxygen barrier also prevents corrosion of any cast iron components or parts such as circulator pumps, fill valves and boiler heating elements. The barrier allows for PEX and PE-RT use in hot water hydronic heating applications such as radiator heating, fan coils, and radiant floor heating. The revision of this section is necessary as it provides a maximum limit for oxygen permeation through the tubing.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

33 Proposals

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Item #: 026

USHGC 2021 Section: 409.3

SUBMITTER: Lance MacNevin Plastic Pipe Institute

RECOMMENDATION: Revise text

409.0 Joints and Connections.

409.3 CPVC/AL/CPVC Plastic Pipe and Joints. Joints between chlorinated polyvinyl chloride/aluminum/ chlorinated polyvinyl chloride (CPVC/AL/CPVC) pipe orand fittings shall be installed in accordance with one of the following methods: (1) Mechanical joints shall include, but not be limited to, flanged, grooved and push-fit fittings. (2) Solvent cement joints for CPVC/AL/CPVC pipe and fittings shall be clean from dirt and moisture. Solvent cements in accordance with ASTM F493, requiring the use of a primer shall be orange in color. The primer shall be colored and be in accordance with ASTM F656. Listed solvent cement in accordance with ASTM F493 that does not require the use of primers, yellow in color, shall be permitted for pipe and fittings manufactured in accordance with ASTM D2846, 1/2 inch (15 mm) through 2 inches (50 mm) in diameter, 1/2 inch (15 mm) through 3 inches (80 mm) in diameter. Apply primer where required inside the fitting and to the depth of the fitting on pipe. Apply liberal coat of cement to the outside surface of pipe to depth of fitting and inside of fitting. Place pipe inside fitting to forcefully bottom the pipe in the socket and hold together until joint is set.

SUBSTANTIATION: Section 409.3 is being revised to clarify that joints refer to piping “and” fittings and not just one or the other. The current language is confusing and should be changed.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

34 Proposals

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Item #: 027

USHGC 2021 Section: 411.4

SUBMITTER: Lee H Stevens LH Stevens Constructors LLc

RECOMMENDATION: Revise text

411.0 Pressure and Flow Controls. 411.4 Automatic Makeup Fluid. Where an automatic makeup fluid supply fill device is used to maintain the fluid content of the heat-source unit, or any closed loop in the system, the makeup supply shall be located at the expansion tank connection or other approved location. Where an automatic makeup water supply fill device for a closed loop system is supplied by a potable water supply, the fill system shall automatically shut off flow when the supplied makeup water volume exceeds the greater of 5 gallons (19 L) or five percent of the total system fluid volume. A manual reset shall be required. Where an automatic makeup fluid fill device for a closed loop system is supplied by an isolated tank, the fluid capacity of the tank shall not exceed the greater of 5 gallons (19 L) or 5 percent of the total system fluid volume. A pressure-reducing valve shall be installed on a makeup water feed line. The pressure of the feed line shall be set in accordance with the design of the system, and connections to potable water shall be in accordance with Section 402.0 to prevent contamination due to backflow.

SUBSTANTIATION: Homeowner insurance property losses for water damage (2011-2015) are the second most frequent loss category, and second costliest per claim. Water damage from a leaking hydronic system can include mold damage, structural damage, and may render a building temporarily uninhabitable and or subject to freezing up with additional damage.

An automatic feed valve will maintain water pressure in a hydronic system, but will also continually supply a breached system at a potentially high rate of flow. Particularly if a breach occurs while a structure is unattended, the potential exists for the consequent water damage to far exceed the actual damage to the hydronic system.

As building codes and industry practices have evolved in recent decades, largely pushed by the mandates of energy codes, hydronic systems have become more susceptible to damage and leakage. 1. Setback thermostats, along with houses being left unattended, increase the risk of freeze-thaw damage. 2. Cast iron boilers have largely been replaced by high-efficiency units with low-mass stainless steel heat exchangers, which are much more subject to corrosion damage due to water quality issues. 3. High efficiency in-floor radiant heating systems inherently have a greater vulnerability to physical damage, such as fastener penetration, than traditional baseboard systems.

A code requirement to limit water release through an automatic feed valve would be a significant step towards addressing consequential damage. This proposal also specifically addresses the trade practice of use of a system feeder, in lieu of an automatic feed valve, for the purpose of limiting water release. A release volume limit as a percentage of total system volume has the intent to address and allow for the usual losses of larger volume systems.

Furthermore, the proposed language will correlate with the actions taken by the UMC Technical Committee for the 2021 code cyle. This submittal is to further the goal of having all related codes correlate in language and intent.

35 COMMITTEE ACTION: REJECT

COMMITTEE STATEMENT: The concept is viable, however, there are concerns with the application of the code change. A warning system would be beneficial, not a shut-off system.

This proposal will force all hydronic systems, from small residential radiant heating systems to large commercial systems in hotels, hospitals, etc. to utilize a series of electronic flow sensors to detect small leaks, to measure the accumulated flow of those leaks over time, and then to automatically shut-off the supply of make-up fluid to the hydronic system when a leak is detected or perceived. There are several concerns about this proposal:

1. In large hydronic systems with a significant volume of fluid (100s to 1000s of gallons), it is not unreasonable that 5 percent of the system volume is entrained air that will be released in the early days and weeks of operation of the system. According to a Taco publication, “Cold water contains dissolved gases such as oxygen, nitrogen, carbon dioxide, and the other gases that constitute air. These gas molecules are dissolved in with the water (H2O) molecules, and thus cannot be seen. A given volume of cold water at a temperature of 50ºF and pressure of 50 psi can be up to 10 percent dissolved gas molecules (90 percent H2O, 10 percent gases). As water is heated its ability to retain these gas molecules decreases. The gas molecules coalesce into tiny bubbles along the surface that is heating the water. This is usually the inside surface of the boiler’s heat exchanger. The tiny bubbles eventually merge into visible bubbles and rise upward within the boiler. This mixture of bubbles and liquid water is not desirable for the reasons cited earlier. Hence, it makes sense to “grab” the air bubbles where they are available and eject them from the system as soon as possible.”

See https://www.tacohvac.com/uploads/FileLibrary/AirElimination.pdf.

Existing air elimination devices perform this function – while the air is eliminated, make-up water or fluid replaces the expelled air. If the theoretical item described in the item was installed, then adequate make-up water of more than 5 percent of system volume would not be allowed into the system, and the hydronic system would fail. Failure includes shutting off (bad) or exploding (very bad).

2. The inclusion of a leak measurement and auto shut-off device or system can create significant safety issues in all affected buildings. This is because with most commercial and residential boilers shutting off the flow of make-up water in the case of a detected leak, or any other reason that tricks the shut-off device into thinking there is a leak, can cause the boiler to malfunction in ways that could result in boiler failure and potential explosion. This is because low water levels in boilers can “boil over” and flash to steam with a tremendous and instantaneous increase in volume, causing pressurized components such as boilers to fail. This can cause grave risk to life and limb of building occupants.

3. If a boiler has an (optional) appropriate low-water fuel cut-off control which prevents low-water levels (that could be caused by a small leak) from causing boiler failure, then the boiler would automatically shut-off after a leak of 5 gallons or 5 percent of the system volume is detected. This would deactivate the heating system for the building, possibly allowing freeze-up and damage throughout the building, lack of domestic water, frozen fire protection sprinklers, and even more serious damage in the cause of a health care facility, for instance. Having no heat on a cold winter day is far more serious than a small water leak.

4. Finally, as far as I’m aware, there are no commercially available leak measurement and auto shut-off devices that would satisfy the new requirements proposed for all types of hydronic systems. This means that new electro- mechanical devices which can measure the accumulated flow of make-up water (due to air elimination and small leaks over time) must be invented, standardized, codified, certified, and put into production in time for 2021 code implementation, at a cost that would likely add $1000s of dollars to every hydronic system using make-up water. More likely, such devices will not be available for many years, and hydronic systems will simply not be able to meet the Code. In essence, the code would then severely restrict the use of hydronic systems.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

36 Proposals

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Item #: 028

USHGC 2021 Section: 411.4, 411.5

SUBMITTER: Lance MacNevin Plastic Pipe Institute

RECOMMENDATION: Revise text

411.0 Pressure and Flow Controls.

411.4 Automatic Makeup Fluid. Where an automatic makeup fluid supply fill device is used to maintain the fluid content of the heat-source unit, or any closed loop in the system, the makeup supply shall be located at the expansion tank connection or other approved location. A pressure-reducing valve shall be installed on a makeup water feed line. The pressure of the feed line shall be set in accordance with the design of the system, and connections to potable water shall be in accordance with Section 402.0 to prevent contamination due to backflow. 411.5 Differential Pressure Regulation. Provisions shall be made to bypass excessive zone flows in excess of design velocity in a multi-zone hydronic system where the closing of some or all of the two-way zone valves is capable ofcauses excess flow through the open zones or deadheading of a fixed-speed circulator or pump.

SUBSTANTIATION: The proposed language revisions pertaining to “Pressure and Flow Controls” are similarly found in the mechanical code.

The revision to Section 411.5 is necessary for clarification on what an excessive flow would be considered. The proposed language makes clear that “excessive” refers to zone flows that are greater than the design velocity in a multi-zone hydronic system. Other revisions to Section 411.4 and Section 411.5 have been included to reflect similar provisions in the UMC.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

37 Proposals

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Item #: 029

USHGC 2021 Section: 411.8

SUBMITTER: Mark Eatherton Advanced Hydronics

RECOMMENDATION: Revise text

411.0 Pressure and Flow Controls. 411.8 Secondary Loops. Secondary loops that are isolated from the primary heat-distribution loop by a heat exchanger are closed-loop hydronic systems and shall have a pressure relief valve in accordance with Section 311.1, an expansion tank in accordance with Section 407.0, an automatic make-up system in accordance with Section 411.4, an air-removal device in accordance with Section 411.6, and an air-separation device in accordance with Section 411.7.

(Section 311.1 and Section 411.4 are shown for information only) 311.1 General. Solar thermal system components containing pressurized fluids shall be protected against pressures exceeding the design limitations with a pressure relief valve. Hydronic or geothermal system components containing pressurized fluids shall be protected against pressures and temperatures exceeding design limitations with a pressure and temperature relief valve. Each section of the system in which excessive pressures are capable of developing shall have a relief valve located so that a section is not capable of being isolated from a relief device. Pressure and temperature relief valves shall be installed in accordance with the terms of their listing and the manufacturer’s installation instructions.

SUBSTANTIATION: The proposed revision to Section 411.8 has been made to include requirements for pressure relief valves and provisions for automatic make-up systems to be used in secondary loops of hydronics systems as these components are necessary. Provisions are already listed under the referenced sections and do not need to be repeated.

COMMITTEE ACTION: ACCEPT AS AMENDED BY THE TC Amend proposal as follows: 411.0 Pressure and Flow Controls. 411.8 Secondary Loops. Secondary loops that are isolated from the primary heat-distribution loop by a heat exchanger are closed-loop hydronic systems and shall have a pressure relief valve in accordance with Section 311.1, an expansion tank in accordance with Section 407.0, an automatic make-up system in accordance with Section 411.4, an air-removal device in accordance with Section 411.6, and an air-separation device in accordance with Section 411.7.

38 COMMITTEE STATEMENT: The proposed language is being amended to remove the requirement for installation of automatic makeup systems in all closed-loop hydronic systems as this requirement is not applicable to all closed-loop hydronic systems. Additionally, this item needs further technical review.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

39 Proposals

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Item #: 030

USHGC 2021 Section: 414.2, 414.5, 414.7

SUBMITTER: Lance MacNevin Plastic Pipe Institute

RECOMMENDATION: Revise text

414.0 Radiant Heating and Cooling. 414.2 Radiant Under-Floor Heating. (remaining text unchanged)

414.5 Poured Floor Structural Concrete Slab Systems (Thermal Mass). (remaining text unchanged)

414.7 Wall and Ceiling Panels. Where piping is installed in the wall stud cavity or the ceiling joist cavity, the cavity shall be insulated with material having an R-value of not less than R-12 material. The insulation shall be installed in such a manner as to prevent heating or cooling from being lostloss from the space intended to be controlled. An air space of not less than 1 inch (25.4 mm) and not more than 3 inches (76 mm) shall be maintained between the insulation and the interior surface of the panel unless a conductive plate is installed.

SUBSTANTIATION: The revisions of the titles for Section 414.2 and Section 414.5 are for clarification for the end user. Thermal mass is a material's ability to absorb, store and release heat. Concrete in this case acts as a heat sink in warm periods and as a heat source during cooling periods. Applying a thermal mass material such as concrete is a suitable method to minimize the energy consumption of buildings or structures. Therefore, the revision of the title is applicable and necessary. Section 414.7 has also been revised to remove the word “material” as it seems redundant in the sentence.

COMMITTEE ACTION: ACCEPT AS AMENDED BY THE TC Amend proposal as follows: 414.0 Radiant Heating and Cooling. 414.2 Radiant Under-Floor Heating. (remaining text unchanged) 414.5 Poured Floor Structural Concrete Slab Systems (Thermal Mass). (remaining text unchanged) 414.7 Wall and Ceiling Panels. Where piping is installed in the wall stud cavity or the ceiling joist cavity, the cavity shall be insulated with material having an R-value of not less than R-12. The insulation shall be installed in such a manner as to prevent heating or coolingthermal energy loss from the space intended to be controlled. An air space of not less than 1 inch (25.4 mm) and not more than 3 inches (76 mm) shall be maintained between the insulation and the interior surface of the panel unless a conductive plate is installed.

COMMITTEE STATEMENT: The inclusion of the term “thermal mass” is unnecessary and, therefore, does not need to be in the title of Section 414.5. Additionally, the title of Section 414.2 is being revised to remove the term "under" as this may cause confusion and imply that there are above-floor radiant systems. Furthermore, "heating or cooling loss" is being revised to "thermal energy" as this is correct industry language.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

40 Proposals

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Item #: 031

USHGC 2021 Section: 414.5.3

SUBMITTER: Michael Cudahy Plastic Pipe & Fittings Association (PPFA)

RECOMMENDATION: Revise text

414.0 Radiant Heating and Cooling.

414.5 Poured Floor Structural Concrete Slab Systems. (remaining text unchanged)

414.5.3 Types of Tube Fasteners. Tubing that is embedded within concrete shall be fastened according to manufacturer's instructions. Unless prohibited by the manufacturer, tube fasteners include the following: (1) Ties made of wire, typically fastened to anchors such as rebar or wire mesh; (2) Plastic tube/cable ties, typically nylon, fastened to anchors such as rebar or wire mesh; (3) Staples made of metal or plastic or combination thereof, without sharp edges that would harm tube, fastened to insulation or subfloor; (4) Plastic rails with integrated tube holders intended for the specific type of tube; (5) Insulation sheets with integrated knobs for holding the specific type of tube and intended for this application. (6) Other fasteners recommended by the manufacturer.

SUBSTANTIATION: The phrase "unless prohibited" is improper language as it makes the manufacturer call out items they wish to prohibit instead of specifying what is acceptable. Not all manufacturers may include language of prohibited fasteners in their documents. The recommendation is to only refer to the manufacturer’s instructions, where they should call out acceptable methods.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 15 NEGATIVE: 1

EXPLANATION OF NEGATIVE:

MACNEVIN: I am voting against this committee action because I prefer to keep most of the original language, with revisions to address any concerns. The committee agreed to form a new "Hydronics TG" which will look into amending this proposal.

41 Proposals

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Item #: 032

USHGC 2021 Section: 414.8

SUBMITTER: Michael Cudahy Plastic Pipe & Fittings Association (PPFA)

RECOMMENDATION: Revise text

414.0 Radiant Heating and Cooling. 414.8 Tubing Fasteners. Tubing that is installed within joist spaces and subfloor panel systems shall be fastened according to manufacturer's instructions. Unless prohibited by the manufacturer, tubing fasteners shall include the following: (1) Heat transfer panel systems made of wood, aluminum or other thermally conductive materials intended for this application and the specific type of tube; (2) Staples made of metal or plastic or combination thereof, without sharp edges that would harm tube, intended for this application and the specific type of tube fastened to subfloor; and (3) Plastic rails with integrated tube holders intended for the specific type of tube. (4) Other fasteners recommended by the manufacturer.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 15 NEGATIVE: 1

EXPLANATION OF NEGATIVE:

42 Proposals

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Item #: 033

USHGC 2021 Section: 416.2

SUBMITTER: Michael Cudahy Plastic Pipe & Fittings Association

RECOMMENDATION: Revise text

416.0 Snow and Ice Melt Systems. 416.2 Types of Tube Fasteners. Tubing that is embedded within concrete shall be fastened according to manufacturer’s instructions. Unless prohibited by the manufacturer, tube fasteners include the following: (1) Ties made of wire, typically fastened to anchors such as rebar or wire mesh; (2) Plastic tube/cable ties, typically nylon, fastened to anchors such as rebar or wire mesh; (3) Staples made of metal or plastic or combination thereof, without sharp edges that would harm tube, fastened to insulation or subfloor; (4) Plastic rails with integrated tube holders intended for the specific type of tube; (5) Insulation sheets with integrated knobs for holding the specific type of tube and intended for this application. (6) Other fasteners recommended by the manufacturer.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 15 NEGATIVE: 1

EXPLANATION OF NEGATIVE:

43 Proposals

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Item #: 034

USHGC 2021 Section: 416.1

SUBMITTER: Mark Eatherton Advanced Hydronics

RECOMMENDATION: Revise text

416.0 Snow and Ice Melt Systems. 416.1 Snow and Ice Melt Controls. An automatic operating control device that controls the supply hydronic fluid temperature to the snow and ice melt area shall be installed in the system. A means shall be provided to prevent low return hydronic solution temperature in accordance with Section 410.4. Snow and ice melt systems shall be protected from freezing with a mixture of propylene glycol and water, or other approved non-toxic fluid.

SUBSTANTIATION: Section 416.1 is being revised to clarify that an approved “non-toxic” fluid may be used as a method of freeze protection for hydronic systems. This clarification is necessary as many toxic anti-freeze solutions contain silicates that tend to clog hydronic piping and disrupt pump function. Additionally, for safety reasons, only non-toxic fluids should be used in hydronics systems.

COMMITTEE ACTION: REJECT

COMMITTEE STATEMENT: The current section already addresses approved fluids; therefore, there is no need to mention "non-toxic" fluid. Additionally, the proposed language does not add further clarity to the code.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

44 Proposals

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Item #: 035

USHGC 2021 Section: 416.1, 416.2, 416.2.4, Table 416.2.1

SUBMITTER: Lance MacNevin Plastic Pipe Institute

RECOMMENDATION: Revise text

416.0 Snow and Ice Melt Systems. 416.1 Use of Chemical Additives and Corrosive Fluids. Where auxiliary systems contain chemical additives, corrosive fluids, or both not intended or designed for use in the primary system, a double wall heat exchanger shall be used in accordance with Section 313.0. The chemical additives in the auxiliary systems shall be compatible with auxiliary system components and accepted for use by the heat exchanger manufacturer. 416.1416.2 Snow and Ice Melt Controls. An automatic operating control device that controls the supply hydronic fluid temperature to the snow and ice melt area shall be installed in the system. A means shall be provided to prevent low return hydronic solution temperature in accordance with Section 410.4401.5. Snow and ice melt systems shall be protected from freezing with a mixture of propylene glycol or ethylene glycol, and water, or other approved fluid. Automotive antifreeze shall not be used.

416.1.4416.2.4 Insulation. Where a poured concrete snow melt system is installed in contact with the soil, insulation recommended by the manufacturer for such application and with a minimum R value of 5 shall be placed between the concrete and the compacted grade and be extended as close as practicable to the outside edges of the concrete.

(renumber remaining sections)

TABLE 416.1.1416.2.1 MAXIMUM LOOP LENGTHS FOR SNOW AND ICE MELT SYSTEMS1, 2 MAXIMUM ACTIVE NOMINAL TUBE SIZE TOTAL LOOP LENGTH LOOP LENGTH (inches) (feet) (feet) PE-RT orand PEX Tubing 1/2 115 140 5/8 225 250 3/4 300 325 1 450 475 Copper Tubing3 1/2 – 140 3/4 – 280

45 2 The manifolds shall be installed as close to the snow melts area as possible. 3 In concrete use not less than Type L copper water tubing. In bituminous pavement use a Type K copper water tubing.

SUBSTANTIATION: The proposed language addresses the design, installation and operation of snow and ice melting systems. Chemical additives and corrosive fluids to be used in snow and ice melt systems need to be addressed so that primary system components are not negatively affected or contaminated by such additives and fluids. This is done by the use of double wall heat exchangers which would protect the primary system components by separating the additives and corrosive fluids from the primary system. Section 313.0 provides further clarification on double wall heat exchangers and does not need to be repeated.

Automotive antifreeze is not applicable for use in hydronics systems as it degrades rubber gaskets and seals as well as clogs systems components. Automotive antifreeze is also toxic and should not be used where it may contaminate potable water lines.

COMMITTEE ACTION: ACCEPT AS AMENDED BY THE TC Amend proposal as follows:

416.0 Snow and Ice Melt Systems. 416.1 Use of Chemical Additives and Corrosive Fluids. Where auxiliary systems contain chemical additives, corrosive fluids, or both not intended or designed for use in the primary system, a double wall heat exchanger shall be used in accordance with Section 313.0. The chemical additives in the auxiliary systems shall be compatible with auxiliary system components and accepted for use by the heat exchanger manufacturer. 416.2 Snow and Ice Melt Controls. An automatic operating control device that controls the supply hydronic fluid temperature to the snow and ice melt area shall be installed in the system. A means shall be provided to prevent low return hydronic solution temperature in accordance with Section 401.5. Snow and ice melt systems shall be protected from freezing with a mixture of propylene glycol or ethylene glycol, and water or other approved fluid. Automotive antifreeze shall not be used.

416.2.4 Insulation. Where a poured concrete snow melt system is installed in contact with the soil, insulation recommended by the manufacturer for such application and with a minimum R value of 5 shall be placed between the concrete and the compacted grade and be extended as close as practicable to the outside edges of the concrete.

(renumber remaining sections)

TABLE 416.2.1 MAXIMUM LOOP LENGTHS FOR SNOW AND ICE MELT SYSTEMS1, 2 MAXIMUM ACTIVE NOMINAL TUBE SIZE TOTAL LOOP LENGTH LOOP LENGTH (inches) (feet) (feet) PE-RT and PEX Tubing 1/2 115 140 5/8 225 250 3/4 300 325 1 450 475 Copper Tubing3 1/2 – 140 3/4 – 280

For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm Notes: 1 The total PE-RT or PEX loop lengths consist of two separate sections, the active loop, and the leader length. The active loop is installed within the heated slab. The leader length is the total distance to and from the manifold and heated slab, including vertical distances. 2 The manifolds shall be installed as close to the snow melt area as possible. 3 In concrete use not less than Type L copper water tubing. In bituminous pavement use a Type K copper water tubing.

46 COMMITTEE STATEMENT: Some of the revisions to Section 416.2 (Snow and Ice Melt Controls) and Section 416.2.4 (Insulation) are being removed as these changes were not accepted during the last USHGC code cycle, and these changes were only carried over to correlate with the UMC. The Committee does not agree with the correlation of these sections. The additional provision on automotive antifreeze is, however, necessary and is being kept.

The Technical Committee agrees with the modifications to Table 416.2.1 and the addition of Section 416.1 (Use of Chemical Additives and Corrosive Fluids).

Additionally, it is not necessary to indicate "double wall" in Section 416.1. This inclusion is overly restrictive as these systems may be low-temperature and this may not allow enough heat to transfer. Furthermore, the new language does not give guidance as to what type of "auxiliary" system is being addressed.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

47 Proposals

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Item #: 036

USHGC 2021 Section: 417.2

SUBMITTER: Lance MacNevin Plastic Pipe Institute

RECOMMENDATION: Revise text

417.0 Piping Installation. 417.2 Embedded Piping Materials and Joints. Piping embedded in concrete shall be steel pipe, Type L copper tubing or plastic pipe or tubing rated at not less than 10080 psi at 180°F (689552 kPa at 82°C). Joints of pipe or tubing that are embedded in a portion of the building, such as concrete or plaster, shall be installed in accordance with Section 417.2.1 through Section 417.2.3.

SUBSTANTIATION: The above values for pressure have been updated to reflect the most current required pressure rating for steel pipe, Type L copper tubing and plastic pipe to be embedded in concrete. Such pressure ratings are required to ensure that any piping or tubing embedded in concrete are capable of withstanding any applied stresses.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

48 Proposals

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Item #: 037

USHGC 2021 Section: 417.5

SUBMITTER: Lance MacNevin Plastic Pipe Institute

RECOMMENDATION: Revise text

417.0 Piping Installation.

417.5 Condensate Drainage. Condensate drains from dehumidifying coils shall be constructed and sloped for condensate removal. Such drains shall be installed in accordance with Section 308.0.

(renumber remaining sections)

SUBSTANTIATION: To facilitate system repairs and maintenance, hydronic piping systems must be sloped and arranged to allow the transfer-medium or condensate to be drained from the system. Each trapped section of the system piping must have drain cocks, unions or some other means of opening the system to drain it. Drainage discharge to the plumbing system must also be by an indirect connection. These provisions and more are provided in Section 308.0 (Condensate Wastes and Control), and referencing this section ensures that such provisions are enforced.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

49 Proposals

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Item #: 038

USHGC 2021 Section: 417.6

SUBMITTER: Mark Eatherton Advanced Hydronics

RECOMMENDATION: Add new text

417.0 Piping Installation. 417.6 Hydronic Makeup Air Units. Hydronic makeup air units that can be affected by freezing shall be protected by an antifreeze-based hydronic solution.

SUBSTANTIATION: The proposed language is being added to address hydronic makeup air units exposed to freezing conditions. Makeup air units are important as they are needed to provide adequate airflow at the desired relative humidity for occupancy comfort. Where makeup air units may be exposed to freezing conditions, the hydronic fluid used must be antifreeze based to ensure the system is able to function. The addition of Section 417.6 is necessary and further enhances the code.

COMMITTEE ACTION: REJECT

COMMITTEE STATEMENT: The provisions listed are explicit to using antifreeze and therefore are overly restrictive. Additionally, similar language is already found in Section 401.8 (Freeze Protection). The inclusion of Section 417.6 is redundant and unnecessary.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

50 Proposals

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Item #: 039

USHGC 2021 Section: 501.4

SUBMITTER: Adam Chrisman SunEarth

RECOMMENDATION: Revise text

501.0 General.

501.4 Draining. Solar thermal system piping shall be installed to permit the draining of the system. Drainback system piping above the fluid level of the drainback reservoir shall have a slope of not less than 1/4 inch per foot (20.8 mm/m).

SUBSTANTIATION: In some circumstances, drainback solar thermal systems have solar loop piping routed below the high point level of the drainback reservoir and are not in danger of freezing. Therefore, such piping does not need to be completely drained into the reservoir in order to accomplish the intended purpose of evacuation of solar collectors and piping fluid to prevent freeze damage.

For the above reasons, the addition of the proposed language is necessary and further enhances the code.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

51 Proposals

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Item #: 040

USHGC 2021 Section: 501.5.4 - 501.5.4.1

SUBMITTER: Chelsea Salaiz V&T Carbonic Inc.

RECOMMENDATION: Revise text

501.0 General.

501.5 Materials. (remaining text unchanged)

501.5.4 Potable Water. Materials in contact with potable water shall comply with NSF 61. Piping in solar systems designed to convey potable water shall be flushed and disinfected in accordance with Section 501.5.4.1. 501.5.4.1 Disinfection of Potable Water Systems. Piping shall be disinfected prior to use where required by the Authority Having Jurisdiction. The method to be followed shall be that prescribed by the Health Authority or, in case no method is prescribed by it, the following: (1) The pipe system shall be flushed with clean, potable water until potable water appears at the points of the outlet. (2) The system or parts thereof shall be filled with a water-chlorine solution containing not less than 50 parts per million of chlorine, and the system or part thereof shall be valved-off and allowed to stand for 24 hours; or, the system or part thereof shall be filled with a water-chlorine solution containing not less than 200 parts per million of chlorine and allowed to stand for 3 hours. (3) Following the allowed standing time, the system shall be flushed with clean, potable water until the chlorine residual in the water coming from the system does not exceed the chlorine residual in the flushing water. (4) The procedure shall be repeated where it is shown by a bacteriological examination made by an approved agency that contamination persists in the system.

SUBSTANTIATION: The additional restrictions for materials in contact with the potable water supply are proposed to address the disinfection of solar system piping and components designed to convey potable water. Disinfection is required to remove or inactivate pathogens that can cause diseases in humans and animals. Direct solar thermal water heating systems heat potable water to be utilized in a building’s potable hot water distribution system. All solar thermal system piping and components (fittings, valves, etc.) must be compatible with the potable water system and must be disinfected for safe use. The inclusion of such provisions are necessary for safety reasons.

The proposed language is in accordance with Section 609.9 (Disinfection of Potable Water Systems) of the 2018 Uniform Plumbing Code and is currently an approved method for disinfection of potable water systems.

COMMITTEE ACTION: ACCEPT AS AMENDED BY THE TC Amend proposal as follows: 501.0 General.

501.5 Materials. (remaining text unchanged)

52 (1) The pipe system shall be flushed with clean, potable water until potable water appears at the points of the outlet. (2) The system or parts thereof shall be filled with a water-chlorine solution containing not less than 50 parts per million of chlorine, and the system or part thereof shall be valved-off and allowed to stand for 24 hours; or, the system or part thereof shall be filled with a water-chlorine solution containing not less than 200 parts per million of chlorine and allowed to stand for 3 hours. (3) Following the allowed standing time, the system shall be flushed with clean, potable water until the chlorine residual in the water coming from the system does not exceed the chlorine residual in the flushing water. (4) The procedure shall be repeated where it is shown by a bacteriological examination made by an approved agency that contamination persists in the system.

COMMITTEE STATEMENT: Section 501.5.4 is being revised to require compliance with the Uniform Plumbing Code rather than repeating provisions already listed there. The Technical Committee agrees that disinfection of piping used in solar thermal systems for domestic hot water applications is necessary for health and safety. For these reasons, the language is being modified.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

53 Proposals

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Item #: 041

USHGC 2021 Section: 501.8

SUBMITTER: Chelsea Salaiz V&T Carbonic Inc.

RECOMMENDATION: Revise text

501.0 General. 501.8 Auxiliary Heating. An auxiliary heating system shall be installed in conjunction with the solar thermal system and shall be adequate to provide service in the absence of solar thermal energy input. Auxiliary heating that utilizes electricity as the energy source shall be in accordance with Section 315.0. Auxiliary heating that utilizes solid fuel or fuel gas as the energy source shall be in accordance with the mechanical code.

SUBSTANTIATION: Section 501.8 is being revised to provide further clarification on the use of auxiliary systems in conjunction with solar thermal systems. The auxiliary or back-up system installed must be readily available to meet the total design load in the event that the solar thermal system is not able to meet the demand. This may occur for a number of reasons with the most likely cause being rainy/cloudy days. For these reasons, the proposed language is necessary.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

54 Proposals

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Item #: 042

USHGC 2021 Section: 501.8, Table 901.1, Table 901.2

SUBMITTER: Chelsea Salaiz V&T Carbonic Inc.

RECOMMENDATION: Add new text

501.0 General.

501.8 Water Heating Systems. Solar water heating systems shall be in accordance with IAPMO S1001.1 or ICC 900/SRCC 300. The solar collector supply and return piping shall be provided with shutoff valves for isolation of the collector loop. Where solar collectors are capable of being isolated from the remainder of the system, a suitable pressure relief valve shall be installed in the isolatable section.

(renumber remaining sections)

TABLE 901.1 REFERENCED STANDARDS REFERENCED STANDARD NUMBER STANDARD TITLE APPLICATION SECTIONS IAPMO S1001.1-2013 Design and Installation of Solar Water Heating Solar Thermal 501.8 Systems System ICC 900/SRCC 300-2015 Solar Thermal System Standard Solar Thermal 501.8 System

(portions of table not shown remain unchanged)

Note: IAPMO S1001.1 and ICC 900/SRCC 300 meet the requirements for mandatory reference standards in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

TABLE 901.2 STANDARDS, PUBLICATIONS, PRACTICES, AND GUIDES DOCUMENT NUMBER DOCUMENT TITLE APPLICATION ICC 900/SRCC 300-2015 Solar Thermal System Standard Collectors

(portions of table not shown remain unchanged)

SUBSTANTIATION: The addition of Section 501.8 is necessary as it addresses requirements for design and installation of solar water heating systems as well as includes isolation of the collector loop by means of shutoff valves.

Shutoff valves are required for manual isolation of the collector loop from the storage tank. This allows for maintenance and repair of the collector loop without disrupting the normal flow of water through the storage tank.

55 The standard, IAPMO S1001.1, pertains to requirements for the design and installation of pre-engineered solar water heating systems intended to be installed as stand-alone systems or in conjunction with auxiliary water heaters, including component selection and sizing criteria.

The standard, ICC 900/SRCC 300, pertains to the design and installation of solar thermal systems to be used in applications for heating, cooling and dehumidification.

COMMITTEE ACTION: ACCEPT AS AMENDED BY THE TC Amend proposal as follows:

501.0 General.

(renumber remaining sections)

(portions of table not shown remain unchanged)

COMMITTEE STATEMENT: Shutoff valves on drainback systems create unnecessary problems. In addition to the installation of shutoff valves, pressure relief valves and other devices are also required to prevent system damage.

Additionally, the design and performance standards are sufficient enough and there is no need for the inclusion of further provisions. For these reasons the proposed language is being modified.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

56 Proposals

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Item #: 043

USHGC 2021 Section: 502.5.2, Table 901.1

SUBMITTER: Chelsea Salaiz V&T Carbonic Inc.

RECOMMENDATION: Revise text

502.0 Solar Collectors.

502.5 Installation. (remaining text unchanged)

502.5.2 Above or on the Roof. New construction of Class A, B, or C type roof coverings shall be in accordance with ASTM E108 or UL 790 where collectors are installed above or on the roof. Collectors located above or on roofs, and functioning as building components, shall not reduce the required fire-resistance and fire-retardance classification of the roof covering materials. Exceptions: (1) One- and two-family dwellings. (2) Collectors located on buildings not exceeding three stories in height, a 9000 square feet (836.13 m2) total floor area; or both providing: (a) The collectors are noncombustible. (b) Collectors with plastic covers have noncombustible sides and bottoms, and the total area covered and the collector shall not exceed the following: 1. Plastic CC1 – 331/3 percent of the roof area. 2. Plastic CC2 – 25 percent of the roof area. (c) Collectors with plastic film covers having a thickness of not more than 0.010 of an inch (0.25 mm) shall have noncombustible sides and bottoms, and the total area covered by the collector shall not exceed 331/3 percent of the roof area.

TABLE 901.1 REFERENCED STANDARDS STANDARD REFERENCED STANDARD TITLE APPLICATION NUMBER SECTIONS ASTM E108-2017 Test Methods for Fire Tests of Roof Coverings Safety 502.5.2 UL 790-2004 Test Methods for Fire Tests of Roof Coverings (with revisions Safety 502.5.2 through October 19, 2018)

(portions of table not shown remain unchanged)

Note: ASTM E108 and UL 790 meet the requirements for mandatory reference standards in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

SUBSTANTIATION: The proposed language is for the addition of standards ASTM E108 and UL 790. Both are fire-test-response standards used to evaluate roof coverings in both residential and commercial roofing applications. The evaluations include simulations that take into account wind conditions and fires originating outside of the building or structure.

57 These standards also measure the surface spread of flames and the roof covering material’s ability to resist fire from reaching the underside of the roofing material. Such addition provides further restrictions on roof coverings for the safety of the end user.

COMMITTEE ACTION: REJECT

COMMITTEE STATEMENT: The proposed change is outside of the scope of the USHGC. The provisions for roof materials can be found in the building code.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

58 Proposals

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Item #: 044

USHGC 2021 Section: 503.2, Table 503.3(1) - Table 503.3(4)

SUBMITTER: Chelsea Salaiz V&T Carbonic Inc.

RECOMMENDATION: Revise text

503.0 Insulation. 503.2 Heat Loss. Insulation shall be installed on interconnecting solar and hot water piping. The final 5 feet (1524 mm) of the cold water supply line, or the entire length where less than 5 feet (1524 mm), shall be insulated. The insulation thickness shall be in accordance with Table 503.3(1) or Table 503.3(2), or the insulation installed shall have an R-value of value not less than R-2.6 degree Fahrenheit hour square foot per British thermal unit (°F·h·ft²/Btu)(R-0.46 K·m2/W). Piping, storage tanks, and circulating air ductwork shall be insulated. Ductwork and piping shall be permitted to not be insulated where exposed in conditioned spaces, and the heat loss from such ducts or piping does not otherwise contribute to the heating or cooling load within such space. Exception: Low temperature, aboveground piping installed for swimming pools, spas, and hot tubs in accordance with the manufacturer’s installation instructions unless such piping is located within a building.

(delete the following table in its entirety) TABLE 503.3(1) MINIMUM PIPE INSULATION

(delete the following table in its entirety) TABLE 503.3(2) IRON PIPE AND COPPER TUBING INSULATION THICKNESS

(delete the following table in its entirety) TABLE 503.3(3) UNIVERSAL PIPE INSULATION THICKNESS BASED ON RADIUS AND IRON PIPE SIZE (IPS)

(delete the following table in its entirety) TABLE 503.3(4) DESIGN VALUES FOR THERMAL CONDUCTIVITY (k) OF INDUSTRIAL INSULATION1, 3, 4, 5

59 TABLE 503.3(1) PIPE INSULATION THICKNESS NPS PIPE INSULATION INSULATION O.D. (inches) (inches) O.D. I.D. INSULATION NOMINAL THICKNESS (inches)* (inches) (inches) ½ ¾ 1 1.5 2 2.5 3 3.5 4 4.5 5 ½ 0.84 0.86 1.84 2.36 2.88 4.00 5.00 6.62 7.62 8.62 9.62 10.75 11.75 ¾ 1.05 1.07 2.06 2.36 2.88 4.00 5.00 6.62 7.62 8.62 9.62 10.75 11.75 1 1.315 1.33 2.32 2.88 3.50 4.50 5.56 6.62 7.62 8.62 9.62 10.75 11.75 1 ¼ 1.660 1.68 2.66 3.28 3.50 5.00 5.56 6.62 7.62 8.62 9.62 10.75 11.75 1 ½ 1.900 1.92 2.78 3.50 4.00 5.00 6.62 7.62 8.62 9.62 10.75 11.75 12.75 2 2.375 2.41 3.42 3.98 4.50 5.56 6.62 7.62 8.62 9.62 10.75 11.75 12.75 2 ½ 2.875 2.91 3.88 4.48 5.00 6.62 7.62 8.62 9.62 10.75 11.75 12.75 14.00 3 3.500 3.53 4.50 4.96 5.56 6.62 7.62 8.62 9.62 10.75 11.75 12.75 14.00 3 ½ 4.000 4.03 4.96 5.56 6.62 7.62 8.62 9.62 10.75 11.75 12.75 12.75 14.00 4 4.500 4.53 5.56 6.58 6.62 7.62 8.62 9.62 10.75 11.75 12.75 14.00 15.00 6 6.625 6.70 7.80 8.12 8.62 9.62 10.75 11.75 12.75 14.00 15.00 16.00 17.00 For SI units: 1 inch = 25 mm * Thickness values are applicable for calcium silicate, cellular foam plastics, cellular glass, mineral fiber, and perlite preformed insulation materials.

TABLE 503.3(2) STANDARD TUBING INSULATION THICKNESS TUBE TUBE INSULATION INSULATION O.D. (inches) SIZE O.D. I.D. INSULATION NOMINAL THICKNESS (inches)* (inches) (inches) (inches) 1 1.5 2 2.5 3 3.5 4 4.5 5 3/8 0.500 0.52 2.38 3.50 4.50 5.56 6.62 - - - - ½ 0.625 0.64 2.88 3.50 4.50 5.56 6.62 - - - - ¾ 0.875 0.89 2.88 4.00 5.00 6.62 7.62 8.62 9.62 10.75 11.75 1 1.125 1.14 2.88 4.00 5.00 6.62 7.62 8.62 9.62 10.75 11.75 1 ¼ 1.375 1.39 3.50 4.50 5.56 6.62 7.62 8.62 9.62 10.75 11.75 1 ½ 1.625 1.64 3.50 4.50 5.56 6.62 7.62 8,62 9.62 10.75 11.75 2 2.125 2.16 4.00 5.00 6.62 7.62 8.62 9.62 10.75 11.75 12.75 2 ½ 2.625 2.66 4.50 5.56 6.62 7.62 8.62 9.62 10.75 11.75 12.75 3 3.125 3.16 5.00 6.61 7.62 8.62 9.62 10.75 11.75 12.75 14.00 3 ½ 3.625 3.66 5.56 6.62 7.62 8.62 9.62 10.75 11.75 12.75 14.00 4 4.125 4.16 6.62 7.62 8.62 9.62 10.75 11.75 12.75 14.00 15.00 5 5.125 5.16 7.62 8.62 9.62 10.75 11.75 12.75 14.00 15.00 16.00 6 6.125 6.20 8.62 9.62 10.75 11.75 12.75 14.00 15.00 16.00 17.00 For SI units: 1 inch = 25 mm *Thickness values are applicable for calcium silicate, cellular foam plastics, cellular glass, mineral fiber, and perlite preformed insulation materials.

SUBSTANTIATION: The proposed language is being added for additional restrictions on insulation installed with solar thermal systems and connecting piping. Proper insulation improves efficiency and prevents heat loss from the system. The minimum thermal resistance provided is a current requirement in the industry and can be found in various local codes.

Tables 503.3(1) through 503.3(4) have been deleted due to a lack of clarification on proper application. The removal was necessary as new tables have been provided that already include proper insulation thicknesses for tubing and

60 piping. Previous tables for conductivity and resistance values are no longer needed for calculation of correct thicknesses. The new tables are applicable for calcium silicate, cellular foam plastics, cellular glass, mineral fiber, and perlite preformed insulation materials and therefore remove the need for the original Table 503.3(2).

These new tables are in accordance with industry standards such as ASHRAE. These values also do not conflict with the Uniform Plumbing Code, and they meet the minimum requirements for thicknesses based strictly on pipe diameters. Values listed in the new Table 503.3(1) correlate with the original Table 503.3(3) and cover a wider range of thickness values. The new Table 503.3(1) then provides tubing insulation thicknesses that are not only restricted to calcium silicate and fibrous glass.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

61 Proposals

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Item #: 045

USHGC 2021 Section: 209.0, 701.1, 701.1.1, 701.4 - 701.11

SUBMITTER: Cary Smith Sound Geothermal Corporation

RECOMMENDATION: Revise text

Part I - General.

701.0 General. 701.1 Applicability. Part I of tThis chapter shall applyapplies to geothermal energy systems such as, but not limited to, building systems coupled with a ground-heat exchanger, submerged heat exchanger using water-based fluid as a heat transfer medium, or groundwater (well). The regulations of this chapter shall govern the construction, location and installation of geothermal energy systems. Indoor piping, fittings, and accessories that are part of the groundwater system shall be in accordance with Section 703.5 and Chapter 4. 701.1.1 Prior to Construction. Documents for permits shall be submitted prior to the construction of a building system, ground heat exchanger, submerged heat exchanger, or water well. Permits shall be issued by the Authority Having Jurisdiction.

701.4 Used Materials. The installation of used pipe, fittings, valves, and other materials shall not be permitted. 701.5 Contact with Building Material. A ground source heat pump ground-loop piping system shall not be in direct contact with building materials that cause the piping or fitting material to degrade or corrode, or that interferes with the operation of the system. 701.6 Strains and Stresses. Piping shall be installed so as to prevent detrimental strains and stresses in the pipe. Provisions shall be made to protect piping from damage resulting from expansion, contraction, and structural settlement. Piping shall be installed so as to avoid structural stresses or strains within building components. 701.7 Flood Hazard. Piping located in a flood hazard area shall be capable of resisting hydrostatic and hydrodynamic loads and stresses, including the effects of buoyancy, during the occurrence of flooding to the design flood elevation. 701.8 Pipe Support. Pipe shall be supported in accordance with Section 317.1. 701.9 Velocities. Ground source heat pump ground-loop systems shall be designed so that the flow velocities do not exceed the maximum flow velocity recommended by the pipe and fittings manufacturer. Flow velocities shall be controlled to reduce the possibility of water hammer. 701.10 Chemical Compatibility. Antifreeze and other materials used in the system shall be chemically compatible with the pipe, tubing, fittings, and mechanical systems. 701.11 Transfer Fluid. The transfer fluid shall be compatible with the makeup water supplied to the system.

209.0 - G -

Geothermal Energy System. A system that uses the earth’s interior thermal energy for space heating and cooling, and water heating. Geothermal Energy System, Closed-Loop. A continuous, sealed, underground, or submerged heat exchanger through which a heat-transfer fluid passes to and returns from a heat pump. Geothermal Energy System, Open-Loop. A liquid-source heat pump system that uses ground water or surface water to extract or reject heat.

SUBSTANTIATION: The proposed language and section relocations have been made to further provide clarification on the three main types of geothermal systems. Chapter 7 (Geothermal Systems) has been divided into four parts discussing general provisions, closed-loop systems, open-loop systems, and direct exchange systems.

62 Part I (General) pertains to all three systems discussed within Chapter 7. New proposed language addresses used materials, strains and stresses, flood hazards, pipe supports, flow velocities, and chemical compatibility. Further topics added under “General” will be addressed in following proposals.

Additionally, definitions for “Geothermal Energy System," “Geothermal Energy System, Closed Loop” and “Geothermal Energy System, Open Loop” have been revised or added to provide clarification for terminology used within Chapter 7.

COMMITTEE ACTION: ACCEPT AS AMENDED BY THE TC Amend proposal as follows:

Part I - General.

701.0 General. 701.1 Applicability. Part I of this chapter shall apply to geothermal energy systems such as, but not limited to, building systems coupled with a ground-heat exchanger, submerged heat exchanger using water-based fluid as a heat transfer medium, or groundwater (well). The regulations of this chapter shall govern the construction, location and installation of geothermal energy systems. Indoor piping, fittings, and accessories that are part of the groundwater system shall be in accordance with Section 703.5 and Chapter 4.

701.1.1 Prior to Construction. Documents for permits shall be submitted prior to the construction of a building system, ground heat exchanger, submerged heat exchanger, or water well. Permits shall be issued by the Authority Having Jurisdiction.

209.0 - G - Geothermal Energy System. A system that usesexchanges thermal energy with the earth for space heating and cooling, and/or water heating.

Geothermal Energy System, Closed-Loop. A continuous, sealed, underground, or submerged heat exchanger through which a heat-transfer fluid passes to and returns from a heat pump.

Geothermal Energy System, Open-Loop. A liquid-source heat pump system that uses ground water or surface water to extract or reject heat.

COMMITTEE STATEMENT: The definition for "Geothermal Energy System" has been amended to cover systems exchanging heat with the earth as well as bodies of water.

Additionally, the definitions for "Geothermal Energy System, Closed Loop" and "Geothermal Energy System, Open Loop" have been revised to also include passive systems (direct use) by removing "heat pumps" from the terminology.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16 63 Proposals

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Item #: 046

USHGC 2021 Section: 703.2 - 703.4.2.1, Table 703.2, Table 703.3, Table 901.1

SUBMITTER: Cary Smith Sound Geothermal Corporation

RECOMMENDATION: Revise text

Part I – General.

703.2 Piping and Tubing Materials Standards. For water-based systems, ground source heat pump ground-loop pipe and tubing shall comply with the standards listed in Table 703.2. Piping and tubing used for DX systems shall be of copper in accordance with Section 715.3.

TABLE 703.2 PLASTIC GROUND SOURCE LOOP PIPING MATERIAL STANDARD Cross-linked polyethylene (PEX) ASTM F876, ASTM F3253, CSA B137.5, CSA C448, NSF 358-3 High Density Polyethylene (HDPE) ASTM D2737, ASTM D3035, ASTM F714, AWWA C901, CSA B137.1, CSA 448, NSF 358-1 Polypropylene (PP) ASTM F2389, CSA B137.11, NSF 358-2 Polyethylene Raised Temperature (PE-RT) ASTM F2623, ASTM F2769, CSA B137.18, CSA C448, NSF 358-4

703.3 Fittings. For water-based systems, fittings for ground source heat pump systems shall be approved for installation with the piping materials to be installed, and shall comply with the standards listed in Table 703.3. Fittings for use in DX systems shall comply with Section 715.3.

TABLE 703.3 GROUND SOURCE LOOP PIPE FITTINGS MATERIAL STANDARD Cross-linked polyethylene (PEX) ASTM F877, ASTM F1055, ASTM F1807, ASTM F1960, ASTM F2080, ASTM F2159, ASTM F2434, ASTM F3253, ASTM F3347, ASTM F3348, CSA B137.5, CSA C448, NSF 358-3 High Density Polyethylene (HDPE) ASTM D2683, ASTM D3261, ASTM F1055, CSA B137.1, CSA C448, NSF 358-1 Polypropylene (PP) ASTM F2389, CSA B137.11, NSF 358-2 Polyethylene Raised Temperature ASTM D3261, ASTM F1055, ASTM F1807, ASTM F2080, ASTM (PE-RT) F2159, ASTM F2769, CSA B137.18, CSA C448, NSF 358-4

64 703.5703.4 Underground Piping and Submerged Materials. Underground and submerged piping for a ground-heat exchanger shall be polyethylene (PE) pipe or tubing in accordance with Section 703.5.1703.4.1 and Section 703.5.1.1703.4.1.1, or cross-linked polyethylene (PEX) pipe or tubing in accordance with Section 703.5.2703.4.2 and Section 703.5.2.1703.4.2.1. 703.5.1703.4.1 Polyethylene (PE). Polyethylene pipe or tubing shall be manufactured to outside diameters, wall thickness, and respective tolerances in accordance with ASTM D3035, ASTM D3350, ASTM F714 or CSA B137.1 in accordance with the standards listed in Table 703.2. Pipe or tubing shall have a minimum wall thickness equal to SDR-11maximum dimension ratio of 11 and shall have a minimum pressure rating of not less than 160 psi (1103 kPa) at 73°F (23°C). Fittings shall be manufactured to dimensional specifications and requirements in accordance with ASTM D2683 for socket fusion fittings, ASTM D3261 for butt/sidewall fusion fittings, or ASTM F1055 for electrofusion fittings. Polyethylene pipe or tubing shall be manufactured from a PE compound that has a pipe material designation code of PE 3608, PE 3708, PE 3710, PE 4608, PE 4708, or PE 4710 as defined in the applicable standards referenced in Table 703.2, with a cell classification in accordance with ASTM D3350 appropriate for the material designation code, and a color and ultraviolet stabilizer code of C or E. Code E compounds shall be stabilized against deterioration from unprotected exposure to ultraviolet rays for not less than 3 years in accordance with the test criteria specified in ASTM D2513. 703.5.1.1703.4.1.1 Joining Methods for Polyethylene Pipe or Tubing. Joints between high density polyethylene (HDPE) plastic pipe or tubing and fittings shall be installed in accordance with the manufacturer’s installation instructions, the appropriate standards listed in accordance with Table 703.3, and one of the following heat fusion methods: (1) Butt-fusion joints shall be made in accordance with ASTM F2620 by heating the squared ends of two pipes, pipe and fitting, or two fittings by holding ends against a heated element. The heated element shall be removed where the proper melt is obtained, and joined ends shall be placed together with applied force. (2) Socket-fusion joints shall be made in accordance with ASTM F2620, by simultaneously heating the outside surface of a pipe end and the inside of a fitting socket. Where the proper melt is obtained, the pipe and fitting shall be joined by inserting one into the other with applied force. The joint shall fuse together and remain undisturbed until cool. (3) Electrofusion joints shall be made in accordance with ASTM F1055be heated internally by a conductor at the interface of the joint. Align and restrain fitting to pipe to prevent movement and apply electric current to the fitting. Turn off the current when the proper time has elapsed to heat the joint. The joint shall fuse together and remain undisturbed until cool. 703.5.2703.4.2 Cross-Linked Polyethylene (PEX). Cross-linked polyethylene pipe shall be manufactured to outside diameters, wall thickness, and respective tolerances in accordance with ASTM F876 or CSA B137.5the standards listed in Table 703.2. Pipe or tubing shall have a dimension ratio of 9PEX shall have a minimum tubing material designation code of PEX 1206 and shall have a minimum pressure rating of not less than 160 psi (1103 kPa) at 73°F (23°C). Fittings shall be manufactured to dimensional specifications and requirements in accordance with ASTM F1055 for electrofusion fittings, and ASTM F1960, ASTM F2080, or CSA B137.5 for cold-expansion compression sleeve fittings. 703.5.2.1703.4.2.1 Joining Methods for Cross-Linked Polyethylene Pipe or Tubing. Joints between cross-linked polyethylene (PEX) pipe or tubing and fittings shall be installed in accordance with the manufacturer’s installation instructions, and the appropriate standards in accordance with Table 703.3.and one of the following methods: (1) Electrofusion joints shall be heated internally by a conductor at the interface of the joint. Align and restrain fitting to pipe to prevent movement and apply electric current to the fitting. Turn off the current when the proper time has elapsed to heat the joint. The joint shall fuse together and remain undisturbed until cool. (2) Cold-expansion joints that are in accordance with ASTM F2080 shall be made, and fittings shall be joined to the pipe by expanding the end of the pipe with the expander tool, inserting the cold-expansion fitting into expanded pipe, then pulling the compression-sleeve over the PEX pipe and the fitting, compressing the pipe between compression-sleeve and the fitting. Cold- expansion joints shall be permitted to be buried with the manufacturer’s approved corrosion covering. (3) Cold-expansion joints that are in accordance with ASTM F1960 shall be made by applying an expansion ring on the pipe end; the pipe shall be expanded using an expander tool and inserting the cold-expansion fitting into the expanded pipe. The pipe shall retract over the fitting, creating the seal. Buried pipes shall comply with the manufacturer’s instructions.

(renumber remaining sections)

TABLE 901.1 REFERENCED STANDARDS STANDARD REFERENCED STANDARD TITLE APPLICATION NUMBER SECTIONS ASTM F3253- Crosslinked Polyethylene (PEX) Tubing with Oxygen Barrier Piping, Fittings Table 703.2 2018 for Hot- and Cold-Water Hydronic Distribution Systems ASTM F3347- Metal Press Insert Fittings with Factory Assembled Stainless Fittings Table 703.3 2019 Steel Press Sleeve for SDR9 Cross-linked Polyethylene (PEX) Tubing ASTM F3348- Plastic Press Insert Fittings with Factory Assembled Stainless Fittings Table 703.3 2019 Steel Press Sleeve for SDR9 Cross-linked Polyethylene (PEX) Tubing NSF 358-4-2018 Polyethylene of Raised Temperature (PE-RT) Tubing and Piping, Fittings Table 703.2, Table Fittings for Water-Based Ground-Source (Geothermal) Heat 703.3 Pump Systems

65 (portions of table not shown remain unchanged)

Note: AWWA C901, CSA standards, ASTM standards, and NSF standards meet the requirements for mandatory reference standards in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

SUBSTANTIATION: New tables have been proposed under “Part I – General” to provide material standards for piping/tubing and fittings for plastic ground source looping. The standards listed in Table 703.2 and Table 703.3 are necessary to ensure the overall success of geothermal systems and help to address corrosion resistance, chemical resistance, flexibility, impact resistance, resistance to slow crack growth, long-term hydrostatic strength (pressure capability), and temperature resistance. In addition, the ground loop heat exchanger materials must provide suitable heat transfer capabilities. PE is the most common pipe material used in ground source heat exchangers. It is flexible and can be heat-fused to form joints stronger than the pipe itself. PE-RT advantages include long-term reliability, flexibility for speedy installation, freeze break resistance, noise and water hammer resistance, and resistance to corrosion, tuberculation, deposits, chlorine and chloramines.

Section 703.4.1 has been revised for clarification on maximum dimension ratios. Published text states that "Piping or tubing shall have a maximum dimension ratio of 11". This is confusing for the end user as the dimension ratio is the ratio of the average outside diameter to the minimum wall thickness, and as the value for dimension ratio (SDR) decreases, the pressure rating increases. By incorporating the minimal wall thickness to achieve a specified SDR, the language is clearer for the end user.

Additionally, standard designation codes for PE and PEX piping compositions have been included to identify the most significant engineering properties: density, resistance and hydrostatic design stress.

Section 703.4.1.1 now addresses HDPE pipe/tubing joint methods and requires that joints comply with ASTM standards. HDPE has been included as it comes in different grades and is very rigid, making it ideal for vertical well fields. HDPE has a high pressure rating and provides the same quality seal as PE pipe, as it also must be joined in a heat fusion process.

COMMITTEE ACTION: ACCEPT AS AMENDED BY THE TC Amend proposal as follows:

Part I – General.

703.3 Fittings. For water-based systems, fittings for ground source heat pump systems shall be approvedrecommended by the manufacturer for installation with the piping materials to be installed, and shall comply with the standards listed in Table 703.3. Fittings for use in DX systems shall comply with Section 715.3.

66 TABLE 703.3 GROUND SOURCE LOOP PIPE FITTINGS MATERIAL STANDARD Cross-linked polyethylene (PEX) ASTM F877, ASTM F1055, ASTM F1807, ASTM F1960, ASTM F2080, ASTM F2159, ASTM F2434, ASTM F3253, ASTM F3347, ASTM F3348, CSA B137.5, CSA C448, NSF 358-3 High Density Polyethylene (HDPE) ASTM D2683, ASTM D3261, ASTM F1055, CSA B137.1, CSA C448, NSF 358-1 Polypropylene (PP) ASTM F2389, CSA B137.11, NSF 358-2 Polyethylene Raised Temperature ASTM D3261, ASTM F1055, ASTM F1807, ASTM F2080, ASTM (PE-RT) F2159, ASTM F2769, CSA B137.18, CSA C448, NSF 358-4

703.4 Underground Piping and Submerged Materials. Underground and submerged piping for a ground-heat exchanger shall be polyethylene (PE) pipe or tubing in accordance with Section 703.4.1 and Section 703.4.1.1, or cross-linked polyethylene (PEX) pipe or tubing in accordance with Section 703.4.2 and Section 703.4.2.1. 703.4.1 Polyethylene (PE). Polyethylene pipe or tubing shall be manufactured in accordance with the standards listed in Table 703.2. Pipe or tubing shall have a minimum wall thickness equal to SDR-11 and shall have a minimum pressure rating of not less than 160 psi (1103 kPa) at 73°F (23°C). Polyethylene pipe or tubing shall be manufactured from a PE compound that has a pipe material designation code of PE 3608, PE 3708, PE 3710, PE 4608, PE 4708, or PE 4710 as defined in the applicable standards referenced in Table 703.2, with a cell classification in accordance with ASTM D3350 appropriate for the material designation code, and a color and ultraviolet stabilizer code of C or E. Code E compounds shall be stabilized against deterioration from unprotected exposure to ultraviolet rays for not less than 3 years in accordance with the test criteria specified in ASTM D2513. 703.4.1.1 Joining Methods for Polyethylene Pipe or Tubing. Joints between high density polyethylene (HDPE) plastic pipe or tubing and fittings shall be installed in accordance with the manufacturer’s installation instructions, the appropriate standards listed in accordance with Table 703.3, and one of the following heat fusion methods: (1) Butt-fusion joints shall be made in accordance with ASTM F2620 . (2) Socket-fusion joints shall be made in accordance with ASTM F2620. (3) Electrofusion joints shall be made in accordance with ASTM F1055. 703.4.2 Cross-Linked Polyethylene (PEX). Cross-linked polyethylene pipe shall be manufactured in accordance with the standards listed in Table 703.2. PEX shall have a minimum tubing material designation code of PEX 1206 and shall have a minimum pressure rating of not less than 160 psi (1103 kPa) at 73°F (23°C).

703.4.2.1 Joining Methods for Cross-Linked Polyethylene Pipe or Tubing. Joints between cross-linked polyethylene (PEX) pipe or tubing and fittings shall be installed in accordance with the manufacturer’s installation instructions and the appropriate standards in accordance with Table 703.3.

(renumber remaining sections)

(portions of table not shown remain unchanged)

67 COMMITTEE STATEMENT: The use of the term "approved" within Section 703.3 is being revised to show "recommended by the manufacturer" for further clarification on what the products are intended for. This revision ensures that the material selected is suitable for the intended purpose.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

68 Proposals

Edit Proposal

Item #: 047

USHGC 2021 Section: 703.5, 704.0 - 704.2, 715.0, 715.5

SUBMITTER: Cary Smith Sound Geothermal Corporation

RECOMMENDATION: Revise text

Part I – General. 703.0 Design of Systems.

703.7703.5 Indoor Piping. Indoor piping, fittings, and accessories that are part of the groundwater system shall be in accordance with Chapter 4. Such materials shall be rated for the operating temperature and pressures of the system and shall be compatible with the type of transfer medium. For DX systems, joints shall be purged with an inert gas and brazed with a brazing alloy having 15 percent silver content in accordance with AWS A5.8.

707.0704.0 Heat Pump and Distribution System Design. 707.2704.1 Heat Pump Distribution System. (remaining text unchanged) 707.3704.2 Circulating Pumps. The circulating pump shall be sized for the operating conditions and the heat transfer fluid properties.

Part IV – Direct Exchange (DX) Systems.

715.0 Direct Exchange (DX) Systems.

715.5 Indoor Piping. For DX systems, joints shall be purged with an inert gas and brazed with a brazing alloy having 15 percent silver content in accordance with AWS A5.8.

Note: AWS A5.8 meets the requirements for a mandatory reference standard in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

SUBSTANTIATION: Section relocations have been made to coincide with the four parts of Chapter 7 previously explained.

Furthermore, the section on “Indoor Piping” is being modified by striking the last sentence that is specific to DX systems. The section is being added to proposed Part IV (Direct Exchange Systems) for ease of use and will guide the end user in determining where all provisions specific to DX systems can be located.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

69 Proposals

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Item #: 048

USHGC 2021 Section: 705.0 - 705.8

SUBMITTER: Cary Smith Sound Geothermal Corporation

RECOMMENDATION: Add new text

Part I – General.

705.0 Valves. 705.1 Where Required. Shutoff valves shall be installed in ground source-loop piping systems in the locations indicated in Section 705.2 through Section 705.8. 705.2 Heat Exchangers. Shutoff valves shall be installed on the supply and return side of a heat exchanger. Exception: Where a heat exchanger is an integral part of a boiler or is a part of a manufactured boiler and heat exchanger packaged unit, and is capable of being isolated from the hydronic system by supply and return valves. 705.3 Central Systems. Shutoff valves shall be installed on the building supply and return of a central utility system. 705.4 Pressure Vessels. Shutoff valves shall be installed on the connection to a pressure vessel. 705.5 Pressure-Reducing Valves. Shutoff valves shall be installed on both sides of a pressure-reducing valve. 705.6 Equipment and Appliances. Shutoff valves shall be installed on connections to mechanical equipment and appliances. 705.7 Expansion Tanks. Shutoff valves shall be installed at connections to nondiaphragm-type expansion tanks. 705.8 Reduced Pressure. A pressure relief valve shall be installed on the low-pressure side of a hydronic piping system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system design.

SUBSTANTIATION: The use of shutoff valves in ground source loop piping systems is necessary for isolation of components for routine maintenance or repair. All proposed language is similarly found in the mechanical code, and all provisions on valves should be included under Part I (General) provisions as they are applicable to open-loop, closed-loop, and DX systems.

In particular, heat exchangers are required to have shutoff valves on the supply and return sides; however, heat exchangers that are integral with boilers as well as boiler heat exchanger packaged units are excluded from this provision as long as they may be isolated from the system.

Additionally, a pressure relief valve should be installed to divert a portion of the fluid through an auxiliary route in order to reduce the pressure within the system until it falls within the design limits.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

70 Proposals

Edit Proposal

Item #: 049

USHGC 2021 Section: 706.0 - 706.4

SUBMITTER: Cary Smith Sound Geothermal Corporation

RECOMMENDATION: Revise text

Part I – General.

705.0706.0 Specific System Components Design. 707.1706.1 General. Ground coupled and water source heat pumps shall be certified in accordance with AHRI/ASHRAE/ISO 13256-1 for water-to-air heat pumps and AHRI/ASHRAE/ISO 13256-2 for water-to-water heat pumps. DX heat pumps shall be certified in accordance with ASHRAE 194. All heat Ppump equipment used in DX systems shall comply with AHRI 870. Heat pumps shall be fitted with a means to indicate that the compressor is locked out. 705.1706.2 Heat Exchangers. (remaining text unchanged) 705.2706.3 Heat-Transfer Medium. (remaining text unchanged) 705.4706.4 Insulation. (remaining text unchanged)

(renumber remaining sections)

SUBSTANTIATION: The proposed change relocates sections to Part I (General) of Chapter 7. The relocation gathers sections in Chapter 7 relating to “Specific System Component Design.”

COMMITTEE ACTION: ACCEPT AS AMENDED BY THE TC Amend proposal as follows: Part I – General.

706.0 Specific System Components Design. 706.1 General. Ground coupled and water source heat pumps shall be certifiedlisted in accordance with AHRI/ASHRAE/ISO 13256-1 for water-to-air heat pumps and AHRI/ASHRAE/ISO 13256-2 for water-to-water heat pumps. DX heat pumps shall be certifiedlisted in accordance with ASHRAE 194. All heat pump equipment used in DX systems shall comply with AHRI 870. Heat pumps shall be fitted with a means to indicate that the compressor is locked out. 706.2 Heat Exchangers. (remaining text unchanged) 706.3 Heat-Transfer Medium. (remaining text unchanged) 706.4 Insulation. (remaining text unchanged)

(renumber remaining sections)

COMMITTEE STATEMENT: The term "certified" is being replaced with "listed" as the term "certified" is not currently defined. Additionally, this modification provides clarity for the end user.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

71 Proposals

Edit Proposal

Item #: 050

USHGC 2021 Section: 707.0 - 707.15, 715.0, 715.6

SUBMITTER: Cary Smith Sound Geothermal Corporation

RECOMMENDATION: Revise text

Part I – General.

704.0707.0 Installation Practices. 707.1 Prior to Construction. Documents for permits shall be submitted prior to the construction of a building system, or water well. Permits shall be issued by the Authority Having Jurisdiction. 707.2 Equipment, Accessories, Components, and Materials. The mechanical equipment, accessories, components, and materials used shall be of the type and rating approved for the specific use. 707.3 Construction Documents. The construction documents for the building system portion of the geothermal energy system shall be submitted to the Authority Having Jurisdiction. 707.4 Site Survey Requirements. The site survey shall identify the physical limitations of the land area, including its extent, structures, existing wells of all types, proximity of other existing ground source heat pump systems, pavements, trees, grading, ponds, waterways, easements, overhead and underground services, septic systems, any identified septic repair areas, utility of rights of way, and any other elements that could affect an open-loop configuration. Permission shall be obtained from any adjoining property owner(s), as evidenced by the registration and approval of a formal easement that meets requirements of the Authority Having Jurisdiction. It shall be received prior to the installation of any open-loop system that will extend into, cross, or interfere with the equipment or rights-of-way of utilities, jurisdictions, and other property owners. The site survey shall include a subsurface investigation that meets the requirements for an open-loop heat exchanger. 707.5 Subsurface Investigation. A subsurface investigation shall be performed in accordance with Section 707.5.1 as determined by the registered design professional conducting the site survey. 707.5.1 Subsurface Conditions. The water well logs and other geological records shall be used to anticipate the subsurface conditions of the aquifer and its potential supply of fresh water, multiple aquifers, saltwater intrusions, contaminated soils and groundwater, hazardous gases, and any interference with neighboring water wells and ground source heat exchangers. Geological issues such as permafrost conditions and building stability shall be considered when reviewing available records. 703.2707.6 Ground Heat-Exchanger Installation Practices. (remaining text unchanged) 704.1707.7 Trenching, Excavation, and Backfill. Prior to excavation, trenching, or drilling, buried utilities, drainage, water, and irrigation systems shall be located. Prior to excavation, trenching, or drilling, the contractor, and owner shall agree in writing to site restoration requirements and submit to the Authority Having Jurisdiction for approval. Prior to any excavation, trenching, or drilling, all buried utilities including drainage and irrigation systems shall be located and flagged by the appropriate utility and ground source heat pump system contractor representative. 704.2707.8 Trenches, Tunneling, and Driving. (remaining text unchanged) 704.3707.9 Excavations and Open Trenches. (remaining text unchanged) 704.4707.10 Protection of Piping, Materials, and Structures. (remaining text unchanged) 704.5707.11 Sleeves. (remaining text unchanged) 704.6707.12 Steel Nail Plates. (remaining text unchanged) 705.3707.13 On Site Storage. Exterior piping shall be fitted with end caps and protected from freezing, UV radiation, corrosion, and degradation. For DX systems, copper piping and fittings shall be stored to prevent physical damage, contamination, and each pipe or tubing shall be pressurized with an inert gas and sealed with a cap. 707.4707.14 Heat Pump and Distribution System Installation. (remaining text unchanged) 707.15 Pressurizing During Installation. Ground source heat pump ground loop piping to be embedded in concrete shall be pressure tested prior to pouring concrete. During pouring, the pipe shall be maintained at the proposed operating pressure.

72 Part IV – Direct Exchange (DX) Systems. 715.0 Direct Exchange (DX) Systems.

715.6 On Site Storage. For DX systems, copper piping and fittings shall be stored to prevent physical damage, contamination, and each pipe or tubing shall be pressurized with an inert gas and sealed with a cap.

SUBSTANTIATION: The proposed language is similarly found in the mechanical code, and additional section relocations have been made to ensure that all “General” provisions are applied to all three systems.

In order to properly design an open-loop, closed-loop or DX geothermal system, it is important to know the pertinent project information identified through site survey processes and subsurface investigations. Construction documents are required to be of a quality and detail such that the Authority Having Jurisdiction can determine that the work conforms to the code and other applicable laws and regulations. All materials and equipment used must be rated and approved for such use to ensure proper functioning and safe use. Supporting documentation for installation practices have been provided.

Section 707.15 has been included to ensure that piping to be embedded in concrete will allow for proper flow once installed. Pressure testing would allow for such determination.

Additionally, Section 707.13 has been revised to exclude information explicit to DX systems, and the text has been moved to Section 715.6 (On Site Storage).

COMMITTEE ACTION: ACCEPT AS AMENDED BY THE TC Amend proposal as follows: Part I – General.

707.0 Installation Practices. 707.1 Prior to Construction. Documents for permits shall be submitted prior to the construction of a building system, or water well. Permits shall be issued by the Authority Having Jurisdiction. 707.2 Equipment, Accessories, Components, and Materials. The mechanical equipment, accessories, components, and materials used shall be of the type and rating approvedrecommended by the manufacturer for the specific use. 707.3 Construction Documents. The construction documents for the building system portion of the geothermal energy system shall be submitted to the Authority Having Jurisdiction. 707.4 Site Survey Requirements. The site survey shall identify the physical limitations of the land area, including its extent, structures, existing wells of all types, proximity of other existing ground source heat pump systems, pavements, trees, grading, ponds, waterways, easements, overhead and underground services, septic systems, any identified septic repair areas, utility of rights of way, and any other elements that could affect an open- loop configuration. Permission shall be obtained from any adjoining property owner(s), as evidenced by the registration and approval of a formal easement that meets requirements of the authority having jurisdiction. It shall be received prior to the installation of any open-loop system that will extend into, cross, or interfere with the equipment or rights-of-way of utilities, jurisdictions, and other property owners. The site survey shall include a subsurface investigation that meets the requirements for an open-loop heat exchanger. 707.5 Subsurface Investigation. A subsurface investigation shall be performed in accordance with Section 707.5.1 as determined by the registered design professional or certified person conducting the site survey. 707.5.1 Subsurface Conditions. The water well logs and other geological records shall be used to anticipate the subsurface conditions of the aquifer and its potential supply of fresh water, multiple aquifers, saltwater intrusions, contaminated soils and groundwater, hazardous gases, and any interference with neighboring water wells and ground source heat exchangers. Geological issues such as permafrost conditions and building stability shall be considered when reviewing available records. 707.6 Ground Heat-Exchanger Installation Practices. (remaining text unchanged) 707.7 Trenching, Excavation, and Backfill. Prior to excavation, trenching, or drilling, buried utilities, drainage, water, and irrigation systems shall be located. Prior to excavation, trenching, or drilling, the contractor, and owner shall agree in writing to site restoration requirements and submit to the Authority Having Jurisdiction for approval. Prior to any excavation, trenching, or drilling, all buried utilities including drainage and irrigation systems shall be located and flagged by the appropriate utility and ground source heat pump system contractor representative. 707.8 Trenches, Tunneling, and Driving. (remaining text unchanged) 707.9 Excavations and Open Trenches. (remaining text unchanged) 707.10 Protection of Piping, Materials, and Structures. (remaining text unchanged) 707.11 Sleeves. (remaining text unchanged) 707.12 Steel Nail Plates. (remaining text unchanged) 707.13 On Site Storage. Exterior piping shall be fitted with end caps and protected from freezing, UV radiation, corrosion, and degradation. 707.14 Heat Pump and Distribution System Installation. (remaining text unchanged)

73 707.15 Pressurizing During Installation. Ground source heat pump ground loop piping to be embedded in concrete shall be pressure tested prior to pouring concrete. During pouring, the pipe shall be maintained at the proposed operating pressure.

Part IV – Direct Exchange (DX) Systems. 715.0 Direct Exchange (DX) Systems.

COMMITTEE STATEMENT: The proposed language in Section 707.5 is being modified to also include "certified person" in addition to "registered design professional."

Additionally, where "approved" is used within Section 707.2, the text is being modified to reflect "recommended by the manufacturer" to ensure equipment, accessories, components and materials are suitable for their intended use.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

74 Proposals

Edit Proposal

Item #: 051

USHGC 2021 Section: 707.0, 707.16 - 707.17.8

SUBMITTER: Cary Smith Sound Geothermal Corporation

RECOMMENDATION: Add new text

Part I – General. 704.0707.0 Installation Practices.

707.16 Horizontal Geothermal Piping - Materials and Methods. Horizontal geothermal piping shall be in accordance with Section 707.16.1 through Section 707.17.8. 707.16.1 Piping Material. Piping materials and joining methods for horizontal piping from the ground heat-exchanger shall be in accordance with Section 703.2 through Section 703.5. 707.16.2 Dissimilar Materials. Transition fittings between dissimilar materials shall be inside or accessible. 707.16.3 Protection of Piping. Pipes passing through walls shall be sleeved and sealed in accordance with Section 318.0. 707.17 Trenches, Excavation, and Backfilled. Excavation for horizontal piping shall comply with Section 707.7 through Section 707.10, Section 707.17.1 through Section 707.17.8, and in accordance with requirements of the Authority Having Jurisdiction. Prior to any excavation, trenching, or drilling, all buried utilities including drainage and irrigation systems shall be located and flagged by the appropriate utility and ground source heat pump system contractor representative. 707.17.1 Trenches. Trenches for underground piping or tubing shall be excavated in accordance with the setback requirements in Section 712.4. 707.17.2 Buried Systems. Buried open-loop system piping, shall be installed not less than 3.3 feet (1006 mm) below the finished grade. 707.17.3 Pipe Installation. Piping in horizontal trenches shall be embedded with not less than 6 inches (152 mm) of inert granular material above and below, or in accordance with the Authority Having Jurisdiction and project specifications. Horizontal piping trenching shall be backfilled with approved material and shall be compacted. 707.17.4 Separation. The horizontal piping shall be separated from fluid-based on-site service systems to prevent excessive short-circuiting heat transfer between such systems. 707.17.5 Insulation. Insulation shall be provided on the piping where there is close proximity of all site services to prevent thermal interference between fluid-based on-site service systems. 707.17.6 Pipe Bends. Sharp bending of pipe shall be prevented or approved elbow fitting shall be used with a bend-radius in accordance with the manufacturer’s installation instructions. 707.17.7 Closed Cell Insulation. Buried horizontal open-loop system pipes passing parallel within 5 feet (1524 mm) of a wall, structure, or water pipe shall be insulated with R-2 minimum closed cell insulation. 707.17.8 Tracer Markings. Means shall be provided for underground detection or utility location of the buried pipe system. This shall include, but is not limited to, metallic detectable tape, with a thickness of not less than 11/64 of an inch (4.4 mm) and width of 6 inches (152 mm). This warning marking shall be permanent, conspicuous and resistant to the environmental conditions and shall be placed within 1 foot to 2 feet (305 mm to 610 mm) on top of the horizontal piping of the heat exchanger installation.

SUBSTANTIATION: The proposed text on materials and methods for horizontal geothermal piping is similarly found in the mechanical code. The listed provisions are applicable to open-loop, closed-loop and DX systems and therefore should be added under Part I (General) provisions.

75 The listed provisions address piping materials and reference Section 703.2 (Piping and Tubing Material Standards) through Section 703.5 (Indoor Piping). The referenced sections provide material standards for piping/tubing and fittings, joining methods and material property designations.

Also addressed are dissimilar materials which require transition fittings to prevent leaks and allow for proper connections between varying materials.

Provisions on protection of piping have already been addressed in Section 318.0 (Protection of Piping, Materials, and Structures) and should therefore be referenced and not repeated. All sections pertaining to trenches, excavation and backfill have also be referenced.

Buried piping must be at least 3.3 feet below grade because at that depth, the earth’s temperature remains relatively constant throughout the year, and ground source heat pumps are designed to capitalize on this. Underground piping must also be separated from site services and insulated to prevent excessive short circuiting heat transfer as well as thermal interference. Additionally, sharp pipe bends should be avoided, and approved elbow fittings should be used. For easy location of underground piping for maintenance and repair, tracer markings should be installed.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

COMMITTEE STATEMENT: Pertaining to Section 707.17.8, other underground detection methods are applicable and available. Such systems should also be included to ensure that the end user knows that there are other appropriate underground detection methods.

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

76 Proposals

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Item #: 052

USHGC 2021 Section: 708.1, 708.3 - 708.8, 715.0, 715.7, Table 901.1

SUBMITTER: Cary Smith Sound Geothermal Corporation

RECOMMENDATION: Revise text

Part I – General.

708.0 System Start-Up. 708.1 General. The following requirements shall be verified prior to system start-up.: (1) Piping shall be cleaned, flushed, and purged. (2) DX systems shall be pressurized using nitrogen for not less than 1 hour. There shall be no allowable variance to the test pressure after being corrected for ambient temperature changes during the test. The test pressure shall not exceed 150 psig (1034 kPa) when pressure testing the compressor unit and indoor system components. (32) The ground heat exchanger and building piping shall be cleaned, flushed, and, where required, shall be filled with the heat transfer fluid medium. The ground loop system shall be tested at the design flow rate(s) and differential pressure(s) recorded. Where the actual pressure change at design flow is more than +/- 10 percent of the design flow pressure drop, the cause shall be identified and corrective action taken. (43) A method for the removal of air and a method for adding heat transfer fluid (where necessary) shall be provided. (54) The heat pumps shall be operational and adjustments shall be made in accordance with the manufacturer’s installation instructions. (65) All necessary additional flow tests of the ground heat exchanger shall be completed prior to heat pump start-up. (76) Ground heat exchanger and building piping, valves, and operating controls, shall be set, adjusted, and operating as required. (87) The system shall be labeled at the loop charging valves with a permanent-type label, indicating the type of heat transfer fluid used. Where antifreeze is used, the labels shall indicate the antifreeze type and concentration. (9) DX systems shall have permanent type labels installed and affixed on the compressor unit with the refrigerant type and quantity. (108) Supply and return lines, as well as associated isolation valves from individual boreholes or water wells, shall be identified and tagged. (11) For DX systems, refrigerant liquid and vapor lines from the loop system shall be identified and tagged. (12 9) Supply and return lines on submerged systems shall be identified in an approved manner, at the point of entry to a surface water resource.

708.3 Labeling and Marking. Ground source heat pump ground-loop system piping shall be marked with tape, metal tags, or other methods where it enters a building. The marking shall indicate the following words: “GROUND SOURCE HEAT PUMP-LOOP SYSTEM.” The marking shall indicate antifreeze used in the system by name and concentration. 708.4 Documentation. The ground source heat pump system as-built installation drawings and instructions shall be provided to the building owner or designated agent. 708.5 Maintenance. The periodic maintenance required, in accordance with the design requirements, shall be provided and be made available to the owner or designated agent. 708.6 Records. The ground source heat pump system construction documents shall be provided to the owner. 708.7 System Start-Up. System startup shall be in accordance with CSA C448.1, CSA C448.2, and Section 708.0. 708.8 Contaminants. Particulate contaminants shall be removed from the indoor piping system prior to initial start-up.

77 Part IV – Direct Exchange (DX) Systems.

715.0 Direct Exchange (DX) Systems.

715.7 System Start-Up. DX system start-up shall be in accordance with Section 708.0 and the following: (1) DX systems shall be pressurized using nitrogen for not less than 1 hour. There shall be no allowable variance to the test pressure after being corrected for ambient temperature changes during the test. The test pressure shall not exceed 150 psig (1034 kPa) when pressure testing the compressor unit and indoor system components. (2) DX systems shall have permanent type labels installed and affixed on the compressor unit with the refrigerant type and quantity. (3) For DX systems, refrigerant liquid and vapor lines from the loop system shall be identified and tagged.

TABLE 901.1 REFERENCED STANDARDS STANDARD STANDARD TITLE APPLICATION REFERENCED NUMBER SECTIONS CSA C448.1- Design and Installation of Ground Source Heat Pump Ground-Source 708.7 2016 Systems for Commercial and Institutional Buildings Heat Pumps CSA C448.2- Design and Installation of Ground Source Heat Pump Ground-Source 708.7 2016 Systems for Residential and Other Small Buildings Heat Pumps

(portions of table not shown remain unchanged)

Note: CSA C448.1 and CSA C448.2 meet the requirements for mandatory referenced standards in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

SUBSTANTIATION: The language pertaining to DX systems has been relocated to Part IV (Direct Exchange Systems) for clarification. Additionally, labeling and marking of ground source heat pump ground loop system piping have been addressed as well as the indication of antifreeze and its concentration for safety reasons.

Proper detailed installation drawings, records, and instructions should be provided to the owner to be used when maintenance, repair or new construction occurs. Records of periodic maintenance should also be provided to ensure all actions are accounted for.

CSA C448.1 and CSA C448.2 are applied to system start-up provisions as both of these standards provide detailed guidelines addressing heat pump performance, valves, operating controls, labeling, delivery documentation, and heat exchanger location. CSA C448.1 pertains to systems installed for commercial use, and CSA C448.2 pertains to systems installed for residential use. Both should be included within this section.

For safety reasons, contaminants must be flushed and removed from the piping system prior to start-up.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

78 Proposals

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Item #: 053

USHGC 2021 Section: 709.0 - 709.1

SUBMITTER: Cary Smith Sound Geothermal Corporation

RECOMMENDATION: Revise text

Part I - General.

701.4 709.0 Decommissioning and Abandonment. 709.1 General. Prior to the abandonment or decommissioning of a ground-heat exchanger, submerged heat exchanger or ground water (well) the owner shall obtain the necessary permits from the Authority Having Jurisdiction. Decommissioning of geothermal systems shall comply with CSA C448. Prior to the abandonment or decommissioning of geothermal systems, the owner shall obtain the necessary permits from the Authority Having Jurisdiction.

Note: CSA C448 meets the requirements for a mandatory reference standard in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

SUBSTANTIATION: Proper decommissioning or abandonment eliminates the physical hazard of the well, eliminates a pathway for migration of contamination, and prevents hydrologic changes in the aquifer system, including changes in hydraulic head and mixing of water between aquifers. The actual method will depend on both the reason for abandonment and the condition and construction details of the borehole or well. Many locations have different requirements; therefore, it is imperative to check with the local jurisdiction.

The section is being rewritten to include CSA C448 as this reference standard addresses decommissioning and abandonment of geothermal systems.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

79 Proposals

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Item #: 054

USHGC 2021 Section: 710.0 - 710.6.2.4, 715.0, 715.4

SUBMITTER: Cary Smith Sound Geothermal Corporation

RECOMMENDATION: Revise text

Part II – Closed-Loop Systems.

710.0 General. 710.1 Applicability. Part II of this chapter shall apply to geothermal energy systems such as, but not limited to, building systems coupled with a closed-loop system using water-based fluid as a heat transfer medium. 710.2 Piping and Tubing. Piping and tubing for closed-loop systems shall be in accordance Section 703.2 and Table 703.2. 710.3 Borehole Piping and Tubing. Borehole piping or tubing for vertical and horizontally drilled closed-loop systems, shall have a minimum wall thickness equal to SDR-11 and shall have a minimum pressure rating of not less than 160 psi (1103 kPa) at 73°F (23°C). 710.4 Underground Fittings. Underground fittings for closed loop systems shall be in accordance with Section 703.3 and Table 703.3. 703.3710.5 Verification. For closed-loop systems, the system shall be flushed of debris and purged of air after completion of the entire ground-heat exchanger. Flow rates and pressure drops shall be compared to calculated values to assure no blockage or kinking of the pipe. A report shall be submitted to the owner to confirm that the loop flow is in accordance with the construction documents. For direct exchange (DX) systems, each u-bend shall be tested and proved tight with an inert gas at not less than 315 psi (2172 kPa) and maintained for 15 minutes without pressure drop. The pressure reading after tremie grouting of the boreholes shall be maintained in the ground heat exchanger for not less than 2 hours, in accordance with CSA C448. 703.4710.6 Vertical Bores. (remaining text unchanged) 703.4.1710.6.1 Backfill. (remaining text unchanged) 703.4.2710.6.2 U-Bends and Headers. (remaining text unchanged) 703.4.2.1710.6.2.1 Test Pressure. The maximum test pressure shall be 1.5 times the system design pressure, as determined by Section 703.4.2.3 710.6.2.3, or Section 703.4.2.4 710.6.2.4, not to exceed 100 psi (689 kPa). Components or devices with lower pressure-ratings than the pipe shall be protected from excessive pressure during testing by removing or isolating from the test section. Exception: Where lower pressure-rated components or devices cannot be removed or isolated from the test section, the maximum test pressure shall not exceed the pressure rating of the component or device. 703.4.2.2710.6.2.2 Testing Procedure. (remaining text unchanged) 703.4.2.3710.6.2.3 Calculation of Static Pressure (Water). (remaining text unchanged) 703.4.2.4710.6.2.4 Calculation of Static Pressure (Other Fluids). (remaining text unchanged)

Part IV – Direct Exchange (DX) Systems.

715.0 Direct Exchange (DX) Systems.

706.2715.4 DX System Testing. For DX systems, each loop shall be tested with an inert gas at not less than 315 psi (2172 kPa) for not less than 15 minutes without pressure drop. The pressure reading after grouting of the boreholes shall be maintained in the ground-heat exchanger for not less than 2 hours. For direct exchange (DX) systems, each u-bend shall be tested and proved tight with an inert gas at not less than 315 psi (2172 kPa) and maintained for 15 minutes without pressure

80 drop. The pressure reading after tremie grouting of the boreholes shall be maintained in the ground heat exchanger for not less than 2 hours, in accordance with CSA C448.

SUBSTANTIATION: Section movements have been made to list all provisions explicit to closed-loop systems in a single location. The addition of Section 710.1 is necessary as it addresses the applicability of the listed provisions. Piping, tubing and fitting material standards and joining methods are already provided in Section 703.2 and Section 703.3, and therefore do not need to be repeated but only referenced.

Additionally, Section 710.3 lists an acceptable minimum wall thickness with a provided dimension ratio and pressure rating for borehole piping and tubing. The addition is necessary as applicable standards of the American Water Works Association (AWWA) require that PE piping and tubing with a minimum dimension ratio of 11 and a pressure rating of not less than a 160 psi for water at 73°F be used for such systems.

Section 710.5 has been revised to exclude information pertaining to DX systems. The removed provisions were then combined with Section 715.4 under Part IV (Direct Exchange Systems) for further clarification on DX system testing.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

81 Proposals

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Item #: 055

USHGC 2021 Section: 711.0 - 711.4

SUBMITTER: Cary Smith Sound Geothermal Corporation

RECOMMENDATION: Revise text

Part II – Closed-Loop Systems.

706.0711.0 Ground-Heat Exchanger Testing. 706.1711.1 Testing. Pressure-testing of the ground-heat exchanger shall be performed in accordance with the testing method in Section 703.4710.6. 711.2 Individual Loop Pressure Testing. Individual loop testing shall be performed as required by the Authority Having Jurisdiction. 711.3 Field Pressure Testing – Final. The ground heat exchanger and building piping shall be cleaned, flushed, and, where required, shall be filled with the heat transfer fluid medium. The ground loop system shall be tested at the design flow rate(s) and differential pressure(s) recorded. Where the actual pressure change at design flow is more than +/- 10 percent of the design flow pressure drop, the cause shall be identified, and corrective action taken. 711.4 Field Flow Testing - Final. Final field flow testing shall be performed as required by the Authority Having Jurisdiction.

SUBSTANTIATION: Ground heat exchanger testing is required for closed-loop systems, and therefore, listed provisions are being moved to Part II (Closed-Loop Systems). Additional provisions on individual loop pressure testing, field pressure testing, and field flow testing have been added to guarantee that such testing is completed. Field pressure testing methods are implemented to ensure that flow rates and differential pressures are within 10% of design parameters.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

82 Proposals

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Item #: 056

USHGC 2021 Section: 712.0 - 712.4

SUBMITTER: Cary Smith Sound Geothermal Corporation

RECOMMENDATION: Revise text

Part III – Open-Loop Systems.

712.0 General. 712.1 Applicability. Part III of this chapter shall apply to geothermal energy systems such as, but not limited to, building systems coupled with a groundwater (well) or surface water open loop using water-based fluid as a heat transfer medium. The regulations of this chapter shall govern the construction, location and installation of geothermal energy systems. Indoor piping, fittings, and accessories that are part of the groundwater system shall be in accordance with Section 703.5 and Chapter 4. 702.1.1712.2 Test Wells. (remaining text unchanged) 702.1.2712.3 Installation of Water Wells. (remaining text unchanged) 712.4 Setbacks. Open loop ground-heat exchangers shall maintain the following minimum setbacks or at distances specified by the Authority Having Jurisdiction: (a) Ten feet (3048 mm) horizontally from a pressure-tested sewer lateral into a building. (b) Twenty feet (6096 mm) horizontally from a non-pressure tested sewer lateral into a building. (c) Three feet (914 mm) horizontally from buried utilities such as electrical, gas, or water. (d) Fifty feet (15 240 mm) from a water well. (e) Fifty feet (15 240 mm) from a septic tank and 100 feet (30 480 mm) from a subsurface sewage leaching field. (f) One hundred feet (30 480 mm) from a spring.

SUBSTANTIATION: Part III (Open-Loop Systems) is being added to display provisions explicit to open-loop systems. Section 712.1 has also be added to clarify the scope and applicability of this part of the chapter.

Setbacks provided are intended to represent geologic averages to create effective retention times for contaminants that may be present in groundwater. Additionally, setbacks are a factor of porosity (the ratio of the void volume of a rock to the total volume of the rock, usually expressed as a percentage) and permeability (the measure of the relative ease with which a porous media can transmit a liquid under a potential gradient) of the subsurface and how groundwater will flow through a property. The proposed setbacks will help ensure safe operation.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

83 Proposals

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Item #: 057

USHGC 2021 Section: 713.0 - 713.3

SUBMITTER: Cary Smith Sound Geothermal Corporation

RECOMMENDATION: Add new text

Part III – Open-Loop Systems. 713.0 Open Ground Water Systems. 713.1 General. The installation and use of water wells shall be in accordance with the Authority Having Jurisdiction. The water well records shall include well logs, pumping tests, and aquifer information. 713.2 Open-Loop Water Well Drilling Logs. The water well drilling logs shall include the following: (1) The subsurface stratigraphy. (2) The aquifer type and conditions such as, but not limited to, confined, unconfined, flowing and depth. (3) The drilling method used and the penetration speed. (4) The presence of substances known to have a potential risk to health and safety shall be documented in the drill logs and the property owner shall be advised of the potential risk to health and safety. 713.3 Design Considerations. A groundwater heat pump system shall be designed by a registered design professional. Due design consideration shall be given to the following: (1) Where multiple heat pumps or fan coils are connected to a common water loop, a diversified building design load shall be used to design a ground water heat pump. (2) The water supply well(s) and injection wells, or water discharge system, shall be capable of being operated at sustainable pumping rates that exceed the maximum daily requirements without causing an adverse impact to existing or future offsite uses of groundwater or surface water bodies. (3) The water temperature and the quality and chemical composition of the water resource are in accordance with the system manufacturer’s recommendations. (4) The groundwater and surface water resources shall be protected by returning water to the source aquifer or an aquifer with the same water quality, or a surface water body. (5) The return capacity of the injection, or surface water body discharge system, shall be suitable under winter conditions. (6) The temperature of the return water shall have no adverse thermal impacts on offsite existing or future uses of groundwater, or on surface water bodies, in accordance with the requirements of the Authority Having Jurisdiction. (7) Pressure gauges shall be provided to aid in start-up and monitoring of the system during operation. (8) The ability to switch over operation of supply and return wells for 100 percent standby, redevelopment, cleaning of wells, and the thermal balancing of the ground and aquifer shall be provided. (9) There shall be no adverse effects on the quality and quantity of offsite existing or future users of groundwater, in accordance with the requirements of the Authority Having Jurisdiction.

SUBSTANTIATION: From a maintenance and repair perspective, documentation for project specific drilling information is critical for the reliable ongoing operation of an open-loop geothermal system. A registered design professional must determine accurate heating/cooling loads, pumping capacity requirements, source water temperature and chemical makeup as well as potential impacts resulting from re-introduction of water from the system at higher or lower temperatures than when extracted.

COMMITTEE ACTION: ACCEPT AS AMENDED BY THE TC

84 Amend proposal as follows:

Part III – Open-Loop Systems.

713.0 Open Ground Water Systems. 713.1 General. The installation and use of water wells shall be in accordance with the Authority Having Jurisdiction. The water well records shall include well logs, pumping tests, and aquifer information. 713.2 Open-Loop Water Well Drilling Logs. The water well drilling logs shall include the following: (1) The subsurface stratigraphy. (2) The aquifer type and conditions such as, but not limited to, confined, unconfined, flowing and depth. (3) The drilling method used and the penetration speed. (4) The presence of substances known to have a potential risk to health and safety shall be documented in the drill logs and the property owner shall be advised of the potential risk to health and safety. 713.3 Design Considerations. A groundwater heat pump system shall be designed by a registered design professional or certified person. Due design consideration shall be given to the following: (1) Where multiple heat pumps or fan coils are connected to a common water loop, a diversified building design load shall be used to design a ground water heat pump. (2) The water supply well(s) and injection wells, or water discharge system, shall be capable of being operated at sustainable pumping rates that exceed the maximum daily requirements without causing an adverse impact to existing or future offsite uses of groundwater or surface water bodies. (3) The water temperature and the quality and chemical composition of the water resource are in accordance with the system manufacturer’s recommendations. (4) The groundwater and surface water resources shall be protected by returning water to the source aquifer or an aquifer with the same water quality, or a surface water body. (5) The return capacity of the injection, or surface water body discharge system, shall be suitable under winter conditions. (6) The temperature of the return water shall have no adverse thermal impacts on offsite existing or future uses of groundwater, or on surface water bodies, in accordance with the requirements of the Authority Having Jurisdiction. (7) Pressure gauges shall be provided to aid in start-up and monitoring of the system during operation. (8) The ability to switch over operation of supply and return wells for 100 percent standby, redevelopment, cleaning of wells, and the thermal balancing of the ground and aquifer shall be provided. (9) There shall be no adverse effects on the quality and quantity of offsite existing or future users of groundwater, in accordance with the requirements of the Authority Having Jurisdiction.

COMMITTEE STATEMENT: The proposed language in Section 713.3 is being modified to include "certified person" in addition to "registered design professional."

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

85 Proposals

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Item #: 058

USHGC 2021 Section: 713.0, 713.4 - 713.6

SUBMITTER: Cary Smith Sound Geothermal Corporation

RECOMMENDATION: Add new text

Part III - Open Loop System.

713.0 Open Ground Water Systems.

713.4 Water Wells and Injection Wells. Water wells and injection wells for groundwater heat pump systems shall be installed by a registered professional who is qualified to drill wells that comply with the requirements of the Authority Having Jurisdiction. Water supply wells and injection wells shall be developed in accordance with NGWA-01. 713.5 Testing and Sampling. Pumping tests and water sampling shall be done as required by the registered design professional. 713.6 Disinfection. Water wells shall be disinfected upon completion in accordance with requirements of the Authority Having Jurisdiction and NGWA-01.

Note: NGWA-01 meets the requirements for a mandatory referenced standard in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

SUBSTANTIATION: Water well and injection well testing must be performed to determine both water flow and quality. In order to gain information about the producing aquifer and relating drawdowns, a multi-well test is required. In this test, the production well pumps at a controlled rate, and at least one nearby well monitors the water level. Testing periods must be 24 hours or longer. The purpose of performing water quality tests is to determine the chemical nature of the water, any impact upon system material selections, and maintenance requirements. Water quality testing is a critical part of the well testing phase as it determines whether water chemistry issues exist.

COMMITTEE ACTION: ACCEPT AS AMENDED BY THE TC Amend proposal as follows:

Part III - Open Loop System.

713.0 Open Ground Water Systems.

713.4 Water Wells and Injection Wells. Water wells and injection wells for groundwater heat pump systems shall be installed by a registered professional who is qualified to drill wells that comply with the requirements of the Authority Having Jurisdiction. Water supply wells and injection wells shall be developed in accordance with NGWA-01. 713.5 Testing and Sampling. Pumping tests and water sampling shall be done as required by the registered design professional or certified person. 713.6 Disinfection. Water wells shall be disinfected upon completion in accordance with requirements of the Authority Having Jurisdiction and NGWA-01.

86 COMMITTEE STATEMENT: The proposed language in Section 713.5 is being modified to also include "certified person" in addition to "registered design professional."

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

87 Proposals

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Item #: 059

USHGC 2021 Section: 714.0 - 714.7

SUBMITTER: Cary Smith Sound Geothermal Corporation

RECOMMENDATION: Add new text

Part III - Open Loop System.

714.0 Testing and Verification. 714.1 Pumping Test. Water supply wells and injection wells shall undergo a stop and start pumping test to demonstrate the sand-free yield. 714.2 Retesting. Where sediment is present, the problem shall be corrected, and the test shall be repeated until acceptable results are obtained. 714.3 Variable Rate Pump Test. The operating conditions of the water supply wells and injection wells shall be evaluated and verified with variable rate pumping. 714.4 Constant Rate Pump Test. The sustainable well yield, aquifer coefficients, and zones of influences on the groundwater flow requirements shall be confirmed with a constant rate-pumping test. The constant rate-pumping test shall be done on the water supply and injection wells at rates and durations as specified by the registered design professional. 714.5 Water Level Monitoring. Water levels shall be monitored in the pumping well and observation wells during pumping and recovery periods. The monitoring time intervals shall be as specified by the registered design professional. 714.6 Injection Wells. Injection testing shall be performed on water wells that are designated to be used as injection wells at rates specified by the registered design professional. The results of the drilling and pumping tests shall be provided to the owner or the owner’s representative and provided in accordance with requirements of the Authority Having Jurisdiction. 714.7 Re-Injected Water. The water quality of re-injected water into the earth shall comply with the requirements of the Authority Having Jurisdiction.

SUBSTANTIATION: Section 714.0 is being added to address testing and verification of open loop systems.

Variable and constant rate pump testing procedures are necessary to ensure that the system is free of leaks and defects as well as to verify that the water supply volume and chemical content are within specified limits.

Monitoring of nearby wells during the testing phase contributes to understanding of the aquifer characteristics, leading to reliable system design and operation. In addition, this section specifies that all water re-injection must comply with AHJ requirements.

COMMITTEE ACTION: ACCEPT AS AMENDED BY THE TC Amend proposal as follows:

Part III - Open Loop System.

88 714.3 Variable Rate Pump Test. The operating conditions of the water supply wells and injection wells shall be evaluated and verified with variable rate pumping. 714.4 Constant Rate Pump Test. The sustainable well yield, aquifer coefficients, and zones of influences on the groundwater flow requirements shall be confirmed with a constant rate-pumping test. The constant rate-pumping test shall be done on the water supply and injection wells at rates and durations as specified by the registered design professional or certified person. 714.5 Water Level Monitoring. Water levels shall be monitored in the pumping well and observation wells during pumping and recovery periods. The monitoring time intervals shall be as specified by the registered design professional or certified person. 714.6 Injection Wells. Injection testing shall be performed on water wells that are designated to be used as injection wells at rates specified by the registered design professional or certified person. The results of the drilling and pumping tests shall be provided to the owner or the owner’s representative and provided in accordance with requirements of the Authority Having Jurisdiction. 714.7 Re-Injected Water. The water quality of re-injected water into the earth shall comply with the requirements of the Authority Having Jurisdiction.

COMMITTEE STATEMENT: The proposed language in Section 714.4, Section 714.5 and Section 714.6 is being modified to also include "certified person" in addition to "registered design professional."

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

89 Proposals

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Item #: 060

USHGC 2021 Section: 715.0 - 715.8

SUBMITTER: Cary Smith Sound Geothermal Corporation

RECOMMENDATION: Revise text

Part IV – Direct Exchange (DX) Systems.

715.0 Direct Exchange (DX) Systems. 715.1 General. The installation and use of Direct Exchange (DX) wells shall be in accordance with the Authority Having Jurisdiction. The DX well records shall include well logs, pressure tests, and aquifer information. 715.2 Applicability. Part IV of this chapter shall apply to geothermal energy systems such as, but not limited to, building systems coupled with a DX closed loop using refrigerant as a heat transfer medium. The regulations of this Chapter shall govern the construction, location and installation of geothermal energy systems. Indoor piping, fittings, and accessories that are part of the ground source system shall be in accordance with Section 703.5 and Chapter 4. 703.6715.3 DX Systems. Copper pipe and tubing installed for DX systems shall be manufactured in accordance with ASTM B280 and copper fittings in accordance with ASME B16.22. Joints shall be purged with an inert gas and brazed with a brazing alloy having 15 percent silver content in accordance with AWS A5.8. Underground piping and tubing shall have a cathodic protection system installed. 706.2715.4 DX System Testing. For DX systems, each loop shall be tested with an inert gas at not less than 315 psi (2172 kPa) for not less than 15 minutes without pressure drop. The pressure reading after grouting of the boreholes shall be maintained in the ground-heat exchanger for not less than 2 hours. For direct exchange (DX) systems, each refrigerant u-bend shall be tested and proved tight with an inert gas at not less than 315 psi (2172 kPa) and maintained for 15 minutes without pressure drop. The pressure reading after tremie grouting of the boreholes shall be maintained in the ground heat exchanger for not less than 2 hours, in accordance with CSA C448. 715.5 Indoor Piping. For DX systems, joints shall be purged with an inert gas and brazed with a brazing alloy having 15 percent silver content in accordance with AWS A5.8. 715.6 On Site Storage. For DX systems, copper piping and fittings shall be stored to prevent physical damage, contamination, and each pipe or tubing shall be pressurized with an inert gas and sealed with a cap. 715.7 System Start-Up. DX system start-up shall be in accordance with Section 708.0 and the following: (1) DX systems shall be pressurized using nitrogen for not less than 1 hour. There shall be no allowable variance to the test pressure after being corrected for ambient temperature changes during the test. The test pressure shall not exceed 150 psig (1034 kPa) when pressure testing the compressor unit and indoor system components. (2) DX systems shall have permanent type labels installed and affixed on the compressor unit with the refrigerant type and quantity. (3) For DX systems, refrigerant liquid and vapor lines from the loop system shall be identified and tagged. 715.8 DX Piping. DX Piping shall be installed in accordance with approved plans and specifications, including provisions for cathodic protection.

Note: AWS A5.8 and CSA C448 meet the requirements for mandatory reference standards in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

90 SUBSTANTIATION: The proposed language combines all current provisions explicit to DX systems under Part IV (Direct Exchange Systems) for clarification. All listed provisions on indoor piping, on site storage, and system start-up are not new to the code.

Additionally, Section 715.2 provides the applicability for the listed provisions as well as references Section 703.5 (Indoor Piping) and Chapter 4 (Hydronics) to address piping, fittings and accessories for indoor piping to be used in DX systems.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

91 Proposals

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Item #: 061

USHGC 2021 Section: Chapter 2, Chapter 8

SUBMITTER: IAPMO Staff - Update Extracts NFPA 70 - Extract Update

RECOMMENDATION: Revise text

CHAPTER 98 SOLAR PHOTOVOLTAIC SYSTEMS

Part I - General.

901.0801.0 General. 901.1801.1 Electrical Wiring and Equipment. Electrical wiring and equipment shall comply with the requirements of NFPA 70, National Electrical Code (NEC), or local ordinances. This chapter does not provide all electrical information necessary for the installation of a photovoltaic (PV) system. Resort shall be had to the edition of NFPA 70 adopted by the Authority Having Jurisdiction. 901.2801.2 Applicability. The provisions of this chapter apply This chapter applies to solar PV electrical energy systems, other than those covered by Section 832.0, including the array circuit(s), inverter(s), and controller(s) for such systems [see Figure 901.2(1) 801.2(1) and Figure 901.2(2) 801.2(2)]. Solar PV The systems covered by this chapter shall be permitted to chapter may be interactive with other electrical power production sources or stand-alone or both, with or without electricaland may or may not be connected to energy storage systems such as batteries. These PV systems shall be permitted to may have ac or dc output for utilization. [NFPA 70:690.1] 901.3 Other Articles. Where the requirements of NFPA 70 and this chapter differ, the requirements of this chapter shall apply. Where the system is operated in parallel with a primary source(s) of electricity, the requirements in Section 901.4 through Section 901.7 shall apply. Exception: Solar PV systems, equipment, or wiring installed in a hazardous (classified) location shall also comply with the applicable portions of Article 500 through Article 516 of NFPA 70. [NFPA 70:690.3] 901.4 Output Characteristics. The output of a generator or other electric power production source operating in parallel with an electrical supply system shall be compatible with the voltage, wave shape, and frequency of the system to which it is connected. [NFPA 70:705.14] 901.5 Interrupting and Short-Circuit Current Rating. Consideration shall be given to the contribution of fault currents from all interconnected power sources for the interrupting and short-circuit current ratings of equipment on interactive systems. [NFPA 70:705.16]

Notes:

1 These diagrams are intended to be a means of identification for photovoltaic system PV power source components, circuits, and connections that make up the PV power source. 2 Disconnecting means required by Section 909.0 are not shown. 3 System grounding and equipment grounding are not shown. See Section 911.0 of this chapter. 2 Custom PV power source designs occur, and some components are optional.

FIGURE 901.2(1) 801.2(1) IDENTIFICATION OF SOLAR PHOTOVOLTAIC SYSTEM PV POWER SOURCE COMPONENTS [NFPA 70: FIGURE 690.1(a)]

Notes: 1 These diagrams are intended to be a means of identification for photo voltaic PV system components, circuits, and connections. 2 The PV system disconnect in these diagrams separates the PV system from all other systems. 23 Not all Ddisconnecting means and overcurrent protection required by Section 909.0 810.0 through Section 811.1.4 are not shown. 34 System grounding and equipment grounding are not shown. See Section 911.0 816.0 through Section 822.1. 45 Custom designs occur in each configuration, and some components are optional.

94 FIGURE 901.2(2) 801.2(2) IDENTIFICATION OF SOLAR PHOTOVOLTAIC PV SYSTEM COMPONENTS IN COMMON SYSTEM CONFIGURATIONS [NFPA 70: FIGURE 690.1(b)]

901.6 Ground-Fault Protection. Where ground-fault protection is used, the output of an interactive system shall be connected to the supply side of the ground-fault protection. Exception: Connection shall be permitted to be made to the load side of ground-fault protection, provided that there is ground- fault protection for equipment from all ground-fault current sources. [NFPA 70:705.32] 901.7 Synchronous Generators. Synchronous generators in a parallel system shall be provided with the necessary equipment to establish and maintain a synchronous condition. [NFPA 70:705.143]

902.0802.0 General Requirements. 902.1802.1 Photovoltaic Systems. Photovoltaic systems shall be permitted to supply a building or other structure in addition to any other electrical supply system(s). [NFPA 70:690.4(A)] 902.2802.2 Equipment. Inverters, motor generators, PV modules, PV panels, ac PV modules, dc combiners, dc-to-dc converters, and charge controllers intended for use in PV power systems shall be listed or field labeled for the PV application. [NFPA 70:690.4(B)] 902.3802.3 Qualified Personnel. The installation of equipment and all associated wiring and interconnections shall be performed only by qualified persons. [NFPA 70:690.4(C)] For purposes of this chapter a qualified person is defined as “one who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved.” [NFPA 70:100] 902.4802.4 Multiple Inverters PV Systems. A Multiple PV systems shall be permitted to have multiple inverters be installed in or on a single building or structure. Where the inverters PV systems are remotely located from each other, a directory in accordance with Section 912.1 823.1 shall be installed provided at each dc PV system disconnecting means., at each ac disconnecting means, and at the main service disconnecting means showing the location of all ac and dc PV system disconnecting means in the building. Exception: A directory shall not be required where inverters and PV dc disconnecting means are grouped at the main service disconnecting means. [NFPA 70:690.4(D)] 802.5 Locations Not Permitted. PV system equipment and disconnecting means shall not be installed in bathrooms. [NFPA 70:690.4(E)] 902.5802.6 Photovoltaic Modules/Panels/Shingles. Photovoltaic modules/panels/shingles shall comply with UL 1703 and shall be installed in accordance with the manufacturer’s installation instructions and the building code.

903.0 Ground-Fault Protection. 903.1 General. Grounded dc PV arrays shall be provided with dc ground-fault protection in accordance with Section 903.2 through Section 903.4 to reduce fire hazards. Ungrounded dc PV arrays shall comply with Section 910.14. Exception: Ground-mounted or pole-mounted PV arrays with not more than two paralleled source circuits and with all dc source and dc output circuits isolated from buildings shall be permitted without ground-fault protection. [NFPA 70:690.5] 903.2 Ground-Fault Detection and Interruption. The ground-fault protection device or system shall comply with the following: (1) Be capable of detecting a groundfault in the PV array dc current-carrying conductors and components, including any intentionally grounded conductors. (2) Interrupt the flow of fault current. (3) Provide an indication of the fault. (4) Be listed for providing PV ground-fault protection. Automatically opening the grounded conductor for measurement purposes or to interrupt the ground-fault current path shall be permitted. Where a grounded conductor is opened to interrupt the ground-fault current path, all conductors of the faulted circuit shall be automatically and simultaneously opened. Manual operation of the main PV dc disconnect shall not activate the ground-fault protection device or result in grounded conductors becoming ungrounded. [NFPA 70:690.5(A)] 903.3 Isolating Faulted Circuits. The faulted circuits shall be isolated by one of the following methods: (1) The ungrounded conductors of the faulted circuit shall be automatically disconnected. (2) The inverter or charge controller fed by the faulted circuit shall automatically cease to supply power to the output circuits. [NFPA 70:690.5(B)] 903.4 Labels and Markings. A warning label shall appear on the utility-interactive inverter or be applied by the installer

95 near the ground-fault indicator at a visible location, stating the following:

WARNING ELECTRICAL SHOCK HAZARD IF A GROUND FAULT IS INDICATED, NORMALLY GROUNDED CONDUCTORS MAY BE UNGROUNDED AND ENERGIZED

Where the PV system also has batteries, the same warning shall also be applied by the installer in a visible location at the batteries. The warning sign(s) or label(s) shall comply with Section 903.4.1. [NFPA 70:690.5(C)]

904.0 803.0 Alternating-Current (ac) Modules. 904.1 803.1 Photovoltaic Source Circuits. The requirements of this chapter pertaining to PV source circuits shall not apply to ac modules. The PV source circuit, conductors, and inverters shall be considered as internal wiring of an ac module. [NFPA 70:690.6(A)] 904.2 803.2 Inverter Output Circuit. The output of an ac module shall be considered an inverter output circuit. [NFPA 70:690.6(B)] 904.3 Disconnecting Means. A single disconnecting means, in accordance with Section 909.2 and Section 909.4 through Section 909.4.4, shall be permitted for the combined ac output of one or more ac modules. Additionally, each ac module in a multiple ac module system shall be provided with a connector, bolted, or terminal-type disconnecting means. [NFPA 70:690.6(C)] 904.4 Overcurrent Protection. The output circuits of ac modules shall be permitted to have overcurrent protection and conductor sizing in accordance with the following [NFPA 70:690.6(D)]: (1) 20-ampere circuits – 18 AWG, not exceeding 50 feet (15 240 mm) of run length (2) 20-ampere circuits – 16 AWG, not exceeding 100 feet (30 480 mm) of run length (3) 20-ampere circuits – Not less than 14 AWG (4) 30-ampere circuits – Not less than 14 AWG (5) 40-ampere circuits – Not less than 12 AWG (6) 50-ampere circuits – Not less than 12 AWG [NFPA 70:240.5(B)(2)]

Part II - Circuit Requirements.

905.0 804.0 Circuit Requirements. 804.1 Maximum Voltage. The maximum voltage of PV system dc circuits shall be the highest voltage between any two circuit conductors or any conductor and ground. PV system dc circuits on or in one- and two-family dwellings shall be permitted to have a maximum voltage of 600 volts or less. PV system dc circuits on or in other types of buildings shall be permitted to have a maximum voltage of 1000 volts or less. Where not located on or in buildings, listed dc PV equipment, rated at a maximum voltage of 1500 volts or less, shall not be required to comply with Parts II and III of Article 490 of NFPA 70. [NFPA 70:690.7] 905.1 804.1.1 Maximum Photovoltaic System Voltage Source and Output Circuits. In a dc PV source circuit or output circuit, the maximum PV system voltage for that circuit shall be calculated as the sum of the rated open-circuit voltage of the series-connected PV modules corrected for the lowest expected ambient temperature. For crystalline and multicrystalline silicon modules, the rated open-circuit voltage shall be multiplied by the correction factor provided in Table 905.1. This voltage shall be used to determine the voltage rating of cables, disconnects, overcurrent devices, and other equipment. Where the lowest expected ambient temperature is below -40°F (-40°C), or where other than crystalline or multicrystalline silicon PV modules are used, the system voltage adjustment shall be made in accordance with the manufacturer’s instructions. Where open-circuit voltage temperature coefficients are supplied in the instructions for listed PV modules, they shall be used to calculate the maximum PV system voltage in accordance with Section 302.1 instead of using Table 905.1. in accordance with one of the following methods: (1) Instructions in listing or labeling of the module: The sum of the PV module–rated open-circuit voltage of the series- connected modules corrected for the lowest expected ambient temperature using the open-circuit voltage temperature coefficients in accordance with the instructions included in the listing or labeling of the module. (2) Crystalline and multicrystalline modules: For crystalline and multicrystalline silicon modules, the sum of the PV module– rated open-circuit voltage of the seriesconnected modules corrected for the lowest expected ambient temperature using the correction factor provided in Table 804.1.1. (3) PV systems of 100 kW or larger – For PV systems with a generating capacity of 100 kW or greater, a documented and stamped PV system design, using an industry standard method and provided by a licensed professional electrical engineer, shall be permitted.

96 The maximum voltage shall be used to determine the voltage rating of conductors, cables, disconnects, overcurrent devices, and other equipment. [NFPA 70:690.7(A)]

TABLE 905.1 804.1.1 VOLTAGE CORRECTION FACTORS FOR CRYSTALLINE AND MULTICRYSTALLINE SILICON MODULES [NFPA 70: TABLE 690.7(A)]1, 2 AMBIENT FACTOR TEMPERATURE (°F) 76 to 68 1.02 67 to 59 1.04 58 to 50 1.06 49 to 41 1.08 40 to 32 1.10 31 to 23 1.12 22 to 14 1.14 13 to 5 1.16 4 to -4 1.18 -5 to -13 1.20 -14 to -22 1.21 -23 to -31 1.23 -32 to -40 1.25

For SI units: °C = (°F-32)/1.8

Notes: 1 Correction factors for ambient temperatures below 77°F (25°C). 2 Multiply the rated open circuit voltage by the appropriate correction factor shown above.

804.1.2 DC-to-DC Converter Source and Output Circuits. In a dc-to-dc converter source and output circuit, the maximum voltage shall be calculated in accordance with Section 804.1.2.1 or Section 804.1.2.2. [NFPA 70:690.7(B)] 804.1.2.1 Single DC-to-DC Converter. For circuits connected to the output of a single dc-to-dc converter, the maximum voltage shall be the maximum rated voltage output of the dc-to-dc converter. [NFPA 70:690.7(B)(1)] 804.1.2.2 Two or More Series Connected DC-to-DC Converters. For circuits connected to the output of two or more series connected dc-to-dc converters, the maximum voltage shall be determined in accordance with the instructions included in the listing or labeling of the dc-to-dc converter. If these instructions do not state the rated voltage of series-connected dc-to-dc converters, the maximum voltage shall be the sum of the maximum rated voltage output of the dc-to-dc converters in series. [NFPA 70:690.7(B)(2)] 905.5 804.2 Bipolar Source and Output Circuits. For two-wire dc circuits connected to bipolar systems PV arrays, the maximum system voltage shall be the highest voltage between the conductors of the two-wire circuit conductors where the following conditions apply: one conductor of the two-wire circuit is connected to the functional ground reference (center tap). To prevent overvoltage in the event of a ground-fault or arc-fault, the array shall be isolated from the ground reference and isolated into two two-wire circuits. [NFPA 70:690.7(C)] (1) One conductor of each circuit of a bipolar subarray is solidly grounded. Exception: The operation of ground fault or arc-fault devices (abnormal operation) shall be permitted to interrupt this connection to ground where the entire bipolar array becomes two distinct arrays isolated from each other and the utilization equipment. (2) Each circuit is connected to a separate subarray. (3) The equipment is clearly marked with a label as follows:

97 WARNING BIPOLAR PHOTOVOLTAIC ARRAY. DISCONNECTION OF NEUTRAL OR GROUNDED CONDUCTORS MAY RESULT IN OVERVOLTAGE ON ARRAY OR INVERTER.

The warning sign(s) or label(s) shall comply with Section 903.4.1. [NFPA 70:690.7(E)] 905.2 Direct-Current Utilization Circuits. The voltage of dc utilization circuits shall comply with Section 905.2.1 through Section 905.2.5. [NFPA 70:690.7(B)] 905.2.1 Occupancy Limitation. In dwelling units and guest rooms or guest suites of hotels, motels, and similar occupancies, the voltage shall not exceed 120 volts, nominal, between conductors that supply the terminals of the following: (1) Luminaires. (2) Cord-and-plug-connected loads 1440 volt-amperes, nominal, or less than 1/4 hp (0.19 kW). [NFPA 70:210.6(A)] 905.2.2 One Hundred Twenty Volts Between Conductors. Circuits not exceeding 120 volts, nominal, between conductors shall be permitted to supply the following: (1) The terminals of lampholders applied within their voltage ratings. (2) Auxiliary equipment of electric-discharge lamps. (3) Cord-and-plug-connected or permanently connected utilization equipment. Exception: For lampholders of infrared industrial heating appliances as provided in Section 905.2.6. [NFPA 70:210.6(B)] 905.2.3 Two Hundred Seventy Seven Volts to Ground. Circuits exceeding 120 volts, nominal, between conductors and not exceeding 277 volts, nominal, to ground shall be permitted to supply the following: (1) Listed electric-discharge or listed light-emitting diodetype luminaires. (2) Listed incandescent luminaires, where supplied at 120 volts or less from the output of a stepdown autotransformer that is an integral component of the luminaire and the outer shell terminal is electrically connected to a grounded conductor of the branch circuit. (3) Luminaires equipped with mogul-base screw shell lampholders. (4) Lampholders, other than the screw shell type, applied within their voltage ratings. (5) Auxiliary equipment of electric-discharge lamps. (6) Cord-and-plug-connected or permanently connected utilization equipment. Exception: For lampholders of infrared industrial heating appliances as provided in Section 905.2.6. [NFPA 70:210.6(C)]

905.2.4 Six Hundred Volts Between Conductors. Circuits exceeding 277 volts, nominal, to ground and not exceeding 600 volts, nominal, between conductors shall be permitted to supply the following: (1) The auxiliary equipment of electric-discharge lamps mounted in permanently installed luminaires where the luminaires are mounted in accordance with one of the following: (a) Not less than a height of 22 feet (6706 mm) on poles or similar structures for the illumination of outdoor areas such as highways, roads, bridges, athletic fields, or parking lots. (b) Not less than a height of 18 feet (5486 mm) on other structures such as tunnels. (2) Cord-and-plug-connected or permanently connected utilization equipment other than luminaires. (3) Luminaires powered from direct-current systems where the luminaire contains a listed, dc-rated ballast that provides isolation between the dc power source and the lamp circuit and protection from electric shock where changing lamps. Exception: For lampholders of infrared industrial heating appliances as provided in Section 905.2.6. [NFPA 70:210.6(D)]

905.2.5 Over 600 Volts Between Conductors. Circuits exceeding 600 volts, nominal, between conductors shall be permitted to supply utilization equipment in installations where conditions of maintenance and supervision ensure that qualified persons service the installation. [NFPA 70:210.6(E)] 905.2.6 Infrared Lamp Industrial Heating Appliances. In industrial occupancies, infrared heating appliance lampholders shall be permitted to be operated in series on circuits exceeding 150 volts to ground, provided the voltage rating of the lampholders is not less than the circuit voltage. Each section, panel, or strip carrying a number of infrared lampholders, (including the internal wiring of such section, panel, or strip) shall be considered an appliance. The terminal connection block of each such assembly shall be considered an individual outlet. [NFPA 70:422.14] 905.3 Photovoltaic Source and Output Circuits. In one-and two-family dwellings, PV source circuits and PV output circuits that do not include lampholders, fixtures, or receptacles shall be permitted to have a PV system voltage not exceeding 600 volts. Other installations with a maximum PV system voltage exceeding 1000 volts shall comply with Section 915.0. [NFPA 70:690.7(C)]

98 905.4 Circuits Over 150 Volts to Ground. In one-and two-family dwellings, live parts in PV source circuits and PV output circuits exceeding 150 volts to ground shall not be accessible to other than qualified persons while energized. [NFPA 70:690.7(D)] 905.6 Disconnects and Overcurrent Protection. Where energy storage device output conductor length exceeds 5 feet (1524 mm), or where the circuits pass through a wall or partition, the installation shall comply with the following: (1) A disconnecting means and overcurrent protection shall be provided at the energy storage device end of the circuit. Fused disconnecting means or circuit breakers shall be permitted. (2) Where fused disconnecting means are used, the line terminals of the disconnecting means shall be connected toward the energy storage device terminals. (3) Overcurrent devices or disconnecting means shall not be installed in energy storage device enclosures where explosive atmospheres can exist. (4) A second disconnecting means located at the connected equipment shall be installed where the disconnecting means required in Section 905.6(1) is not within sight of the connected equipment. (5) Where the energy storage device disconnecting means is not within sight of the PV system ac and dc disconnecting means, placards or directories shall be installed at the locations of all disconnecting means indicating the location of all disconnecting means. [NFPA 70:690.7(F)] 905.7 Live Parts Guarded Against Accidental Contact. Live parts of electrical equipment operating at 50 volts or more shall be guarded against accidental contact by approved enclosures or by one of the following means: (1) By location in a room, vault, or similar enclosure that is accessible only to qualified persons. (2) By suitable permanent, substantial partitions or screens arranged so that qualified persons have access to the space within reach of the live parts. Openings in such partitions or screens shall be sized and located so that persons are not likely to come into accidental contact with the live parts or to bring conducting objects into contact with them. (3) By location on a suitable balcony, gallery, or platform elevated and arranged so as to exclude unqualified persons. (4) By elevation above the floor or other working surface in accordance with the following: (a) Not less than 8 feet (2438 mm) for 50 volts to 300 volts. (b) Not less than 81/2 feet (2591 mm) for 301 volts to 600 volts. [NFPA 70:110.27(A)] 905.8 Prevent Physical Damage. In locations where electrical equipment is likely to be exposed to physical damage, enclosures or guards shall be so arranged and of such strength to prevent such damage. [NFPA 70:110.27(B)] 905.9 Warning Signs. Entrances to rooms and other guarded locations that contain exposed live parts shall be marked with conspicuous warning signs forbidding unqualified persons to enter. The marking shall comply with the requirements in Section 903.4.1. [NFPA 70:110.27(C)]

906.0 805.0 Circuit Sizing and Current. 906.1 805.1 Calculation of Maximum Circuit Current. The maximum current for the specific circuit shall be calculated as follows: in accordance with Section 805.1.1 through Section 805.1.6. Where the requirements of Section 805.1.1 and Section 805.2.1 are both applied, the resulting multiplication factor is 156 percent. [NFPA 70:690.8(A)] (1) 805.1.1 Photovoltaic Source Circuit Currents. The maximum current shall be calculated by one of the following methods: (1) Tthe sum of parallel-connected PV module-rated short-circuit currents multiplied by 125 percent. (2) For PV systems with a generating capacity of 100 kW or greater, a documented and stamped PV system design, using an industry standard method and provided by a licensed professional electrical engineer, shall be permitted. The calculated maximum current value shall be based on the highest 3-hour current average resulting from the simulated local irradiance on the PV array accounting for elevation and orientation. The current value used by this method shall not be less than 70 percent of the value calculated using Section 805.1.1(1). [NFPA 70:690.8(A)(1)] (2) 805.1.2 Photovoltaic Output Circuit Currents. The maximum current shall be the sum of parallel source circuit maximum currents as calculated in Section 906.1(1) 805.1.1. [NFPA 70:690.8(A)(2)] (3) 805.1.3 Inverter Output Circuit Current. The maximum current shall be the inverter continuous output current rating. [NFPA 70:690.8(A)(3)] (4) 805.1.4 Stand-Alone Inverter Input Circuit Current. The maximum current shall be the stand-alone continuous inverter input current rating where when the inverter is producing rated power at the lowest input voltage. [NFPA 70:690.8(A)(4)] (5) 805.1.5 DC-to-DC Converter Source Circuit Current. The maximum current shall be the dc-to-dc converter continuous output current rating. [NFPA 70:690.8(A)(5)] 805.1.6 DC-to-DC Converter Output Circuit Current. The maximum current shall be the sum of parallel connected dc-to- dc converter source circuit currents as calculated in Section 805.1.5. [NFPA 70:690.8(A)(6)] 906.2 805.2 Conductor Ampacity. PV system currents shall be considered to be continuous. Circuit conductors shall be sized to carry not less than the larger of one of the following: Section 805.2.1 or Section 805.2.2 or where protected by a listed adjustable electronic overcurrent protective device in accordance with Section 806.2(3), not less than the current in Section 805.2.3. [NFPA 70:690.8(B)] (1)805.2.1 Before Application of Adjustment and Correction Factors. One hundred twenty-five percent of the maximum currents as calculated in Section 906.1 805.1 before the application of adjustment and correction factors.

99 Exception: Circuits containing an assembly, together with its overcurrent device(s), that is listed for continuous operation at 100 percent of its rating shall be permitted to be used at 100 percent of its rating. [NFPA 70:690.8(B)(1)] (2)805.2.2 After Application of Adjustment and Correction Factors. The maximum currents calculated in accordance with Section 906.1 805.1 after the application of adjustment and correction factors. [NFPA 70:690.8(B)(2)] 805.2.3 Adjustable Electronic Overcurrent Protective Device. The rating or setting of an adjustable electronic overcurrent protective device installed in accordance with Section 805.5. [NFPA 70:690.8(B)(3)] 906.3 805.3 Systems with Multiple Direct-Current Voltages. For a PV power source that has multiple output circuit voltages and employs a common-return conductor, the ampacity of the common-return conductor shall be not less than the sum of the ampere ratings of the overcurrent devices of the individual output circuits. [NFPA 70:690.8(C)] 906.4 805.4 Sizing of Module Interconnection Conductors. Where a single overcurrent device is used to protect a set of two or more parallel-connected module circuits, the ampacity of each of the module interconnection conductors shall be not less than the sum of the rating of the single overcurrent device plus 125 percent of the short-circuit current from the other parallel- connected modules. [NFPA 70:690.8(D)] 805.5 Standard Ampere Ratings. Standard ampere ratings shall be in accordance with Section 805.5.1 through Section 805.5.3. 805.5.1 Fuses and Fixed-Trip Circuit Breakers. The standard ampere ratings for fuses and inverse time circuit breakers shall be considered as shown in Table 805.5.1. Additional standard ampere ratings for fuses shall be 1, 3, 6, 10, and 601. The use of fuses and inverse time circuit breakers with nonstandard ampere ratings shall be permitted. [NFPA 70:240.6(A)] 805.5.2 Adjustable-Trip Circuit Breakers. The rating of adjustable-trip circuit breakers having external means for adjusting the current setting (long-time pickup setting), not meeting the requirements of Section 805.5.3, shall be the maximum setting possible. [NFPA 70:240.6(B)] 805.5.3 Restricted Access Adjustable-Trip Circuit Breakers. A circuit breaker(s) that has restricted access to the adjusting means shall be permitted to have an ampere rating(s) that is equal to the adjusted current setting (long-time pickup setting). Restricted access shall be defined as located behind one of the following: (1) Removable and sealable covers over the adjusting means (2) Bolted equipment enclosure doors (3) Locked doors accessible only to qualified personnel [NFPA 70:240.6(C)]

TABLE 805.5.1 STANDARD AMPERE RATINGS FOR FUSES AND INVERSE TIME CIRCUIT BREAKERS [NFPA 70:TABLE 240.6(A)] STANDARD AMPERE RATINGS 15 20 25 30 35 40 45 50 60 70 80 90 100 110 125 150 175 200 225 250 300 350 400 450 500 600 700 800 1000 1200 1600 2000 2500 3000 4000 5000 6000 — — —

907.0 806.0 Overcurrent Protection. 907.1 806.1 Circuits and Equipment. PV source circuit, PV output circuit, system dc circuit and inverter output circuit, and storage battery circuit conductors and equipment shall be protected against overcurrent. Overcurrent protective devices shall not be required for circuits with sufficient ampacity for the highest available current. in accordance with the requirements of Article 240 of NFPA 70. Protection devices for PV source circuits and PV output circuits shall be in accordance with the requirements of Section 907.2 through Section 907.5. Circuits, either ac or dc, connected to current-limited supplies (e.g., PV modules, ac output of utility-interactive inverters), and connected to sources having higher current availability (e.g., parallel strings of modules, utility power), shall be protected at the source from overcurrent. Circuits connected to current limited supplies (e.g., PV modules, dc-to-dc converters, interactive inverter output circuits) and also connected to sources having higher current availability (e.g., parallel strings of modules, utility power) shall be protected at the higher current source connection. Exception: An overcurrent device shall not be required for PV modules or PV source circuit or dc-to-dc converters source circuit conductors sized in accordance with Section 906.2 805.2 where one of the following applies: (1) There are no external sources such as parallel-connected source circuits, batteries, or backfeed from inverters. (2) The short-circuit currents from all sources do not exceed the ampacity of the conductors and the maximum overcurrent protective device size rating specified on for the PV module nameplate or dc-to-dc converter. [NFPA 70:690.9(A)] 907.2 806.2 Overcurrent Device Ratings. Overcurrent devices used in PV system dc circuits shall be listed for use in PV systems. Overcurrent devices, where required, shall be rated in accordance with one of the following:

100 (1) device ratings shall be nNot less than 125 percent of the maximum currents calculated in accordance with Section 906.1 805.1. (2) Exception: Circuits containing aAn assembly, together with its overcurrent device(s), that is listed for continuous operation at 100 percent of its rating shall be permitted to be used at 100 percent of its rating. (3) Adjustable electronic overcurrent protective devices rated or set in accordance with Section 805.5. [NFPA 70:690.9(B)] 907.3 Direct-Current Rating. Overcurrent devices, either fuses or circuit breakers, used in the dc portion of a PV power system shall be listed and shall have the appropriate voltage, current, and interrupt ratings. [NFPA 70:690.9(C)] 907.4 806.3 Photovoltaic Source and Output Circuits. Listed PV overcurrent devices A single overcurrent protective device, where required, shall be required to provide overcurrent protection in PV source and output circuits. permitted to protect the PV modules and conductors of each source circuit or the conductors of each output circuit. Where single overcurrent protection devices are used to protect PV source or output circuits, all overcurrent devices shall be placed in the same polarity for all circuits within a PV system. The overcurrent devices shall be accessible but shall not be required to be readily accessible. [NFPA 70:690.9(D) 690.9(C)] 907.5 Series Overcurrent Protection. In grounded PV source circuits, a single overcurrent protection device, where required, shall be permitted to protect the PV modules and the interconnecting conductors. In underground PV source circuits that are in accordance with Section 910.14, an overcurrent protection device, where required, shall be installed in each undergrounded circuit conductor and shall be permitted to protect the PV modules and the interconnecting cables. [NFPA 70:690.9(E)] 907.6 806.4 Power Transformers. Overcurrent protection for a transformer with a source(s) on each side shall be provided in accordance with Section 450.3 of NFPA 70 by considering first one side of the transformer, then the other side of the transformer, as the primary. Exception: A power transformer with a current rating on the side connected toward the utility-interactive inverter output, not less than the rated continuous output current of the inverter, shall be permitted without overcurrent protection from the inverter. [NFPA 70:690.9(F)690.9(D)]

908.0 807.0 Stand-Alone Systems. 908.1 General 807.1 General. The premises wiring system shall be adequate to comply with the requirements of NFPA 70 for a similar installation connected to a service. The wiring on the supply side of the building or structure disconnecting means shall comply with NFPA 70, except as modified in accordance with Section 908.2 through Section 908.6. The wiring system connected to a stand-alone system shall be installed in accordance with Section 807.2. [NFPA 70:690.10] 908.2 Inverter Output. The ac output from a stand-alone inverter(s) shall be permitted to supply ac power to the building or structure disconnecting means at current levels less than the calculated load connected to that disconnect. The inverter output rating or the rating of an alternate energy source shall be not less than the load posed by the largest single utilization equipment connected to the system. Calculated general lighting loads shall not be considered as a single load. [NFPA 70:690.10(A)] 807.2 Wiring System. Premises wiring systems shall be adequate to meet the requirements of this chapter and NFPA 70 for similar installations supplied by a feeder or service. The wiring on the supply side of the building or structure disconnecting means shall comply with the requirements of this chapter and NFPA 70, except as modified by Section 807.2.1 through Section 807.2.6. [NFPA 70:710.15] 807.2.1 Supply Output. Power supply to premises wiring systems shall be permitted to have less capacity than the calculated load. The capacity of the stand-alone supply shall be equal to or greater than the load posed by the largest single utilization equipment connected to the system. Calculated general lighting loads shall not be considered as a single load. [NFPA 70:710.15(A)] 908.3807.2.2 Sizing and Protection. The circuit conductors between the inverter output and the a stand-alone source and a building or structure disconnecting means shall be sized based on the sum of the output rating of the inverter stand-alone sources. These conductors shall be protected from overcurrents in accordance with Article 240 of NFPA 70. The overcurrent protection shall be located at the output of the inverter. [NFPA 70:690.10(B)710.15(B)] 908.4807.2.3 Single 120-Volt Supply. The inverter output of a stand-alone solar PV system Stand-alone systems shall be permitted to supply 120 volts to single-phase, three-wire, 120/240-volt service equipment or distribution panels where there are no 240-volt outlets and where there are no multiwire branch circuits. In all installations, the sum of the ratings of the overcurrent device connected to the output of the inverter power sources shall be less than the rating of the neutral bus in the service equipment. This equipment shall be marked with the following words or equivalent:

WARNING SINGLE 120-VOLT SUPPLY. DO NOT CONNECT MULTIWIRE BRANCH CIRCUITS!

The warning sign(s) or label(s) shall comply with Section 903.4.1 810.1.2.1. [NFPA 70:690.10(C)710.15(C)] 908.5 807.2.4 Energy Storage or Backup Power System Requirements. Energy storage or backup power supplies are not required. [NFPA 70:690.10(D)710.15(D)] 908.6 807.2.5 Back-Fed Circuit Breakers. Plug-in type back-fed circuit breakers connected to a stand-alone or multimode

101 inverter output in stand-alone systems an interconnected supply shall be secured in accordance with Section 908.6.1807.2.5.1. Circuit breakers marked “line” and “load” shall not be back-fed. [NFPA 70:690.10(E)710.15(E)] 908.6.1 807.2.5.1 Back-Fed Devices. Plug-in-type overcurrent protection devices or plug-in type main lug assemblies that are back-fed and used to terminate field-installed ungrounded supply conductors shall be secured in place by an additional fastener that requires other than a pull to release the device from the mounting means on the panel. [NFPA 70:408.36(D)] 807.2.6 Voltage and Frequency Control. The stand-alone supply shall be controlled so that voltage and frequency remain within suitable limits for the connected loads. [NFPA 70:710.15(F)]

908.7808.0 Arc-Fault Circuit Protection (Direct Current). 808.1 Arc-Fault Circuit Protection. Photovoltaic systems with dc source circuits, dc output circuits or both, operating at a PV system maximum system voltage of not less than operating at 80 volts dc or greater between any two conductors, shall be protected by a listed (dc) PV arc-fault circuit interrupter, PV type, or other system components listed to provide equivalent protection. The PV arc-fault protection means shall comply with the following requirements: (1) The system shall detect and interrupt arcing faults resulting from a failure in the intended continuity of a conductor, connection, module, or other system component in the dc PV source and dc PV output PV system dc circuits. (2) The system shall require that the disabled or disconnected equipment be manually restarted. (3) The system shall have an annunciator that provides a visual indication that the circuit interrupter has operated. This indication shall not reset automatically. Exception: For PV systems not installed on or in buildings, PV output circuits and dc-to-dc converter output circuits that are direct buried, installed in metallic raceways, or installed in enclosed metallic cable trays are permitted without arc-fault circuit protection. Detached structures whose sole purpose is to house PV system equipment shall not be considered buildings according to this exception. [NFPA 70:690.11]

908.8 809.0 Rapid Shutdown of PV Systems on Buildings. 809.1 Reduce Shock Hazard. PV system circuits installed on or in buildings shall include a rapid shutdown function that controls specific conductors to reduce shock hazard for emergency responders in accordance with the following: Section 809.1.1 through Section 809.1.4. Exception: Ground mounted PV system circuits that enter buildings, of which the sole purpose is to house PV system equipment, shall not be required to comply with Section 809.1. [NFPA 70:690.12] (1) 809.1.1 Controlled Conductors. Requirements for controlled conductors shall apply only to PV system conductors of more than 5 feet (1524 mm) in length inside a building, or more than 10 feet (3048 mm) from a PV array. circuits supplied by the PV system. [NFPA 70:690.12(A)] (2) Controlled conductors shall be limited to not more than 30 volts and 240 volt-amperes within 10 seconds of rapid shutdown initiation. (3) Voltage and power shall be measured between any two conductors and between any conductor and ground. (4) The rapid shutdown initiation methods shall be labeled in accordance with Section 912.8. (5) Equipment that performs the rapid shutdown shall be listed and identified.[NFPA 70:690.12] 809.1.2 Controlled Limits. The use of the term array boundary in this section is defined as 1 foot (305 mm) from the array in all directions. Controlled conductors outside the array boundary shall comply with Section 809.1.2.1 and inside the array boundary shall comply with Section 809.1.2.2. [NFPA 70:690.12(B)] 809.1.2.1 Outside the Array Boundary. Controlled conductors located outside the boundary or more than 3 feet (914 mm) from the point of entry inside a building shall be limited to not more than 30 volts within 30 seconds of rapid shutdown initiation. Voltage shall be measured between any two conductors and between any conductor and ground. [NFPA 70:690.12(B) (1)] 809.1.2.2 Inside the Array Boundary. The PV system shall comply with one of the following: (1) The PV array shall be listed or field labeled as a rapid shutdown PV array. Such a PV array shall be installed and used in accordance with the instructions included with the rapid shutdown PV array listing or field labeling. (2) Controlled conductors located inside the boundary or not more than 3 feet (914 mm) from the point of penetration of the surface of the building shall be limited to not more than 80 volts within 30 seconds of rapid shutdown initiation. Voltage shall be measured between any two conductors and between any conductor and ground. (3) PV arrays with no exposed wiring methods, no exposed conductive parts, and installed more than 8 feet (2438 mm) from exposed grounded conductive parts or ground shall not be required to comply with Section 809.1.2.2. The requirement of Section 809.1.2.2 shall become effective January 1, 2019. [NFPA 70:690.12(B)(2)] 809.1.3 Initiation Device. The initiation device(s) shall initiate the rapid shutdown function of the PV system. The device “off” position shall indicate that the rapid shutdown function has been initiated for all PV systems connected to that device. For one-family and two-family dwellings, an initiation device(s) shall be located at a readily accessible location outside the building. The rapid shutdown initiation device(s) shall consist of at least one of the following: (1) Service disconnecting means

102 (2) PV system disconnecting means (3) Readily accessible switch that plainly indicates whether it is in the “off” or “on” position Where multiple PV systems are installed with rapid shutdown functions on a single service, the initiation device(s) shall consist of not more than six switches or six sets of circuit breakers, or a combination of not more than six switches and sets of circuit breakers, mounted in a single enclosure, or in a group of separate enclosures. These initiation device(s) shall initiate the rapid shutdown of all PV systems with rapid shutdown functions on that service. Where auxiliary initiation devices are installed, these auxiliary devices shall control all PV systems with rapid shutdown functions on that service. [NFPA 70:690.12(C)] 809.1.4 Equipment. Equipment that performs the rapid shutdown functions, other than initiation devices such as listed disconnect switches, circuit breakers, or control switches, shall be listed for providing rapid shutdown protection. [NFPA 70:690.12(D)]

Part III - Disconnecting Means.

909.0 810.0 Disconnecting Means. 909.1 810.1 Building or Other Structure Supplied by a Photovoltaic System Disconnecting Means. Means shall be provided to disconnect ungrounded dc conductors of a the PV system from other conductors in a building or other structure all wiring systems including power systems, energy storage systems, and utilization equipment and its associated premises wiring. [NFPA 70:690.13] 909.1.1 810.1.1 Location. The PV system disconnecting means shall be installed at a readily accessible location. either on the outside of a building or structure or inside nearest the point of entrance of the system conductors. Exception: Installations that comply with Section 910.6 shall be permitted to have the disconnecting means located remote from the point of entry of the system conductors. The PV system disconnecting means shall not be installed in bathrooms. [NFPA 70:690.13(A)] 909.1.2 810.1.2 Markings. Each PV system disconnecting means shall be permanently marked to identify it as a PV system disconnect. plainly indicate whether in the open (off) or closed (on) position and be permanently marked “PV SYSTEM DISCONNECT” or equivalent. Additional markings shall be permitted based upon the specific system configuration. For PV system disconnecting means where the line and load terminals may be energized in the open position, the device shall be marked with the following words or equivalent:

WARNING ELECTRIC SHOCK HAZARD TERMINALS ON THE LINE AND LOAD SIDES MAY BE ENERGIZED IN THE OPEN POSITION

The warning sign(s) or label(s) shall comply with Section 810.1.2.1. [NFPA 70:690.13(B)]

903.4.1 810.1.2.1 Field-Applied Hazard Markings. Where caution, warning, or danger signs or labels are required by this chapter, the labels shall comply with the following requirements: (1) The marking shall adequately warn of the hazards using effective words, colors, or symbols, or any combination thereof. (2) The label shall be permanently affixed to the equipment or wiring method and shall not be hand written. Exception: Portions of labels or markings that are variable, or that could be subject to changes, shall be permitted to be hand written and shall be legible. (3) The label shall be durable as of sufficient durability to withstand the environment involved. [NFPA 70:110.21(B)] 909.1.3 810.1.3 Suitable for Use. Each If the PV system is connected to the supply side of the service disconnecting means shall not be required to be suitable as permitted in Article 230.82(6) of NFPA 70, the PV system disconnecting means shall be listed as suitable for use as service equipment. [NFPA 70:690.13(C)] 909.1.4 810.1.4 Maximum Number of Disconnects. The Each PV system disconnecting means shall consist of not more than six switches or six sets of circuit breakers or a combination of not more than six switches and sets of circuit breakers, mounted in a single enclosure or in a group of separate enclosures. A single PV system disconnecting means shall be permitted for the combined ac output of one or more inverters or ac modules in an interactive system. [NFPA 70:690.13(D)] 909.1.5 810.1.5 Grouping Rating. The PV system disconnecting means shall be grouped with other disconnecting means for the system to be in accordance with Section 909.1.4. A PV disconnecting means shall not be required at the PV module or array location have ratings sufficient for the maximum circuit current available short-circuit current, and voltage that is available at the terminals of the PV system disconnect. [NFPA 70:690.13(E)] 810.1.6 Type of Disconnect. The type(s) of disconnect shall be in accordance with the Section 810.1.6.1 through Section 810.1.6.3. 810.1.6.1 Simultaneous Disconnection. The PV system disconnecting means shall simultaneously disconnect the PV

103 system conductors of the circuit from all conductors of other wiring systems. The PV system disconnecting means shall be an externally operable general-use switch or circuit breaker, or other approved means. A dc PV system disconnecting means shall be marked for use in PV systems or be suitable for backfeed operation. [NFPA 70:690.13(F)(1)] 810.1.6.2 Devices Marked “Line” and “Load.” Devices marked with “line” and “load” shall not be permitted for backfeed or reverse current. [NFPA 70:690.13(F)(2)] 810.1.6.3 DC-Rated Enclosed Switches, Open-Type Switches, and Low-Voltage Power Circuit Breakers. DC- rated, enclosed switches, open-type switches, and low-voltage power circuit breakers shall be permitted for backfeed operation. [NFPA 70:690.13(F)(3)]

909.2811.0 Disconnection of Photovoltaic Equipment. 811.1 Isolating Devices. Means Isolating devices shall be provided to disconnect equipment, such as inverters, batteries, isolate PV modules, ac PV modules, fuses, dc-to-dc converters inverters, and charge controllers from ungrounded conductors of all sources. Where the equipment is energized from more than one source, the disconnecting means shall be grouped and identified. A single disconnecting means in accordance with Section 909.4 through Section 909.4.4 shall be permitted for the combined ac output of one or more inverters or ac modules in an interactive system. all conductors that are not solidly grounded. An equipment disconnecting means or a PV system disconnecting means shall be permitted in place of an isolating device. Where the maximum circuit current is greater than 30 amperes for the output circuit of a dc combiner or the input circuit of a charge controller or inverter, an equipment disconnecting means shall be provided for isolation. Where a charge controller or inverter has multiple input circuits, a single equipment disconnecting means shall be permitted to isolate the equipment from the input circuits. [NFPA 70:690.15] 811.1.1 Location. Isolating devices or equipment disconnecting means shall be installed in circuits connected to equipment at a location within the equipment, or within sight and within 10 feet (3048 mm) of the equipment. An equipment disconnecting means shall be permitted to be remote from the equipment where the equipment disconnecting means can be remotely operated from within 10 feet (3048 mm) of the equipment. [NFPA 70:690.15(A)] 811.1.2 Interrupting Rating. An equipment disconnecting means shall have an interrupting rating sufficient for the maximum short-circuit current and voltage that is available at the terminals of the equipment. An isolating device shall not be required to have an interrupting rating. [NFPA 70:690.15(B)] 811.1.3 Isolating Device. An isolating device shall not be required to simultaneously disconnect all current-carrying conductors of a circuit. The isolating device shall be one of the following: (1) A connector meeting the requirements of Section 814.1 and listed and identified for use with specific equipment (2) A finger safe fuse holder (3) An isolating switch that requires a tool to open (4) An isolating device listed for the intended application An isolating device shall be rated to open the maximum circuit current under load or be marked “Do Not Disconnect Under Load” or “Not for Current Interrupting.” [NFPA 70:690.15(C)] 811.1.4 Equipment Disconnecting Means. An equipment disconnecting means shall simultaneously disconnect all current carrying conductors that are not solidly grounded of the circuit to which it is connected. An equipment disconnecting means shall be externally operable without exposing the operator to contact with energized parts, shall indicate whether in the open (off) or closed (on) position, and shall be lockable in accordance with Section 110.25 of NFPA 70. An equipment disconnecting means shall be one of the following devices: (1) A manually operable switch or circuit breaker (2) A connector meeting the requirements of Section 814.1.5(1) (3) A load break fused pull out switch (4) A remote-controlled circuit breaker that is operable locally and opens automatically when control power is interrupted For equipment disconnecting means, other than those complying with Section 814.1, where the line and load terminals can be energized in the open position, the device shall be marked in accordance with the warning in Section 810.1.2. [NFPA 70:690.15(D)] 909.2.1 Utility-Interactive Inverters Mounted in Not Readily Accessible Locations. Utility-interactive inverters shall be permitted to be mounted on roofs or other exterior areas that are not readily accessible and shall comply with the following: (1) A dc PV disconnecting means shall be mounted within sight of or in each inverter. (2) An ac disconnecting means shall be mounted within sight of or in each inverter. (3) The ac output conductors from the inverter and an additional ac disconnecting means for the inverter shall comply with Section 909.1.1. (4) A plaque shall be installed in accordance with Section 912.1. [NFPA 70:690.15(A)] 909.2.2 Equipment. Equipment such as PV source circuit isolating switches, overcurrent devices, dc-to-dc converters, and blocking diodes shall be permitted on the PV side of the PV disconnecting means. [NFPA 70:690.15(B)] 909.2.3 Direct-Current Combiner Disconnects. The dc output of dc combiners mounted on roofs of dwellings or other

104 buildings shall have a load break disconnecting means located in the combiner or within 6 feet (1829 mm) of the combiner. The disconnecting means shall be permitted to be remotely controlled but shall be manually operable locally when control power is not available. [NFPA 70:690.15(C)] 909.2.4 Maximum Number of Disconnects. The PV system disconnecting means shall consist of not more than six switches or six circuit breakers mounted in a single enclosure or in a group of separate enclosures. [NFPA 70:690.15(D)] 909.3 Disconnecting and Servicing of Fuses. Disconnecting means shall be provided to disconnect a fuse from sources of supply where the fuse is energized from both directions. Such a fuse in a PV source circuit shall be capable of being disconnected independently of fuses in other PV source circuits. [NFPA 70:690.16(A)] Disconnecting means shall be installed on PV output circuits where overcurrent devices (fuses) are required to be serviced that are not capable of being isolated from energized circuits. The disconnecting means shall be within sight of, and accessible to, the location of the fuse or integral with fuse holder and shall be in accordance with Section 909.4 through Section 909.4.4. Where the disconnecting means are located exceeding 6 feet (1829 mm) from the overcurrent device, a directory showing the location of each disconnect shall be installed at the overcurrent device location. Non-load-break-rated disconnecting means shall be marked “Do not open under load.” [NFPA 70:690.16(B)] 909.4 Disconnect Type. The disconnecting means for ungrounded PV conductors shall consist of a manually operable switch(es) or circuit breaker(s). The disconnecting means shall be permitted to be power operable with provisions for manual operation in the event of a power-supply failure. The disconnecting means shall be one of the following listed devices: (1) A PV industrial control switch marked for use in PV systems. (2) A PV molded-case circuit breaker marked for use in PV systems. (3) A PV molded-case switch marked for use in PV systems. (4) A PV enclosed switched marked for use in PV systems. (5) A PV open-type switch marked for use in PV systems. (6) A dc-rated molded-case circuit breaker suitable for backfeed operation. (7) A dc-rated molded-case switch suitable for backfeed operation. (8) A dc-rated enclosed switch. (9) A dc-rated open-type switch. (10) A dc-rated rated low-voltage power circuit breaker. [NFPA 70:690.17(A)] 909.4.1 Simultaneous Opening of Poles. The PV disconnecting means shall simultaneously disconnect all ungrounded supply conductors. [NFPA 70:690.17(B)] 909.4.2 Externally Operable and Indicating. The PV disconnecting means shall be externally operable without exposing the operator to contact with live parts and shall indicate whether in the open or closed position. [NFPA 70:690.17(C)] 909.4.3 Disconnection of Grounded Conductor. A switch, circuit breaker, or other device shall not be installed in a grounded conductor where operation of that switch, circuit breaker, or other device leaves the marked, grounded conductor in an ungrounded and energized state. Exceptions: (1) A switch or circuit breaker that is part of a ground-fault detection system required by Section 903.1 through Section 903.4, or that is part of an arc-fault detection or interruption system required by Section 908.7, shall be permitted to open the grounded conductor when that switch or circuit breaker is automatically opened as a normal function of the device in responding to ground faults. (2) A disconnecting switch shall be permitted in a grounded conductor where in accordance with the following: (a) The switch is used only for PV array maintenance. (b) The switch is accessible only by qualified persons. (c) The switch is rated for the maximum dc voltage and current that could be present during any operation, including ground- fault conditions. [NFPA 70:690.17(D)] 909.4.4 Interrupting Rating. The building or structure disconnecting means shall have an interrupting rating sufficient for the maximum circuit voltage and current that is available at the line terminals of the equipment. Where terminals of the disconnecting means are capable of being energized in the open position, a warning sign shall be mounted on or adjacent to the disconnecting means. The sign shall be clearly legible and have the following words or equivalent:

WARNING ELECTRIC SHOCK HAZARD. DO NOT TOUCH TERMINALS. TERMINALS ON BOTH THE LINE AND LOAD SIDES MAY BE ENERGIZED IN THE OPEN POSITION.

The warning sign(s) or label(s) shall comply with Section 903.4.1. Exception: A connector shall be permitted to be used as an ac or a dc disconnecting means, provided that it is in accordance with the requirements of Section 910.12 and is listed and identified for use with specific equipment. [NFPA 70:690.17(E)]

105 909.5 Installation and Service of an Array. Open circuiting, short circuiting, or opaque covering shall be used to disable an array or portions of an array for installation and service. [NFPA 70:690.18]

Part IV - Wiring Methods.

910.0 812.0 Wiring Methods Permitted. 910.1 812.1 General Wiring Systems. All Rraceway and cable wiring methods included in NFPA 70this chapter, other wiring systems and fittings specifically listed for use on PV arrays, and wiring as part of a listed system shall be permitted. Where wiring devices with integral enclosures are used, sufficient length of cable shall be provided to facilitate replacement. Where PV source and output circuits operating at maximum system voltages exceeding greater than 30 volts are installed in readily accessible locations, circuit conductors shall be guarded or installed in a Type MC cable or in raceway. For ambient temperatures exceeding 86°F(30°C), conductor ampacities shall be corrected in accordance with Table 812.1. [NFPA 70:690.31(A)]

TABLE 910.5 812.1 CORRECTION FACTORS [NFPA 70: TABLE 690.31(E)(A)] TEMPERATURE RATING OF CONDUCTOR AMBIENT TEMPERATURE 140°F 167°F 194°F 221°F (°F) 86 1.00 1.00 1.00 1.00 87–95 0.91 0.94 0.96 0.97 96–104 0.82 0.88 0.91 0.93 105–113 0.71 0.82 0.87 0.89 114–122 0.58 0.75 0.82 0.86 123–131 0.41 0.67 0.76 0.82 132–140 — 0.58 0.71 0.77 141–158 — 0.33 0.58 0.68 159–176 — — 0.41 0.58

For SI units: °C = (°F - 32)/1.8

910.2 812.2 Identification and Grouping. PV source circuits and PV output circuits shall not be contained in the same raceway, cable tray, cable, outlet box, junction box, or similar fitting as conductors, feeders, branch circuits of other non-PV systems, or inverter output circuits, unless the conductors of the different systems are separated by a partition. The means of identification shall be permitted by separate color coding, marking tape, tagging, or other approved means. PV system circuit conductors shall be identified and grouped as follows: required by Section 812.2.1 through Section 812.2.2. The means of identification shall be permitted by separate color coding, marking tape, tagging, or other approved means. [NFPA 70:690.31(B)] 812.2.1 Identification. (1) PV source circuits system circuit conductors shall be identified at all accessible points of termination, connection, and splices. The means of identification shall be permitted by separate color coding, marking tape, tagging, or other approved means. Only solidly grounded PV system circuit conductors, in accordance with Section 816.1(5), shall be marked in accordance with Section 200.6 of NFPA 70. (2) The conductors of PV output circuits and inverter input and output circuits shall be identified at points of termination, connection, and splices. (3) Where the conductors of more than one PV system occupy the same junction box, raceway, or equipment, the conductors of each system shall be identified at termination, connection, and splice points. Exception: Where the identification of the conductors is evident by spacing or arrangement, further identification shall not be required. [NFPA 70:690.31(B)(1)] 812.2.2 Grouping. (4) Where the conductors of more than one PV system occupy the same junction box or raceway with a

106 removable cover(s), the ac and dc conductors of each system shall be grouped separately by cable ties or similar means not less than at least once, and shall then be grouped at intervals not to exceed 6 feet (1829 mm). Exception: The requirement for grouping shall not apply where the circuit enters from a cable or raceway unique to the circuit that makes the grouping obvious. [NFPA 70:690.31(B)(2)] 910.3 812.3 Single-Conductor Cable. Single-conductor cable tType USE-2, and single-conductor cable listed and labeled identified as photovoltaic (PV) wire shall be permitted in exposed outdoor locations in PV source circuits for PV module interconnections within the PV array. PV wire shall be installed in accordance with Section 338.10(B)(4)(b) of NFPA 70 and Section 334.30 of NFPA 70. Exception: Raceways shall be used where required by Section 910.1. [NFPA 70:690.31(C)(1)] 910.3.1 812.3.1 Cable Tray. PV source circuits and PV output circuits using single-conductor cable listed and labeled identified as photovoltaic (PV) wire of all sizes, with or without a cable tray marking or/rating, shall be permitted in cable trays installed in outdoor locations, provided that the cables are supported at intervals not to exceed 12 inches (305 mm) and secured at intervals not to exceed 41/2 feet (1372 mm). [NFPA 70:690.31(C)(2)] 910.4 812.4 Multiconductor Cable. Jacketed Mmulticonductor cable Type TC-ER or Type USE-2 assemblies listed and identified for the application shall be permitted in outdoor locations in PV inverter output circuits where used with utility- interactive inverters mounted in locations that are not readily accessible. The cable shall be secured at intervals not exceeding 6 feet (1829 mm). Equipment grounding for the utilization equipment shall be provided by an equipment grounding conductor within the cable. [NFPA 70:690.31(D)]

910.5 812.5 Flexible Cords and Cables. Flexible cords and flexible cables, where used to connect connected to the moving parts of tracking PV modules arrays, shall comply with Article 400 of NFPA 70 and shall be of a type identified as a hard service cord or portable power cable; they shall be suitable for extra-hard usage, listed for outdoor use, water resistant, and sunlight resistant. Allowable ampacities shall be in accordance with Section 400.5 of NFPA 70. For ambient temperatures exceeding 86°F (30°C), the ampacities shall be derated by the appropriate factors given in Table 910.5. Stranded copper PV wire shall be permitted to be connected to moving parts of tracking PV arrays in accordance with the minimum number of strands specified in Table 812.5. [NFPA 70:690.31(E)]

TABLE 812.5 MINIMUM PV WIRE STRANDS [NFPA 70: TABLE 690.31(E)]

PV WIRE AWG MINIMUM STRANDS 18 17 16 – 10 19 8 – 4 49 2 130 1 AWG – 1000 MCM 259

910.6 812.6 Small-Conductor Cables. Single-conductor cables listed for outdoor use that are sunlight resistant and moisture resistant in sizes 16 AWG and 18 AWG shall be permitted for module interconnections where such cables comply with meet the ampacity requirements of Section 400.5 of NFPA 70. Section 310.15 of NFPA 70 shall be used to determine the cable ampacity adjustment and correction factors. [NFPA 70:690.31(F)] 910.7 812.7 Direct-Current Photovoltaic Source and System Direct-Current Output on or Circuits Inside On or In a Building. Where dc PV source or dc PV output PV system dc circuits from run inside a building-integrated systems or other PV systems are run inside a building or structure, they shall be contained in metal raceways, tType MC metal-clad cable that is in accordance with Section 250.118(10) of NFPA 70 812.7.5(10), or metal enclosures from the point of penetration of the surface of the building or structure to the first readily accessible disconnecting means. The disconnecting means shall comply with Section 909.1.2 810.1.2, Section 909.1.3 810.1.3, Section 909.2.1 811.1.1 and Section 909.2.2 811.1.2. The wiring methods shall comply with the additional installation requirements in Section 910.7.1 812.7.1 through Section 910.7.4 812.7.4. [NFPA 70:690.31(G)] 910.7.1 812.7.1 Embedded in Building Surfaces. Where circuits are embedded in built-up, laminate, or membrane roofing materials in roof areas not covered by PV modules and associated equipment, the location of circuits shall be clearly marked using a marking protocol that is approved as being suitable for continuous exposure to sunlight and weather. [NFPA 70:690.31(G)(1)] 910.7.2 812.7.2 Flexible Wiring Methods. Where flexible metal conduit (FMC) less smaller than the trade size 3/4 (21 metric designator 21) or Type MC cable less than 1 inch (25 mm) in diameter containing PV power circuit conductors is installed across ceilings or floors joists, the raceway or cable shall be protected by substantial guard strips that are not less than the height of at least as high as the raceway or cable. Where run exposed, other than within 6 feet (1829 mm) of their connection to

107 equipment, these wiring methods shall closely follow the building surface or be protected from physical damage by an approved means. [NFPA 70:690.31(G)(2)] 910.7.3 812.7.3 Marking and Labeling Required. The following wiring methods and enclosures that contain PV power source system dc circuit conductors shall be marked with the wording “WARNING: Photovoltaic Power Source” by means of permanently affixed labels or other approved permanent markings: (1) Exposed raceways, cable trays, and other wiring methods. (2) Covers or enclosures of pull boxes and junction boxes. (3) Conduit bodies where in which any of the available conduit openings are unused. [NFPA 70:690.31(G)(3)] 910.7.4 812.7.4 Markings and Labeling Methods and Locations. The labels or markings shall be visible after installation. The labels shall be reflective, and all letters shall be capitalized and shall be of a minimum height of not less than 3/8 of an inch (9.5 mm) in white on a red background. PV power system dc circuit labels shall appear on every sections of the wiring system that is separated by enclosures, walls, partitions, ceilings, or floors. Spacing between labels or markings, or between a label and a marking, shall not exceedbe more than 10 feet (3048 mm). Labels required by this section shall be suitable for the environment where they are installed. [NFPA 70:690.31(G)(4)] 911.3.7 812.7.5 Types of Equipment Grounding Conductors. The equipment grounding conductor installed with or enclosing the circuit conductors shall be one or more or a combination of the following: (1) A copper, aluminum, or copper-clad aluminum conductor. This conductor shall be solid or stranded; insulated, covered, or bare; and in the form of a wire or a busbar of any shape. (2) Rigid metal conduit. (3) Intermediate metal conduit. (4) Electrical metallic tubing. (5) Listed flexible metal conduit meeting all the following conditions: (a) The conduit is terminated in listed fittings. (b) The circuit conductors contained in the conduit are protected by overcurrent devices rated at 20 amperes or less. (c) The size of the conduit does not exceed trade size 1 ¼ (35 metric designator). (c)(d) The combined length of flexible metal conduit and flexible metallic tubing and liquidtight flexible metal conduit in the same ground-fault current path shall does not exceed 6 feet (1829 mm). (d)(e) Where If used to connect equipment where flexibility is necessary to minimize the transmission of vibration from equipment or to provide flexibility for equipment that requires movement after installation, an equipment grounding conductor shall be installed. (6) Listed liquidtight flexible metal conduit meeting the following conditions: (a) The conduit is terminated in listed fittings. (b) For trade sizes 3/8 through 1/2 (12 through 16 metric designator), the circuit conductors contained in the conduit are protected by overcurrent devices rated at 20 amperes or less. (c) For trade sizes 3/4 through 11/4 (21 through 35 metric designator), the circuit conductors contained in the conduit are protected by overcurrent devices rated not more than 60 amperes and there is no flexible metal conduit, flexible metallic tubing, or liquidtight flexible metal conduit in trade sizes 3/8 through 1/2 (12 through 16 metric designator) in the ground-fault current path. (d) The combined length of flexible metal conduit and flexible metallic tubing and liquidtight flexible metal conduit in the same ground-fault current path shall not exceed 6 feet (1829 mm). (e) Where If used to connect equipment where flexibility is necessary to minimize the transmission of vibration from equipment or to provide flexibility for equipment that requires movement after installation, an equipment grounding conductor shall be installed. (7) Flexible metallic tubing where the tubing is terminated in listed fittings and meeting the following conditions: (a) The circuit conductors contained in the tubing are protected by overcurrent devices rated at 20 amperes or less. (b) The combined length of flexible metal conduit and flexible metallic tubing and liquidtight flexible metal conduit in the same ground-fault current path shall not exceed 6 feet (1829 mm). (8) Armor of Type AC cable in accordance with Section 911.1.5 320.108 of NFPA 70. (9) The copper sheath of mineral-insulated, metal-sheathed cable Type MI. (10) Type MC cable that provides an effective ground-fault current path in accordance with one or more of the following: (a) It contains an insulated or uninsulated equipment grounding conductor in accordance with Section 911.3.7(1) 812.7.5(1). (b) The combined metallic sheath and uninsulated equipment grounding/bonding conductor of interlocked metal tape-type MC cable that is listed and identified as an equipment grounding conductor. (c) The metallic sheath or the combined metallic sheath and equipment grounding conductors of the smooth or corrugated tube- type MC cable that is listed and identified as an equipment grounding conductor. (11) Cable trays in accordance with Section 392.10 of NFPA 70 and Section 392.60 of NFPA 70. (12) Cablebus framework in accordance with Section 370.60(1) of NFPA 70. (13) Other listed electrically continuous metal raceways and listed auxiliary gutters. (14) Surface metal raceways listed for grounding. [NFPA 70:250.118] 910.8 812.8 Flexible, Fine-Stranded Cables. Flexible, fine-stranded cables shall be terminated only with terminals, lugs, devices, or connectors in accordance with Section 110.14 of NFPA 70. [NFPA 70:690.31(H)] 910.9 812.9 Bipolar PV Systems. Where the sum, without consideration of polarity, of the PV system voltages of the two

108 monopole subarrays exceeds the rating of the conductors and connected equipment, monopole subarrays in a bipolar PV system shall be physically separated, and the electrical output circuits from each monopole subarray shall be installed in separate raceways until connected to the inverter. The disconnecting means and overcurrent protective devices for each monopole subarray output shall be in separate enclosures. All Cconductors from each separate monopole subarray shall be routed in the same raceway. Solidly grounded Bbipolar PV systems shall be clearly marked with a permanent, legible warning notice indicating that the disconnection of the grounded conductor(s) shall be permitted to may result in overvoltage on the equipment. Exception: Listed switchgear rated for the maximum voltage between circuits and containing a physical barrier separating the disconnecting means for each monopole subarray shall be permitted to be used instead of disconnecting means in separate enclosures. [NFPA 70:690.31(I)] 910.10 Module Connection Arrangement. The connection to a module or panel shall be arranged so that removal of a module or panel from a PV source circuit does not interrupt a grounded conductor connection to other PV source circuits. [NFPA 70:690.31(J)]

910.11813.0 Component Interconnections. 813.1 Concealed Fittings and Connectors. Fittings and connectors that are intended to be concealed at the time of on- site assembly, where listed for such use, shall be permitted for on-site interconnection of modules or other array components. Such fittings and connectors shall be equal to the wiring method employed in insulation, temperature rise, and fault-current withstand, and shall be capable of resisting the effects of the environment in which they are used. [NFPA 70:690.32]

910.12814.0 Connectors. 814.1 General. The cConnectors, permitted by this chapter other than those covered by Section 813.1, shall be in accordance comply with Section 910.12.1 814.1.1 through Section 910.12.5 814.1.5. [NFPA 70:690.33] 910.12.1 814.1.1 Configuration. The connectors shall be polarized and shall have a configuration that is noninterchangeable with receptacles in other electrical systems on the premises. [NFPA 70:690.33(A)] 910.12.2 814.1.2 Guarding. The connectors shall be constructed and installed so as to guard against inadvertent contact with live parts by persons. [NFPA 70:690.33(B)] 910.12.3 814.1.3 Type. The connectors shall be of the latching or locking type. Connectors that are readily accessible and that are used in circuits operating at over 30 volts dc, nominal, maximum system voltage for dc circuits, or 30 volts for ac circuits, or 15 volts ac shall require a tool for opening. [NFPA 70:690.33(C)] 910.12.4 814.1.4 Grounding Member. The grounding member shall be the first to make and the last to break contact with the mating connector. [NFPA 70:690.33(D)] 910.12.5 814.1.5 Interruption of Circuit. Connectors shall comply with one of the following be either Section 814.1.5(1) or Section 814.1.5(2): (1) Be rated for interrupting current without hazard to the operator. (2) Be a type that requires the use of a tool to open and marked “Do Not Disconnect Under Load” or “Not for Current Interrupting.” [NFPA 70:690.33(E)]

910.13815.0 Access to Boxes. 815.1 Junction, Pull, and Outlet Boxes. Junction, pull, and outlet boxes located behind modules or panels shall be so installed that the wiring contained in them is can be rendered accessible directly or by displacement of a module(s) or panel(s) secured by removable fasteners and connected by a flexible wiring system. [NFPA 70:690.34] 910.14 Ungrounded Photovoltaic Power Systems. Photovoltaic power systems shall be permitted to operate with ungrounded PV source and output circuits where the system is in accordance with Section 910.14.1 through Section 910.14.7. [NFPA 70:690.35] 910.14.1 Disconnects. PV source and output circuit conductors shall have disconnects in accordance with Section 909.0. [NFPA 70:690.35(A)] 910.14.2 Overcurrent Protection. PV source and output circuit conductors shall have overcurrent protection in accordance with Section 907.0. [NFPA 70:690.35(B)] 910.14.3 Ground-Fault Protection. PV source and output circuits shall be provided with a ground-fault protection device or system that is in accordance with the following: (1) Detects ground fault(s) in the PV array dc current-carrying conductors and components. (2) Indicates that a ground fault has occurred. (3) Automatically disconnects conductors or causes the inverter or charge controller connected to the faulted circuit to automatically cease supplying power to output circuits. (4) Is listed for providing PV ground-fault protection. [NFPA 70:690.35(C)] 910.14.4 Conductors. The PV source conductors shall consist of the following: (1) Metallic or nonmetallic jacketed multiconductor cables. (2) Conductors installed in raceways. (3) Conductors listed and identified as PV wire installed as exposed, single conductors. (4) Conductors that are direct-buried and identified for direct-burial use. [NFPA 70:690.35(D)]

109 910.14.5 Battery Systems. The PV power system direct-current circuits shall be permitted to be used with ungrounded battery systems in accordance with Section 914.7. [NFPA 70:690.35(E)] 910.14.6 Marking. The PV power source shall be labeled with the following warning at each junction box, combiner box, disconnect, and device where energized, ungrounded circuits are capable of being exposed during service:

WARNING ELECTRIC SHOCK HAZARD. THE DC CONDUCTORS OF THIS PHOTOVOLTAIC SYSTEM ARE UNGROUNDED AND MAY BE ENERGIZED.

The warning sign(s) or label(s) shall comply with Section 903.4.1. [NFPA 70:690.35(F)] 910.14.7 Equipment. The inverters or charge controllers used in systems with ungrounded PV source and output circuits shall be listed for the purpose. [NFPA 70:690.35(G)]

Part V - Grounding and Bonding.

911.0 816.0 Grounding and Bonding. 911.1 816.1 PV System Grounding Configurations. Photovoltaic systems shall comply with one of the following One or more of the following system grounding configurations shall be employed: (1) Ungrounded systems shall comply with Section 910.14. (2) Grounded two-wire systems shall have one conductor grounded or be impedance grounded, and the system shall comply with Section 903.0. (3) Grounded bipolar systems shall have the reference (center tap) conductor grounded or be impedance grounded, and the system shall comply with Section 903.0. (4) Other methods that provide equivalent system protection in accordance with Section 911.1.1 through Section 911.1.5 with equipment listed and identified for the use shall be permitted to be used. (1) 2-wire PV arrays with one functional grounded conductor. (2) Bipolar PV arrays according to Section 804.2 with a functional ground reference (center tap). (3) PV arrays not isolated from the grounded inverter output circuit. (4) Ungrounded PV arrays. (5) Solidly grounded PV arrays as permitted in Section 816.2 (Exception). (6) PV systems that use other methods that accomplish equivalent system protection in accordance with Section 816.1.1 through Section 816.1.5 with equipment listed and identified for the use. [NFPA 70:690.41(A)] 911.1.1 816.1.1 Electrical System Grounding. Electrical systems that are grounded shall be connected to earth in a manner that will limit the voltage imposed by lightning, line surges, or unintentional contact with higher-voltage lines and that will stabilize the voltage to earth during normal operation. [NFPA 70:250.4(A)(1)] 911.1.2 816.1.2 Grounding of Electrical Equipment. Normally non-current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected to earth so as to limit the voltage to ground on these materials. [NFPA 70:250.4(A)(2)] 911.1.3 816.1.3 Bonding of Electrical Equipment. Normally non-current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected together and to the electrical supply source in a manner that establishes an effective ground-fault current path. [NFPA 70:250.4(A)(3)] 911.1.4 816.1.4 Bonding of Electrically Conductive Materials and Other Equipment. Normally non-current-carrying electrically conductive materials that are likely to become energized shall be connected together and to the electrical supply source in a manner that establishes an effective ground-fault current path. [NFPA 70:250.4(A)(4)] 911.1.5 816.1.5 Effective Ground-Fault Current Path. Electrical equipment and wiring and other electrically conductive material that likely to become energized shall be installed in a manner that creates a low-impedance circuit facilitating the operation of the overcurrent device or ground detector for high-impedance grounded systems. It shall be capable of safely carrying the maximum ground-fault current likely to be imposed on it from any point on the wiring system where a ground fault occurs may occur to the electrical supply source. The earth shall not be considered as an effective ground-fault current path. [NFPA 70:250.4(A)(5)] 816.2 Ground-Fault Protection. DC PV arrays shall be provided with dc ground-fault protection meeting the requirements of Section 816.3 and Section 816.4 to reduce fire hazards. Exception: PV arrays with not more than two PV source circuits and with all PV system dc circuits not on or in buildings shall be permitted without ground-fault protection where solidly grounded. [NFPA 70:690.41(B)] 816.3 Ground-Fault Detection. The ground fault protective device or system shall detect ground fault(s) in the PV array dc current-carrying conductors and components, including any functional grounded conductors, and be listed for providing PV ground-fault protection. [NFPA 70:690.41(B)(1)]

110 816.4 Isolating Faulted Circuits. The faulted circuits shall be isolated by one of the following methods: (1) The current-carrying conductors of the faulted circuit shall be automatically disconnected. (2) The inverter or charge controller fed by the faulted circuit shall automatically cease to supply power to output circuits and isolate the PV system dc circuits from the ground reference in a functional grounded system. [NFPA 70:690.41(B)(2)]

911.2817.0 Point of System Grounding Connection. 817.1 Grounding Connection. The dc circuit grounding connection shall be made at any single point on the PV output circuit. Exception: Systems with a ground-fault protection device in accordance with Section 903.0 shall be permitted to have the required grounded conductor-to-ground bond made by the ground-fault protection device. This bond, where internal to the ground-fault equipment, shall not be duplicated with an external connection. Systems with a ground-fault protection device in accordance with Section 816.2 shall have any current-carrying conductor-to-ground connection made by the ground-fault protective device. For solidly grounded PV systems, the dc circuit grounding connection shall be made at any single point on the PV output circuit. [NFPA 70:690.42]

911.3818.0 Equipment Grounding and Bonding. 818.1 General. Equipment grounding conductors and devices shall comply with Section 911.3.1 through Section 911.3.6. [NFPA 70:690.43] 911.3.1 General. Exposed non-current-carrying metal parts of PV module frames, electrical equipment, and conductor enclosures shall be grounded in accordance with Section 911.3.1.1 818.2 or Section 911.3.1.2 818.4, regardless of voltage. Equipment grounding conductors and devices shall comply with Section 818.1.1 through Section 818.1.3. [NFPA 70:690.43(A)] 911.3.4 818.1.1 Photovoltaic Mounting Systems and Devices. Devices and systems used for mounting PV modules that are also used to provide grounding of the module frames shall be identified for the purpose of grounding PV modules. for bonding module frames shall be listed, labeled, and identified for bonding PV modules. Devices that mount adjacent PV modules shall be permitted to bond adjacent PV modules. [NFPA 70:690.43(D)(A)] 911.3.2 Equipment Grounding Conductor Required. An equipment grounding conductor between a PV array and other equipment shall be required in accordance with Section 911.3.2.1. [NFPA 70:690.43(B)] 911.3.3 818.1.2 Structure as Equipment Grounding Conductor Secured to Grounded Metal Supports. Devices listed, labeled, and identified for bonding and grounding the metallic frames metal parts of PV systems modules, or other equipment shall be permitted to bond the exposed metal surfaces or other equipment to mounting structures grounded metal supports. Metallic mounting structures, other than building steel, used for grounding purposes shall be identified as equipment- grounding conductors or support structures shall have identified bonding jumpers or devices connected between the separate metallic sections and shall be bonded to the grounding system or shall be identified for equipment bonding and shall be connected to the equipment grounding conductor. [NFPA 70:690.43(C)(B)] 911.3.6 818.1.3 Combined With Circuit Conductors. Equipment grounding conductors for the PV array and support structure (where installed) shall be contained within the same raceway, cable, or otherwise installed run with the PV array circuit conductors where when those circuit conductors leave the vicinity of the PV array. [NFPA 70:690.43(F)(C)] 911.3.1.1 818.2 Equipment Fastened in Place or Connected by Permanent Wiring Methods (Fixed) — Grounding. Unless grounded by connection to the grounded circuit conductor as permitted by Section 250.32, Section 250.140 and Section 250.142 of NFPA 70, non-current-carrying metal parts of equipment, raceways, and other enclosures, where if grounded, shall be connected to an equipment grounding conductor by one of the following methods methods specified in Section 818.2.1 or Section 818.2.2. [NFPA 70:250.134] 818.2.1 Equipment Grounding Conductor Types. (1) By connecting to an any of the equipment grounding conductors in accordance with by Section 911.3.7 812.7.5. [NFPA 70:250.134(A)] 818.2.2 With Circuit Conductors. (2) By connecting to an equipment grounding conductor contained within the same raceway, cable, or otherwise run with the circuit conductors. Exceptions: (1) As provided in Section 911.3.8 818.3, the equipment grounding conductor shall be permitted to be run separately from the circuit conductors. (2) For dc circuits, the equipment grounding conductor shall be permitted to be run separately from the circuit conductors. [NFPA 70:250.134(B)] 911.3.8 818.3 Nongrounding Receptacle Replacement or Branch Circuit Extensions. The equipment grounding conductor of a grounding-type receptacle or a branch-circuit extension shall be permitted to be connected to one any of the following: (1) An Any accessible point on the grounding electrode system in accordance with Section 250.50 of NFPA 70. (2) An Any accessible point on the grounding electrode conductor. (3) The equipment grounding terminal bar within the enclosure where the branch circuit for the receptacle or branch circuit originates. (4) An equipment grounding conductor that is part of another branch circuit that originates from the enclosure where the branch circuit for the receptacle or branch circuit originates.

111 (5) For grounded systems, the grounded service conductor within the service equipment enclosure. (6) For ungrounded systems, the grounding terminal bar within the service equipment enclosure. [NFPA 70:250.130(C)] 911.3.1.2 818.4 Equipment Considered Secured to Grounded Metal Supports. The normally non-current-carrying metal parts of the equipment shall be considered grounded where the eElectrical equipment is secured to and in electrical contact with a metal rack or structure provided for its support and connected to an equipment grounding conductor by one of the means indicated in Section 911.3.1.1 818.2. The structural metal frame of a building shall not be used as the required equipment grounding conductor for ac equipment. [NFPA 70:250.136(A)] 911.3.2.1 Equipment Fastened in Place (Fixed) or Connected by Permanent Wiring Methods. Exposed, normally non–current-carrying metal parts of fixed equipment supplied by or enclosing conductors or components that are likely to become energized shall be connected to an equipment grounding conductor in accordance with one of the following conditions: (1) Where within 8 feet (2438 mm) vertically or 5 feet (1524 mm) horizontally of ground or grounded metal objects and subject to contact by persons. (2) Where located in a wet or damp location and not isolated. (3) Where in electrical contact with metal. (4) Where in a hazardous (classified) location. (5) Where supplied by a wiring method that provides an equipment grounding conductor. (6) Where equipment operates with a terminal at over 150 volts to ground. Exceptions: (1) Where exempted by special permission, the metal frame of electrically heated appliances that have the frame permanently and effectively insulated from ground shall not be required to be grounded. (2) Distribution apparatus, such as transformer and capacitor cases, mounted on wooden poles at a height exceeding 8 feet (2438 mm) above ground or grade level shall not be required to be grounded. (3) Listed equipment protected by a system of double insulation, or its equivalent, shall not be required to be connected to the equipment grounding conductor. Where such a system is employed, the equipment shall be distinctively marked. [NFPA 70:250.110] 911.3.5 Adjacent Modules. Devices identified and listed for bonding the metallic frames of PV modules shall be permitted to bond the exposed metallic frames of PV modules to the metallic frames of adjacent PV modules. [NFPA 70:690.43(E)]

911.4819.0 Size of Equipment Grounding Conductors. 819.1 General. Equipment grounding conductors for PV source and PV output circuits shall be sized in accordance with Section 250.122 of NFPA 70. Where no overcurrent protective device is used in the circuit, an assumed overcurrent device rated at the PV maximum circuit current in accordance with Section 806.2 shall be used in accordance with when applying Table 911.4 819.1. Increases in equipment grounding conductor size to address voltage drop considerations shall not be required. An equipment grounding conductor shall not be less than 14 AWG. [NFPA 70:690.45] 911.4.1 819.1.1 Equipment Grounding Conductor Installation. An equipment grounding conductor shall be installed in accordance with Section 911.4.2 819.1.2, through Section 911.4.4 819.1.3, and Section 819.1.4. [NFPA 70:250.120] 911.4.2 819.1.2 Raceway, Cable Trays, Cable Armor, Cablebus, or Cable Sheaths. Where it consists of a raceway, cable tray, cable armor, cablebus framework, or cable sheath or where it is a wire within a raceway or cable, it shall be installed in accordance with the applicable provisions of NFPA 70 using fittings for joints and terminations approved for use with the type raceway or cable used. All connections, joints, and fittings shall be made tight using suitable tools. [NFPA 70:250.120(A)] 911.4.3 819.1.3 Aluminum and Copper-Clad Aluminum Conductors. Equipment grounding conductors of bare or insulated aluminum or copper-clad aluminum shall be permitted. Bare conductors shall not come in direct contact with masonry or the earth or where subject to corrosive conditions. Aluminum or copper-clad aluminum conductors shall not be terminated within 18 inches (457 mm) of the earth. [NFPA 70:250.120(B)] 911.4.4 819.1.4 Equipment Grounding Conductors Less Smaller Than 6 AWG. Where not routed with circuit conductors as permitted in Section 911.3.1.1 818.3 (Exception 2) and Section 911.3.8 818.2.2 (Exception 2), equipment grounding conductors less than 6 AWG shall be protected from physical damage by an identified raceway or cable armor unless installed within hollow spaces of the framing members of buildings or structures and where not subject to physical damage. [NFPA 70:250.120(C)]

911.5820.0 Array Equipment Grounding Conductors. 820.1 PV Modules. For PV modules, equipment grounding conductors less smaller than 6 AWG shall comply with Section 911.4.4 819.1.4. Where installed in raceways, equipment grounding conductors and grounding electrode conductors not more than 6 AWG shall be permitted to be solid. [NFPA 70:690.46]

112 TABLE 911.4 819.1 MINIMUM SIZE EQUIPMENT GROUNDING CONDUCTORS FOR GROUNDING RACEWAY AND EQUIPMENT1 [NFPA 70: TABLE 250.122] RATING OR SETTING OF SIZE (AWG or kcmil) AUTOMATIC OVERCURRENT ALUMINUM OR DEVICE IN CIRCUIT AHEAD OF COPPER CLAD EQUIPMENT, CONDUIT, ETC., COPPER 2 NOT EXCEEDING (AMPERES) ALUMINUM 15 14 12 20 12 10 60 10 8 100 8 6 200 6 4 300 4 2 400 3 1 500 2 1/0 600 1 2/0 800 1/0 3/0 1000 2/0 4/0 1200 3/0 250 1600 4/0 350 2000 250 400 2500 350 600 3000 400 600 4000 500 750 5000 700 1200 6000 800 1200

Notes: 1 Where necessary to comply with Section 911.1.5 816.1.5 of this chapter or 250.4(B)(4) of NFPA 70, the equipment grounding conductor shall be sized larger than given in this table. 2 See installation restrictions in Section 911.4.1 819.1.1.

911.6821.0 Grounding Electrode System. 821.1 Electrode System. Grounding of electrode systems shall comply with Section 911.6.1 821.2 through and Section 911.6.4 821.3. 911.6.1 Alternating-Current Systems. Where installing an ac system, a grounding electrode system shall be provided in accordance with Section 250.50 through Section 250.60 of NFPA 70. The grounding electrode conductor shall be installed in accordance with Section 911.6.1.1 through Section 911.6.1.4. [NFPA 70:690.47(A)] 821.2 Buildings or Structures Supporting a PV Array. A building or structure supporting a PV array shall have a grounding electrode system installed in accordance with Part III of Article 250 of NFPA 70. PV array equipment grounding conductors shall be connected to the grounding electrode system of the building or structure supporting the PV array in accordance with Part VII of Article 250 of NFPA 70. This connection shall be in addition to any other equipment grounding conductor requirements in Section 818.1.3. The PV array equipment grounding conductors shall be sized in accordance with Section 819.1. For PV systems that are not solidly grounded, the equipment grounding conductor for the output of the PV system, connected to associated distribution equipment, shall be permitted to be the connection to ground for ground-fault protection and equipment grounding of the PV array. For solidly grounded PV systems, as permitted in Section 816.1(5), the grounded conductor shall be connected to a grounding electrode system by means of a grounding electrode conductor sized in accordance with Section 821.2.1 through Section 821.2.6. [NFPA 70:690.47(A)]

113 821.2.1 Size of the Direct-Current Grounding Electrode Conductor. The size of the grounding electrode conductor for a dc system shall be as specified in Section 821.2.2 and Section 821.2.3, except as permitted by Section 821.2.4 through Section 821.2.6. The grounding electrode conductor for a dc system shall meet the sizing requirements in this section but shall not be required to be larger than 3/0 copper or 250 kcmil aluminum. [NFPA 70:250.166] 911.6.2.1 821.2.2 Not Smaller Than the Neutral Conductor. Where the dc system consists of a three-wire balancer set or balancer winding with overcurrent protection in accordance with Section 445.12(D) of NFPA 70, the grounding electrode conductor shall be not be smaller than the neutral conductor and shall be not smaller than 8 AWG copper or 6 AWG aluminum. [NFPA 70:250.166(A)] 911.6.2.2 821.2.3 Not Smaller Than the Largest Conductor. Where the dc system is other than as in accordance with Section 911.6.2.1 821.2.2, the grounding electrode conductor shall be not be smaller than the largest conductor supplied by the system, and be not smaller than 8 AWG copper or 6 AWG aluminum. [NFPA 70:250.166(B)] 911.6.2.3 821.2.4 Connected to Rod, Pipe, or Plate Electrodes. Where connected to rod, pipe, or plate electrodes as in accordance with Section 911.6.2.3.1 821.3.5 or Section 911.6.2.3.2 821.3.7, that portion of the grounding electrode conductor that is the sole connection to the grounding electrode shall not be required to be more larger than 6 AWG copper wire or 4 AWG aluminum wire. [NFPA 70:250.166(C)] 911.6.2.4 821.2.5 Connected to a Concrete-Encased Electrode. Where connected to a concrete-encased electrode in accordance with Section 911.6.2.4.1 821.3.3, that portion of the grounding electrode conductor that is that the sole connection to the grounding electrode shall not be required to be more than 4 AWG copper wire. [NFPA 70:250.166(D)] 911.6.2.5 821.2.6 Connected to a Ground Ring. Where connected to a ground ring as in accordance with Section 911.6.2.5.1 821.3.4, that portion of the grounding electrode conductor that is the sole connection to the grounding electrode shall not be required to be larger than the conductor used for the ground ring. [NFPA 70:250.166(E)] 911.6.1.1 Installation of Electrodes. Grounding electrode conductor(s) and bonding jumpers interconnecting grounding electrodes shall be installed in accordance with one of the following methods. The grounding electrode conductor shall be sized for the largest grounding electrode conductor required among the electrodes connected to it. (1) The grounding electrode conductor shall be permitted to be run to a convenient grounding electrode available in the grounding electrode system where the other electrode(s), where any, is connected by bonding jumpers that are installed in accordance with Section 911.6.1.2 and Section 911.6.1.3. (2) Grounding electrodes conductor(s) shall be permitted to be run to one or more grounding electrode(s) individually. (3) Bonding jumper(s) from grounding electrode(s) shall be permitted to be connected to an aluminum or copper busbar not less than 1/4 of an inch by 2 inches (6.4 mm by 51 mm). The busbar shall be securely fastened and shall be installed in an accessible location. Connections shall be made by a listed connector or by the exothermic welding process. The grounding electrode conductor shall be permitted to be run to the busbar. Where aluminum busbars are used, the installation shall be in accordance with Section 911.6.1.2. [NFPA 70:250.64(F)] 911.6.1.2 Aluminum or Copper-Clad Aluminum Conductors. Bare aluminum or copper-clad aluminum grounding electrode conductors shall not be used where in direct contact with masonry, earth, or where subject to corrosive conditions. Where used outside, aluminum or copper-clad aluminum grounding electrode conductors shall not be terminated within 18 inches (457 mm) of the earth. [NFPA 70:250.64(A)] 911.6.1.3 Securing and Protection Against Physical Damage. Where exposed, a grounding electrode conductor or its enclosure shall be securely fastened to the surface on which it is carried. Grounding electrode conductors shall be permitted to be installed on or through framing members. A 4 AWG or large copper or aluminum grounding electrode conductor shall be protected where exposed to physical damage. A 6 AWG grounding electrode conductor that is free from exposure to physical damage shall be permitted to be run along the surface of the building construction without metal covering or protection where it is securely fastened to the construction; otherwise, it shall be protected in rigid metal conduit (RMC), intermediate metal conduit (IMC), rigid polyvinyl chloride conduit (PVC), reinforced thermosetting resin conduit (RTRC), electrical metallic tubing (EMT), or cable armor. Grounding electrode conductors less than 6 AWG shall be protected in RMC, IMC, PVC, RTRC, EMT, or cable armor. Grounding electrode conductors and grounding electrode bonding jumpers shall not be required to comply with Section 300.5 of NFPA 70. [NFPA 70:250.64(B)] 911.6.1.4 Continuous. Grounding electrode conductor(s) shall be installed in one continuous length without a splice or joint. Where necessary, splices or connections shall be made in accordance with the following: (1) Splicing of the wire-type grounding electrode conductor shall be permitted by irreversible compression-type connectors listed as grounding and bonding equipment or by the exothermic welding process. (2) Sections of busbars shall be permitted to be connected together to form a grounding electrode conductor. (3) Bolted, riveted, or welded connections of structural metal frames of building structures. (4) Threaded, welded, brazed, soldered, or bolted-flange connections of metal water piping. [NFPA 70:250.64(C)]

911.6.2 Direct-Current Systems. Where installing a dc system, a grounding electrode system shall be provided in accordance with Section 911.6.2.1 through Section 911.6.2.5 for grounded systems or Section 911.6.2.6 for ungrounded systems. The grounding electrode conductor shall be installed in accordance with Section 911.6.1.1 through Section 911.1.6.1.4. A common dc grounding-electrode conductor shall be permitted to serve multiple inverters. The size of the common grounding electrode and the tap conductors shall be in accordance with Section 911.6.2.1 through Section 911.6.2.5. The tap conductors

114 shall be connected to the common grounding-electrode conductor by exothermic welding or with connectors listed as grounding and bonding equipment in such a manner that the common grounding electrode conductor remains without a splice or joint. An ac equipment grounding system shall be permitted to be used for equipment grounding of inverters and other equipment and for the ground-fault detection reference for ungrounded PV systems. [NFPA 70:690.47(B)]

911.6.2.6 Ungrounded Direct-Current Separately Derived Systems. Except as otherwise permitted in Section 250.34 of NFPA 70 for portable and vehicle-mounted generators, an ungrounded dc separately derived system supplied from a stand- alone power source (such as an engine-generator set) shall have a grounding electrode conductor connected to an electrode that is in accordance with Article 250, Part III of NFPA 70 to provide for grounding of metal enclosures, raceways, cables, and exposed non-current-carrying metal parts of equipment. The grounding electrode conductor connection shall be to the metal enclosure at a point on the separately derived system from the source to the first system disconnecting means or overcurrent device, or it shall be made at the source of a separately derived system that has no disconnecting means or overcurrent devices. The size of the grounding electrode conductor shall be in accordance with Section 911.6.2.1 through Section 911.6.2.5. [NFPA 70:250.169] 911.6.3 Systems with Alternating-Current and Direct-Current Grounding Requirements. Photovoltaic systems having dc circuits and ac circuits with no direct connection between the dc grounded conductor and ac grounded conductor shall have a dc grounding system. The dc grounding system shall be bonded to the ac grounding system by one of the methods in Section 911.6.3.1 through Section 911.6.3.3. This section shall not apply to ac PV modules. Where methods in Section 911.6.3.2 or Section 911.6.3.3 are used, the existing ac grounding electrode system shall be in accordance with the applicable requirements in Article 250, Part III of NFPA 70. [NFPA 70:690.47(C)] 911.6.3.1 Separate Direct-Current Grounding Electrode System Bonded to the Alternating-Current Grounding Electrode System. A separate dc grounding electrode or system shall be installed, and it shall be bonded directly to the ac grounding electrode system. The size of a bonding jumper(s) between the ac and dc systems shall be based on the larger size of the existing ac grounding electrode conductor or the size of the dc grounding electrode conductor in accordance with Section 911.6.2.1 through Section 911.6.2.5. The dc grounding electrode system conductor(s) or the bonding jumpers to the ac grounding electrode system shall not be used as a substitute for required ac equipment grounding conductors. [NFPA 70:690.47(C)(1)] 911.6.3.2 Common Direct-Current and Alternating-Current Grounding Electrode. A dc grounding electrode conductor of the size specified in Section 911.6.2.1 through Section 911.6.2.5 shall be run from the marked dc grounding electrode connection point to the ac grounding electrode. Where an ac grounding electrode is not accessible, the dc grounding electrode conductor shall be connected to the ac grounding electrode conductor in accordance with Section 911.6.1.4(1) or Section 911.6.1.4(2) or by using a connector listed for grounding and bonding. This dc grounding electrode conductor shall not be used as a substitute for required ac equipment grounding conductors. [NFPA 70:690.47(C)(2)] 911.6.3.3 Combined Direct-Current Grounding Electrode Conductor and Alternating-Current Equipment Grounding Conductor. An unspliced, or irreversibly spliced, combined grounding conductor shall be run from the marked dc grounding electrode conductor connection point along with the ac circuit conductors to the grounding busbar in the associated ac equipment. This combined grounding conductor shall be the larger of the sizes specified in Section 250.122 of NFPA 70 or Section 911.6.2.1 through Section 911.6.2.5, and shall be installed in accordance with Section 250.64(E) of NFPA 70. For underground systems, this conductor shall be sized in accordance with Section 250.122 of NFPA 70 and shall not be required to be larger than the largest ungrounded phase conductor. [NFPA 70:690.47(C)(3)] 911.6.4 821.3 Additional Auxiliary Electrodes for Array Grounding. A gGrounding electrodes shall be permitted to be installed in accordance with Section 911.6.2.3.1, Section 911.6.2.3.2, Section 911.6.2.4.1, Section 911.6.2.5.1, Section 911.6.4.1 through Section 911.6.4.5 Section 821.3.1 through Section 821.3.9; and Section 250.54 of NFPA 70 at the location of all ground- and pole-mounted PV arrays and as close as practicable to the location of roof-mounted PV arrays. The electrodes shall be permitted to be connected directly to the array frame(s) or structure. The dc grounding electrode conductor shall be sized in accordance with Section 911.6.2.1 through Section 911.6.2.5 according to Section 250.66 of NFPA 70. Additional electrodes are not permitted to be used as a substitute for equipment bonding or equipment grounding conductor requirements. The structure of a ground- or pole-mounted ground-mounted PV array shall be permitted to be considered a grounding electrode where in accordance with if it meets the requirements of Section 911.6.2.3.1, Section 911.6.2.3.2, Section 911.6.2.4.1, Section 911.6.2.5.1, and Section 911.6.4.1 through Section 911.6.4.5 Section 821.3.1 through Section 821.3.9. Roof-mounted PV arrays shall be permitted to use the metal frame of a building or structure where in accordance with if the requirements of Section 911.6.4.2 821.3.2 are met. Exceptions: (1) An array grounding electrode(s) shall not be required where the load served by the array is integral with the array. (2) An additional array grounding electrode(s) shall not be required where located within 6 feet (1829 mm) of the premises wiring electrode. [NFPA 70:690.47(D)(B)] 911.6.4.1 821.3.1 Metal Underground Water Pipe. A metal underground water pipe in direct contact with the earth for 10 feet (3048 mm) or more (including any metal well casing bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode

115 conductor and the bonding conductor(s) or jumper(s), where if installed. [NFPA 70:250.52(A)(1)] 911.6.4.2 Metal Frame of the Building or Structure. The metal frame of the building or structure that is connected to the earth by one or more of the following methods: (1) At least one structural metal member that is in direct contact with the earth for 10 feet (3048 mm) or more, with or without concrete encasement. (2) Hold-down bolts securing the structural steel column that are connected to a concrete-encased electrode that are in accordance with Section 911.6.2.4.1 and is located in the support footing or foundation. The hold-down bolts shall be connected to the concrete-encased electrode by welding, exothermic welding, the usual steel tie wires, or other approved means. 821.3.2 Metal In-Ground Support Structure(s). One or more metal in-ground support structure(s) in direct contact with the earth vertically for 10 feet (3048 mm) or more, with or without concrete encasement. If multiple metal in-ground support structures are present at a building or a structure, it shall be permissible to bond only one into the grounding electrode system. [NFPA 70:250.52(A)(2)] 911.6.2.4.1 821.3.3 Concrete-Encased Electrode. A concrete-encased electrode shall consist of not less than at least 20 feet (6096 mm) of one of the following: (1) Not less than one One or more bare or zinc galvanized or other electrically conductive coated steel reinforcing bars or rods of not less than 1/2 of an inch (12.7 mm) in diameter, installed in one continuous 20 feet foot (6096 mm) length, or where if in multiple pieces connected together by the usual steel tie wires, exothermic welding, welding, or other effective means to create a length of not less than 20 feet foot (6096 mm) or greater length; or. (2) Bare copper conductor not less than 4 AWG. Metallic components shall be encased by not less than at least 2 inches (51 mm) of concrete and shall be located horizontally within that portion of a concrete foundation or footing that is in direct contact with the earth or within vertical foundations or structural components or members that are in direct contact with the earth. Where If multiple concrete-encased electrodes are present at a building or structure, it shall be permissible to bond only one into the grounding electrode system. Concrete installed with insulation, vapor barriers, films or similar items separating the concrete from the earth shall not be is not considered to be in “direct contact” with the earth. [NFPA 70:250.52(A)(3)] 911.6.2.5.1 821.3.4 Ground Ring. A ground ring encircling the building or structure, in direct contact with the earth, consisting of not less than 20 feet (6096 mm) of bare copper conductor not less than 2 AWG. [NFPA 70:250.52(A)(4)] 911.6.2.3.1 821.3.5 Rod and Pipe Electrodes. Rod and pipe electrodes shall be not be less than 8 feet (2438 mm) in length and shall consist of the following materials: (1) Grounding electrodes of pipe or conduit shall be not be smaller than trade size 3/4 (21 metric designator) and, where of steel, shall have the outer surface galvanized or otherwise metal-coated for corrosion protection. (2) Rod-type grounding electrodes of stainless steel and copper or zinc coated steel shall be not less than 5/8 of an inch (15.9 mm) in diameter, unless listed. [NFPA 70:250.52(A)(5)] 911.6.4.3 821.3.6 Other Listed Electrodes. Other listed grounding electrodes shall be permitted. [NFPA 70:250.52(A)(6)] 2 911.6.2.3.2 821.3.7 Plate Electrodes. A Each plate electrode shall expose not less than 2 square feet (0.2 m ) of surface to exterior soil. Electrodes of bare or conductively electrically conductive coated iron or steel plates shall be not less than at least 1/4 of an inch (6.4 mm) in thickness. Solid, uncoated electrodes of nonferrous metal shall be not less than at least 0.06 of an inch (1.52 mm) in thickness. [NFPA 70:250.52(A)(7)] 911.6.4.4 821.3.8 Other Local Metal Underground Systems or Structures. Other local metal underground systems or structures such as piping systems, underground tanks, and underground metal well casings that are not bonded to a metal water pipe. [NFPA 70:250.52(A)(8)] 911.6.4.5 821.3.9 Not Permitted for Use as Grounding Electrodes. The following systems and materials shall not be used as grounding electrodes: (1) Metal underground gas piping systems. (2) Aluminum. (3) The structures and structural reinforcing steel described in Section 680.26(B)(1) of NFPA 70 and Section 680.26(B)(2) of NFPA 70. [NFPA 70:250.52(B)] 911.7 Continuity of Equipment Grounding Systems. Where the removal of equipment disconnects the bonding connection between the grounding electrode conductor and exposed conducting surfaces in the PV source or output circuit equipment, a bonding jumper shall be installed while the equipment is removed. [NFPA 70:690.48] 911.8 Continuity of Photovoltaic Source and Output Circuit Grounded Conductors. Where the removal of the utility-interactive inverter or other equipment disconnects the bonding connection between the grounding electrode conductor and the PV source, PV output circuit grounded conductor, or both, a bonding jumper shall be installed to maintain the system grounding while the inverter or other equipment is removed. [NFPA 70:690.49]

911.9822.0 Equipment Bonding Jumpers. 822.1 Bonding Jumpers. Equipment bonding jumpers, where if used, shall be in accordance comply with Section 911.4.4 819.1.4. [NFPA 70:690.50]

116 Part VI - Marking.

912.0 823.0 Marking. 912.1 823.1 Directory. A permanent plaque or directory, denoting the location of all electrical power sources source disconnecting means on or in the premises, shall be installed at each service equipment location and at location(s) of the system disconnect(s) for all electric power production sources capable of being interconnected. The marking shall comply with Section 810.1.2.1. Exception: Installations with large numbers of power production sources shall be permitted to be designated by groups. [NFPA 70:705.10] 912.2 823.2 Modules. Modules shall be marked with identification of terminals or leads as to polarity, maximum overcurrent device rating for module protection, and with the following ratings: (1) Open-circuit voltage (2) Operating voltage (3) Maximum permissible system voltage (4) Operating current (5) Short-circuit current (6) Maximum power [NFPA 70:690.51] 903.4.2823.3 Format.The marking requirements in Section 903.4.1810.1.2.1 shall be provided in accordance with the following: (1) Red background (2) White lettering (3) Not less than 3/8 of an inch (9.5 mm) letter height (4) Capital letters (5) Made of reflective weather-resistant material

912.3824.0 Alternating-Current Photovoltaic Modules. 824.1 Identification. Alternating-current modules shall be marked with identification of terminals or leads and with identification of the following ratings: (1) Nominal operating ac voltage. (2) Nominal operating ac frequency. (3) Maximum ac power. (4) Maximum ac current. (5) Maximum overcurrent device rating for ac module protection. [NFPA 70:690.52]

912.4825.0 Direct-Current Photovoltaic Power Source. 825.1 Labeling. A permanent label for the direct-current dc PV power source indicating the information specified in Section 825.1(1) through Section 825.1(3) shall be provided by the installer at the accessible location at the PV disconnecting means as follows: dc PV system disconnecting means and at each dc equipment disconnecting means required by Section 811.1. Where a disconnecting means has more than one dc PV power source, the values in Section 825.1(1) through Section 825.1(3) shall be specified for each source. (1) Rated maximum power-point current. (2) Rated maximum power-point voltage. (3)(1) Maximum system voltage (see Section 804.1 for voltage). (4)(2) Maximum circuit current. Where the PV power source has multiple outputs, Section 912.4(1) and Section 912.4(4) shall be specified for each output. (see Section 805.1 for calculation of maximum circuit current) (5)(3) Maximum rated output current of the charge controller or dc-to-dc converter (where if installed). [NFPA 70:690.53] 912.5 825.2 Interactive System Point of Interconnection. All Iinteractive system(s) points of interconnection with other sources shall be marked at an accessible location at the disconnecting means as a power source and with the rated ac output current and the nominal operating ac voltage. [NFPA 70:690.54]

912.6826.0 Photovoltaic Power Systems Employing Connected to Energy Storage Systems. 826.1 Marking. Photovoltaic power systems employing energy storage shall be marked with the maximum operating voltage, including any equalization voltage and the polarity of the grounded circuit conductor. The PV system output circuit conductors shall be marked to indicate the polarity where connected to energy storage systems. [NFPA 70:690.55]

912.7827.0 Facilities with Stand-Alone Systems. 827.1 General. A Any structure or building with a PV power system that is not connected to a utility service source and is a stand-alone system shall have a permanent plaque or directory installed on the exterior of the building or structure at a readily visible location acceptable to the Authority Having Jurisdiction. The plaque or directory shall indicate the location of system disconnecting means and that the structure contains a stand-alone electrical power system. The marking shall be in accordance

117 with Section 910.5. [NFPA 70:690.56(A)] 912.8 827.2 Facilities with Utility Services and PV Photovoltaic Systems. Buildings or structures with both utility service and a PV system shall have a permanent plaque or directory providing the location of the service disconnecting means and the PV system disconnecting means, where not located at the same location. The warning sign(s) or label(s) shall comply with Section 903.4.1. Plaques or directories shall be installed in accordance with Section 823.1. [NFPA 70:690.56(B)] 912.9 827.3 Facilities Buildings with Rapid Shutdown. Buildings or structures with both utility service and a PV system, in accordance with Section 908.8, shall have a permanent plaque or directory including the following wording:

PHOTOVOLTAIC SYSTEM EQUIPPED WITH RAPID SHUTDOWN

The plaque or directory shall be reflective, with all letters capitalized and having a minimum height of 3/8 of an inch (9.5 mm), in white on red background. Buildings with PV systems shall have permanent labels as described in Section 827.3.1 through Section 827.3.3. [NFPA 70:690.56(C)] 827.3.1 Rapid Shutdown Type. The type of PV system rapid shutdown shall be labeled as described in Section 827.3.1(1) or Section 827.3.1(2): (1) For PV systems that shut down the array and conductors leaving the array:

SOLAR PV SYSTEM IS EQUIPPED WITH RAPID SHUTDOWN. TURN RAPID SHUTDOWN SWITCH TO THE “OFF” POSITION TO SHUT DOWN PV SYSTEM AND REDUCE SHOCK HAZARD IN ARRAY.

The title “SOLAR PV SYSTEM IS EQUIPPED WITH RAPID SHUTDOWN” shall utilize capitalized characters with a minimum height of 3/8 of an inch (9.5 mm) in black on yellow background, and the remaining characters shall be capitalized with a minimum height of 3/16 of an inch (4.8 mm) in black on white background. [see Figure 827.3.1(1)]

FIGURE 827.3.1(1) LABEL FOR PV SYSTEMS THAT SHUT DOWN THE ARRAY AND THE CONDUCTORS LEAVING THE ARRAY [NFPA 70: FIGURE 690.56(C)(1)(a)] (2) For PV systems that only shut down conductors leaving the array:

SOLAR PV SYSTEM IS EQUIPPED WITH RAPID SHUTDOWN TURN RAPID SHUTDOWN SWITCH TO THE “OFF” POSITION TO SHUT DOWN CONDUCTORS OUTSIDE THE ARRAY. CONDUCTORS IN

118 ARRAY REMAIN ENERGIZED IN SUNLIGHT.

The title “SOLAR PV SYSTEM IS EQUIPPED WITH RAPID SHUTDOWN” shall utilize capitalized characters with a minimum height of 3/8 of an inch (9.5 mm) in white on red background, and the remaining characters shall be capitalized with a minimum height of 3/16 of an inch (4.8 mm) in black on white background. [see Figure 827.3.1(2).]

FIGURE 827.3.1(2) LABEL FOR PV SYSTEMS THAT SHUT DOWN THE CONDUCTORS LEAVING THE ARRAY ONLY [NFPA 70: FIGURE 690.56(C)(1)(b)] The labels in Section 827.3.1(1) and Section 827.3.1(2) shall include a simple diagram of a building with a roof. The diagram shall have sections in red to signify sections of the PV system that are not shut down when the rapid shutdown switch is operated.

The rapid shutdown label in Section 827.3.1 shall be located on or not more than 3 feet (914 mm) from the service disconnecting means to which the PV systems are connected and shall indicate the location of all identified rapid shutdown switches if not at the same location. [NFPA 70:690.56(C)(1)] 827.3.2 Buildings with More Than One Rapid Shutdown Type. For buildings that have PV systems with both rapid shutdown types or a PV system with a rapid shutdown type and a PV system with no rapid shutdown, a detailed plan view diagram of the roof shall be provided showing each different PV system and a dotted line around areas that remain energized after the rapid shutdown switch is operated. [NFPA 70:690.56(C)(2)] 827.3.3 Rapid Shutdown Switch. A rapid shutdown switch shall have a label located on or no more than 3 feet (914 mm) from the switch that includes the following wording:

RAPID SHUTDOWN SWITCH FOR SOLAR PV SYSTEM

The label shall be reflective, with all letters capitalized and having a minimum height of 3/8 of an inch (9.5 mm), in white on red background. [NFPA 70:690.56(C)(3)]

Part VII - Connection to Other Sources.

913.0 828.0 Connection to Other Sources. 828.1 PV Systems. PV systems connected to other sources shall be installed in accordance with Parts I and II of Article 705 of NFPA 70. [NFPA 70:690.59] 913.1 Load Disconnect. A load disconnect that has multiple sources of power shall disconnect all sources where in the off position. [NFPA 70:690.57] 913.2 Identified Interactive Equipment. Inverters and ac modules listed and identified as interactive shall be permitted in interactive systems. [NFPA 70:690.60] 913.3 Loss of Interactive System Power. An inverter or an ac module in an interactive solar PV system shall automatically de-energize its output to the connected electrical production and distribution network upon loss of voltage in that system and shall remain in that state until the electrical production and distribution network voltage has been restored.

119 A normally interactive solar PV system shall be permitted to operate as a stand-alone system to supply loads that have been disconnected from electrical production and distribution network sources. [NFPA 70:690.61] 913.4 Unbalanced Interconnections. Single-phase inverters for hybrid systems and ac modules in interactive hybrid systems shall be connected to three-phase power systems in order to limit unbalanced voltages to not more than 3 percent. [NFPA 70:705.100(A)] Three-phase inverters and three-phase ac modules in interactive systems shall have all phases automatically de-energized upon loss of, or unbalanced, voltage in one or more phases unless the interconnected system is designed so that significant unbalanced voltages will not result. [NFPA 70:705.100(B)] 913.5 Point of Connection. The output of an interconnected electrical power source shall be connected as specified in Section 913.5.1 through Section 913.5.4. [NFPA 70:705.12] 913.5.1 Supply Side. An electric power production source shall be permitted to be connected to the supply side of the service disconnecting means in accordance with Section 230.82(6) of NFPA 70. The sum of the ratings of all overcurrent devices connected to power production sources shall not exceed the rating of the service. [NFPA 70:705.12(A)] 913.5.2 Integrated Electrical Systems. The outputs shall be permitted to be interconnected at a point or points elsewhere on the premises where the system qualifies as an integrated electrical system and incorporates protective equipment in accordance with applicable sections of Article 685 of NFPA 70. [NFPA 70:705.12(B)] 913.5.3 Greater Than 100 kW. The outputs shall be permitted to be interconnected at a point or points elsewhere on the premises where the following conditions are met: (1) The aggregate of non-utility sources of electricity has a capacity in excess of 100 kilowatt hours (kW•h) (360 MJ), or the service is more than 1000 volts. (2) The conditions of maintenance and supervision ensure that qualified persons service and operate the system. (3) Safeguards, documented procedures, and protective equipment are established and maintained. [NFPA 70:705.12(C)] 913.5.4 Utility-Interactive Inverters. The output of an utility-interactive inverter shall be permitted to be connected to the load side of the service disconnecting means of the other source(s) at any distribution equipment on the premises. Where distribution equipment, including switchgear, switchboards or panelboards, is fed simultaneously by a primary source(s) of electricity and one or more utility-interactive inverters, and where this distribution equipment is capable of supplying multiple branch circuits or feeders, or both, the interconnecting provisions for the utility-interactive inverter(s) shall be in accordance with Section 913.5.4.1 through Section 913.5.4.6. [NFPA 70:705.12(D)] 913.5.4.1 Dedicated Overcurrent and Disconnect. The source interconnection of one or more inverters installed in one system shall be made at a dedicated circuit breaker or fusible disconnecting means. [NFPA 70:705.12(D)(1)] 913.5.4.2 Bus or Conductor Ampere Rating. One hundred twenty-five percent of the inverter output circuit current shall be used in ampacity calculations for the following: (1) Where the inverter output connection is made to a feeder at a location other than the opposite end of the feeder from the primary source overcurrent device, that portion of the feeder on the load side of the inverter output connection shall be protected by one of the following: (a) The feeder ampacity shall be not less than the sum of the primary source overcurrent device and 125 percent of the inverter output circuit current. (b) An overcurrent device on the load side of the inverter connection shall be rated not more than the ampacity of the feeder. (2) In Systems where inverter output connections are made at feeders, any taps shall be sized based on the sum of 125 percent of the inverter output circuit current and the rating of the overcurrent device protecting the feeder conductors as calculated in Section 240.21(B) of NFPA 70. (3) One of the following methods shall be used to determine the ratings of busbars in panelboard: (a) The sum of 125 percent of the inverter output circuit current and the rating of the overcurrent device protecting the busbar shall not exceed the ampacity of the busbar. (b) Where two sources, one a utility and the other an inverter, are located at opposite ends of a busbar that contains loads, the sum of 125 percent of the inverter output circuit current and the rating of the overcurrent device protecting the busbar shall not exceed 120 percent of the ampacity of the busbar. The busbar shall be sized for the loads connected in accordance with Article 220 of NFPA 70. A permanent warning label shall be applied to the distribution equipment adjacent to the back-fed breaker from the inverter that displays the following or equivalent wording:

WARNING: INVERTER OUTPUT CONNECTION; DO NOT RELOCATE THIS OVERCURRENT DEVICE.

The warning sign(s) or label(s) shall comply with Section 903.4.1. (c) The sum of the ampere ratings of all overcurrent devices on panelboards, both load and supply devices, excluding the rating of the overcurrent device protecting the busbar, shall not exceed the ampacity of the busbar. The rating of the overcurrent device protecting the busbar shall not exceed the rating of the busbar. Permanent warning labels shall be applied to distribution equipment that displays the following or equivalent wording:

120 WARNING: THIS EQUIPMENT FED BY MULTIPLE SOURCES. TOTAL RATING OF ALL OVERCURRENT DEVICES, EXCLUDING MAIN SUPPLY OVERCURRENT DEVICE, SHALL NOT EXCEED AMPACITY OF BUSBAR.

The warning sign(s) or label(s) shall comply with Section 903.4.1. (d)Connections shall be permitted on multiple-ampacity busbars or center-fed panelboards where designed under engineering supervision that includes fault studies and busbar load calculations. [NFPA 70:705.12(D)(2)] 913.5.4.3 Marking. Equipment containing overcurrent devices in circuits supplying power to a busbar or conductor supplied from multiple sources shall be marked to indicate the presence of all sources. [NFPA 70:705.12(D)(3)] 913.5.4.4 Suitable for Backfeed. Circuit breakers, where back-fed, shall be suitable for such operation. [NFPA 70:705.12(D)(4)] 913.5.4.5 Fastening. Listed plug-in-type circuit breakers backfed from utility-interactive inverters that are listed and identified as interactive shall be permitted to omit the additional fastener required in accordance with Section 908.6.1 for such application. [NFPA 70:705.12(D)(5)] 913.5.4.6 Wire Harness and Exposed Cable Arc-Fault Protection. A utility-interactive inverter(s) that has a wire harness or cable output circuit rated 240 V, 30 amperes, or less, that is not installed within an enclosed raceway, shall be provided with listed ac AFCI protection. [NFPA 70:705.12(D)(6)]

Part VIII - Energy Storage Systems.

914.0 829.0 Storage Batteries Energy Storage Systems. 829.1 General. An energy storage system connected to a PV system shall be installed in accordance with Article 706 of NFPA 70. [NFPA 70:690.71] 914.1 Installation. Storage batteries in a solar photovoltaic system shall be installed in accordance with the provisions of Article 480 of NFPA 70. The interconnected battery cells shall be considered grounded where the photovoltaic power source is installed in accordance with Section 911.1. [NFPA 70:690.71(A)] 914.2 Dwellings. Storage batteries for dwellings shall have the cells connected so as to operate at a voltage of 50 volts, nominal, or less. Exception: Where live parts are not accessible during routine battery maintenance, a battery system voltage in accordance with Section 905.0 shall be permitted. [NFPA 70:690.71(B)(1)] Live parts of battery systems for dwellings shall be guarded to prevent accidental contact by persons or objects, regardless of voltage or battery type. [NFPA 70:690.71(B)(2)] 914.3 Current Limiting. A listed, current-limiting, overcurrent device shall be installed in each circuit adjacent to the batteries where the available short-circuit current from a battery or battery bank exceeds the interrupting or withstand ratings of other equipment in that circuit. The installation of current-limiting fuses shall comply with Section 909.3. [NFPA 70:690.71(C)] 914.4 Battery Nonconductive Cases and Conductive Racks. Flooded, vented, lead-acid batteries with more than 24 two-volt cells connected in series (48 volts, nominal) shall not use conductive cases or shall not be installed in conductive cases. Conductive racks used to support the nonconductive cases shall be permitted where no rack material is located within 6 inches (152 mm) of the tops of the nonconductive cases. This requirement shall not apply to a type of valve-regulated lead-acid (VRLA) battery or any other types of sealed batteries that require steel cases for proper operation. [NFPA 70:690.71(D)] 914.5 Disconnection of Series Battery Circuits. Battery circuits subject to field servicing, where more than 24 two-volt cells are connected in series (48 volts, nominal), shall have provisions to disconnect the series-connected strings into segments of 24 cells or less for maintenance by qualified persons. Non-load-break bolted or plug-in disconnects shall be permitted. [NFPA 70:690.71(E)] 914.6 Battery Maintenance Disconnecting Means. Battery installations, where there are more than 24 two-volt cells connected in series (48 volts, nominal), shall have a disconnecting means, accessible only to qualified persons, that disconnects the grounded circuit conductor(s) in the battery electrical system for maintenance. This disconnecting means shall not disconnect the grounded circuit conductor(s) for the remainder of the photovoltaic electrical system. A non-load-break-rated switch shall be permitted to be used as the disconnecting means. [NFPA 70:690.71(F)] 914.7 Battery Systems Exceeding 48 Volts. On photovoltaic systems where the battery system consists of more than 24 two-volt cells connected in series (exceeding 48 volts, nominal), the battery system shall be permitted to operate with ungrounded conductors, provided the following conditions are met: (1) The photovoltaic array source and output circuits shall comply with Section 911.1. (2) The dc and ac load circuits shall be solidly grounded. (3) Main ungrounded battery input, output, or both circuit conductors shall be provided with switched disconnects and overcurrent protection.

121 (4) A ground-fault detector and indicator shall be installed to monitor for ground faults in the battery bank. [NFPA 70:690.71(G)] 914.8 Disconnects and Overcurrent Protection. Where energy storage device input and output terminals are more than 5 feet (1524 mm) from connected equipment, or where the circuits from these terminals pass through a wall or partition, the installation shall comply with the following: (1) A disconnecting means and overcurrent protection shall be provided at the energy storage device end of the circuit. Fused disconnecting means or circuit breakers shall be permitted to be used. (2) Where fused disconnecting means are used, the line terminals of the disconnecting means shall be connected toward the energy storage device terminals. (3) Overcurrent devices or disconnecting means shall not be installed in energy storage device enclosures where explosive atmospheres can exist. (4) A second disconnecting means located at the connected equipment shall be installed where the disconnecting means required in accordance with Section 914.8(1) is not within sight of the connected equipment. (5) Where the energy storage device disconnecting means is not within sight of the PV system ac and dc disconnecting means, placards or directories shall be installed at the locations of all disconnecting means indicating the location of all disconnecting means. [NFPA 70:690.71(H)]

830.0 Batteries. 914.9 830.1 Battery Locations. Battery locations shall comply with the following: (1) Provisions appropriate to the battery technology shall be made for sufficient diffusion and ventilation of the gases from the battery, where present, to prevent the accumulation of an explosive mixture. [NFPA 70:480.9(A)] (21) Battery rooms shall be provided with an exhaust rate of not less than 1 cubic foot per minute per square foot [(ft3/min)/ft2] [0.005 (m3/s)/m2] of floor area of the room to prevent the accumulation of flammable vapors. Such exhaust shall discharge directly to an approved location at the exterior of the building. (32) Makeup air shall be provided at a rate equal to the rate that air is exhausted by the exhaust system. Makeup air intakes shall be located so as to avoid recirculation of contaminated air. (43) Batteries shall be protected against physical damage. (54) Batteries shall not be located in areas where open use, handling or dispensing of combustible, flammable, or explosive materials occurs. (65) Batteries shall not be located near combustible material to constitute a fire hazard and shall have a clearance of not less than 12 inches (305 mm) from combustible material.

914.10831.0 Self-Regulating Charge Control. 831.1 General. Equipment shall be provided to control the charging process of the battery. The PV source circuit shall be considered to comply with the requirements of Section 831.1.1 through Section 831.1.5 if: (1) Charge control shall not be required where the design of the photovoltaic The PV source circuit is matched to the voltage rating and charge current requirements of the interconnected battery cells and, (2) tThe maximum charging current multiplied by 1 hour is less than 3 percent of the rated battery capacity expressed in ampere- hours or as recommended by the battery manufacturer. All adjusting means for control of the charging process shall be accessible only to qualified persons. [NFPA 70:690.72(A)] A charging controller shall comply with UL 1741. 831.1.1 Charge Control. Provisions shall be provided to control the charging process of the Energy Storage System (ESS). All adjustable means for control of the charging process shall be accessible only to qualified persons. [NFPA 70:706.23(A)] 831.1.2 Diversion Charge Controller, Sole Means of Regulating Charging. An ESS employing a diversion charge controller as the sole means of regulating charging shall be equipped with a second independent means to prevent overcharging of the storage device. [NFPA 70:706.23(B)(1)] 831.1.3 Diversion Charge Controller, Circuits with Diversion Charge Controller and Diversion Load. Circuits containing a diversion charge controller and a diversion load shall comply with the following: (1) The current rating of the diversion load shall be less than or equal to the current rating of the diversion load charge controller. The voltage rating of the diversion load shall be greater than the maximum ESS voltage. The power rating of the diversion load shall be at least 150 percent of the power rating of the charging source. (2) The conductor ampacity and the rating of the overcurrent device for this circuit shall be at least 150 percent of the maximum current rating of the diversion charge controller. [NFPA 70:706.23(B)(2)] 831.1.4 Energy Storage Systems Using Utility-Interactive Inverters. Systems using utility-interactive inverters to control energy storage state-of-charge by diverting excess power into the utility system shall comply with Section 831.1.4(1) and Section 831.1.4(2). (1) These systems shall not be required to comply with Section 831.1.3. (2) These systems shall have a second, independent means of controlling the ESS charging process for use when the utility is not present or when the primary charge controller fails or is disabled. [NFPA 70:706.23(B)(3)] 831.1.5 Charge Controllers and DC-to-DC Converters. Where charge controllers and other DC-to-DC power converters

122 that increase or decrease the output current or output voltage with respect to the input current or input voltage are installed, all of the following shall apply: (1) The ampacity of the conductors in output circuits shall be based on the maximum rated continuous output current of the charge controller or converter for the selected output voltage range. (2) The voltage rating of the output circuits shall be based on the maximum voltage output of the charge controller or converter for the selected output voltage range. [NFPA 70:706.23(C)] 914.10.1 Sole Means of Regulating Charging. A photovoltaic power system employing a diversion charge controller as the sole means of regulating the charging of a battery shall be equipped with a second independent means to prevent overcharging of the battery. [NFPA 70:690.72(B)(1)] 914.10.2 Circuits with Direct-Current Diversion Charge Controller and Diversion Load. Circuits containing a dc diversion charge controller and a dc diversion load shall be in accordance with the following: (1) The current rating of the diversion load shall be less than or equal to the current rating of the diversion load charge controller. The voltage rating of the diversion load shall exceed the maximum battery voltage. The power rating of the diversion load shall be not less than 150 percent of the power rating of the photovoltaic array. (2) The conductor ampacity and the rating of the overcurrent device for this circuit shall be not less than 150 percent of the maximum current rating of the diversion charge controller. [NFPA 70:690.72(B)(2)] 914.10.3 PV Systems Using Utility-Interactive Inverters. Photovoltaic power systems using utility-interactive inverters to control battery state-of-charge by diverting excess power into the utility system shall be in accordance with the following: (1) These systems shall not be required to be in accordance with Section 914.10.2. The charge regulation circuits used shall be in accordance with the requirements of Section 400.5 of NFPA 70. (2) These systems shall have a second, independent means of controlling the battery charging process for use where the utility is not present or where the primary charge controller fails or is disabled. [NFPA 70:690.72(B)(3)] 914.10.4 Buck/Boost Direct-Current Converters. Where buck/boost charge controllers and other dc power converters that increase or decrease the output current or output voltage with respect to the input current or input voltage are installed, the requirements shall comply with the following: (1) The ampacity of the conductors in output circuits shall be based on the maximum rated continuous output current of the charge controller or converter for the selected output voltage range. (2) The voltage rating of the output circuits shall be based on the maximum voltage output of the charge controller or converter for the selected output voltage range. [NFPA 70:690.72(C)] 914.11 Battery Interconnections. Flexible cables, as identified in Article 400 of NFPA 70, in sizes not less than 2/0 AWG shall be permitted within the battery enclosure from battery terminals to a nearby junction box where they shall be connected to an approved wiring method. Flexible battery cables shall also be permitted between batteries and cells within the battery enclosure. Such cables shall be listed for hard-service use and identified as moisture resistant. Flexible, fine-stranded cable shall be terminated with terminals, lugs, devices, or connectors in accordance with Section 110.14 of NFPA 70. [NFPA 70:690.74]

915.0 Systems Over 1000 Volts. 915.1 General. Solar PV systems with a system voltage exceeding 1000 volts dc shall comply with Section 915.4 through Section 915.10, Article 490 of NFPA 70, and other requirements applicable to installations with a system voltage exceeding 1000 volts. [NFPA 70:690.80] 915.2 Listing. Products listed for PV systems shall be permitted to be used and installed in accordance with their listing. PV wire that is listed for direct burial at voltages above 600 volts, but not exceeding 2000 volts, shall be installed in accordance with Table 300.50, column 1 of NFPA 70. [NFPA 70:690.81] 915.3 Definitions. For the purposes of Section 914.0, the voltages used to determine cable and equipment ratings are as follows: (1) In battery circuits, the highest voltage experienced under charging or equalizing conditions. (2) In dc PV source circuits and PV output circuits, the maximum system voltage. [NFPA 70:690.85] 915.4 Guarding of High-Voltage Energized Parts Within a Compartment. Where access for other than visual inspection is required to a compartment that contains energized high-voltage parts, barriers shall be provided to prevent accidental contact by persons, tools, or other equipment with energized parts. Exposed live parts shall be permitted in compartments accessible to qualified persons. Fuses and fuseholders designed to enable future replacement without de- energizing the fuseholder shall be permitted for use by qualified persons. [NFPA 70:490.32] 915.5 High-Voltage Equipment. Doors that would provide unqualified persons access to high-voltage energized parts shall be locked. Permanent signs in accordance with Section 903.4.1 shall be installed on panels or doors that provide access to live parts over 1000 volts and shall read "DANGER – HIGH VOLTAGE – KEEP OUT". [NFPA 70:490.35(A)] 915.6 Circuit Breakers. Circuit breakers installed indoors shall be mounted either in metal-enclosed units or fire-resistant cell-mounted units, or they shall be permitted to be open-mounted in locations accessible to qualified persons. [NFPA 70:490.21(A)(1)(a)] 915.7 Operating Characteristics. Circuit breakers shall have the following equipment or operating characteristics: (1) An accessible mechanical or other identified means for manual tripping, independent of control power. (2) Be release free (trip free).

123 (3) Where capable of being opened or closed manually while energized, main contacts that operate independently of the speed of the manual operation. (4) A mechanical position indicator at the circuit breaker to show the open or closed position of the main contacts. (5) A means of indicating the open and closed position of the breaker at the point(s) from which they are operated. [NFPA 70:490.21(A)(2)] 915.8 Nameplate. A circuit breaker shall have a permanent and legible nameplate showing manufacturer’s name or trademark, manufacturer’s type or identification number, continuous current rating, interrupting rating in megavolt-amperes (MVA) or amperes, and maximum voltage rating. Modification of a circuit breaker affecting its rating(s) shall be accompanied by an appropriate change of nameplate information. [NFPA 70:490.21(A)(3)] 915.9 High-Voltage Fuses. Switchgear and substations that utilize high-voltage fuses shall be provided with a gang- operated disconnecting switch. Isolation of the fuses from the circuit shall be provided by either connecting a switch between the source and the fuses or providing roll-out switch and fuse-type construction. The switch shall be of the load-interrupter type, unless mechanically or electrically interlocked with a load-interrupting device arranged to reduce the load to the interrupting capacity of the switch. Exception: More than one switch shall be permitted as the disconnecting means for one set of fuses where the switches are installed to provide connection to more than a set of supply conductors. The switches shall be mechanically or electrically interlocked to permit access to the fuses where all switches are open. A conspicuous sign shall be placed at the fuses identifying the presence of more than one source. [NFPA 70:490.21(B)(7)] 915.10 Voltage Rating. The maximum voltage rating of power fuses shall not be less than the maximum circuit voltage. Fuses shall not be applied below the minimum recommended operating voltage. [NFPA 70:490.21(B)(3)]

Part IX - Large-Scale Photovoltaic (PV) Electric Power Production Facility.

832.0 Large-Scale Photovoltaic (PV) Electric Power Production Facility. 832.1 Scope. Section 832.2 through Section 832.9 covers the installation of large-scale PV electric power production facilities with a generating capacity of no less than 5000 kW, and not under exclusive utility control. [NFPA 70:691.1] 832.2 Special Requirements for Large-Scale PV Electric Supply Stations. Large-scale PV electric supply stations shall be accessible only to authorized personnel and comply with the following: (1) Electrical circuits and equipment shall be maintained and operated only by qualified personnel. (2) Access to PV electric supply stations shall be restricted by fencing or other adequate means in accordance with Section 110.31 of NFPA 70. Field-applied hazard markings shall be applied in accordance with Section 810.1.2.1. (3) The connection between the PV electric supply station and the system operated by a utility for the transfer of electrical energy shall be through medium- or high voltage switch gear, substation, switch yard, or similar methods whose sole purpose shall be to safely and effectively interconnect the two systems. (4) The electrical loads within the PV electric supply station shall only be used to power auxiliary equipment for the generation of the PV power. (5) Large-scale PV electric supply stations shall not be installed on buildings. [NFPA 70:691.4] 832.3 Equipment Approval. All electrical equipment shall be approved for installation by one of the following: (1) Listing and labeling (2) Field labeling (3) Where products complying with Section 832.3(1) or Section 832.3(2) are not available, by engineering review validating that the electrical equipment is tested to relevant standards or industry practice [NFPA 70:691.5] 832.4 Engineered Design. Documentation of the electrical portion of the engineered design of the electric supply station shall be stamped and provided upon request of the Authority Having Jurisdiction. Additional stamped independent engineering reports detailing compliance of the design with applicable electrical standards and industry practice shall be provided upon request of the AHJ. The independent engineer shall be a licensed professional electrical engineer retained by the system owner or installer. This documentation shall include details of conformance of the design with this chapter, and any alternative methods to this chapter, or other articles of NFPA 70. [NFPA 70:691.6] 832.5 Conformance of Construction to Engineered Design. Documentation that the construction of the electric supply station conforms to the electrical engineered design shall be provided upon request of the Authority Having Jurisdiction. Additional stamped independent engineering reports detailing the construction conforms with this chapter, applicable standards and industry practice shall be provided upon request of the Authority Having Jurisdiction. The independent engineer shall be a licensed professional electrical engineer retained by the system owner or installer. This documentation, where requested, shall be available prior to commercial operation of the station. [NFPA 70:691.7] 832.6 Direct Current Operating Voltage. For large-scale PV electric supply stations, calculations shall be included in the documentation required in Section 832.4. [NFPA 70:691.8] 832.7 Disconnection of Photovoltaic Equipment. Isolating devices shall be permitted to be more than 6 feet (1829 mm) from the equipment where written safety procedures and conditions of maintenance and supervision ensure that only qualified persons service the equipment. Buildings whose sole purpose is to house and protect supply station equipment shall not be required to comply with Section

124 809.1. Written standard operating procedures shall be available at the site detailing necessary shutdown procedures in the event of an emergency. [NFPA 70:691.9] 832.8 Arc-Fault Mitigation. PV systems that do not comply with the requirements of Section 808.1 shall include details of fire mitigation plans to address dc arc-faults in the documentation required in Section 832.4. [NFPA 70:691.10] 832.9 Fence Grounding. Fence grounding requirements and details shall be included in the documentation required in Section 832.4. [NFPA 70:691.11]

203.0 – A –

Array. A mechanically integrated assembly of module(s) or panel(s) with a support structure and foundation, tracker, and other components, as required, to form a direct-current dc or ac power-producing unit. [NFPA 70:690.2]

204.0 – B –

Bipolar Photovoltaic Array. A dc PV array that has two outputs each having opposite polarity to a common reference point or center tap. [NFPA 70:690.2]

Blocking Diode. A diode used to block reverse flow of current into a PV source circuit. [NFPA 70:690.2]

Building Integrated Photovoltaics. Photovoltaic cells, devices, modules, or modular materials that are integrated into the outer surface or structure of a building and serve as the outer protective surface of that building. [NFPA 70:690.2]

205.0 – C –

Charge Controller. Equipment that controls dc voltage or dc current, or both, and that is used to charge a battery or other energy storage device. [NFPA 70:100]

206.0 – D –

DC-to-DC Converter. A device installed in the PV source circuit or PV output circuit that can provide an output dc voltage and current at a higher or lower value than the input dc voltage and current. [NFPA 70:690.2]

DC-to-DC Converter Output Circuit. Circuit conductors between the dc-to-dc converter source circuit(s) and the inverter or dc utilization equipment. [NFPA 70:690.2]

DC-to-DC Converter Source Circuit. Circuits between dc-to-dc converters and from dc-to-dc converters to the common connection point(s) of the dc system. [NFPA 70:690.2]

Direct-Current (DC) Combiner. A device used in the PV source and PV output circuits to combine two or more dc circuit inputs and provide on one dc circuit output. [NFPA 70:690.2]

207.0 – E –

Electric Supply Stations. Locations containing the generating stations and substations, including their associated generator, storage battery, transformer, and switchgear areas. [NFPA 70:691.2]

208.0 – F –

Functional Grounded PV System. A PV system that has an electrical reference to ground that is not solidly grounded. [NFPA 70:690.2]

209.0 – G –

Generating Capacity. The sum of the parallel-connected inverter rated maximum continuous output power at 104°F (40°C) in kilowatts (kW). [NFPA 70:691.2]

Generating Station. A plant wherein electric energy is produced by conversion from some other form of energy (e.g., chemical, nuclear, solar, wind, mechanical, or hydraulic) by means of suitable apparatus. [NFPA 70:691.2]

210.0 – H –

Hybrid System. A system comprised of multiple power sources. These power sources may could include photovoltaic, wind, micro-hydro generators, engine-driven generators, and others, but do not include electric power production and distribution

125 network systems. Energy storage systems, such as batteries, flywheels, or superconducting magnetic storage equipment do not constitute a power source for the purpose of this definition. The energy regenerated by an overhauling (descending) elevator does not constitute a power source for the purpose of this definition. [NFPA 70:100]

211.0 – I –

Interactive Inverter Output Circuit. The conductors between the interactive inverter and the service equipment or another electrical power production and distribution network. [NFPA 70:690.2]

Interactive System. A solar PV system that operates in parallel with and may deliver power to an electrical production and distribution network. For the purpose of this definition, an energy storage subsystem of a solar PV system, such as a battery, is not another electrical production source. [NFPA 70:690.2]

Inverter Input Circuit. Conductors between the inverter and the battery in stand-alone systems or the conductors between the inverter and the PV output circuits for electrical production and distribution network connected to the dc input of an inverter. [NFPA 70:690.2]

Inverter Output Circuit. Conductors between the inverter and an ac panelboard for stand-alone systems or the conductors between the inverter and the service equipment or another electric power production source, such as a utility, for electrical production and distribution network connected to the ac output of an inverter. [NFPA 70:690.2]

215.0 – M –

Module. A complete environmentally protected unit consisting of solar cells, optics, and other components, exclusive of tracker, designed to generate dc power where when exposed to sunlight. [NFPA 70:690.2]

Monopole Subarray. A PV subarray that has two conductors in the output circuit, one positive (+) and one negative (-). Two monopole PV subarrays are used to form a bipolar PV array. [NFPA 70:690.2]

Multimode Inverter. Equipment having the capabilities of both the utility-interactive inverter and the stand-alone inverter. [NFPA 70:690.2]

218.0 – P –

Photovoltaic Panel. A collection of modules mechanically fastened together, wired, and designed to provide a field- installable unit. [NFPA 70:690.2]

Photovoltaic System DC Circuit. Any dc conductor supplied by a PV power source, including PV source circuits, PV output circuits, dc-to-dc converter source circuits, or dc-to-dc converter output circuits. [NFPA 70:690.2]

Photovoltaic System Voltage. The direct current (dc) voltage of any PV source or PV output circuit. For multiwire installations, the PV system voltage is the highest voltage between any two dc conductors. [NFPA 70:690.2]

221.0 – S –

Solar Cell. The basic PV device that generates electricity where when exposed to light. [NFPA 70:690.2]

Note: NFPA 70 meets the requirements for a mandatory reference standard in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

SUBSTANTIATION: The photovoltaic definitions in Chapter 2 and the provisions in Chapter 8 are being modified to keep the language current with the source document NFPA 70-2017 (latest version) in accordance with Section 16.0 of the IAPMO Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes (Extract Guidelines).

Section 16.3 states the following:

“16.3 Procedures for Updating Extracts. The extract procedure requires that the extracted text be kept current with that of the source document in a timely appropriate manner……… If the extract is determined to be eligible for processing, the secretariat shall letter ballot the technical committee in accordance with the Regulations Governing Consensus Development on the updating of the extracted text, including any editorial revisions necessary to

126 conform to the style of the document.”

The proposed language brings forward Item # 126.01 of the 2018 USHGC cycle for correlation with NFPA 70-2017 (latest edition).

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

127 Proposals

Edit Proposal

Item #: 062

USHGC 2021 Section: 802.2.1, Table 802.2.1, Table 901.1, Table 901.2

SUBMITTER: Christopher Jensen UL LLC

RECOMMENDATION: Add new text

802.0 General Requirements.

802.2 Equipment. (remaining text unchanged) 802.2.1 Listing Requirements. Equipment used in PV power systems shall be listed or field labeled in accordance with Table 802.2.1.

TABLE 802.2.1 STANDARDS FOR PV EQUIPMENT EQUIPMENT STANDARDS Building-integrated PV Modules and Panels UL 1703 or UL 61730-11, UL 61730-21 Building-integrated PV Mounting Systems UL 2703 Charge controllers UL 1741 Combiner boxes UL 1741 Concentrator PV modules UL 8703 DC-to-DC Converters UL 1741 or UL 62109-1 Flat-plate PV modules UL 1703 or UL 61730-11, UL 61730-21 Inverters UL 1741 or UL 62109-1 PV AC modules UL 17032, UL 17412 or UL 61730-11, UL 61730-21 PV Modules and Panels UL 1703 or UL 61730-11, UL 61730-21 PV DC Arc Fault Circuit Interrupters UL 1699B PV DC connectors UL 6703 PV Solar Trackers UL 3703 PV wire UL 4703 Rack mounting systems UL 2703 Rapid shutdown equipment and systems UL 1741 Notes: 1 UL 61730-1 shall be used in conjunction with UL 61730-2. 2 UL 1703 shall be used in conjunction with UL 1741.

128 TABLE 901.1 REFERENCED STANDARDS STANDARD REFERENCED STANDARD TITLE APPLICATION NUMBER SECTION Photovoltaic (PV) DC Arc-Fault Circuit UL 1699B-2018 Electrical Table 802.2.1 Protection Mounting Systems, Mounting Devices, Clamping/Retention Devices, and Ground Lugs UL 2703-2015 Electrical Table 802.2.1 for Use with Flat-Plate Photovoltaic Modules and Panels UL 3703-2015 Solar Trackers Electrical Table 802.2.1 UL 4703-2014 Photovoltaic Wire Electrical Table 802.2.1 Connectors for Use in Photovoltaic Systems UL 6703-2014 Electrical Table 802.2.1 (with revisions through December 22, 2017) Outline of Investigation for Concentrator UL 8703-2011 Electrical Table 802.2.1 Photovoltaic Modules and Assemblies Photovoltaic (PV) Module Safety Qualification UL 61730-1-2017 Electrical Table 802.2.1 - Part 1: Requirements for Construction Photovoltaic (PV) Module Safety Qualification UL 61730-2-2017 Electrical Table 802.2.1 - Part 2: Requirements for Testing Safety of Power Converters for Use in UL 62109-1-2014 Photovoltaic Power Systems - Part 1: General Electrical Table 802.2.1 Requirements

(portions of table not shown remain unchanged)

Note:UL 1699B, UL 1703, UL 1741, UL 2703, UL 3703, UL 4703, UL 6703, UL 61730-1, UL 61730-2 and UL 62109-1 meet the requirements for mandatory referenced standards in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

Note: UL 8703 does not meet the requirements for a consensus referenced standard in accordance with Section 15.2 of IAPMO's Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

TABLE 901.2 STANDARDS, PUBLICATIONS, PRACTICES, AND GUIDES DOCUMENT NUMBER DOCUMENT TITLE APPLICATION UL 4703-2014 Photovoltaic Wire Electrical Connectors for Use in Photovoltaic Systems UL 6703-2014 Electrical (with revisions through March 2, 2017) Outline of Investigation for Concentrator UL 8703-2011 Electrical Photovoltaic Modules and Assemblies

(portions of table not shown remain unchanged)

SUBSTANTIATION: The USHGC requires that all equipment associated with a PV system must be listed or field labeled; however, the USHGC falls short on identifying the applicable safety standards. The 2017 National Electrical Code (NEC) includes Annex A (Product Safety Standards) which provides product safety standards used for product listing where that listing is required by the NEC. Since the majority of Chapter 8 (Solar Photovoltaic Systems) is extracted material without the extraction of Annex A, the information that is necessary for the AHJ to determine approval of the product is not available within this code.

129 COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

130 Proposals

Edit Proposal

Item #: 063

USHGC 2021 Section: Table 901.1, Table 901.2

SUBMITTER: Connor Barbaree ASHRAE

RECOMMENDATION: Revise text

TABLE 901.1 REFERENCED STANDARDS STANDARD REFERENCED STANDARD TITLE APPLICATION NUMBER SECTIONS ASHRAE 194- Method of Test for Direct-Expansion Ground-Source Heat Ground-Source 707.1 20122017 Pumps Heat Pumps

(portions of table not shown remain unchanged)

Note: ASHRAE 194 meets the requirements for a mandatory reference standard in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

TABLE 901.2 STANDARDS, PUBLICATIONS, PRACTICES, AND GUIDES DOCUMENT NUMBER DOCUMENT TITLE APPLICATION ASHRAE 90.1-20132016 Energy Standard for Buildings Except Low-Rise Residential Buildings Energy

(portions of table not shown remain unchanged)

SUBSTANTIATION: The above revisions reflect the latest updates to the ASHRAE standards that are referenced in Table 901.1 and Table 901.2.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

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Item #: 064

USHGC 2021 Section: Table 901.1, Table 901.2

SUBMITTER: Carlton Ramcharran/Angel Guzman ASME

RECOMMENDATION: Revise text

TABLE 901.1 REFERENCED STANDARDS REFERENCED STANDARD NUMBER STANDARD TITLE APPLICATION SECTIONS ASME B1.20.1-2013 409.2(3), 409.4(7), Pipe Threads, General Purpose (Inch) Joints (R2018) 409.11(3), 409.12(2) Pipe Flanges and Flanged Fittings: NPS ½ ASME B16.5-20132017 Fittings Table 408.1 tThrough NPS 24 Metric/Inch ASME B16.9-20122018 Factory-Made Wrought Buttwelding Fittings Fittings Table 408.1 Cast Copper Alloy Threaded Fittings: Classes ASME B16.15-20132018 Fittings Table 408.1 125 and 250 Cast Copper Alloy Solder Joint Pressure ASME B16.18-20122018 Fittings Table 408.1 Fittings Wrought Copper and Copper Alloy Solder- ASME B16.22-20132018 Fittings 703.6, Table 408.1 Joint Pressure Fittings Cast Copper Alloy Fittings for Flared Copper ASME B16.26-20132018 Fittings Table 408.1 Tubes Wrought Copper and Wrought Copper Alloy ASME B16.29-20122017 Fittings Table 408.1 Solder-Joint Drainage Fittings – DWV Copper and Copper Alloy Press-Connect ASME B16.51-20132018 Fittings Table 408.1 Pressure Fittings ASME BPVC Section Rules for Construction of Pressure Vessels 407.3, 601.2.1, Miscellaneous VIII.1-20152017 Division 1 603.6, 605.3 Pressure Vessel ASME BPVC Section X- Fiber-Reinforced Plastic Pressure Vessels Construction, 603.6 20152017 Pressure Vessels

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Note: The ASME standards meet the requirements for mandatory reference standards in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

132 TABLE 901.2 STANDARDS, PUBLICATIONS, PRACTICES, AND GUIDES DOCUMENT NUMBER DOCUMENT TITLE APPLICATION ASME B16.34-2013 2017 Valves – Flanged, Threaded, and Welding End Valves Large Diameter Steel Flanges: NPS 26 Through NPS 60 ASME B16.47-2011 2017 Fittings Metric/Inch ASME BPVC Section IV-2015 Rules for Construction of Heating Boilers Miscellaneous 2017 ASME BPVC Section IX-2015 Welding, Brazing, and Fusing Qualifications Certification 2017

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SUBSTANTIATION: The above revisions reflect the latest updates to the ASME standards that are referenced in Table 901.1 and Table 901.2.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

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Item #: 065

USHGC 2021 Section: Table 901.1, Table 901.2

SUBMITTER: Steve Mawn ASTM

RECOMMENDATION: Revise text

TABLE 901.1 REFERENCED STANDARDS REFERENCED STANDARD NUMBER STANDARD TITLE APPLICATION SECTIONS ASTM A53/A53M-2012 2018 Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Piping Table 408.1 Welded and Seamless ASTM A106/A106M- Seamless Carbon Steel Pipe for High-Temperature Piping Table 408.1 2015 2018 Service ASTM A312/A312M- Seamless, Welded, and Heavily Cold Worked AusteniticPiping Table 408.1 2017 2018a Stainless Steel Pipes ASTM B135/B135M- Seamless Brass Tube Piping Table 408.1 2010 2017 ASTM B251/B251M- General Requirements for Wrought Seamless Copper Piping Table 408.1 20102017 and Copper-Alloy Tube ASTM B280-20162018 Seamless Copper Tube for Air Conditioning and Piping 703.6 Refrigeration Field Service ASTM B302-20122017 Threadless Copper Pipe, Standard Sizes Piping Table 408.1 ASTM B813-20102016 Liquid and Paste Fluxes for Soldering of Copper and Joints 409.4(6) Copper Alloy Tube ASTM C411-20112019 Hot-Surface Performance of High-Temperature Duct Coverings 502.4.1 Thermal Insulation and Linings ASTM D1785-20152015e1 Poly(Vinyl Chloride) (PVC) Plastic Pipe, Schedules 40, Piping Table 408.1 80, and 120 ASTM D2466-20152017 Poly(Vinyl Chloride) (PVC) Plastic Pipe Fittings, Fittings Table 408.1 Schedule 40 ASTM D2513-2016a2018a Polyethylene (PE) Gas Pressure Pipe, Tubing, and Piping Table 408.1 Fittings ASTM D2564-2012(R2018) Solvent Cements for Poly(Vinyl Chloride) (PVC) Joints 409.11(2) Plastic Piping Systems ASTM Chlorinated Poly(Vinyl Chloride) (CPVC) Plastic Hot- Piping 409.2(2), D2846/D2846M- 20142019a and Cold-Water Distribution Systems 409.3(2), Table 408.1 ASTM E84-20162019a Surface Burning Characteristics of Building Materials Miscellaneous 401.2, 502.4, 503.1, 606.5

134 ASTM F438-20152017 Socket-Type Chlorinated Poly(Vinyl Chloride) (CPVC) Fittings Table 408.1 Plastic Pipe Fittings, Schedule 40 ASTM F876-2015a2017 Crosslinked Polyethylene (PEX) Tubing Piping 409.5, 703.5.2, Table 408.1 ASTM F877-2011a2018a Crosslinked Polyethylene (PEX) Hot- and Cold-Water Piping Table 408.1 Distribution Systems ASTM F1281-20112017 Crosslinked Polyethylene/-Aluminum/Crosslinked Piping Table 408.1 Polyethylene (PEX-AL-PEX) Pressure Pipe ASTM F1807-20172019 Fittings Table 408.1 Metal Insert Fittings Utilizing a Copper Crimp Ring, or Alternate Stainless Steel Clamps, for SDR9 Cross- linked Polyethylene (PEX) Tubing and SDR9 Polyethylene of Raised Temperature (PE-RT) Tubing

ASTM F1960-20152018a Cold Expansion Fittings with PEX Reinforcing Rings Fittings 703.5.2, for Use with Cross-linked Polyethylene (PEX) and 703.5.2.1(3), Polyethylene of Raised Temperature (PE-RT) Tubing Table 408.1 ASTM F1961-2009 Metal Mechanical Cold Flare Compression Fittings Fittings Table 408.1 with Disc Spring for Crosslinked Polyethylene (PEX) Tubing(WITHDRAWN) ASTM F2080-20162018 Cold-Expansion Fittings with Metal Compression- Fittings 703.5.2, Sleeves for Cross-linked Polyethylene (PEX) Pipe and 703.5.2.1(2), SDR9 Polyethylene of Raised Temperature (PE-RT) Table 408.1 Pipe ASTM F2098-20152018 Stainless Steel Clamps for Securing SDR9 Cross-linked Fittings Table 408.1 Polyethylene (PEX) Tubing and SDR9 Polyethylene of Raised Temperature (PE-RT) to Metal Insert and Plastic Insert Fittings ASTM F2159-20142019 Fittings Table 408.1 Plastic Insert Fittings Utilizing a Copper Crimp Ring, or Alternate Stainless Steel Clamps for SDR9 Cross-linked Polyethylene (PEX) Tubing and SDR9 Polyethylene of Raised Temperature (PE-RT) Tubing

ASTM F2262-2009 Crosslinked Polyethylene/ Aluminum/ Crosslinked Piping, Plastic Table 408.1 Polyethylene Tubing OD Controlled SDR9(WITHDRAWN) ASTM F2434-20142018 Metal Insert Fittings Utilizing a Copper Crimp Ring for Pipe Fittings 409.6(1), Table SDR9 Cross-linked Polyethylene (PEX) Tubing and 408.1 SDR9 Cross-linked Polyethylene/Aluminum/Cross- linked Polyethylene (PEX-AL-PEX) Tubing ASTM F2735- Plastic Insert Fittings for SDR9 Cross-linked Fittings Table 408.1 2009(R2016) 2018 Polyethylene (PEX) and Polyethylene of Raised Temperature (PE-RT) Tubing ASTM F2769-20162018 Polyethylene of Raised Temperature (PE-RT) Plastic Piping, Fitting Table 408.1 Hot and Cold-Water Tubing and Distribution Systems

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Note: The ASTM standards meet the requirements for mandatory reference standards in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

135 TABLE 901.2 STANDARDS, PUBLICATIONS, PRACTICES, AND GUIDES DOCUMENT NUMBER DOCUMENT TITLE APPLICATION ASTM A377-2003 (R2014)2018 Ductile- Iron Pressure Pipe Piping, Ferrous ASTM D93-2016a2018 Flash Point by Pensky-Martens Closed Cup Tester Testing ASTM D635-20142018 Rate of Burning and/or Extent and Time of Burning of Plastics Testing in a Horizontal Position

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SUBSTANTIATION: The above revisions reflect the latest updates to the ASTM standards that are referenced in Table 901.1 and Table 901.2.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

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Item #: 066

USHGC 2021 Section: Table 901.1

SUBMITTER: Peter Portela American Welding Society (AWS)

RECOMMENDATION: Revise text

TABLE 901.1 REFERENCED STANDARDS REFERENCED STANDARD NUMBER STANDARD TITLE APPLICATION SECTIONS AWS A5.8M/A5.8-2011- Filler Metals for Brazing and Braze Welding Joints 409.4(1), 703.6, 703.7 AMD 1

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Note: AWS A5.8M meets the requirements for a mandatory reference standard in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

SUBSTANTIATION: The above revision reflects the latest update to the AWS standard that is referenced in Table 901.1.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

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Item #: 067

USHGC 2021 Section: Table 901.2

SUBMITTER: Paul Olson American Water Works Association (AWWA)

RECOMMENDATION: Revise text

TABLE 901.2 STANDARDS, PUBLICATIONS, PRACTICES, AND GUIDES DOCUMENT NUMBER DOCUMENT TITLE APPLICATION Ball Valves, 6 iIn. through 60 iIn. (150 mm tThrough 1,500 AWWA C507-2015 2018 Valves mm)

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SUBSTANTIATION: The above revision reflects the latest update to AWWA C507 that is referenced in Table 901.2.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

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Item #: 068

USHGC 2021 Section: Table 901.2

SUBMITTER: Ed Tsang BSI

RECOMMENDATION: Revise text

TABLE 901.2 STANDARDS, PUBLICATIONS, PRACTICES, AND GUIDES DOCUMENT DOCUMENT TITLE APPLICATION NUMBER Thermal Solar Systems and Components – Solar Collectors – Part 2: BS EN 12975-2- Test Methods Solar Energy – Solar Thermal Collectors – Test Collector 2006 ISO 9806-2017 Methods

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SUBSTANTIATION: The above revision reflects the latest update to the BSI standard that is referenced in Table 901.2.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

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Item #: 069

USHGC 2021 Section: Table 901.1

SUBMITTER: Nikki Kidd Canadian Standards Association (CSA)

RECOMMENDATION: Revise text

TABLE 901.1 REFERENCED STANDARDS STANDARD REFERENCED STANDARD TITLE APPLICATION NUMBER SECTIONS Design and Installation of Ground Source Heat Pump CSA/IGSHPA 703.3, 703.4, Systems Miscellaneous C448-2016 703.4.2 for Commercial and Residential Buildings Gas Water Heaters, Volume I, Storage Water Heaters with CSA Z21.10.1- Fuel Gas, Input Ratings of 75,000 Btu Per Hour or Less (same as CSA Table 403.2 20142017 Appliances 4.1) Gas-Fired Water Heaters, Volume III, Storage Water Heaters CSA Z21.10.3- Fuel Gas, with Input Ratings Above 75,000 Btu Per Hour, Circulating Table 403.2 20152017 Appliances and Instantaneous (same as CSA 4.3)

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Note: CSA/IGSHPA C448, CSA Z21.10.1 and CSA Z21.10.3 meet the requirements for mandatory reference standards in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

SUBSTANTIATION: The above revisions reflect the latest updates to the CSA standards that are referenced in Table 901.1.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

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Item #: 070

USHGC 2021 Section: Table 901.2

SUBMITTER: Kyle Thompson IAPMO

RECOMMENDATION: Revise text

TABLE 901.2 STANDARDS, PUBLICATIONS, PRACTICES, AND GUIDES DOCUMENT NUMBER DOCUMENT TITLE APPLICATION IAPMO PS-117-20162018 Press and Nail Connections Fittings

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SUBSTANTIATION: The above revision reflects the latest update to the IAPMO standard that is referenced in Table 901.2.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

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Item #: 071

USHGC 2021 Section: Table 901.2

SUBMITTER: Anasthasie Sainvilus IEEE

RECOMMENDATION: Revise text

TABLE 901.2 STANDARDS, PUBLICATIONS, PRACTICES, AND GUIDES

DOCUMENT DOCUMENT TITLE APPLICATION NUMBER Interconnection and Interoperability of Interconnecting Distributed Energy Connections, IEEE 1547-20032018 Resources with Associated Electric Power Systems Interfaces Photovoltaic

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SUBSTANTIATION: The above revision reflects the latest update to the IEEE standard that is referenced in Table 901.2.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

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Item #: 072

USHGC 2021 Section: Table 901.2

SUBMITTER: David Thompson Manufacturers Standardization Society (MSS)

RECOMMENDATION: Revise text

TABLE 901.2 STANDARDS, PUBLICATIONS, PRACTICES, AND GUIDES DOCUMENT DOCUMENT TITLE APPLICATION NUMBER Pipe Hangers and Supports – Materials, Design, Manufacture, MSS SP-58-20092018 Fuel Gas Selection, Application, and Installation

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SUBSTANTIATION: The above revision reflects the latest update to the MSS standard that is referenced in Table 901.2.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

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Item #: 073

USHGC 2021 Section: Table 901.1, Table 901.2

SUBMITTER: Heath Dehn National Fire Protection Association (NFPA)

RECOMMENDATION: Revise text

TABLE 901.1 REFERENCED STANDARDS

STANDARD STANDARD TITLE APPLICATION REFERENCED SECTIONS NUMBER 315.1, 801.1, 804.1, 806.4, 807.2, 810.1.3, 811.1.4, 812.1, 812.2.1, 812.3, 812.5, 812.6, 812.7.5(8), 812.7.5(11), NFPA 70-20142017 National Electrical Code Miscellaneous 812.7.5(12), 812.8, 818.2, 818.3(1), 819.1, 819.1.2, 821.2, 821.2.2, 821.3, 821.3.9(3), 828.1, 829.1, 832.2, 832.4, B 104.1, C 101.9(7)

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TABLE 901.2 STANDARDS, PUBLICATIONS, PRACTICES, AND GUIDES

DOCUMENT NUMBER DOCUMENT TITLE APPLICATION NFPA 54/Z223.1-20152018 National Fuel Gas Code Fuel Gas

Test Method to Evaluate Fire Performance Characteristics of Pipe NFPA 274-20132018 Pipe Insulation Insulation

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SUBSTANTIATION: The above revisions reflect the latest updates to the NFPA standards that are referenced in Table 901.1 and Table 901.2.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

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Item #: 074

USHGC 2021 Section: Table 901.1, Table 901.2

SUBMITTER: Jeremy Brown NSF International (NSF)

RECOMMENDATION: Revise text

TABLE 901.1 REFERENCED STANDARDS STANDARD REFERENCED STANDARD TITLE APPLICATION NUMBER SECTIONS NSF 60-20162017 Drinking Water Treatment Chemicals - Health Effects Backfill 703.4.1 NSF 61-20162018 Drinking Water System Components - Health Effects Miscellaneous 501.5.4 Polypropylene Pipe and Fittings for Water-Based NSF 358-2-20122017 Piping, Fittings Table 408.1 Ground-Source “Geothermal” Heat Pump Systems

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Note: NSF 60, NSF 61 and NSF 358-2 meet the requirements for mandatory reference standards in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

TABLE 901.2 STANDARDS, PUBLICATIONS, PRACTICES, AND GUIDES STANDARD STANDARD TITLE APPLICATION NUMBER NSF 14-2016a2018 Plastic Piping System Components and Related Materials Piping, Plastic

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SUBSTANTIATION: The above revisions reflect the latest updates to the NSF standards that are referenced in Table 901.1 and Table 901.2.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

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Item #: 075

USHGC 2021 Section: Table 901.1, Table 901.2

SUBMITTER: Christopher Jensen UL LLC

RECOMMENDATION: Revise text

TABLE 901.1 REFERENCED STANDARDS DOCUMENT REFERENCED DOCUMENT TITLE APPLICATION NUMBER SECTIONS UL 723-2008 Test for Surface Burning Characteristics of Building 401.2, 502.4, Miscellaneous 2018 Materials (with revisions through August 12, 2013) 503.1, 606.5 Motor-Operated Water Pumps (with revisions through UL 778-2016 Pumps 310.1 February 22, 2017 January 17, 2019) Heating, Water Supply, and Power Boilers - Electric (with UL 834-2004 Appliances Table 403.2 revisions through December 9, 2013 September 24, 2018) Flat-Plate Photovoltaic Modules and Panels (with revisions UL 1703-2002 Electrical 802.6 through March 10, 2017 September 26, 2018) Inverters, Converters, Controllers and Interconnection System Equipment for Use With Distributed Energy UL 1741-2010 Electrical 831.1 Resources (with revisions through September 7, 2016 February 15, 2018) Solid Fuel-Fired Hydronic Heating Appliances, Water Fuel Gas, UL 2523-2009 Heaters, and Boilers (with revisions through February 8, Table 403.2 Appliances 2013 March 16, 2018)

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Note: The UL standards meet the requirements for mandatory reference standards in accordance with Section 15.0 of IAPMO’s Regulations Governing Consensus Development of the Uniform Solar, Hydronics & Geothermal and Swimming Pool, Spa & Hot Tub Codes.

TABLE 901.2 STANDARDS, PUBLICATIONS, PRACTICES, AND GUIDES DOCUMENT DOCUMENT TITLE APPLICATION NUMBER Electric Booster and Commercial Storage Tank Water Heaters (with UL 1453-2016 Appliances revisions through March 9, 2017 May 18, 2018) Connectors for Use in Photovoltaic Systems (with revisions through March UL 6703-2014 Electrical 2, 2017 December 22, 2017)

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146 SUBSTANTIATION: The above revisions reflect the latest updates to the Underwriters Laboratories, Inc. (UL) standards that are referenced in Table 901.1 and Table 901.2.

COMMITTEE ACTION: ACCEPT AS SUBMITTED

TOTAL ELIGIBLE TO VOTE: 16

VOTING RESULTS: AFFIRMATIVE: 16

147

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TABLE OF CONTENTS Note: Page numbers and section numbers will be updated before publishing.

CHAPTER 1 ADMINISTRATION ...... 1 107.2 Limitations of Authority ...... 5 101.0 General ...... 1 Table 104.5 System Permit Fees ...... 6 101.1 Title ...... 1 101.2 Scope ...... 1 CHAPTER 2 DEFINITIONS ...... 7 101.3 Purpose ...... 1 201.0 General ...... 7 101.4 Unconstitutional ...... 1 201.1 Applicability ...... 7 101.5 Validity ...... 1 202.0 Definition of Terms ...... 7 102.0 Applicability ...... 1 202.1 General ...... 7 102.1 Conflicts Between Codes ...... 1 202.2 Terms Defined in Other Documents ...... 7 102.2 Existing Installation ...... 1 102.3 Maintenance ...... 1 CHAPTER 3 GENERAL REGULATIONS ...... 15 102.4 Additions, Alterations, Renovations, or Repairs ...... 1 301.0 General ...... 15 102.5 Health and Safety ...... 1 301.1 Applicability ...... 15 102.6 Changes in Building Occupancy . . . .1 302.0 Standards and Alternates ...... 15 102.7 Moved Structures ...... 1 302.1 Minimum Standards ...... 15 102.8 Appendices ...... 1 302.2 Alternate Materials and Methods of Construction 103.0 Duties and Powers of the Equivalency ...... 15 Authority Having Jurisdiction ...... 1 302.3 Flood Hazard Areas ...... 15 103.1 General ...... 1 302.4 Alternative Engineered 103.2 Liability ...... 2 Design ...... 16 103.3 Applications and Permits ...... 2 303.0 Iron Pipe Size (IPS) Pipe ...... 16 103.4 Right of Entry ...... 2 303.1 General ...... 16 104.0 Permits ...... 2 304.0 Accessibility for Service ...... 16 104.1 Permits Required ...... 2 304.1 General ...... 16 104.2 Exempt Work ...... 2 304.2 Access to Appliances 104.3 Application for Permit ...... 2 on Roofs ...... 16 104.4 Permit Issuance ...... 3 304.3 Appliances in Attics and 104.5 Fees ...... 3 Under-Floor Spaces ...... 17 105.0 Inspections and Testing ...... 4 304.4 Appliances on Roofs ...... 17 105.1 General ...... 4 305.0 Installation ...... 17 105.2 Required Inspection ...... 4 305.1 Listed Appliances ...... 17 105.3 Testing of Systems ...... 5 305.2 Dissimilar Metals ...... 17 105.4 Connection to Service Utilities . . . . .5 305.3 Direction of Flow ...... 17 106.0 Violations and Penalties ...... 5 305.4 Changes in Direction ...... 17 106.1 General ...... 5 305.5 Improper Location ...... 18 106.2 Notices of Correction or Violation . . .5 305.6 Insulation ...... 18 106.3 Penalties ...... 5 305.7 Drainage Pan ...... 18 106.4 Stop Orders ...... 5 305.8 Anchorage ...... 18 106.5 Authority to Disconnect 305.9 Structural Design Loads ...... 18 Utilities in Emergencies ...... 5 305.10 Location ...... 18 106.6 Authority to Condemn ...... 5 305.11 Ownership ...... 18 107.0 Board of Appeals ...... 5 306.0 Workmanship ...... 18 107.1 General ...... 5 306.1 Engineering Practices ...... 18

UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT xv TABLE OF CONTENTS

306.2 Concealing Imperfections ...... 18 312.5 Pressure Reducing Valves ...... 21 306.3 Burred Ends ...... 18 312.6 Equipment, Components, 306.4 Installation Practices ...... 18 and Appliances ...... 21 307.0 Labeling ...... 18 312.7 Expansion Tanks ...... 21 307.1 Fuel-Burning Appliances ...... 18 312.8 Flow Balancing Valves ...... 21 307.2 Electric Heating Appliances ...... 18 312.9 Control Valves ...... 21 307.3 Heat Pump and Electric 312.10 Thermosiphoning ...... 21 Cooling Appliances ...... 18 312.11 Air Removal Device 307.4 Absorption Units ...... 19 or Air Vents ...... 21 308.0 Condensate Wastes 312.12 Closed Loop Systems ...... 21 and Control ...... 19 312.13 Fullway Valves ...... 21 308.1 Condensate Disposal ...... 19 312.14 Accessible ...... 21 308.2 Condensate Control ...... 19 313.0 Heat Exchangers ...... 21 308.3 Condensate Waste Pipe 313.1 General ...... 21 Material and Sizing ...... 19 314.0 Unlawful Connections ...... 22 Table 308.3 Minimum Condensate 314.1 Prohibited Installation ...... 22 Pipe Size ...... 19 315.0 Electrical ...... 22 308.4 Appliance Condensate 315.1 Wiring ...... 22 Drains ...... 20 315.2 Controls ...... 22 308.5 Point of Discharge ...... 20 315.3 Solar Photovoltaic 308.6 Condensate Waste from (PV) Systems ...... 22 Air-Conditioning Coils ...... 20 316.0 Disposal of Liquid Waste ...... 22 308.7 Plastic Fittings ...... 20 316.1 General ...... 22 309.0 Safety Requirements ...... 20 316.2 Connections to Drainage 309.1 Welding ...... 20 System Required ...... 22 309.2 Spark or Flame ...... 20 316.3 Drainage ...... 22 309.3 Hazardous Heat-Transfer 316.4 Nonpotable Discharge ...... 22 Mediums ...... 20 317.0 Hangers and Supports ...... 22 309.4 Discharge ...... 20 317.1 General ...... 22 310.0 Circulators and Pumps ...... 20 317.2 Material ...... 22 310.1 General ...... 20 317.3 Suspended Piping ...... 22 310.2 Mounting ...... 20 317.4 Alignment ...... 22 310.3 Sizing ...... 20 317.5 Underground Installation ...... 22 310.4 Drainback Systems ...... 20 317.6 Hanger Rod Sizes ...... 22 310.5 Pumps Used in Parallel ...... 20 Table 317.6 Hanger Rod Sizes ...... 22 310.6 Cavitation ...... 20 317.7 Strength ...... 22 310.7 Materials ...... 20 318.0 Protection of Piping, 310.8 Operation ...... 20 Materials, and Structures ...... 22 311.0 Safety Devices ...... 20 318.1 General ...... 22 311.1 General ...... 20 Table 317.3 Hangers and Supports ...... 23 311.2 Pressurized Vessels ...... 21 318.2 Installation ...... 23 311.3 Discharge Piping ...... 21 318.3 Fire-Resistant Construction ...... 23 311.4 Vacuum Relief Valves ...... 21 318.4 Waterproofing of Openings ...... 23 311.5 Temperature Regulation ...... 21 318.5 Steel Nail Plates ...... 23 312.0 Valves ...... 21 318.6 Sleeves ...... 23 312.1 General ...... 21 318.7 Firewalls ...... 24 312.2 Where Required ...... 21 318.8 Structural Members ...... 24 312.3 Heat Exchanger ...... 21 318.9 Rodentproofing ...... 24 312.4 Pressure Vessels ...... 21 318.10 Metal Collars ...... 24 xvi UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT TABLE OF CONTENTS

319.0 Protection of System 404.7 Heat Transfer Fluid ...... 26 Components ...... 24 405.0 Installation, Testing, 319.1 Materials ...... 24 and Inspection ...... 26 319.2 Corrosion ...... 24 405.1 Operating Instructions ...... 26 319.3 Mechanical Damage ...... 24 405.2 Pressure Testing ...... 26 320.0 Trenching, Excavation, 405.3 Flushing ...... 26 and Backfill ...... 24 405.4 Oxygen Diffusion Corrosion ...... 26 320.1 Trenches ...... 24 406.0 Heating Appliances 320.2 Tunneling and Driving ...... 24 and Equipment ...... 26 320.3 Open Trenches ...... 24 406.1 General ...... 26 320.4 Excavations ...... 24 406.2 Boilers ...... 26 321.0 Abandonment ...... 24 406.3 Dual-Purpose Water Heaters . . . . .26 321.1 General ...... 24 406.4 Solar Heat Collector Systems . . . . .26 321.2 Storage Tank ...... 24 407.0 Expansion Tanks ...... 26 322.0 Other Systems ...... 24 407.1 General ...... 26 322.1 General ...... 24 407.2 Installation ...... 27 322.2 Duct Systems ...... 24 407.3 Closed-Type Expansion Tanks ...... 27 CHAPTER 4 HYDRONICS ...... 25 407.4 Open-Type 401.0 General ...... 25 Expansion Tanks ...... 27 401.1 Applicability ...... 25 408.0 Materials ...... 27 401.2 Insulation ...... 25 408.1 Pipe, Tube, Tubing, and Fittings ...... 27 401.3 Water Hammer Protection ...... 25 408.2 Expansion and Contraction ...... 27 401.4 Manifolds ...... 25 408.3 Hangers and Supports ...... 27 401.5 Heat Emitters ...... 25 409.0 Joints and Connections ...... 27 401.6 Mechanical Devices ...... 25 409.1 General ...... 27 401.7 Flexible Connectors ...... 25 409.2 Chlorinated Polyvinyl 401.8 Freeze Protection ...... 25 Chloride (CPVC) Pipe ...... 27 402.0 Protection of Potable 409.3 CPVC/AL/CPVC Plastic Water Supply ...... 25 Pipe and Joints ...... 27 402.1 Prohibited Sources ...... 25 Table 408.1 Materials for Hydronics 402.2 Protection of Potable Water ...... 25 and Solar Thermal System, 402.3 Compatibility ...... 25 Piping, Tubing, and Fittings ...... 28 403.0 Capacity of Heat Source ...... 25 409.4 Copper or Copper 403.1 Heat Source ...... 25 Alloy Pipe and Tubing ...... 28 403.2 Dual Purpose Water Heater ...... 25 409.5 Cross-Linked Polyethylene (PEX) Pipe ...... 29 Table 403.2 Water Heaters ...... 25 409.6 Cross-Linked 403.3 Tankless Water Heater ...... 25 Polyethylene/Aluminum/ 404.0 Identification of Cross-Linked Polyethylene Piping Systems ...... 25 (PEX-AL-PEX) Pipe ...... 29 404.1 General ...... 25 409.7 Polyethylene (PE) 404.2 Color and Information ...... 25 Plastic Pipe/Tubing ...... 29 404.3 Potable Water ...... 25 409.8 Polyethylene/Aluminum/ Table 404.3 Minimum Length of Color Polyethylene (PE-AL-PE) ...... 30 Field and Size of Letters ...... 26 409.9 Polyethylene of Raised 404.4 Nonpotable Water ...... 26 Temperature (PE-RT) ...... 30 404.5 Location of Piping 409.10 Polypropylene (PP) Pipe ...... 30 Identification ...... 26 409.11 Polyvinyl Chloride (PVC) Pipe . . . . .30 404.6 Flow Directions ...... 26 409.12 Steel Pipe and Tubing ...... 30

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409.13 Joints Between 415.1 General ...... 34 Different Materials ...... 31 416.0 Snow and Ice Melt 410.0 System Controls ...... 31 Systems ...... 34 410.1 Water Temperature Controls ...... 31 416.1 Snow and Ice Melt 410.2 Operating Steam Controls ...... 31 Controls ...... 34 410.3 Occupied Spaces ...... 31 Table 416.1.1 Maximum Loop Lengths for Snow and Ice Melt 410.4 Return-Water Systems ...... 34 Low-Temperature Protection ...... 31 416.2 Types of Tube 410.5 Simultaneous Operation ...... 31 Fasteners ...... 35 410.6 Temperature Reading ...... 31 416.3 Spacing of Tube 411.0 Pressure and Flow Controls ...... 31 Fasteners ...... 35 411.1 Balancing ...... 31 417.0 Piping Installation ...... 35 411.2 Low-Water Control ...... 31 417.1 General ...... 35 411.3 Flow-Sensing Devices ...... 31 417.2 Embedded Piping 411.4 Automatic Makeup Fluid ...... 31 Materials and Joints ...... 35 411.5 Differential Pressure 417.3 Pressure Testing ...... 35 Regulation ...... 31 417.4 System Drainage ...... 35 411.6 Air-Removal Device ...... 32 417.5 Clearance to Combustibles ...... 35 411.7 Air-Separation Device ...... 32 411.8 Secondary Loops ...... 32 CHAPTER 5 SOLAR THERMAL 412.0 Hydronic Space Heating ...... 32 SYSTEMS ...... 37 412.1 General ...... 32 501.0 General ...... 37 412.2 Installation ...... 32 501.1 Applicability ...... 37 412.3 Balancing ...... 32 501.2 Connections ...... 37 412.4 Heat Transfer Fluid ...... 32 501.3 Stagnation Condition ...... 37 413.0 Steam Systems ...... 32 501.4 Draining ...... 37 413.1 Steam Traps ...... 32 501.5 Materials ...... 37 413.2 Sloping for Two-Pipe System . . . . .32 501.6 Thermosiphon Systems ...... 37 413.3 Sloping for One-Pipe System . . . . .32 501.7 Drainback Systems ...... 37 413.4 Automatic Air Vents ...... 32 501.8 Auxiliary Heating ...... 37 413.5 Condensate Flow ...... 32 501.9 Automatic Air Vents ...... 37 413.6 Steam-Distribution Piping ...... 32 501.10 Waterproofing ...... 37 414.0 Radiant Heating and Cooling . . . . .32 501.11 Protection ...... 37 414.1 Installation ...... 32 501.12 Freeze Protection ...... 37 414.2 Radiant Floor Heating ...... 32 501.13 Circulators ...... 38 414.3 Radiant Cooling Systems ...... 32 501.14 Protection Against Decay ...... 38 414.4 Tube Placement ...... 32 501.15 Flash Points ...... 38 Table 414.4 Maximum Loop Lengths 501.16 Storage Tanks ...... 38 of Continuous Tubing 502.0 Solar Collectors ...... 38 for Radiant Systems ...... 33 502.1 General ...... 38 414.5 Poured Floor Structural 502.2 Fire Safety Requirements ...... 38 Concrete Slab Systems ...... 33 502.3 Flat Plate Collector Glass ...... 38 414.6 Joist Systems and Subfloors ...... 33 502.4 Air Collectors ...... 38 414.7 Wall and Ceiling Panels ...... 33 502.5 Installation ...... 38 414.8 Tubing Fasteners ...... 33 502.6 Listing ...... 38 414.9 Radiant Heating and Cooling Panels ...... 34 503.0 Insulation ...... 39 415.0 Indirect-Fired Domestic 503.1 General ...... 39 Hot-Water Storage Tanks ...... 34 503.2 Heat Loss ...... 39 xviii UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT TABLE OF CONTENTS

503.3 Piping ...... 39 605.0 Expansion Tanks ...... 46 503.4 Fittings ...... 39 605.1 Where Required ...... 46 503.5 Installation ...... 39 605.2 Systems with Open 503.6 Ducts ...... 39 Type Expansion Tanks ...... 46 504.0 Testing ...... 39 605.3 Closed-Type Systems ...... 46 504.1 Piping ...... 39 605.4 Minimum Capacity of Closed-Type Tank ...... 46 504.2 System Requirements ...... 39 Table 605.4(1) Expansion Tank Capacities 505.0 Swimming Pools, for Gravity Hot Water Systems . . . .46 Spas, and Hot Tubs ...... 39 Table 605.4(2) Expansion Tank Capacities 505.1 Water Chemistry ...... 39 for Forced Water Systems ...... 47 505.2 Parameters ...... 39 606.0 Dry Storage Systems ...... 47 Table 503.3(1) Minimum Pipe Insulation ...... 39 606.1 Waterproofing ...... 47 Table 505.2 Water Chemistry ...... 40 606.2 Detecting Water Intrusion ...... 47 505.3 Filter ...... 40 606.3 Rock as Storage Material ...... 47 505.4 Corrosion Resistant ...... 40 606.4 Odor and Particulate Control ...... 47 Table 503.3(2) Iron Pipe and Copper Tubing 606.5 Combustibles Within Insulation Thickness ...... 41 Ducts or Plenums ...... 47 Table 503.3(3) Universal Pipe Insulation Thickness Based on Radius and Iron Pipe Size (IPS) ...... 42 CHAPTER 7 GEOTHERMAL ENERGY SYSTEMS ...... 49 Table 503.3(4) Design Values for Thermal Conductivity (k) of Industrial 701.0 General ...... 49 Insulation ...... 43 701.1 Applicability ...... 49 Table 503.6 Insulation of Ducts ...... 44 701.2 Construction Documents ...... 49 701.3 Site Survey ...... 49 CHAPTER 6 THERMAL STORAGE ...... 45 701.4 Decommissioning and 601.0 General ...... 45 Abandonment ...... 49 601.1 Applicability ...... 45 702.0 Groundwater Systems ...... 49 601.2 Test Pressure for 702.1 General ...... 49 Storage Tanks ...... 45 703.0 Design of Systems ...... 49 601.3 Storage Tank Connectors ...... 45 703.1 Ground-Heat Exchanger 602.0 Insulation ...... 45 Design ...... 49 602.1 Thickness ...... 45 703.2 Installation Practices ...... 49 Table 602.1 Minimum Tank Insulation ...... 45 703.3 Verification ...... 50 603.0 Storage Tanks ...... 45 703.4 Vertical Bores ...... 50 603.1 Plans ...... 45 703.5 Underground Piping and 603.2 Atmospheric Tanks ...... 45 Submerged Materials ...... 50 603.3 Prefabricated Tanks ...... 45 703.6 DX Systems ...... 51 603.4 Separate Storage Tanks ...... 45 703.7 Indoor Piping ...... 51 603.5 Underground Tanks ...... 45 704.0 Installation ...... 51 603.6 Pressure Vessels ...... 45 704.1 Trenching, Excavation, and Backfill ...... 51 603.7 Devices ...... 45 704.2 Trenches, Tunneling, 603.8 Tank Covers ...... 46 and Driving ...... 51 604.0 Materials ...... 46 704.3 Excavations and 604.1 General ...... 46 Open Trenches ...... 51 604.2 Construction ...... 46 704.4 Protection of Piping, 604.3 Concrete ...... 46 Materials, and Structures ...... 51 604.4 Metal Tanks ...... 46 704.5 Sleeves ...... 51 604.5 Filler Metal ...... 46 704.6 Steel Nail Plates ...... 51

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705.0 Specific System 805.0 Circuit Sizing and Current ...... 57 Components Design ...... 52 805.1 Calculation of Maximum 705.1 Heat Exchangers ...... 52 Circuit Current ...... 57 705.2 Heat-Transfer Medium ...... 52 805.2 Conductor Ampacity ...... 57 705.3 On Site Storage ...... 52 805.3 Systems with Multiple 705.4 Insulation ...... 52 Direct-Current Voltages ...... 57 706.0 Ground-Heat Exchanger 805.4 Sizing of Module Interconnection Conductors ...... 57 Testing ...... 52 805.5 Standard Ampere Ratings ...... 57 706.1 Testing ...... 52 Table 805.5.1 Standard Ampere Ratings 706.2 DX System Testing ...... 52 for Fuses and Inverse 707.0 Heat Pump and Distribution Time Circuit Breakers ...... 58 System Design ...... 52 806.0 Overcurrent Protection ...... 58 707.1 General ...... 52 806.1 Circuits and Equipment ...... 58 707.2 Heat Pump Distribution 806.2 Overcurrent Device Ratings ...... 58 System ...... 52 806.3 Photovoltaic Source 707.3 Circulating Pumps ...... 52 and Output Circuits ...... 58 707.4 Heat Pump and Distribution System Installation ...... 52 806.4 Power Transformers ...... 58 708.0 System Start-Up ...... 52 807.0 Stand-Alone Systems ...... 58 708.1 General ...... 52 807.1 General ...... 58 708.2 Operation and 807.2 Wiring System ...... 58 Maintenance Manual ...... 53 808.0 Arc-Fault Circuit Protection (Direct Current) ...... 59 CHAPTER 8 SOLAR PHOTOVOLTAIC 808.1 Arc-Fault Circuit SYSTEMS ...... 55 Protection ...... 59 PART I General ...... 55 809.0 Rapid Shutdown of PV Systems on Buildings ...... 59 801.0 General ...... 55 809.1 Reduce Shock Hazard ...... 59 801.1 Electrical Wiring and Equipment ...... 55 PART III Disconnecting Means ...... 60 801.2 Applicability ...... 55 810.0 Disconnecting Means ...... 60 802.0 General Requirements ...... 56 810.1 Photovoltaic System 802.1 Photovoltaic Systems ...... 56 Disconnecting Means ...... 60 802.2 Equipment ...... 56 811.0 Disconnection of Photovoltaic Equipment ...... 61 802.3 Qualified Personnel ...... 56 811.1 Isolating Devices ...... 61 802.4 Multiple PV Systems ...... 56 PART IV Wiring Methods ...... 61 802.5 Locations Not Permitted ...... 56 812.0 Wiring Methods Permitted ...... 61 802.6 Photovoltaic Modules/Panels/ Shingles ...... 56 812.1 Wiring Systems ...... 61 803.0 Alternating-Current (ac) Table 812.1 Correction Factors ...... 61 Modules ...... 56 812.2 Identification and Grouping ...... 61 803.1 Photovoltaic Source Circuits ...... 56 812.3 Single-Conductor Cable ...... 62 803.2 Inverter Output Circuit ...... 56 812.4 Multiconductor Cable ...... 62 PART II Circuit Requirements ...... 56 812.5 Flexible Cords and Cables ...... 62 804.0 Circuit Requirements ...... 56 Table 812.5 Minimum PV Wire Strands ...... 62 804.1 Maximum Voltage ...... 56 812.6 Small-Conductor Cables ...... 62 Table 804.1.1 Voltage Correction Factors for 812.7 Photovoltaic System Crystalline and Multicrystalline Direct-Current Circuits Silicon Modules ...... 56 on or in a Building ...... 62 804.2 Bipolar Source and 812.8 Flexible, Fine-Stranded Output Circuits ...... 57 Cables ...... 64 xx UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT TABLE OF CONTENTS

812.9 Bipolar PV Systems ...... 64 823.1 Directory ...... 68 813.0 Component Interconnections . . . . .64 823.2 Modules ...... 68 813.1 Concealed Fittings 823.3 Format ...... 68 and Connectors ...... 64 824.0 Alternating-Current 814.0 Connectors ...... 64 Photovoltaic Modules ...... 69 814.1 General ...... 64 824.1 Identification ...... 69 815.0 Access to Boxes ...... 64 825.0 Direct-Current Photovoltaic 815.1 Junction, Pull, and Power Source ...... 69 Outlet Boxes ...... 64 825.1 Labeling ...... 69 PART V Grounding and Bonding ...... 64 825.2 Interactive System Point 816.0 Grounding and Bonding ...... 64 of Interconnection ...... 69 816.1 PV System Grounding 826.0 Photovoltaic Systems Configurations ...... 64 Connected to Energy 816.2 Ground-Fault Protection ...... 65 Storage Systems ...... 69 816.3 Ground-Fault Detection ...... 65 826.1 Marking ...... 69 816.4 Isolating Faulted Circuits ...... 65 827.0 Facilities with 817.0 Point of System Stand-Alone Systems ...... 69 Grounding Connection ...... 65 827.1 General ...... 69 817.1 Grounding Connection ...... 65 827.2 Facilities with Utility 818.0 Equipment Grounding Services and and Bonding ...... 65 Photovoltaic Systems ...... 69 818.1 General ...... 65 827.3 Buildings with Rapid Shutdown ...... 69 818.2 Equipment Fastened in Place or Connected by PART VII Connection to Other Permanent Wiring Methods Sources ...... 70 (Fixed) — Grounding ...... 65 828.0 Connection to Other Sources . . . . .70 818.3 Nongrounding Receptacle 828.1 PV Systems ...... 70 Replacement or Branch PART VIII Energy Storage Systems ...... 70 Circuit Extensions ...... 65 829.0 Energy Storage Systems ...... 70 818.4 Equipment Secured to Grounded Metal Supports ...... 66 829.1 General ...... 70 819.0 Size of Equipment 830.0 Batteries ...... 70 Grounding Conductors ...... 66 830.1 Battery Locations ...... 70 819.1 General ...... 66 831.0 Self-Regulating Charge Table 819.1 Minimum Size Equipment Control ...... 70 Grounding Conductors for 831.1 General ...... 70 Grounding Raceway and PART IX Large-Scale Photovoltaic Equipment ...... 66 (PV) Electric Power 820.0 Array Equipment Production Facility ...... 71 Grounding Conductors ...... 67 832.0 Large-Scale Photovoltaic 820.1 PV Modules ...... 67 (PV) Electric Power 821.0 Grounding Electrode System . . . . .67 Production Facility ...... 71 821.1 Electrode System ...... 67 832.1 Scope ...... 71 821.2 Buildings or Structures 832.2 Special Requirements for Supporting a PV Array ...... 67 Large-Scale PV Electric 821.3 Additional Auxiliary Supply Stations ...... 71 Electrodes for Array 832.3 Equipment Approval ...... 71 Grounding ...... 67 832.4 Engineered Design ...... 71 822.0 Equipment Bonding Jumpers . . . . .68 832.5 Conformance of Construction 822.1 Bonding Jumpers ...... 68 to Engineered Design ...... 71 PART VI Marking ...... 68 832.6 Direct Current 823.0 Marking ...... 68 Operating Voltage ...... 71

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832.7 Disconnection of Photovoltaic Equipment ...... 72 832.8 Arc-Fault Mitigation ...... 72 832.9 Fence Grounding ...... 72

CHAPTER 9 REFERENCED STANDARDS . . . .73 901.0 General ...... 73 901.1 Standards ...... 73 Table 901.1 Referenced Standards ...... 73 901.2 Standards, Publications, Practices, and Guides ...... 78 Table 901.2 Standards, Publications, Practices, and Guides ...... 78

APPENDICES TABLE OF CONTENTS ...... 81 Appendix A Engineered Solar Energy Systems ...... 83 Appendix B Solar Photovoltaic System Installation Guidelines ...... 85 Appendix C Supplemental Checklist for Solar Photovoltaic Systems ...... 91

USEFUL TABLES ...... 93

INDEX ...... 97

xxii UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT CHAPTER 1 ADMINISTRATION

101.0 General. 102.4 Additions, Alterations, Renovations, or Repairs. 101.1 Title. This document shall be known as the “Uniform Additions, alterations, renovations or repairs shall Solar, Hydronics and Geothermal Code,” may be cited as conform to that required for a new system without requiring such, and will be referred to herein as “this code.” the existing system to be in accordance with the requirements of this code. Additions, alterations, renovations or repairs 101.2 Scope. The provisions of this code shall apply to the shall not cause an existing system to become unsafe, insani- erection, installation, alteration, addition, repair, relocation, tary, or overloaded. replacement, addition to, use or maintenance of solar energy, water heating, appliances intended for space heating or cool- Additions, alterations, renovations or repairs to existing ing, swimming pool heating, process heating, geothermal and system installations shall comply with the provisions for new hydronic systems, snow and ice melt systems and use of any construction unless such deviations are found to be necessary solar energy systems or swimming pool, spa or hot tub sys- and are first approved by the Authority Having Jurisdiction. tems within this jurisdiction. 102.5 Health and Safety. Where compliance with the pro- 101.3 Purpose. This code is an ordinance providing mini- visions of this code fails to eliminate or alleviate a nuisance, mum requirements and standards for the protection of the or other dangerous or insanitary condition that involves health public health, safety, and welfare. or safety hazards, the owner or the owner’s agent shall install 101.4 Unconstitutional. Where a section, subsection, sen- such additional facilities or shall make such repairs or alter- tence, clause, or phrase of this code is, for a reason, held to be ations as ordered by the Authority Having Jurisdiction. 102.6 Changes in Building Occupancy. unconstitutional, such decision shall not affect the validity of Systems that the remaining portions of this code. The legislative body are a part of a building or structure undergoing a change in hereby declares that it would have passed this code, and each use or occupancy, as defined in the building code, shall be in section, subsection, sentence, clause, or phrase thereof, irre- accordance with the requirements of this code that are appli- spective of the fact that one or more sections, subsections, cable to the new use or occupancy. sentences, clauses, and phrases are declared unconstitutional. 102.7 Moved Structures. Parts of the system of a building 101.5 Validity. Where a provision of this code, or the appli- or part thereof that is moved from one foundation to another, cation thereof to a person or circumstance, is held invalid, the or from one location to another, shall be in accordance with remainder of the code, or the application of such provision to the provisions of this code for new installations and com- other persons or circumstances, shall not be affected thereby. pletely tested as prescribed elsewhere in this section for new work, except that walls or floors need not be removed during 102.0 Applicability. such test where equivalent means of inspection acceptable to the Authority Having Jurisdiction are provided. 102.1 Conflicts Between Codes. Where the requirements 102.8 Appendices. The provisions in the appendices are within the jurisdiction of this code conflict with the require- intended to supplement the requirements of this code and ments of the plumbing or mechanical code, this code shall shall not be considered part of this code unless formally prevail. In instances where this code, applicable standards, or adopted as such. the manufacturer’s installation instructions conflict, the more stringent provisions shall prevail. Where there is a conflict between a general requirement and a specific requirement, 103.0 Duties and Powers of the Authority Having the specific requirement shall prevail. Jurisdiction. 102.2 Existing Installation. Systems lawfully in existence 103.1 General. The Authority Having Jurisdiction shall be at the time of the adoption of this code shall be permitted to the Authority duly appointed to enforce this code. For such have their use, maintenance, or repair continued where the purposes, the Authority Having Jurisdiction shall have the use, maintenance, or repair is in accordance with the original powers of a law enforcement officer. The Authority Having design and location and no hazard to life, health, or property Jurisdiction shall have the power to render interpretations of has been created by such system. this code and to adopt and enforce rules and regulations sup- 102.3 Maintenance. Systems, materials, and appurte- plemental to this code as deemed necessary in order to clar- nances, both existing and new, of a premise under the Author- ify the application of the provisions of this code. Such ity Having Jurisdiction shall be maintained in operating interpretations, rules, and regulations shall comply with the condition. Devices or safeguards required by this code shall intent and purpose of this code. be maintained in accordance with the code edition under In accordance with the prescribed procedures and with which installed. the approval of the appointing authority, the Authority Hav- The owner or the owner’s designated agent shall be ing Jurisdiction shall be permitted to appoint a such number responsible for maintenance of the system. To determine of technical officers, inspectors, and other employees as shall compliance with this subsection, the Authority Having Juris- be authorized from time to time. The Authority Having Juris- diction shall be permitted to cause a system to be reinspected. diction shall be permitted to deputize such inspectors or

UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT 1 ADMINISTRATION

employees as necessary to carry out the functions of the code 104.0 Permits. enforcement agency. 104.1 Permits Required. It shall be unlawful for a person, The Authority Having Jurisdiction shall be permitted to firm, or corporation to make an installation, alteration, repair, request the assistance and cooperation of other officials of this replacement, or remodel a system regulated by this code jurisdiction so far as required for the discharge of the duties except as permitted in Section 104.2, or to cause the same to required by this code or other pertinent law or ordinance. be done without first obtaining a separate permit for each sep- 103.2 Liability. The Authority Having Jurisdiction charged arate building or structure. with the enforcement of this code, acting in good faith and 104.2 Exempt Work. A permit shall not be required for the without malice in the discharge of the Authority Having Juris- following: diction’s duties, shall not thereby be rendered personally (1) The repairing of leaks in pipes, valves, or components, pro- liable for damage that accrues to persons or property as a vided such repairs do not involve or require the replace- result of an act or by reason of an act or omission in the dis- ment or rearrangement of valves, pipes, or components. charge of such duties. A suit brought against the Authority Having Jurisdiction or employee because of such act or omis- (2) Replacement of a component part that does not alter its sion performed in the enforcement of provisions of this code original approval and is in accordance with other appli- shall be defended by legal counsel provided by this jurisdic- cable requirements of this code. tion until final termination of such proceedings. Exemption from the permit requirements of this code 103.3 Applications and Permits. The Authority Having shall be deemed not to grant authorization for work to be done Jurisdiction shall be permitted to require the submission of in violation of the provisions of the code or other laws or ordinances of this jurisdiction. plans, specifications, drawings, and such other information 104.3 Application for Permit. in accordance with the Authority Having Jurisdiction, prior To obtain a permit, the to the commencement of, and at a time during the progress of, applicant shall first file an application therefore in writing on work regulated by this code. a form furnished by the Authority Having Jurisdiction for that The issuance of a permit upon construction documents purpose. Such application shall: shall not prevent the Authority Having Jurisdiction from (1) Identify and describe the work to be covered by the per- thereafter requiring the correction of errors in said construc- mit for which application is made. tion documents or from preventing construction operations (2) Describe the land upon which the proposed work is to be being carried on thereunder where in violation of this code or done by legal description, street address, or similar of other pertinent ordinance or from revoking a certificate of description that will readily identify and definitely locate approval where issued in error. the proposed building or work. 103.3.1 Licensing. Provision for licensing shall be (3) Indicate the use or occupancy for which the proposed determined by the Authority Having Jurisdiction. work is intended. 103.4 Right of Entry. Where it is necessary to make an (4) Be accompanied by construction documents in accor- inspection to enforce the provisions of this code, or where the dance with Section 104.3.1. Authority Having Jurisdiction has reasonable cause to believe (5) Be signed by the permittee or the permittee’s authorized that there exists in a building or upon a premises a condition or agent. The Authority Having Jurisdiction shall be per- violation of this code that makes the building or premises mitted to require evidence to indicate such authority. unsafe, insanitary, dangerous, or hazardous, the Authority Hav- ing Jurisdiction shall be permitted to enter the building or prem- (6) Give such other data and information in accordance with ises at reasonable times to inspect or to perform the duties the Authority Having Jurisdiction. 104.3.1 Construction Documents. imposed upon the Authority Having Jurisdiction by this code, Construction provided that where such building or premises is occupied, the documents, engineering calculations, diagrams, and other Authority Having Jurisdiction shall present credentials to the data shall be submitted in two or more sets with each occupant and request entry. Where such building or premises is application for a permit. The construction documents, unoccupied, the Authority Having Jurisdiction shall first make computations, and specifications shall be prepared by, a reasonable effort to locate the owner or other person having and the system designed by, a registered design profes- charge or control of the building or premises and request entry. sional. Construction documents shall be drawn to scale Where entry is refused, the Authority Having Jurisdiction has with clarity to identify that the intended work to be per- recourse to every remedy provided by law to secure entry. formed is in accordance with the code. Where the Authority Having Jurisdiction shall have first Exception: The Authority Having Jurisdiction shall be obtained an inspection warrant or other remedy provided by permitted to waive the submission of construction docu- law to secure entry, no owner, occupant, or person having ments, calculations, or other data where the Authority charge, care or control of a building or premises shall fail or Having Jurisdiction finds that the nature of the work neglect, after a request is made as herein provided, to applied for is such that reviewing of construction docu- promptly permit entry herein by the Authority Having Juris- ments is not necessary to obtain compliance with the code. diction for the purpose of inspection and examination pur- 104.3.2 Plan Review Fees. Where a plan or other data suant to this code. is required to be submitted in accordance with Section

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104.3.1, a plan review fee shall be paid at the time of sub- diction. No permit presuming to give authority to violate mitting construction documents for review. or cancel the provisions of this code shall be valid. The plan review fees for system work shall be deter- The issuance of a permit based upon plans, specifi- mined and adopted by this jurisdiction. cations, or other data shall not prevent the Authority Hav- The plan review fees specified in this subsection are ing Jurisdiction from thereafter requiring the correction separate fees from the permit fees specified in Section of errors in said plans, specifications, and other data or 104.5. from preventing building operations being carried on thereunder where in violation of this code or of other Where plans are incomplete or changed so as to ordinances of this jurisdiction. require additional review, a fee shall be charged at the 104.4.3 Expiration. rate shown in Table 104.5. A permit issued by the Authority Having Jurisdiction under the provisions of this code 104.3.3 Time Limitation of Application. Applica- shall expire by limitation and become null and void tions for which no permit is issued within 180 days fol- where the work authorized by such permit is not com- lowing the date of application shall expire by limitation, menced within 180 days from the date of such permit, or plans and other data submitted for review thereafter, shall where the work authorized by such permit is suspended be returned to the applicant or destroyed by the Author- or abandoned at a time after the work is commenced for ity Having Jurisdiction. The Authority Having Jurisdic- a period of 180 days. Before such work is recommenced, tion shall be permitted to extend the time for action by a new permit shall first be obtained to do so, and the fee the applicant for a period not to exceed 180 days upon therefore shall be one-half the amount required for a new request by the applicant showing that circumstances permit for such work, provided no changes have been beyond the control of the applicant have prevented action made or will be made in the original construction docu- from being taken. No application shall be extended more ments for such work, and provided further that such sus- than once. In order to renew action on an application pension or abandonment has not exceeded 1 year. after expiration, the applicant shall resubmit plans and 104.4.4 Extensions. pay a new plan review fee. A permittee holding an unexpired permit shall be permitted to apply for an extension of the 104.4 Permit Issuance. The application, construction doc- time within which work shall be permitted to commence uments, and other data filed by an applicant for a permit shall under that permit where the permittee is unable to com- be reviewed by the Authority Having Jurisdiction. Such plans mence work within the time required by this section. The shall be permitted to be reviewed by other departments of this Authority Having Jurisdiction shall be permitted to jurisdiction to verify compliance with applicable laws under extend the time for action by the permittee for a period their jurisdiction. Where the Authority Having Jurisdiction not exceeding 180 days upon written request by the per- finds that the work described in an application for permit and mittee showing that circumstances beyond the control of the plans, specifications, and other data filed therewith are in the permittee have prevented the action from being taken. accordance with the requirements of the code and other per- No permit shall be extended more than once. In order to tinent laws and ordinances, and that the fees specified in Sec- renew action on a permit after expiration, the permittee tion 104.5 have been paid, the Authority Having Jurisdiction shall pay a new full permit fee. shall issue a permit therefore to the applicant. 104.4.5 Suspension and Revocation. 104.4.1 Approved Plans or Construction Docu- The Author- ity Having Jurisdiction shall be permitted to, in writing, ments. Where the Authority Having Jurisdiction issues suspend or revoke a permit issued under the provisions of the permit where plans are required, the Authority Hav- this code where the permit is issued in error or on the ing Jurisdiction shall endorse in writing or stamp the con- basis of incorrect information supplied or in violation of struction documents “APPROVED.” Such approved other ordinance or regulation of the jurisdiction. construction documents shall not be changed, modified, 104.4.6 Retention of Plans. or altered without authorization from the Authority Hav- One set of approved con- ing Jurisdiction, and the work shall be completed in struction documents and computations shall be retained accordance with approved plans. by the Authority Having Jurisdiction until final approval of the work covered therein. The Authority Having Jurisdiction shall be permitted to issue a permit for the construction of a part of a system One set of approved construction documents, com- before the entire construction documents for the whole sys- putations, and manufacturer’s installation instructions tem have been submitted or approved, provided adequate shall be returned to the applicant, and said set shall be information and detailed statements have been filed in kept on the site of the building or work at times during accordance with the pertinent requirements of this code. which the work authorized thereby is in progress. The holder of such permit shall be permitted to proceed at 104.5 Fees. Fees shall be assessed in accordance with the the holder’s risk without assurance that the permit for the provisions of this section and as set forth in the fee schedule, entire building, structure, or system will be granted. Table 104.5. The fees are to be determined and adopted by 104.4.2 Validity of Permit. The issuance of a permit or this jurisdiction. approval of construction documents shall not be con- 104.5.1 Work Commencing Before Permit strued to be a permit for, or an approval of, a violation of Issuance. Where work for which a permit is required the provisions of this code or other ordinance of the juris- by this code has been commenced without first obtaining

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said permit, a special investigation shall be made before responsible person by the Authority Having Jurisdiction. a permit is issued for such work. The requirements of this section shall not be considered 104.5.2 Investigation Fees. An investigation fee, in to prohibit the operation of system equipment installed to addition to the permit fee, shall be collected whether or replace existing equipment serving an occupied portion of not a permit is then or subsequently issued. The investi- the building in the event a request for inspection of such gation fee shall be equal to the amount of the permit fee equipment has been filed with the Authority Having Juris- that is required by this code if a permit were to be issued. diction not more than 72 hours after such replacement The payment of such investigation fee shall not exempt work is completed, and before a portion of such system is a person from compliance with other provisions of this concealed by a permanent portion of the building. code, nor from a penalty prescribed by law. 105.2.2 Other Inspections. In addition to the inspec- 104.5.3 Fee Refunds. The Authority Having Jurisdic- tions required by this code, the Authority Having Juris- tion shall be permitted to authorize the refunding of a fee diction shall be permitted to require other inspections to as follows: ascertain compliance with the provisions of this code and other laws that are enforced by the Authority Having (1) The amount paid hereunder that was erroneously Jurisdiction. paid or collected. 105.2.3 Inspection Requests. It shall be the duty of (2) Refunding of not more than a percentage, as deter- the person doing the work authorized by a permit to mined by this jurisdiction where no work has been notify the Authority Having Jurisdiction that such work done under a permit issued in accordance with this is ready for inspection. The Authority Having Jurisdic- code. tion shall be permitted to require that a request for The Authority Having Jurisdiction shall not author- inspection be filed not less than 1 working day before ize the refunding of a fee paid except upon written appli- such inspection is desired. Such request shall be permit- cation filed by the original permittee not to exceed 180 ted to be made in writing or by telephone, at the option days after the date of fee payment. of the Authority Having Jurisdiction. It shall be the duty of the person requesting inspec- 105.0 Inspections and Testing. tions in accordance with this code to provide access to 105.1 General. Systems for which a permit is required by this and means for proper inspection of such work. code shall be inspected by the Authority Having Jurisdiction. 105.2.4 Advance Notice. It shall be the duty of the No system or portion thereof shall be covered, concealed, person doing the work authorized by the permit to notify or put into use until inspected and approved as prescribed in the Authority Having Jurisdiction, orally or in writing this code. Neither the Authority Having Jurisdiction nor the that said work is ready for inspection. Such notification jurisdiction shall be liable for expense entailed in the removal shall be given not less than 24 hours before the work is or replacement of material required to permit inspection. Sys- to be inspected. tems regulated by this code shall not be connected to the 105.2.5 Responsibility. It shall be the duty of the water, energy fuel supply, or the sewer system until author- holder of a permit to make sure that the work will stand ized by the Authority Having Jurisdiction. the test prescribed before giving the notification. 105.2 Required Inspection. New system work and such The equipment, material, and labor necessary for portions of existing systems as affected by new work, or inspection or tests shall be furnished by the person to changes, shall be inspected by the Authority Having Juris- whom the permit is issued or by whom inspection is diction to ensure compliance with the requirements of this requested. code and to ensure that the installation and construction of 105.2.6 Reinspections. A reinspection fee shall be the system is in accordance with approved plans. The Author- permitted to be assessed for each inspection or reinspec- ity Having Jurisdiction shall make the following inspections tion where such portion of work for which inspection is and other such inspections as necessary. The permittee or the called is not complete or where required corrections have permittee’s authorized agent shall be responsible for the not been made. scheduling of such inspections as follows: This provision shall not be interpreted as requiring (1) Underground inspection shall be made after trenches or reinspection fees the first time a job is rejected for failure ditches are excavated and bedded, piping installed, and to be in accordance with the requirements of this code, before backfill is put in place. but as controlling the practice of calling for inspections (2) Rough-in inspection shall be made prior to the installa- before the job is ready for inspection or reinspection. tion of wall or ceiling membranes. Reinspection fees shall be permitted to be assessed (3) Final inspection shall be made upon completion of the where the approved plans are not readily available to the installation. inspector, for failure to provide access on the date for 105.2.1 Uncovering. Where a system, or part thereof, which the inspection is requested, or for deviating from which is installed, altered, or repaired, is covered or con- plans requiring the approval of the Authority Having cealed before being inspected, tested, and approved as pre- Jurisdiction. scribed in this code, it shall be uncovered for inspection To obtain reinspection, the applicant shall file an after notice to uncover the work has been issued to the application therefore in writing upon a form furnished

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for that purpose and pay the reinspection fee in accor- a violation of this code and shall be subject to the penalties set dance with Table 104.5. forth by the governing laws of the jurisdiction. In instances where reinspection fees have been 106.3 Penalties. A person, firm, or corporation violating a assessed, no additional inspection of the work will be provision of this code shall be deemed guilty of a misde- performed until the required fees have been paid. meanor, and upon conviction thereof, shall be punishable by 105.3 Testing of Systems. Systems shall be tested and a fine, imprisonment, or both set forth by the governing laws approved in accordance with this code or the Authority Hav- of the jurisdiction. Each separate day or portion thereof, during Jurisdiction. Tests shall be conducted in the presence of ing which a violation of this code occurs or continues, shall the Authority Having Jurisdiction or the Authority Having be deemed to constitute a separate offense. Jurisdiction’s duly appointed representative. No test or 106.4 Stop Orders. Where work is being done contrary to inspection shall be required where a system, or part thereof, the provisions of this code, the Authority Having Jurisdiction is set up for exhibition purposes and has no connection with shall be permitted to order the work stopped by notice in writ- water or an energy fuel supply. In cases where it would be ing served on persons engaged in the doing or causing such impractical to provide the required water or air tests, or for work to be done, and such persons shall forthwith stop work minor installations and repairs, the Authority Having Juris- until authorized by the Authority Having Jurisdiction to pro- diction shall be permitted to make such inspection as deemed ceed with the work. advisable in order to be assured that the work has been per- 106.5 Authority to Disconnect Utilities in Emergen- formed in accordance with the intent of this code. Joints and cies. The Authority Having Jurisdiction shall have the author- connections in a system shall be airtight, gastight, or water- ity to disconnect a system to a building, structure, or equipment tight for the pressures required by the test. regulated by this code in case of an emergency where necessary 105.3.1 Defective Systems. In buildings or premises to eliminate an immediate hazard to life or property. condemned by the Authority Having Jurisdiction because 106.6 Authority to Condemn. Where the Authority Having of an insanitary condition of the system, or part thereof, Jurisdiction ascertains that a system or portion thereof, regu- the alterations in such system shall be in accordance with lated by this code, has become hazardous to life, health, or prop- the requirements of this code. erty, or has become insanitary, the Authority Having Jurisdiction 105.3.2 Retesting. Where the Authority Having Juris- shall order in writing that such system either be removed or diction finds that the work will not pass the test, neces- placed in a safe or sanitary condition. The order shall fix a rea- sary corrections shall be made, and the work shall be sonable time limit for compliance. No person shall use or main- resubmitted for test or inspection. tain a defective system after receiving such notice. 105.3.3 Approval. Where prescribed tests and inspec- Where such system is to be disconnected, written notice tions indicate that the work is in accordance with this code, shall be given. In cases of immediate danger to life or prop- a certificate of approval shall be issued by the Authority erty, such disconnection shall be permitted to be made imme- Having Jurisdiction to the permittee on demand. diately without such notice. 105.4 Connection to Service Utilities. No person shall 107.0 Board of Appeals. make connections from a source of energy or fuel to a system or equipment regulated by this code and for which a permit is 107.1 General. In order to hear and decide appeals of orders, required until approved by the Authority Having Jurisdiction. decisions, or determinations made by the Authority Having No person shall make connection from a water-supply line Jurisdiction relative to the application and interpretations of nor shall connect to a sewer system regulated by this code this code, there shall be and is hereby created a Board of and for which a permit is required until approved by the Appeals consisting of members who are qualified by experi- Authority Having Jurisdiction. The Authority Having Juris- ence and training to pass upon matters pertaining to a system diction shall be permitted to authorize temporary connection design, construction, and maintenance and the public health of the system equipment to the source of energy or fuel for the aspects of such systems and who are not employees of the purpose of testing the equipment. jurisdiction. The Authority Having Jurisdiction shall be an ex-officio member and shall act as secretary to said board but 106.0 Violations and Penalties. shall have no vote upon a matter before the board. The Board of Appeals shall be appointed by the governing body and shall 106.1 General. It shall be unlawful for a person, firm, or cor- hold office at its pleasure. The board shall adopt rules of pro- poration to erect, construct, enlarge, alter, repair, move, cedure for conducting its business and shall render decisions improve, remove, convert, demolish, equip, use, or maintain a and findings in writing to the appellant with a duplicate copy system or permit the same to be done in violation of this code. to the Authority Having Jurisdiction. 106.2 Notices of Correction or Violation. Notices of 107.2 Limitations of Authority. The Board of Appeals correction or violation shall be written by the Authority Hav- shall have no authority relative to interpretation of the admin- ing Jurisdiction and shall be permitted to be posted at the site istrative provisions of this code, nor shall the board be of the work, mailed, or delivered to the permittee or their empowered to waive requirements of this code. authorized representative. Refusal, failure, or neglect to comply with such notice or order within 10 days of receipt thereof, shall be considered

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TABLE 104.5 SYSTEM PERMIT FEES2

Permit Issuance 1. For issuing each permit...... 1______2. For issuing each supplemental permit...... 1______

Unit Fee Schedule (in addition to Items 1 and Item 2 above) 1. For Collectors (including related piping and regulating devices): Up to 1000 square feet ...... 1______Between 1001 square feet and 2000 square feet...... 1______More than 2000 square feet, $5.00 plus $1.00 per 1000 square feet or fraction thereof over 2000 square feet...... 1______2. For Storage Tanks (including related piping and regulating devices): Up to 750 gallons ...... 1______Between 751 gallons and 2000 gallons...... 1______Exceeding 2000 gallons, $3.00 plus $1.00 per 1000 or fraction thereof exceeding 2000 gallons...... 1______3. For Rock Storage: Up to 1500 cubic feet...... 1______Between 1501 cubic feet and 3000 cubic feet...... 1______More than 3000 cubic feet, $3.00 plus $1.00 per 1000 cubic feet or fraction thereof over 3000 cubic feet...... 1______4. For each appliance or piece of equipment regulated by this code for which no fee is listed ...... 1______

Other Inspections and Fees 1. Inspections outside of normal business hours...... 1______2. Reinspection fee...... 1______3. Inspections for which no fee is specifically indicated ...... 1______4. Additional plan review required by changes, additions, or 1 1 revisions to approved plans (minimum charge - ⁄2 hour) ...... ______5. Plan Check Fee: Where specific plans are required, a plan check fee shall be charged equal to one-half the total permit fee, excluding the permit issuance fee...... 1______For SI units: 1 square foot = 0.0929 m2, 1 gallon = 3.785 L, 1 cubic foot = 0.0283 m3 Notes: 1 Jurisdiction will indicate its fees here. 2 These fees do not include permit fees for parts of the system that are subject to the requirements of other applicable codes.

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201.0 General. Appliance. A device that utilizes an energy source to pro- 201.1 Applicability. For the purpose of this code, the fol- duce light, heat, power, refrigeration, or air conditioning. lowing terms have the meaning indicated in this chapter. Approved. Acceptable to the Authority Having Jurisdiction. No attempt is made to define ordinary words, which are Approved Testing Agency. An organization primarily used in accordance with their established dictionary mean- established for purposes of testing to approved standards and ings, except where a word has been used loosely, and it is nec- approved by the Authority Having Jurisdiction. essary to define its meaning as used in this code to avoid Appurtenance, Plumbing. A manufactured device, a pre- misunderstanding. fabricated assembly, or an on-the-job assembly of component parts that is an adjunct to the basic piping system. An appur- 202.0 Definition of Terms. tenance demands no additional water supply, nor does it add 202.1 General. The definitions of terms are arranged alpha- a discharge load to the drainage system. It performs some use- betically according to the first word of the term. ful function in the operation, maintenance, servicing, econ- 202.2 Terms Defined in Other Documents. omy, or safety of the system. Where Appurtenance, Solar. terms are not defined in this chapter and defined in the build- A manufactured device, a prefabri- ing code, mechanical code, plumbing code, electrical code, cated assembly, or an on-the-job assembly of component parts and fire code; such terms shall have meanings as defined in that is an adjunct to a solar energy system. Area, Absorber. those codes. The total projected heat transfer area from which the absorbed solar irradiation heats the transfer media. 203.0 – A – Area, Aperture. The maximum projected area of a solar col- Absorber. lector through which the unconcentrated solar radiant energy That part of the solar collector that receives the is admitted. incident radiation energy. Area, Gross Collector. Absorptance. The maximum projected area of The collecting of heat, measured as a percent the complete collector module, including integral mounting of total radiation available. means. Accepted Engineering Practice. That which conforms Array. A mechanically integrated assembly of module(s) or to technical or scientific-based principles, tests, or standards panel(s) with a support structure and foundation, tracker, and that are accepted by the engineering profession. Accessible. other components, as required, to form a dc or ac power-pro- Where applied to a device, appliance, or equip- ducing unit. [NFPA 70:690.2] ment, “accessible” means having access thereto, but which Authority Having Jurisdiction. The organization, office, first may require the removal of an access panel, door, or sim- or individual responsible for enforcing the requirements of a ilar obstruction. Accessible, Readily. code or standard, or for approving equipment, materials, Having a direct access without the installations, or procedures. The Authority Having Jurisdic- necessity of removing panel, door, or similar obstruction. tion shall be a federal, state, local, or other regional depart- Air Break, Drainage. The drain from an appliance or ment or an individual such as a plumbing official, mechanical appurtenance that discharges indirectly into another receptor official, labor department official, health department official, at a point below the flood level rim and above the trap seal. building official, or others having statutory authority. In the Air Gap, Drainage. The unobstructed vertical distance absence of a statutory authority, the Authority Having Juris- through the free atmosphere between the lowest openings diction may be some other responsible party. This definition from a pipe, appliance, or appurtenance conveying waste to shall include the Authority Having Jurisdiction’s duly author- the flood-level rim of the receptor. ized representative. Auxiliary Energy System. Air Mass. The ratio of the mass of atmosphere, in the actual Equipment using non-solar earth-sun path, to the mass that would exist if the sun were energy sources to supplement or backup the output provided directly overhead at sea level. by a solar energy system. Alternating-Current (AC) Module (Alternating-Cur- rent Photovoltaic Module). A complete environmentally 204.0 – B – protected unit consisting of solar cells, optics, inverter, and Backflow. The flow of water or other liquids, mixtures, or other components, exclusive of tracker, designed to generate substances into the distributing pipes of a potable supply of ac power where exposed to sunlight. [NFPA 70:690.2] water from sources other than its intended source. Ambient Temperature. Surrounding temperature. Balancing Valves. A valve that regulates the flow rate of Angle of Incidence. The angle between the direct solar liquid, to achieve uniform distribution, throughout multiple irradiation and the normal to the aperture plane. collectors.

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Bipolar Photovoltaic Array. A dc PV array that has two (1) Class II liquids having a flash point above 100°F (38°C) outputs each having opposite polarity to a common reference and below 140°F (60°C). point or center tap. [NFPA 70:690.2] (2) Class IIIA liquids having a flash point at or above 140°F Boiler. A closed vessel used for heating water or liquid, or for (60°C) and below 200°F (93°C). generating steam or vapor by direct application of heat from (3) Class IIIB liquids having a flash point at or above 200°F combustible fuels or electricity. (93°C). Building. A structure built, erected, and framed of compo- The classifications of combustible liquids do not include nent structural parts designed for the housing, shelter, enclo- compressed gases or cryogenic fluids. sure, or support of persons, animals, or property of any kind. Concentration Ratio. Building Code. The ratio of the aperture area to the The building code that is adopted by the absorber area (in concentrating solar collectors). jurisdiction. Concentrator. Reflector of lens designed to focus solar energy into a reduced area. 205.0 – C – Condensate. The liquid phase produced by condensation Calcium Hardness. A measure of dissolved calcium com- of a particular gas or vapor. pounds and mineral content of water. It is measured as cal- Conditioned Space. An area, room, or space normally cium carbonate (CaCO3). occupied and being heated or cooled for human habitation by Certified Person. A person trained and certified by the any equipment. equipment manufacturer, or by a recognized organization Construction Documents. Plans, specifications, written, through a formal certification program for the system to be graphic, and pictorial documents prepared or assembled for serviced or cleaned; that is acceptable to the Authority Hav- describing the design, location, and physical characteristics ing Jurisdiction. of the elements of a project necessary for obtaining a permit. Charge Controller. Equipment that controls dc voltage or Contamination. An impairment of the quality of the potable dc current, or both, and that is used to charge a battery or other water that creates an actual hazard to the public health through energy storage device. [NFPA 70:100] poisoning or through the spread of disease by sewage, indus- Circulating Air. Air being conveyed from or to a collector trial fluids, or waste. Also defined as High Hazard. through openings, ducts, plenums, or concealed spaces to a Cooling. Air cooling to provide a room or space tempera- heat exchanger or storage media. ture of 68°F (20°C) or above. Circulators (Circulating Pump). A device that circulates Cooling System. All of the equipment, including associ- liquids within a closed circuit for an intended purpose. ated refrigeration, intended or installed for the purpose of Closed-Loop System. A system where the fluid is cooling air by mechanical means and discharging such air into enclosed in a piping system that is not vented to the atmos- any room or space. This definition shall not include an evap- phere. orative cooler. Coastal High Hazard Areas. An area within the flood haz- Copper Alloy. A homogenous mixture of two or more met- ard area that is subject to high-velocity wave action, and als in which copper is the primary component, such as brass shown on a Flood Insurance Rate Map or other flood hazard and bronze. map as Zone V, VO, VE or V1-30. Cover, Collector (Glazing). The material covering the Code. A standard that is an extensive compilation of provi- aperture to provide thermal and environmental protection. sions covering broad subject matter or that is suitable for Crawl Space. In a building, an area accessible by crawling, adoption into law independently of other codes and standards. having a clearance less than human height, for access to Collector. See Solar Collector. plumbing or wiring, storage, etc. Critical Level. Collector, Concentrating. A solar collector that uses The critical level (C-L or C/L) marking on a reflectors, lenses, or other optical elements to concentrate the backflow prevention device or vacuum breaker is a point con- radiant energy passing through the aperture onto an absorber forming to approved standards and established by the testing of which the surface area is smaller than the aperture area. laboratory (usually stamped on the device by the manufac- Collector System. That section of the solar system that turer) that determines the minimum elevation above the flood- includes the collector and piping or ducts from the collector level rim of the fixture or receptor served at which the device may be installed. Where a backflow prevention device does to the storage system. Collector Tilt. not bear a critical level marking, the bottom of the vacuum The angle above horizontal at which a solar breaker, combination valve, or the bottom of such approved heat collector is positioned. device shall constitute the critical level. Combination Temperature and Pressure-Relief Cross-Connection. Valve. A connection or arrangement, physi- A relief valve that actuates when a set temperature, cal or otherwise, between a potable water supply system and pressure, or both is reached. Also known as a T&P valve. a tank, receptor, equipment, or device through which it may Combustible Liquid. A liquid having a flash point at or be possible for nonpotable, used, unclean, polluted and con- above 100°F (38°C). Combustible liquids shall be divided taminated water, or other substances to enter into a part of into the following classifications: such potable water system under any condition.

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206.0 – D – Draindown. An active solar energy system in which the DC-to-DC Converter. A device installed in the PV source fluid in the solar collector is drained from the solar energy circuit or PV output circuit that can provide an output dc volt- system under prescribed circumstances. age and current at a higher or lower value than the input dc Duct. A tube or conduit for transmission of air, fumes, voltage and current. [NFPA 70:690.2] vapors, or dusts. This definition shall not include: DC-to-DC Converter Output Circuit. Circuit conductors (1) A vent, vent connector, or chimney connector. between the dc-to-dc converter source circuit(s) and the (2) A tube or conduit wherein the pressure of the air exceeds inverter or dc utilization equipment. [NFPA 70:690.2] 1 psi (7 kPa). DC-to-DC Converter Source Circuit. Circuits between (3) The air passages of listed self-contained systems. dc-to-dc converters and from dc-to-dc converters to the common connection point(s) of the dc system. [NFPA 70:690.2] 207.0 – E – Department Having Jurisdiction. The Authority Having Electric Supply Stations. Jurisdiction, including other law enforcement agencies Locations containing the gen- affected by a provision of this code, whether such agency is erating stations and substations, including their associated specifically named or not. generator, storage battery, transformer, and switchgear areas. Design Flood Elevation. [NFPA 70:691.2] The elevation of the “design Electrical (Auxiliary) Heating. flood,” including wave height, relative to the datum specified Electrical heating element on the community’s legally designated flood hazard map. In immersed into the storage. areas designated as Zone AO, the design flood elevation shall Electrical Production and Distribution Network. A be the elevation of the highest existing grade of the building’s power production, distribution, and utilization system, such as perimeter plus the depth number in feet (m) specified on the a utility system and connected loads, that is external to and flood hazard map. In areas designated as Zone AO where a not controlled by the PV power system. [NFPA 70:690.2] depth number is not specified on the map, the depth number Emittance. The amount of heat radiated back from the solar shall be taken as being equal to 2 feet (610 mm). collector, measured as a percent of energy absorbed by the Design Pressure. The maximum allowable pressure for collector. which a specific part of a system is designed. Enclosure. A room or box used to store solar components. Design Temperature. The maximum allowable continu- Energy Collector Fluid. That fluid used to transfer energy ous or intermittent temperature for which a specific part of a from the collector to the storage system or point of use. solar energy system is designed to operate safely and reliably. Energy Storage Fluid (or Media). Developed Length. That fluid (or media) The length along the center line of a used in the storage container for storing collected energy. pipe and fittings. Energy Transfer Fluid. Diameter. That fluid used within a closed sys- Unless specifically stated, “diameter” is the nom- tem either from the collector to the storage system or from inal diameter as designated commercially. the storage system to the point of use. Direct-Current (DC) Combiner. A device used in the PV Equipment. A general term including materials, fittings, source and PV output circuits to combine two or more dc cir- devices and apparatus used as part of or in connection with cuit inputs and provide one dc circuit output. [NFPA 70:690.2] installations regulated by this code. Direct Exchange (DX). A ground-source heat pump that Essentially Nontoxic Transfer Fluid. Fluid generally rec- circulates a refrigerant through a closed-loop system. ognized as safe by the Food and Drug Administration (FDA) Direct Expansion System. See Direct Exchange (DX). as food grade. Discrete Products in Plenums. Individual distinct prod- Existing Work. A solar system or part thereof that has been ucts which are non-continuous such as pipe hangers, duct reg- installed prior to the effective date of this code. isters, duct fittings and duct straps. External Auxiliary Heating. Auxiliary heating device Distribution System. That section of the solar system from located outside the storage. The heat is transferred to the stor- the storage system to the point of use. age by direct or indirect charging via a charge loop. Diversion Charge Controller. Equipment that regulates the charging process of a battery by diverting power from 208.0 – F – energy storage to direct-current or alternating-current loads Field Evaluation Body (FEB). or to an interconnected utility service. [NFPA 70:690.2] An organization or part of Drain. an organization that performs field evaluations of electrical A pipe that carries waste or waterborne wastes in a or other equipment. [NFPA 70:100] building drainage system. Field Labeled (as applied to evaluated products). Drainage System. Includes the piping within a premise that Equipment or materials to which has been attached a label, conveys liquid waste to a legal point of disposal. symbol, or other identifying mark of an FEB indicating the Drainback System. A closed-loop system, which allows equipment or materials were evaluated and found to comply gravity draining of the heat transfer fluid into, lower portions with requirements as described in an accompanying field or the solar loop under prescribed circumstances. evaluation report. [NFPA 70:100]

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Flammable Liquid. Any liquid that has a flash point below Geothermal Energy System, Open-Loop. A liquid- 100°F (38°C) and has a vapor pressure not exceeding 40 psi source system that uses ground water or surface water to (276 kPa) at 100°F (38°C). Flammable liquids shall be known extract or reject heat. as Class I liquids and shall be divided into the following clas- Grade. The slope or fall of a line of pipe in reference to a sifications: horizontal plane. In drainage, it is usually expressed as the (1) Class IA liquids having a flash point below 73°F (23°C) fall in a fraction of an inch (mm) or percentage slope per foot and a boiling point below 100°F (38°C). (m) length of pipe. Gravity Tank. (2) Class IB liquids having a flash point below 73°F (23°C) A water storage tank in which fluid is stored and a boiling point at or above 100°F (38°C). at atmospheric pressure and distributed by gravity flow in a (3) Class IC liquids having a flash point at or above 73°F downfeed system. Ground-Heat Exchanger. (23°C) and below 100°F (38°C). An underground closed-loop heat exchanger through which a heat-transfer medium passes Flash Point. The minimum temperature corrected to a pres- to and from a heat pump or other rated mechanical equipment. sure of 14.7 psi (101 kPa) at which a test flame causes the It includes the buried pipe and connecting main(s) up to and vapors of a portion of the sample to ignite under the condi- terminating with the building. tions specified by the test procedures and apparatus. The flash Ground-Source Heat Pump. point of a liquid shall be determined in accordance with A term that is applied to a ASTM D56, ASTM D93, or ASTM D3278. variety of systems that use the ground, groundwater, or surface water as a heat source and sink. The general terms Flat Plate Collector. A panel (nonconcentrating type) of a include ground-coupled (GCHP), groundwater (GWHP), and suitable material that converts solar energy into usable energy surface-water (SWHP) heat pumps. Many parallel terms exist and the absorbing surface is essentially planar. [e.g., geothermal heat pumps (GHP), geo-exchange, and Flood Hazard Area. The greater of the following two areas: ground-source (GS) systems] and are used to meet a variety (1) The area within a floodplain subject to a 1 percent or of marketing or institutional needs. greater chance of flooding in any given year. Groundwater Source. A geothermal energy system that (2) The area designated as a flood hazard area on a commu- uses the groundwater as a heat source or sink. nity’s flood hazard map, or otherwise legally designated. Flood-Level Rim. The top edge of a receptor from which 210.0 – H – water overflows. Hangers. See Supports. Freeze Protection. Any method for protecting solar ther- Hazardous Material. A substance or mixture of substances mal systems from damage due to freezing conditions where that is toxic, corrosive, flammable, an irritant, a sensitizer, installed in locations where freezing ambient temperature and that presents a potential threat to the health of humans or conditions exist. animals. Freeze Protection, Fail-Safe. A freeze-protection method Heat Exchanger. A device that transfers heat from one that does not rely on the activation or continued operation of medium to another. any mechanical or electrical component. Heat Transfer Medium. The medium used to transfer Functional Grounded PV System. A PV system that has energy from the solar collectors to the thermal storage or load. an electrical reference to ground that is not solidly grounded. Heating Degree Day. A unit, based upon temperature dif- [NFPA 70:690.2] ference and time, used in estimating fuel consumption and specifying nominal annual heating load of a building. For any 209.0 – G – one day when the mean temperature is less than 65°F (18°C), Generating Capacity. there exist as many degree days as there are Fahrenheit The sum of the parallel-connected degrees difference in temperature between mean temperature inverter rated maximum continuous output power at 104°F for the day and 65°F (18°C). (40°C) in kilowatts (kW). [NFPA 70:691.2] Heating Equipment. Generating Station. Includes warm air furnaces, warm air A plant wherein electric energy is pro- heaters, combustion products vents, heating air-distribution duced by conversion from some other form of energy (e.g., ducts and fans, and all steam and hot water piping, together chemical, nuclear, solar, wind, mechanical, or hydraulic) by with all control devices and accessories installed as part of, or means of suitable apparatus. [NFPA 70:691.2] in connection with, any environmental heating system or Geoexchange. See Geothermal Energy System. appliance regulated by this code. Heliostat. Geothermal Energy System. A system that uses the A reflecting surface mounted on an axis to direct earth’s interior exchanges thermal energy with the earth for the sun’s rays to a fixed point. space heating and cooling, and/or water heating. High Hazard. See Contamination. Geothermal Energy System, Closed-Loop. A continu- Horizontal Pipe. A pipe or fitting that is installed in a hor- ous, sealed, underground, or submerged heat exchanger izontal position or which makes an angle of less than 45 through which a heat-transfer fluid passes. degrees (0.79 rad) with the horizontal.

10 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT DEFINITIONS

Hybrid System. A system comprised of multiple power Inverter Output Circuit. Conductors connected to the ac sources. These power sources could include photovoltaic, output of an inverter. [NFPA 70:690.2] wind, micro-hydro generators, engine-driven generators, and Irradiation, Instantaneous. The quantity of solar radiation others, but do not include electric power production and dis- incident on a unit surface area in unit time, measured in British tribution network systems. Energy storage systems, such as thermal unit per square foot hour [Btu/(ft2•h)] (kW/m2). batteries, flywheels, or superconducting magnetic storage Irradiation, Integrated Average. equipment do not constitute a power source for the purpose of The solar radiation inci- this definition. The energy regenerated by an overhauling dent on a unit surface area during a specified time period (descending) elevator does not constitute a power source for divided by the duration of that time period. the purpose of this definition. [NFPA 70:100] 212.0 – J – Hydronic System. Relating to, or being a system of heating or cooling that involves the transfer of heat by a circulat- Joint, Brazed. A joint obtained by joining of metal parts ing fluid (such as water or vapor). with alloys that melt at temperatures exceeding 840°F Hydronics. Of or relating to a heating or cooling system that (449°C), but less than the melting temperature of the parts to transfers energy by circulating a fluid through a system of be joined. pipes or tubing. Joint, Compression. A multipiece joint with cup-shaped threaded nuts that, when tightened, compress tapered sleeves 211.0 – I – so that they form a tight joint on the periphery of the tubing Ignition Source. they connect. Appliances or equipment due to their Joint, Flanged. intended use and operation, are capable of providing suffi- One made by bolting together a pair of cient temperature and energy to raise its ignition temperature flanged ends. and capable of igniting flammable vapors or fumes. Sources Joint, Flared. A metal-to-metal compression joint in which may include appliance or equipment burners, burner igniters a conical spread is made on the end of a tube that is com- or electric switching devices. pressed by a flare nut against a mating flare. Immersed Heat Exchanger. Heat exchanger, which is Joint, Mechanical. General form for gastight or liquid-tight completely surrounded with the fluid in the storage tank. joints obtained by the joining of parts through a positive hold- Indirect Waste Pipe. A waste pipe that does not connect ing mechanical construction. directly with the drainage system, but that discharges into the Joint, Soldered. A joint obtained by the joining of metal drainage system through an air break or air gap into a trap, parts with metallic mixtures or alloys that melt at a tempera- fixture, receptor or interceptor. ture up to and including 840°F (449°C). Insolation. The rate of solar energy received on a unit sur- Joint, Welded. A gastight joint obtained by the joining of face in a unit time. metal parts in the plastic molten state. Instantaneous Efficiency. The amount of energy removed by the transfer fluid per gross collector area. During the spec- 213.0 – K – ified time period, divided by the total solar radiation incident on the collector per unit area during the same test period, No definitions. under steady state or quasi-steady state. 214.0 – L – Integral Collector Storage. A solar thermal heating system that uses a solar collector that has all or most of its heat Labeled. Equipment or materials bearing a label of a listing transfer liquid inside the collector. agency (accredited conformity assessment body). See Listed Interactive Inverter Output Circuit. The conductors (Third-Party Certified). between the interactive inverter and the service equipment or Langelier Saturation Index. A formula used to measure another electrical power production and distribution network. water balance or mineral saturation control of pool, spa, or [NFPA 70:690.2] hot tub water. Total alkalinity, calcium hardness, pH, water Interactive System. A PV system that operates in parallel temperature, and total dissolved solids are measured, given a with and may deliver power to an electrical production and factor, and calculated to determine whether water has a ten- distribution network. [NFPA 70:690.2] dency to be corrosive or scale forming. 2 Inverter. Equipment that is used to change voltage level or Langley (calth/cm ). A unit of measurement of insolation, waveform, or both, of electrical energy. Commonly, an inverter equal to 4.184 E+04 joules per square meter (J/m2). [also known as a power conditioning unit (PCU) or power con- Listed (Third Party Certified). Equipment or materials version system (PCS)] is a device that changes dc input to an included in a list published by a listing agency (accredited ac output. Inverters may also function as battery chargers that conformity assessment body) that maintains periodic inspec- use alternating current from another source and convert it into tion on current production of listed equipment or material and direct current for charging batteries. [NFPA 70:690.2] whose listing states either that the equipment or material com- Inverter Input Circuit. Conductors connected to the dc plies with approved standards or has been tested and found input of an inverter. [NFPA 70:690.2] suitable for use in a specified manner.

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Listing Agency. An agency accredited by an independent subject to increase in combustibility or flame-spread index and authoritative conformity assessment body to operate a beyond the limits herein established, through the effects of material and product listing and labeling (certification) sys- age, moisture, or other atmospheric condition. tem and that is accepted by the Authority Having Jurisdic- Nuisance. Includes, but is not limited to: tion, which is in the business of listing and labeling. The (1) A public nuisance known at common law or in equity system includes initial and ongoing product testing, a peri- jurisprudence. odic inspection on current production of listed (certified) products, and that makes available a published report of such (2) Where a work regulated by this code is dangerous to listing in which specific information is included that the mate- human life or detrimental to health and property. rial or product is in accordance with applicable standards and (3) Inadequate or unsafe water supply or sewage disposal found safe for use in a specific manner. system. Load. The heat output of the storage during discharge. The load is defined as the product of the mass, specific thermal 217.0 – O – capacity and temperature increase of the water as it passes the Occupancy. The purpose for which a building or part solar hot water system. thereof is used or intended to be used. Low Hazard. See Pollution. Offset. A combination of elbows or bends in a line of piping that brings one section of the pipe out of line but into a line 215.0 – M – parallel with the other section. May. A permissive term. Open-Loop System. A system where the fluid is enclosed Mechanical Code. The mechanical code that is adopted by in a piping system that is vented to the atmosphere. the jurisdiction. Where a mechanical code is not adopted or Out-Gassing. As applied to thermal energy, the thermal where the content of the mechanical code adopted by the process by which materials expel gas. jurisdictions is not applicable, then mechanical code shall mean the Uniform Mechanical Code (UMC) promulgated by 218.0 – P – the International Association of Plumbing and Mechanical Panel, Photovoltaic. Officials (IAPMO). A collection of modules mechanically fastened together, wired, and designed to provide a field- Module. A complete environmentally protected unit con- installable unit. [NFPA 70:690.2] sisting of solar cells, optics, and other components, exclusive Passive Solar Systems. of tracker, designed to generate dc power when exposed to As used in these requirements, sunlight. [NFPA 70:690.2] are solar systems that utilize elements of a building, without augmentation by mechanical components such as blowers or Monopole Subarray. A PV subarray that has two conductors in the output circuit, one positive (+) and one negative (-). Two pumps, to provide for the collections, storage, or distribution monopole PV subarrays are used to form a bipolar PV array. of solar energy for heating, cooling, or both. PE. [NFPA 70:690.2] Polyethylene. PE-AL-PE. Multimode Inverter. Equipment having the capabilities of Polyethylene-aluminum-polyethylene. both the interactive inverter and the stand-alone inverter. PE-RT. Polyethylene of raised temperature. [NFPA 70:690.2] Person. A natural person, his heirs, executor, administrators, or assigns and shall also include a firm, corporation, munici- 216.0 – N – pal or quasi-municipal corporation, or governmental agency. Noncombustible Material. As applied to building con- Singular includes plural, male includes female. struction material, means a material that in the form in which PEX. Cross-linked polyethylene. it is used is either one of the following: PEX-AL-PEX. Cross-linked polyethylene-aluminum-cross- (1) A material that, in the form in which it is used and under linked polyethylene. the conditions anticipated, will not ignite, burn, support pH. The log of the reciprocal of the hydrogen ion concentra- combustion, or release flammable vapors when subjected tion of a solution, and a measure of the acidity or alkalinity of to fire or heat. Materials that are reported as passing the water. It is determined by the concentration of hydrogen ASTM E136 are considered noncombustible material. ions in a specific volume of water. (2) Material having a structural base of noncombustible Photolysis. A chemical decomposition caused by radiation. material as defined in 1 above, with a surfacing material 1 Photosynthesis. not over ⁄8 of an inch (3.2 mm) thick that has a flame- The building up of chemical compounds spread index not higher than 50. with the help of radiation. Photovoltaic. Noncombustible does not apply to surface finish materi- Relating to electricity produced by the action als. Material required to be noncombustible for reduced clear- of solar radiation on a solar cell. ances to flues, heating appliances, or other sources of high Photovoltaic Output Circuit. Circuit conductors between temperature shall refer to material in accordance with 1 the PV source circuit(s) and the inverter or dc utilization above. No material shall be classed as noncombustible that is equipment. [NFPA 70:690.2]

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Photovoltaic Power Source. An array or aggregate of Pressure Test. The minimum gauge pressure to which a arrays that generates dc power at system voltage and current. specific system component is subjected under test condition. [NFPA 70:690.2] PVC. Polyvinyl Chloride. Photovoltaic Source Circuit. Circuits between modules Pyranometer. A device used to measure the total solar radi- and from modules to the common connection point(s) of the ation incident upon a surface per unit time per unit area. dc system. [NFPA 70:690.2] Pyrheliometer. A device used to measure the direct radia- Photovoltaic System DC Circuit. Any dc conductor sup- tion on a surface normal to the sun’s rays. plied by a PV power source, including PV source circuits, PV output circuits, dc-to-dc converter source circuits, or dc-to- 219.0 – Q – dc converter output circuits. [NFPA 70:690.2] Quasi-Steady State. Pipe. A cylindrical conduit or conductor conforming to the The state of the solar collector test particular dimensions commonly known as “pipe size.” where the flow rate and temperature of the fluid entering the Piping. collector are constant but the exit fluid temperature changes The pipe or tube mains for interconnecting the var- gradually due to the normal change in irradiation that occurs ious parts of a system. Piping includes pipe, tube, flanges, with time for clear sky conditions. bolting, gaskets, valves, fittings, the pressure-containing parts Quick-Acting Valve. A valve that closes quickly or abruptly of other components such as expansion joints, strainers, and where manually released or electrically actuated. devices that serve such purposes as mixing, separating, snub- bing, distributing, metering, or controlling flow, pipe-supporting fixtures and structural attachments. 220.0 – R – Plastic CC1. Plastic materials that have a burning extent of Radiant Heater. A heater designed to transfer heat primarily 1 inch (25.4 mm) or less where tested in nominal 0.060 of an by direct radiation. inch (1.52 mm) thickness by ASTM D635 or in the thickness Registered Design Professional. An individual who is intended for use. registered or licensed by the laws of the state to perform such Plastic CC2. Plastic materials that have a burning rate of design work in the jurisdiction. 150 inches per hour (in/h) (63.5 mm/min) or less where tested Relief Valve, Vacuum. A device which automatically opens in nominal 0.060 inch (1.52 mm) thickness by ASTM D635 or closes for relieving a vacuum with the system, depending or in the thickness intended for use. on whether the vacuum is above or below a predetermined Plenum. An air compartment or chamber to which one or value. more ducts are connected and that forms part of either the Rock Storage. A bin, basement, or other container filled conditioned air supply, circulating air, or exhaust air system, with rock to act as an energy reservoir for a solar system. other than the occupied space being conditioned. Plumbing Code. The plumbing code that is adopted by the 221.0 – S – jurisdiction. Where a plumbing code is not adopted or where Selective Surface. A special coating applied to solar col- the content of the plumbing code adopted by the jurisdiction lectors, having high absorption and low emission factors. is not applicable, then plumbing code shall mean the Uniform Shall. Plumbing Code (UPC) promulgated by the International Indicates a mandatory requirement. Association of Plumbing and Mechanical Officials (IAPMO). Size. See Diameter. Pollution. An impairment of the quality of the potable water Solar Cell. The basic PV device that generates electricity to a degree that does not create a hazard to the public health when exposed to light. [NFPA 70:690.2] but which does adversely and unreasonably affect the aes- Solar Collector. A device used to absorb energy from the thetic qualities of such potable water for domestic use. Also sun. defined as Low Hazard. Solar Constant. Potable Water. The average amount of solar radiation Water that is satisfactory for drinking, culi- reaching the earth’s atmosphere per unit time [about 2 lang- nary, and domestic purposes and that meets the requirements leys per minute [1395 J/(m2•s)]. of the Health Authority Having Jurisdiction. Solar Energy System. Pressure. A configuration of equipment and The normal force exerted by a homogeneous liq- components to collect, convey, store, and convert the sun’s uid or gas, per unit of area, on the wall of the container. energy for a purpose. Pressure, Residual. The pressure available at the fix- Solar Energy System Components. Any appliance, ture or water outlet after allowance is made for pressure assembly, device, equipment, or piping used in the conver- drop due to friction loss, head, meter, and other losses in sion of solar energy into thermal energy for service water the system during maximum demand periods. heating, pool water heating, space heating and cooling, and Pressure, Static. The pressure existing without any electrical service. flow. Solar Thermal System. A complete assembly of subsys- Pressure-Limiting Device. A pressure-responsive mech- tems which convert solar energy into thermal energy and uti- anism designed to automatically stop the operation of the lize this energy for service water heating, pool water heating, pressure-imposing element at a predetermined pressure. space heating and cooling purposes.

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Stand-Alone System. A solar PV system that supplies Transfer System. The intermediate piping, ducts, or both power independently of an electrical production and distri- between the various components of the solar system. bution network. [NFPA 70:690.2] Transfer Time. Time period during which energy is trans- Standard. A document, the main text of which contains only ferred through the connections for charge (x=C) or discharge mandatory provisions using the word “shall” to indicate (x=D). The transfer time is calculated over one of more test requirements and which is in a form generally suitable for sequences, excluding time periods used for conditioning at mandatory reference by another standard or code or for adop- the beginning of the test sequences. tion into law. Nonmandatory provisions shall be located in an Trickling Collector. A solar collector in which fluids free appendix, footnote, or fine print note and are not to be con- flow over the collector surface. sidered a part of the requirements of a standard. Standard Air. Air weighing 0.075 of a pound per cubic foot 223.0 – U – (lb/ft3) (1.20 kg/m3) and is equivalent in density to dry air at a temperature of 70°F (21°C) and standard barometric pres- No definitions. sure of 29.92 of an inch Hg. (101.32 kPa). Storage Tank. See Thermal Storage. 224.0 – V – Storage Temperature. Temperature of the storage medium. Valve, Pressure-Relief. A pressure-actuated valve held Stored Energy. Accumulated energy that is available for closed by a spring or other means and designed to automati- use. cally relieve pressure in excess of its setting. Venetian Blind Collector. Stratified. State where thermal stratification is inside the A solar collector in which mov- storage. able vanes are employed to absorb or reject energy. Subarray. An electrical subset of a PV array. [NFPA 70:690.2] 225.0 – W – Supports. Supports, hangers, and anchors are devices for Water-Distribution Pipe. In a building or premises, a pipe properly supporting and securing pipe, fixtures, and equip- that conveys potable water from the building supply pipe to ment. the plumbing fixtures and other water outlets. Water Supply System. The building supply pipe, the 222.0 – T – water-distribution pipes, and the necessary connecting pipes, Termination, Duct. The final or intended end-portion of a fittings, control valves, backflow prevention devices, and all duct system that is designed and functions to fulfill the obli- appurtenances carrying or supplying potable water in or adja- gations of the system in a satisfactory manner. [NFPA cent to the building or premises. 96:3.3.19] Water Well. An excavation that is drilled, cored, bored, Thermal Storage. A tank or vessel used in a solar thermal, washed, driven, dug, jetted, or otherwise constructed for the hydronic, or geothermal system, in which thermal energy is purposes of extracting groundwater, using the geothermal stored. properties of the earth or injecting water into an aquifer or subsurface reservoir. Thermal Stratification. State where the local storage temperature is a function of the vertical storage height, with the temperature decreasing from top to bottom. 226.0 – X – Thermosiphon. The natural circulation of fluids due to No definitions. temperature differential. Tilt Angle. The angle above horizontal of a plane surface. 227.0 – Y – Time Constant. The time required for the fluid leaving a No definitions. solar collector to attain 63.2 percent of its steady state value following a step change in insolation or inlet fluid temperature. 228.0 – Z – Total Alkalinity. The sum of all alkaline minerals in the water that is primarily in bicarbonate form, but also as No definitions. sodium, calcium, magnesium, potassium carbonates, and hydroxides. It is a measure of the water’s ability to resist changes in pH. Total Dissolved Solids (TDS). A measure (by electrical conductivity) of the amount of soluble matter that is present in the water. Total Incident Irradiation. The total solar radiant energy incident upon a unit surface area during a specified time period expressed in British thermal unit per square foot (Btu/ft2) (J/m2).

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301.0 General. 302.1.3 Existing Buildings. In existing buildings or 301.1 Applicability. This chapter shall govern the general premises in which system installations are to be altered, requirements for the installation, design, construction, and repaired, or renovated, the Authority Having Jurisdiction repair of a solar energy, hydronic, or geothermal system. has discretionary powers to permit deviation from the provisions of this code, provided that such proposal to deviate is first submitted for proper determination in 302.0 Standards and Alternates. order that health and safety requirements, as they pertain 302.1 Minimum Standards. Pipe, pipe fittings, appliances, to the system, shall be observed. 302.2 Alternate Materials and Methods of Construc- appurtenances, equipment, material, and devices used shall tion Equivalency. be listed (third party certified) by a listing agency (accredited Nothing in this code is intended to pre- conformity assessment body) as complying with the approved vent the use of systems, methods, or devices of equivalent or applicable recognized standards referenced in this code, and superior quality, strength, fire-resistance, effectiveness, dura- shall be free from defects. Unless otherwise provided for in bility, and safety over those prescribed by this code. Techni- this code, materials, appurtenances, or devices used or enter- cal documentation shall be submitted to the Authority Having ing into the construction of a system, or parts thereof, shall be Jurisdiction to demonstrate equivalency. The Authority Hav- submitted to the Authority Having Jurisdiction for approval. ing Jurisdiction shall have the authority to approve or disap- prove the system, method, or device for the intended purpose. 302.1.1 Marking. Each length of pipe and each pipe fit- However, the exercise of this discretionary approval by ting, material, and device used shall have cast, stamped, the Authority Having Jurisdiction shall have no effect beyond or indelibly marked on it any markings required by the the jurisdictional boundaries of said Authority Having Juris- applicable referenced standards and listing agency, and diction. An alternate material or method of construction so the manufacturer’s mark or name, which shall readily approved shall not be considered as in accordance with the identify the manufacturer to the end user of the product. requirements, intent, or both of this code for a purpose other Where required by the approved standard that applies, than that granted by the Authority Having Jurisdiction where the product shall be marked with the weight and the qual- the submitted data does not prove equivalency. ity of the product. Materials and devices used or entering 302.2.1 Testing. The Authority Having Jurisdiction into the construction of a system, or parts thereof shall be shall have the authority to require tests, as proof of equiv- marked and identified in a manner satisfactory to the alency. Authority Having Jurisdiction. Such marking shall be 302.2.1.1 Tests. Tests shall be made in accordance done by the manufacturer. Field markings shall not be with approved or applicable standards, by an acceptable. approved testing agency at the expense of the appli- Exception: Markings shall not be required on nipples cant. In the absence of such standards, the Authority created from cutting and threading of approved pipe. Having Jurisdiction shall have the authority to spec- 302.1.2 Standards. Standards listed or referred to in ify the test procedure. this chapter or other chapters cover materials that will 302.2.1.2 Request by Authority Having Juris- conform to the requirements of this code, where used in diction. The Authority Having Jurisdiction shall accordance with the limitations imposed in this or other have the authority to require tests to be made or chapters thereof and their listing. Where a standard cov- repeated where there is a reason to believe that a ers materials of various grades, weights, quality, or con- material or device no longer is in accordance with figurations, the portion of the listed standard that is the requirements on which its approval was based. applicable shall be used. Design and materials for spe- 302.3 Flood Hazard Areas. Systems shall be located cial conditions or materials not provided for herein shall above the elevation in accordance with the building code for be permitted to be used by special permission of the utilities and attendant equipment or the elevation of the low- Authority Having Jurisdiction after the Authority Hav- est floor, whichever is higher. ing Jurisdiction has been satisfied as to their adequacy. A Exception: Systems shall be permitted to be located below list of standards that appear in specific sections of this the elevation in accordance with the building code for utilities code are referenced in Table 901.1. Standards referenced and attendant equipment or the elevation of the lowest floor, in Table 901.1 shall be applied as indicated in the appli- whichever is higher, provided that the systems are designed cable referenced section. A list of additional standards, and installed to prevent water from entering or accumulating publications, practices and guides that are not referenced within their components and the systems are constructed to in specific sections of this code appear in Table 901.2. resist hydrostatic and hydrodynamic loads and stresses, The documents indicated in Table 901.2 shall be permit- including the effects of buoyancy, during the occurrence of ted in accordance with Section 302.2. flooding to such elevation.

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302.3.1 Coastal High Hazard Areas. Systems in dance with the submitted testing and inspection plan and buildings located in coastal high hazard areas shall be in the requirements of this code. accordance with the requirements of Section 302.3, and systems, pipes, tubing, and appurtenances shall not be 303.0 Iron Pipe Size (IPS) Pipe. mounted on or penetrate through walls that are intended 303.1 General. to breakaway under flood loads in accordance with the Iron, steel, brass, and copper pipe shall be building code. standard-weight iron pipe size (IPS) pipe. 302.3.2 Flood Resistant Materials. System components installed in flood hazard areas and below the design 304.0 Accessibility for Service. flood elevation shall be made of flood damage-resistant 304.1 General. All Aappliances shall be located with materials. respect to building construction and other equipment so as to 302.4 Alternative Engineered Design. An alternative permit access to the appliance. Sufficient clearance shall be engineered design shall comply with the intent of the provi- maintained to permit cleaning of heating surfaces; the sions of this code and shall provide an equivalent level of replacement of filters, blowers, motors, burners, controls, and quality, strength, effectiveness, fire resistance, durability, and vent connections; the lubrication of moving parts where nec- safety. Material, equipment, or components shall be designed essary; the adjustment and cleaning of burners and pilots; and and installed in accordance with the manufacturer’s installa- the proper functioning of explosion vents, where if provided. tion instructions. For attic installation, the passageway and servicing area adja- 302.4.1 Permit Application. The registered design cent to the appliance shall be floored. [NFPA 54:9.2.1] professional shall indicate on the design documents that Unless otherwise specified, not less than 30 inches (762 the system, or parts thereof, is an alternative engineered mm) in depth, width, and height of working space shall be design so that it is noted on the construction permit appli- provided. cation. The permit and permanent permit records shall indicate that an alternative engineered design was part of Exception: A platform shall not be required for unit heaters the approved installation. or room heaters. 304.2 Access to Appliances on Roofs. 302.4.2 Technical Data. The registered design pro- Appliances fessional shall submit sufficient technical data to sub- located on roofs or other elevated locations shall be accessi- stantiate the proposed alternative engineered design and ble. [NFPA 54:9.4.3.1] to prove that the performance meets the intent of this 304.2.1 Access. Buildings exceeding 15 feet (4572 code. mm) in height shall have an inside means of access to 302.4.3 Design Documents. The registered design the roof unless other means acceptable to the Authority professional shall provide two complete sets of signed Having Jurisdiction are used. and sealed design documents for the alternative engi- Exception: In Group R occupancies of less than 6 neered design for submittal to the Authority Having dwelling units and Group U occupancies. Jurisdiction. The design documents shall include floor 304.2.2 Access Type. The inside means of access shall plans of the work. Where appropriate, the design docu- be a permanent or foldaway inside stairway or ladder, ments shall indicate location, sizing, and loading of terminating in an enclosure, scuttle, or trap door. Such appurtenances, equipment, appliances, and devices. scuttles or trap doors shall be at least 22 inches by 24 302.4.4 Design Approval. An approval of an alterna- inches (559 mm by 610 mm) in size, shall open easily tive engineered design shall be at the discretion of the and safely under all conditions, especially snow;, and Authority Having Jurisdiction. The exercise of this dis- shall be constructed so as to permit access from the roof cretionary approval by the Authority Having Jurisdiction side unless deliberately locked on the inside. shall have no effect beyond the jurisdictional boundaries At least 6 feet (1829 mm) of clearance shall be avail- of said Authority Having Jurisdiction. An alternative able between the access opening and the edge of the roof or engineered design so approved shall not be considered similar hazard or rigidly fixed rails or guards a minimum of as in accordance with the requirements, intent, or both 42 inches (1067 mm) in height shall be provided on the of this code for a purpose other than that granted by the exposed side. Where parapets or other building structures Authority Having Jurisdiction. 302.4.5 Design Review. are utilized in lieu of guards or rails, they shall be a mini- The Authority Having Juris- mum of 42 inches (1067 mm) in height. [NFPA 54:9.4.3.3] diction shall have the authority to require testing of the 304.2.3 Permanent Ladders. alternative engineered design in accordance with Section Permanent ladders 302.2.1, including the authority to require an independ- required by Section 304.2.2 shall be constructed in accor- ent review of the design documents by a registered dance with the following: design professional selected by the Authority Having (1) Side railings shall extend not less than 30 inches Jurisdiction and at the expense of the applicant. (762 mm) above the roof or parapet wall. 302.4.6 Inspection and Testing. The alternative (2) Landings shall not exceed 18 feet (5486 mm) apart engineered design shall be tested and inspected in accor- measured from the finished grade.

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(3) Width shall be not less than 14 inches (356 mm) on 304.4.2 Fasteners. All access locks, screws, and bolts center. shall be of corrosion-resistant material. [NFPA (4) Rungs spacing shall not exceed 12 inches (305 mm) 54:9.4.1.3] on center, and each rung shall be capable of sup- 304.4.3 Installation of Appliances on Roofs. porting a 300 pound (136.1 kg) load. Appliances shall be installed in accordance with the man- (5) Toe space shall be not less than 6 inches (152 mm). ufacturer’s installation instructions. [NFPA 54:9.4.2.1] 304.4.4 Clearance. 304.2.4 Permanent Lighting. Permanent lighting Equipment and appliances shall be shall be provided at the roof access. The switch for such installed on a well-drained surface of the roof. Not less lighting shall be located inside the building near the than 6 feet (1829 mm) of clearance shall be between a access means leading to the roof. [NFPA 54:9.4.3.4] part of the equipment or appliance and the edge of a roof 304.2.5 Sloped Roof. or similar hazard, or rigidly fixed rails, guards, parapets, Where equipment or appliances or other building structures not less than 42 inches (1067 that require service are installed on a roof having a slope mm) in height shall be provided on the exposed side. of 4 units vertical in 12 units horizontal (33 percent Clearance requirements shall not apply to solar equip- slope) or more, a level platform of not less than 30 inches ment. by 30 inches (762 mm by 762 mm) shall be provided at 304.4.5 Electrical Power. All appliances requiring an the service side of the equipment or appliance. 304.3 Appliances in Attics and Under-Floor Spaces. external source of electrical power for its operation shall be provided with the following: An attic or under floor space in which an appliance is installed (1) A readily accessible electrical disconnecting means shall be accessible through an opening and passageway not within sight of the appliance that completely de- less than the largest component of the appliance, and not less energizes the appliance. than 22 inches by 30 inches (559 mm by 762 mm). 304.3.1 Length of Passageway. (2) A 120V ac grounding-type receptacle outlet on the Where the height of roof adjacent to the appliance on the supply side of the passageway is less than 6 feet (1829 mm), the dis- the disconnect switch. [NFPA 54:9.4.2.3] tance from the passageway access to the appliance shall 304.4.6 Platform or Walkway. not exceed 20 feet (6096 mm) measured along the cen- Where water stands on terline of the passageway. [NFPA 54:9.5.1.1] the roof at the appliance or in the passageways to the 304.3.2 Width of Passageway. appliance, or where the roof is of a design having a water The passageway shall seal, a suitable platform, walkway, or both shall be pro- be unobstructed and shall have solid flooring not less vided above the waterline. Such platform(s) or walk- than 24 inches (610 mm) wide from the entrance open- way(s) shall be located adjacent to the appliance and ing to the appliance. [NFPA 54:9.5.1.2] control panels so that the appliance can be safely serv- 304.3.3 Work Platform. A level working platform not iced where water stands on the roof. [NFPA 54:9.4.2.4] less than 30 inches by 30 inches (762 mm by 762 mm) shall be provided in front of the service side of the appli- 305.0 Installation. ance. [NFPA 54:9.5.2] 305.1 Listed Appliances. Except as otherwise provided Exception: A working platform need not be provided in this code, the installation of appliances regulated by this where the furnace is capable of being serviced from the code shall be in accordance with the conditions of the listing. required access opening. The furnace service side shall The appliance installer shall leave the manufacturer’s instal- not exceed 12 inches (305 mm) from the access opening. lation and operating instructions attached to the appliance. 304.3.4 Lighting and Convenience Outlet. A per- Clearances of listed appliances from combustible materials manent 120V receptacle outlet and a lighting fixture shall shall be as specified in the listing or on the rating plate. be installed near the appliance. The switch controlling 305.2 Dissimilar Metals. Except for necessary valves, the lighting fixture shall be located at the entrance to the where intermembering or mixing of dissimilar metals occur, passageway. [NFPA 54:9.5.3] the point of connection shall be confined to exposed or acces- 304.4 Appliances on Roofs. Appliances on roofs shall be sible locations. designed or enclosed so as to withstand climatic conditions in The Authority Having Jurisdiction shall be permitted to the area in which they are installed. Where enclosures are pro- require the use of an approved dielectric insulator on the pip- vided, each enclosure shall permit easy entry and movement, ing connections of an open-loop system. shall be of reasonable height, and shall have at least a 30 inch 305.3 Direction of Flow. Valves, pipes, and fittings shall be (762 mm) clearance between the entire service access panel(s) installed in correct relationship to the direction of flow. of the appliance and the wall of the enclosure. [NFPA 305.4 Changes in Direction. Changes in direction shall be 54:9.4.1.1] 304.4.1 Load Capacity. made by the approved use of fittings, except that changes in Roofs on which appliances direction in copper tubing shall be permitted to be made with are to be installed shall be capable of supporting the addi- bends provided that such bends are made with bending equip- tional load or shall be reinforced to support the additional ment that does not deform or create a loss in the cross-sec- load. [NFPA 54:9.4.1.2] tional area of the tubing.

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305.5 Improper Location. Piping or equipment shall not 306.3 Burred Ends. Burred ends of pipe and tubing shall be located as to interfere with the normal use thereof or with be reamed to the full bore of the pipe or tube, and chips shall the normal operation and use of windows, doors, or other be removed. required facilities. 306.4 Installation Practices. A system shall be installed 305.6 Insulation. Piping, tubing, and fittings shall be insu- in a manner that is in accordance with this code, applicable lated where located in areas capable of reaching a surface standards, and the manufacturer’s installation instructions. temperature below the dew point of the surrounding air and 306.4.1 On-Site. The installer shall leave the manu- located in spaces or areas where condensation is capable of facturer’s installation and operating instructions with the creating a hazard for the building occupants or damage to the system owner. structure. 305.7 Drainage Pan. Where a water heater, boiler, or ther- 307.0 Labeling. mal storage tank is located in an attic, or in or on an attic-ceiling assembly, floor-ceiling assembly, or floor subfloor 307.1 Fuel-Burning Appliances. Fuel-burning heating assembly where damage results from a leaking water heater, appliances shall bear a permanent and legible factory applied boiler, or tank, a watertight pan of corrosion-resistant mate- nameplate on which shall appear: rials shall be installed beneath the water heater, boiler, or tank, 3 (1) The name or trademark of the manufacturer. with not less than ⁄4 of an inch (20 mm) diameter drain to an 1 approved location. Such pan shall be not less than 1 ⁄2 inches (2) The approved fuel input rating of the appliance, (38 mm) in depth. expressed in Btu/h (kW). 305.8 Anchorage. Appliances and equipment designed to (3) The model number or equivalent. be fixed in position shall be securely fastened in place in (4) The serial number. accordance with the manufacturer’s installation instructions. (5) Instructions for the lighting, operation, and shutdown of The supports shall be designed and constructed to sustain ver- the appliance. tical and horizontal loads within the stress limitations specified in the building code. (6) The type of fuel approved for use with the appliance. 305.9 Structural Design Loads. System components, (7) The symbol of an approved agency certifying compli- including building components and attachments, shall be ance of the equipment with recognized standards. designed and constructed to withstand the following loads in (8) Required clearances from combustible surfaces on which accordance with the building code: or adjacent to which it is permitted to be mounted. (1) Dead loads 307.2 Electric Heating Appliances. Electric heating (2) Live loads appliances shall bear a permanent and legible factory applied (3) Snow loads nameplate on which shall appear: (4) Wind loads (1) The name or trademark of the manufacturer. (5) Seismic loads (2) The model number or equivalent. (6) Flood loads (3) The serial number. (7) Expansion and contraction loads resulting from temper- (4) The electrical rating in volts, amperes (or watts), and, for ature changes other than single phase, the number of phases. 305.10 Location. Except as otherwise provided in this code, (5) The output rating in Btu/h (kW). no system, or parts thereof shall be located in a lot other than (6) The electrical rating in volts, amperes, or watts of each the lot that is the site of the building, structure, or premises field-replaceable electrical component. served by such facilities. 305.11 Ownership. (7) The symbol of an approved agency certifying compli- No subdivision, sale, or transfer of ance of equipment with recognized standards. ownership of existing property shall be made in such manner that the area, clearance, and access requirements of this code (8) Required clearances from combustible surfaces on which are decreased. or adjacent to which it is permitted to be mounted. An appliance shall be accompanied by clear and com- 306.0 Workmanship. plete installation instructions, including required clearances 306.1 Engineering Practices. from combustibles other than mounting or adjacent surfaces, Design, construction, and and temperature rating of field-installed wiring connections workmanship shall comply with accepted engineering prac- exceeding 140°F (60°C). tices and shall be of such character as to secure the results 307.3 Heat Pump and Electric Cooling Appliances. sought to be obtained by this code. 306.2 Concealing Imperfections. Heat pumps and electric cooling appliances shall bear a per- It is unlawful to con- manent and legible factory-applied nameplate on which shall ceal cracks, holes, or other imperfections in materials by appear: welding, brazing, or soldering or by using therein or thereon a paint, wax, tar, solvent cement, or other leak-sealing or (1) The name or trademark of the manufacturer. repair agent. (2) The model number or equivalent.

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(3) The serial number. vent the equipment from operating during a failure. Sep- (4) The amount and type of refrigerant. arate pumps shall be permitted to connect to a single gravity indirect waste where equipped with check valves (5) The factory test pressures or pressures applied. and approved by the Authority Having Jurisdiction. (6) The electrical rating in volts, amperes, and, for other than Motor operated condensate pumps rated 600 volts or less single phase, the number of phases. shall be listed and labeled in accordance with UL 778. (7) The output rating in Btu/h (kW). 308.2 Condensate Control. Where an equipment or appli- (8) The electrical rating in volts, amperes, or watts of each ance is installed in a space where damage is capable of result- field replaceable electrical component. ing from condensate overflow, other than damage to (9) The symbol of an approved agency certifying compli- replaceable lay-in ceiling tiles, a drain line shall be provided ance of the equipment with recognized standards. and shall be drained in accordance with Section 308.1. An (10) Required clearances from combustible surfaces on which additional protection method for condensate overflow shall or adjacent to which it is permitted to be mounted. be provided in accordance with one of the following: An appliance shall be accompanied by clear and com- (1) A water level detecting device that will shut off the plete installation instructions, including required clearances equipment or appliance in the event the primary drain is from combustible other than mounting or adjacent surfaces, blocked. and temperature rating of field-installed wiring connections (2) An additional watertight pan of corrosion-resistant mate- exceeding 140°F (60°C). rial, with a separate drain line, installed beneath the cool- 307.4 Absorption Units. Absorption units shall bear a per- ing coil, unit, or appliance to catch the overflow manent and legible factory-applied nameplate on which shall condensate due to a clogged primary condensate drain. appear: (3) An additional drain line at a level that is higher that the (1) The name or trademark of the manufacturer. primary drain line connection of the drain pan. (2) The model number or equivalent. (4) An additional watertight pan of corrosion-resistant material with a water level detection device installed beneath (3) The serial number. the cooling coil, unit, or the appliance to catch the over- (4) The amount and type of refrigerant. flow condensate due to a clogged primary condensate (5) Hourly rating in Btu/h (kW). drain and to shut off the equipment. (6) The type of fuel approved for use with the unit. The additional pan or the additional drain line connec- 3 4 (7) Cooling capacity Btu/h (kW). tion shall be provided with a drain pipe of not less than ⁄ of an inch (20 mm) nominal pipe size, discharging at a point that (8) Required clearances from combustible surfaces on which is readily observed. or adjacent to which it is permitted to be mounted. 308.2.1 Protection of Appurtenances. Where insu- (9) The symbol of an approved agency certifying compli- lation or appurtenances are installed where damage is ance of the equipment with recognized standards. capable of resulting from a condensate drain pan overfill, such installations shall occur above the rim of the drain 308.0 Condensate Wastes and Control. pan with supports. Where the supports are in contact with the condensate waste, the supports shall be of approved 308.1 Condensate Disposal. Condensate from air wash- corrosion-resistant material. ers, air-cooling coils, condensing appliances, and the over- 308.3 Condensate Waste Pipe Material and Sizing. flow from evaporative coolers and similar water supplied equipment or similar air-conditioning equipment shall be col- Condensate waste pipes from air-cooling coils shall be sized lected and discharged to an approved plumbing fixture or dis- in accordance with the equipment capacity as specified in posal area. Where discharged into the drainage system, Table 308.3. The material of the piping shall comply with the equipment shall drain by means of an indirect waste pipe. The pressure and temperature rating of the appliance or equip- 1 waste pipe shall have a slope of not less than ⁄8 inch per foot ment, and shall be approved for use with the liquid being dis- (10.4 mm/m) or 1 percent slope and shall be of approved cor- charged. rosion- resistant material not smaller than the outlet size in accordance with Section 308.3 or Section 308.4 for air-cool- TABLE 308.3 ing coils or condensing appliances, respectively. Condensate MINIMUM CONDENSATE PIPE SIZE MINIMUM CONDENSATE or wastewater shall not drain over a public way. EQUIPMENT CAPACITY IN TONS PIPE DIAMETER 308.1.1 Condensate Pumps. OF REFRIGERATION Where approved by the (inches) Authority Having Jurisdiction, condensate pumps shall 3 Up to 20 ⁄4 be installed in accordance with the manufacturer’s instal- 21 – 40 1 lation instructions. Pump discharge shall rise vertically to 1 41 – 90 1 ⁄4 a point where it is possible to connect to a gravity con- 1 densate drain and discharged to an approved disposal 91 – 125 1 ⁄2 point. Each condensing unit shall be provided with a sep- 126 – 250 2 arate sump and interlocked with the equipment to pre- For SI units: 1 ton of refrigeration = 3.52 kW, 1 inch = 25 mm

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The size of condensate waste pipes is for one unit or a 310.0 Circulators and Pumps. combination of units, or as recommended by the manufac- 310.1 General. 1 Circulators and pumps shall be selected for turer. The capacity of waste pipes assumes a ⁄8 inch per foot their intended use based on the heat transfer fluid, intended (10.4 mm/m) or 1 percent slope, with the pipe running three- operating temperature range and pressure. Circulators and quarters full at the following pipe conditions: pumps shall be installed to allow for service and maintenance. The manufacturer’s installation instructions shall be followed Outside Air – 20% Room Air – 80% for correct orientation and installation. Motor operated pumps DB WB DB WB rated 600V or less shall be listed and labeled in accordance 90°F 73°F 75°F 62.5°F with UL 778. 310.2 Mounting. For SI units: °C = (°F-32)/1.8 The circulator or pump shall be installed in such a way that strain from the piping is not transferred to the circulator or pump housing. The circulator or pump shall Condensate drain sizing for other slopes or other condi- be permitted to be directly connected to the piping, provided tions shall be approved by the Authority Having Jurisdiction. the piping is supported on each side of the circulator or pump. 308.3.1 Cleanouts. Condensate drain lines shall be Where the installation of a circulator or pump will cause configured or provided with a cleanout to permit the strain on the piping, the circulator or pump shall be installed clearing of blockages and for maintenance without on a mounting bracket or base plate. Where means for con- requiring the drain line to be cut. trolling vibration of a circulator or pump is required, an 308.4 Appliance Condensate Drains. Condensate drain approved means for support and restraint shall be provided. lines from individual condensing appliances shall be sized as 310.3 Sizing. The selection and sizing of a circulator or required by the manufacturer’s instructions. Condensate drain pump shall be based on all of the following: lines serving more than one appliance shall be approved by (1) Loop or system head pressure, feet of head (m) the Authority Having Jurisdiction prior to installation. (2) Capacity, gallons per minute (L/s) 308.5 Point of Discharge. Air-conditioning condensate (3) Maximum and minimum temperature, °F (°C) waste pipes shall connect indirectly, except where permitted in Section 308.6, to the drainage system through an air gap or (4) Maximum working pressure, pounds-force per square air break to trapped and vented receptors, dry wells, leach inch (kPa) pits, or the tailpiece of plumbing fixtures. A condensate drain (5) Fluid type shall be trapped in accordance with the appliance manufac- 310.4 Drainback Systems. For drainback solar thermal turer’s instructions or as approved. systems, a circulator without a check valve shall be installed. 308.6 Condensate Waste from Air-Conditioning 310.5 Pumps Used in Parallel. Coils. A check valve shall be Where the condensate waste from air conditioning installed downstream of each circulator installed in parallel. coils discharges by direct connection to a lavatory tailpiece or Circulators with integral check valves shall be permitted. to an approved accessible inlet on a bathtub overflow, the con- 310.6 Cavitation. Systems, which utilize circulators, shall nection shall be located in the area controlled by the same be designed such that the pressure of the system is more than person controlling the air-conditioned space. the vapor pressure of the liquid it conveys. 308.7 Plastic Fittings. Female plastic threaded fittings shall 310.7 Materials. Circulating pumps shall be constructed of be used with plastic male fittings and plastic male threads. materials that are compatible with the heat transfer medium. 310.8 Operation. 309.0 Safety Requirements. Over-temperature protection shall be provided for circulating pumps. The temperature set point of the 309.1 Welding. Welding shall be done by approved welders pump shall comply with the manufacturer’s instructions. The in accordance with nationally recognized standards. Such pumps shall automatically turn off when the system is not in welding shall be subject to the approval of the Authority Hav- operation. ing Jurisdiction. 309.2 Spark or Flame. Equipment that generates a glow, 311.0 Safety Devices. spark, or flame capable of igniting flammable vapors shall be 311.1 General. Solar thermal system components containing permitted to be installed in a residential garage provided the pressurized fluids shall be protected against pressures exceed- pilots and burners, heating elements, motors, controllers, or ing the design limitations with a pressure relief valve. switches are not less than 18 inches (457 mm) above the floor Hydronic or geothermal system components containing pres- level unless listed as flammable vapor ignition resistant. 309.3 Hazardous Heat-Transfer Mediums. surized fluids shall be protected against pressures and tem- Heat-trans- peratures exceeding design limitations with a pressure and fer mediums that are hazardous shall not be used, except temperature relief valve. Each section of the system in which where approved by the Authority Having Jurisdiction. excessive pressures are capable of developing shall have a 309.4 Discharge. The collector, collector manifold, and relief valve located so that a section is not capable of being manifold relief valve shall not discharge directly or indirectly isolated from a relief device. Pressure and temperature relief into the building or toward an open flame or other source of valves shall be installed in accordance with the terms of their ignition. listing and the manufacturer’s installation instructions.

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311.2 Pressurized Vessels. Pressurized vessels shall be 312.7 Expansion Tanks. Isolation valves shall be installed provided with overpressure protection by means of a listed at connections to non-diaphragm-type expansion tanks. pressure relief valve installed in accordance with the manu- 312.8 Flow Balancing Valves. Where flow balancing facturer’s installation instructions. valves are installed, such valves shall be capable of increas- 311.3 Discharge Piping. The discharge piping serving a ing or decreasing the amount of flow by means of adjustment. temperature relief valve, pressure relief valve, or combina- 312.8.1 Location. Balancing valves shall be installed tion of both shall have no valves, obstructions, or means of at the outlet of each group of collectors. isolation and be provided with the following: 312.9 Control Valves. An approved three-way valve shall (1) Equal to the size of the valve outlet and shall discharge be permitted to be installed for manual control systems. An full size to the flood level of the area receiving the dis- approved electric control valve shall be permitted to be charge and pointing down. installed for automatic control systems. The installation and (2) Materials shall be rated at not less than the operating tem- operation of automatic control valves shall comply with the perature of the system and approved for such use. manufacturer’s instructions. 312.9.1 Mixing or Temperature Control Valves. (3) Discharge pipe shall discharge independently by gravity through an air gap into the drainage system or outside of Where mixing or temperature control valves are the building with the end of the pipe not exceeding 2 feet installed, such valves shall be capable of obtaining the (610 mm) and not less than 6 inches (152 mm) above the design water temperature and design flow requirements. ground and pointing downwards. 312.10 Thermosiphoning. An approved type check valve (4) Discharge in such a manner that does not cause personal shall be installed on hydronic piping to control thermosi- injury or structural damage. phoning of heated fluids. 312.11 Air Removal Device or Air Vents. (5) No part of such discharge pipe shall be trapped or subject Isolation to freezing. valves shall be installed where air removal devices or automatic air vents are utilized to permit cleaning, inspection, or (6) The terminal end of the pipe shall not be threaded. repair without shutting the system down. (7) Discharge from a relief valve into a water heater pan 312.12 Closed-Loop Systems. Closed-loop systems, shall be prohibited. 311.4 Vacuum Relief Valves. where hose bibbs or similar valves are used to charge or drain System components that are the system, shall be of loose key type; have valve outlets subjected to a vacuum while in operation or during shutdown capped; or have handles removed where the system is opera- shall be protected with vacuum relief valves. Where the pip- tional. ing configuration, equipment location, and valve outlets are 312.13 Fullway Valves. A fullway valve shall be installed located below the storage tank elevation, the system shall be in the following locations: equipped with a vacuum relief valve at the highest point. (1) On the water supply to a solar thermal system. 311.5 Temperature Regulation. Where a system is capable of providing potable water at temperatures that exceed (2) On the water supply pipe to a gravity or pressurized 140°F (60°C), a thermostatic mixing valve that is in accor- water tank. dance with ASSE 1017 shall be provided to limit the water (3) On the water supply pipe to a water heater. supplied to the potable hot water distribution system to a tem- 312.14 Accessible. Required fullway or shutoff valves perature of 140°F (60°C) or less. shall be accessible.

312.0 Valves. 313.0 Heat Exchangers. 312.1 General. Valves shall be rated for the operating tem- 313.1 General. Systems utilizing heat exchangers shall pro- perature and pressure of the system. Valves shall be compati- tect the potable water system from being contaminated by the ble with the type of heat transfer medium and piping material. heat transfer medium. Systems that incorporate a single-wall 312.2 Where Required. Valves shall be installed in a solar heat exchanger to separate potable water from the heat-trans- thermal, hydronic, or geothermal system in accordance with fer fluid shall meet the following requirements: Section 312.3 through Section 312.14. (1) Heat transfer medium is either potable water or contains 312.3 Heat Exchanger. Isolation valves shall be installed fluids recognized as safe by the Food and Drug Admin- on the supply and return side of the heat exchanger. istration (FDA) as food grade. 312.4 Pressure Vessels. Isolation valves shall be installed (2) A tag or label shall be securely affixed to the heat source on connections to pressure vessels. with the word “CAUTION” and the following state- 312.5 Pressure Reducing Valves. Isolation valves shall ments: be installed on both sides of a pressure reducing valve. (a) The heat transfer medium shall be water or other 312.6 Equipment, Components, and Appliances. nontoxic fluid recognized as safe by the FDA. Serviceable equipment, components, and appliances within (b) The maximum operating pressure of the heat the system shall have isolation valves installed upstream and exchanger shall not exceed the maximum operating downstream of such devices. pressure of the potable water supply.

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(3) The word “CAUTION” and the statements listed above 316.2 Connections to Drainage System Required. shall have an uppercase height of not less than 0.120 of Receptors, drains, appurtenances, and appliances, used to an inch (3.05 mm). The vertical spacing between lines of receive or discharge liquid wastes, shall be connected to the type shall be not less than 0.046 of an inch (1.168 mm). drainage system of the building or premises in accordance Lowercase letters shall be not less than compatible with with the requirements of this code. the uppercase letter size specification. 316.3 Drainage. For heating or hot-water-supply boiler Systems that do not comply with the requirements for a applications, the boiler room shall be equipped with a floor single-wall heat exchanger shall install a double-wall heat drain or other approved means for disposing of the accumu- exchanger. Double-wall heat exchangers shall separate the lation of liquid wastes incident to cleaning, recharging, and potable water from the heat transfer medium by providing a routine maintenance. No steam pipe shall be directly con- space between the two walls that are vented to the atmosphere. nected to a part of a plumbing or drainage system, nor shall a 313.2 Shutoff Valves. Shutoff valves shall be installed on water having a temperature above 140°F (60°C) be dis- the supply and return side of a heat exchanger. charged under pressure directly into a part of a drainage sys- Exception: Where a heat exchanger is an integral part of a tem. Pipes from boilers shall discharge by means of indirect boiler or is a part of a manufactured boiler and heat exchanger waste piping, as determined by the Authority Having Juris- packaged unit, and is capable of being isolated from the diction or the boiler manufacturer’s instructions. hydronic system by supply and return valves. 316.4 Nonpotable Discharge. The discharge location for a relief device on a system utilizing other than potable water 314.0 Unlawful Connections. shall be in accordance with Section 316.1. 314.1 Prohibited Installation. No piping installation, or part thereof, shall be made in such a manner that it will be 317.0 Hangers and Supports. possible for used, unclean, polluted, or contaminated water, 317.1 General. Piping, tubing, appliances, and appurte- mixtures, or substances to enter a portion of the potable water nances shall be supported in accordance with this code, the system from a pipe, tank, receptor, or equipment by reason manufacturer’s installation instructions, and in accordance of backsiphonage, suction, or other cause, either during nor- with the Authority Having Jurisdiction. mal use and operation thereof, or where such pipe, tank, 317.2 Material. receptor, or equipment is subject to pressure exceeding the Hangers and anchors shall be of sufficient operating pressure in the potable water system. strength to support the weight of the pipe or tubing, and its contents. Piping shall be isolated from incompatible materials. 317.3 Suspended Piping. 315.0 Electrical. Suspended piping or tubing 315.1 Wiring. shall be supported at intervals not to exceed those shown in Electrical connections, wiring and devices Table 317.3. shall be installed in accordance with NFPA 70. Electrical 317.4 Alignment. equipment, appliances, and devices installed in areas that con- Piping or tubing shall be supported in such tain flammable vapors or dusts shall be of a type approved a manner as to maintain its alignment and prevent sagging. 317.5 Underground Installation. for such environment. Piping or tubing in the 315.2 Controls. Required electrical, mechanical, safety, and ground shall be laid on a firm bed for its entire length; where operating controls shall be listed and labeled by a listing other support is otherwise provided, it shall be approved in agency. Electrical controls shall be of such design and con- accordance with Section 302.0. struction as to be suitable for installation in the environment 317.6 Hanger Rod Sizes. Hanger rod sizes shall be not in which they are located. smaller than those shown in Table 317.6. 315.3 Solar Photovoltaic (PV) Systems. Solar photovoltaic systems shall be installed in accordance with Chapter 8. TABLE 317.6 315.3.1 Fire Code. Solar photovoltaic systems shall HANGER ROD SIZES comply with the requirements of the applicable fire code. PIPE AND TUBE SIZE ROD SIZE 315.3.2 Building Code. (inches) (inches) Solar photovoltaic systems 1 3 shall comply with the requirements of the applicable ⁄2 – 4 ⁄8 1 building code. 5 – 8 ⁄2 5 10 – 12 ⁄8 316.0 Disposal of Liquid Waste. For SI units: 1 inch = 25.4 mm 316.1 General. It shall be unlawful for a person to cause, 317.7 Strength. suffer, or permit the disposal of liquid wastes, heat transfer Hangers and supports shall be of sufficient medium, or other liquids, in a place or manner, except through strength to withstand all static and dynamic loading condi- and by means of an approved drainage system installed and tions in accordance with its intended use. Pipe and tube hang- maintained in accordance with the provisions of this code. ers and supports with direct contact with piping or tubing Waste that is deleterious to surface or subsurface waters shall shall be of approved materials that are compatible with the not be discharged into the ground or into a waterway. piping and will not cause galvanization.

22 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT GENERAL REGULATIONS

TABLE 317.3 HANGERS AND SUPPORTS MATERIALS TYPES OF JOINTS HORIZONTAL VERTICAL 5 feet, except 10 feet where Baseand each floor, Lead and Oakum 10 foot lengths areinstalled1, 2, 3 notto exceed 15 feet Cast Every other joint, unless over Baseand each floor, Compression Gasket 4 feet then support each joint1, 2, 3 notto exceed 15 feet Every other joint, unless over Baseand each floor, Cast Iron Hubless Shielded Coupling 4 feet then support each joint1, 2, 3, 4 notto exceed 15 feet 1 Copper & Copper Soldered, Brazed, Threaded, 1 ⁄2 inches and smaller, 6 feet; Each floor, notto exceed 10 feet5 Alloys or Mechanical 2 inches and larger, 10 feet 3 ⁄4 inch and smaller, 10 feet; Every other floor, Steel Pipe for Water Threaded or Welded 1 inch and larger, 12 feet notto exceed 25 feet5 Baseand each floor; provide Schedule 40 PVC and All sizes, 4 feet; allow for Solvent Cemented mid-story guides; Provide for ABS expansion every 30 feet3 expansion every 30 feet. 1 inch and smaller, 3 feet; Baseand each floor; CPVC Solvent Cemented 1 1 ⁄4 inches and larger, 4 feet provide mid-story guides Steel Mechanical In accordance with standards acceptable to the Authority Having Jurisdiction 1 inch and smaller, 32 inches; Baseand each floor; PE-RT Insertand Compression 1 1 ⁄4 inches and larger, 4 feet provided mid-story guides Cold Expansion 1 inch and smaller, 32 inches; Baseand each floor; PEX 1 Insertand Compression 1 ⁄4 inches and larger, 4 feet provide mid-story guides 1 ⁄2 inch Metal Insert and 3 Base and each floor; PEX-AL-PEX ⁄4 inch All sizes 98 inches Metal Compression provide mid-story guides 1 inch } 1 ⁄2 inch Metal Insert and 3 Base and each floor; PE-AL-PE ⁄4 inch All sizes 98 inches Metal Compression provide mid-story guides 1 inch } Fusion weld (socket, butt,saddle, 1 inch and smaller, 32 inches; Baseand each floor; Polypropylene (PP) electrofusion), threaded (metal 1 1 ⁄4 inches and larger, 4 feet provide mid-story guides threads only), or mechanical For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm Notes: 1 Support adjacent to joint, not to exceed 18 inches (457 mm). 2 Brace not to exceed 40 foot (12 192 mm) intervals to prevent horizontal movement. 3 Support at each horizontal branch connection. 4 Hangers shall not be placed on the coupling. 5 Vertical water lines shall be permitted to be supported in accordance with recognized engineering principles with regard to expansion and contraction, where first approved by the Authority Having Jurisdiction.

318.0 Protection of Piping, Materials, and Structures. 318.3 Fire-Resistant Construction. Piping penetrations of 318.1 General. Piping or tubing passing under or through fire-resistance-rated walls, partitions, floors, floor/ceiling assem- walls shall be protected from breakage. Piping passing blies, roof/ceiling assemblies, or shaft enclosures shall be pro- through or under cinders or other corrosive materials shall be tected in accordance with the requirements of the building code. protected from external corrosion in an approved manner. 318.4 Waterproofing of Openings. Joints at the roof Approved provisions shall be made for expansion of hot liq- around pipes, ducts, or other appurtenances shall be made uid piping. Voids around piping or tubing passing through watertight by the use of lead, copper, galvanized iron, or other concrete floors on the ground shall be sealed. approved flashings or flashing material. Exterior wall open- 318.2 Installation. Piping or tubing shall be installed so that ings shall be made watertight. piping, tubing, or connections will not be subject to undue 318.5 Steel Nail Plates. Plastic and copper or copper alloy strains or stresses, and provisions shall be made for expan- piping penetrating framing members to within 1 inch (25.4 sion, contraction, and structural settlement. No piping or tub- mm) of the exposed framing shall be protected by steel nail ing, unless designed and listed for such use, shall be directly plates not less than No. 18 gauge (0.0478 inches) (1.21 mm) embedded in concrete or masonry. No structural member shall in thickness. The steel nail plate shall extend along the fram- 1 be seriously weakened or impaired by cutting, notching, or ing member not less than 1 ⁄2 inches (38 mm) beyond the out- otherwise, as defined in the building code. side diameter of the pipe or tubing.

UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT 23 GENERAL REGULATIONS

318.6 Sleeves. Sleeves shall be provided to protect piping depth of the trench, with a maximum length of 8 feet (2438 through concrete and masonry walls, and concrete floors. mm). Where pipes are driven, the drive pipe shall be not less Exception: Sleeves shall not be required where openings are than one size larger than the pipe to be laid. drilled or bored. 320.3 Open Trenches. Excavations required to be made 318.6.1 Building Loads. Piping through concrete or for the installation of a system or a part thereof, within the masonry walls shall not be subject to a load from build- walls of a building, shall be open trench work and shall be ing construction. kept open until it has been inspected, tested, and accepted. 320.4 Excavations. 318.6.2 Exterior Walls. In exterior walls, annular Excavations shall be completely back- space between sleeves and pipes shall be sealed and filled as soon after inspection as practicable. Precaution shall made watertight, as approved by the Authority Having be taken to ensure compactness of backfill around piping Jurisdiction. A penetration through fire-resistive con- without damage to such piping. Trenches shall be backfilled struction shall be in accordance with Section 318.3. in thin layers to 12 inches (305 mm) above the top of the piping with clean earth, which shall not contain stones, boulders, 318.7 Firewalls. A pipe sleeve through a firewall shall have cinder fill, frozen earth, construction debris, or other materi- space around the pipe completely sealed with an approved als that will damage or break the piping or cause corrosive fire-resistive material in accordance with other codes. 318.8 Structural Members. action. Mechanical devices such as bulldozers, graders, etc., A structural member weak- shall be permitted to then be used to complete backfill to ened or impaired by cutting, notching, or otherwise shall be grade. Fill shall be properly compacted. Precautions shall be reinforced, repaired, or replaced so as to be left in a safe struc- taken to ensure permanent stability for pipe laid in filled or tural condition in accordance with the requirements of the made ground. building code. 318.9 Rodentproofing. Solar thermal, hydronic, and geot- 321.0 Abandonment. hermal systems shall be constructed in such a manner as to 321.1 General. restrict rodents or vermin from entering a building by fol- An abandoned system or part thereof shall be lowing the duct work from the outside into the building. disconnected from remaining systems, drained, plugged, and 318.10 Metal Collars. capped in an approved manner. In or on buildings where openings 321.2 Storage Tank. have been made in walls, floors, or ceilings for the passage of An underground water storage tank pipes, such openings shall be closed and protected by the that has been abandoned or discontinued otherwise from use installation of approved metal collars securely fastened to the shall be completely drained and filled with earth, sand, gravel, adjoining structure. concrete, or other approved material or removed in a manner satisfactory to the Authority Having Jurisdiction. 319.0 Protection of System Components. 322.0 Other Systems. 319.1 Materials. System components in contact with heat- 322.1 General. transfer mediums shall be approved for such use. Compo- Other systems installed in conjunction with nents, installed outdoors, shall be resistant to UV radiation. solar energy, hydronic, or geothermal systems for the purpose 319.2 Corrosion. Systems and components subject to cor- of domestic hot water, comfort cooling or heating, swimming rosion shall be protected in an approved manner. Metal parts pools, spas, or other similar facilities, shall comply with the exposed to atmospheric conditions shall be of corrosion-resis- applicable codes. 322.2 Duct Systems. tant material. Ducts and plenums that are portions 319.3 Mechanical Damage. Portions of a system installed of a heating, cooling, absorption or evaporative cooling, or where subjected to mechanical damage shall be guarded exhaust system shall comply with the requirements of the against such damage by being installed behind approved bar- Mechanical Code. riers or, where located within a garage, be elevated or located out of the normal path of a vehicle.

320.0 Trenching, Excavation, and Backfill. 320.1 Trenches. Trenches deeper than the footing of a building or structure, and paralleling the same, shall be located not less than 45 degrees (0.79 rad) from the bottom exterior edge of the footing, or as approved in accordance with Section 302.0. 320.2 Tunneling and Driving. Tunneling and driving shall be permitted to be done in yards, courts, or driveways of a building site. Where sufficient depth is available to permit, tunnels shall be permitted to be used between open-cut trenches. Tunnels shall have a clear height of 2 feet (610 mm) above the pipe and shall be limited in length to one-half the

24 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT CHAPTER 4 HYDRONICS

401.0 General. 402.0 Protection of Potable Water Supply. 401.1 Applicability. This chapter shall apply to hydronic 402.1 Prohibited Sources. Hydronic systems or parts piping systems that are part of heating, cooling, ventilation, thereof, shall be constructed in such a manner that polluted, refrigeration, and air conditioning systems. Such piping sys- contaminated water, or substances shall not enter a portion of tems include steam, hot water, chilled water, steam conden- the potable water system either during normal use or where sate, condenser water, solar thermal systems, and ground the system is subject to pressure that exceeds the operating source heat pump systems. The regulations of this chapter pressure in the potable water system. Piping, components, and shall govern the construction, location, and installation of devices in contact with the potable water shall be approved hydronic piping systems. for such use and where an additive is used it shall not affect 401.2 Insulation. the performance of the system. Surfaces within reach of building occu- 402.2 Chemical Injection. pants shall not exceed 140°F (60°C). Where sleeves are Where systems include an installed, the insulation shall continue full size through them. additive, chemical injection or provisions for such injection, the potable water supply shall be protected by an air gap, or Coverings and insulation used for piping shall be of a reduced-pressure principle backflow prevention assembly material approved for the operating temperature of the sys- listed and labeled in accordance with ASSE 1013. Such addi- tem and the installation environment. Where installed in a tive or chemical shall be compatible with system components. plenum, the insulation, jackets, and lap-seal adhesives, 402.2 402.3 Protection of Potable Water. including pipe coverings and linings, shall have a flame- The potable water system shall be protected from backflow in accordance spread index not to exceed 25 and a smoke-developed index with the Uniform Plumbing Code. not to exceed 50 where tested in accordance with ASTM E84 402.3 402.4 Compatibility. or UL 723. Fluids used in hydronic sys- 401.3 Water Hammer Protection. tems shall be compatible with all components that will contact The flow of the the fluid. Where a heat exchanger is installed with a dual pur- hydronic piping system shall be controlled designed to pre- pose water heater, such application shall comply with the vent water hammer. requirements for a single wall heat exchanger in Section 313.1. 401.4 Terminal Units. Terminal units, valves, and flow control devices shall be installed in accordance with the manu- 403.0 Capacity of Heat Source. facturer’s installation instructions. 403.1 Heat Source. 410.4 401.5 Return-Water Low-Temperature Protec- The heat source shall be sized to the tion. design load. Where a minimum return-water temperature to the heat 403.2 Dual Purpose Water Heater. source is specified by the manufacturer, the heating system Water heaters utilized shall be designed and installed to meet or exceed the mini- for combined space-and water-heating applications shall be mum return-water temperature during the normal operation listed and labeled in accordance with the standards referenced of the heat source. in Table 403.2, and shall be installed in accordance with the 401.4 401.6 Manifolds. manufacturer’s installation instructions. The total heating Manifolds shall be equipped with capacity of a dual purpose water heater shall be based on the isolation valves on the supply and return lines. Manifolds sum of the potable hot water requirements and the space heat- shall be capable of withstanding the pressure and tempera- ing design requirements corrected for hot water first hour ture of the system. The material of the manifold shall be com- draw recovery. patible with the system fluid and shall be installed in accordance with the manufacturer’s installation instructions. TABLE 403.2 WATER HEATERS 401.5 401.7 Heat Emitters. Heat emitters shall be installed in accordance with the manufacturer’s installation instruc- TYPE STANDARDS tions. Gas-Fired, 75,000 Btu/hr or less, Storage CSA Z21.10.1 401.6 401.8 Mechanical Devices. Where listed mechani- Gas-Fired, aAbove 75,000 Btu/hr, Storage, CSA Z21.10.3 cal devices are used, the manufacturer’s installation instruc- Circulating and Instantaneous tions as to the location and method of installation shall be Electric, sSpace hHeating UL 834 followed. Solid fFuel-Fired, hydronic UL 2523 401.7 401.9 Flexible Connectors. Listed flexible con- For SI units: 1000 British thermal units per hour = 0.293 kW nectors shall be installed in readily accessible locations, unless otherwise listed. 401.8 401.10 Freeze Protection. Hydronic systems and 403.3 Tankless Water Heater. Tankless water heaters used components shall be designed, installed, and protected from in space-heating applications shall be rated by the manufac- freezing. turer for space-heating applications, and the output perform-

UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT 25 HYDRONICS

ance shall be determined by the temperature rise and flow rate 405.0 Installation, Testing, and Inspection. of water through the unit. The ratings shall be expressed by 405.1 Operating Instructions. Operating and mainte- the water temperature rise at a given flow rate. Manufac- nance information shall be provided to the building owner. turer’s flow rates shall not be exceeded. 405.2 Pressure Testing. System piping and components shall be tested with a pressure of not less than one and one- 404.0 Identification of Piping Systems. half times the operating pressure but not less than 100 psi 404.1 General. In buildings where potable water and non- (689 kPa). Piping shall be tested with water or air except that potable water system are installed, each system shall be plastic pipe shall not be tested with air. Test pressures shall be clearly identified in accordance with Section 404.2 through held for a period of not less than 30 minutes with no percep- Section 404.5. tible drop in pressure. These tests shall be made in the presence of the Authority Having Jurisdiction. 404.2 Color and Information. Each system shall be identified with a colored pipe or band and coded with paints, Exception: For PEX, PP-R, PP-RCT, PEX-AL-PEX, PE-RT, wraps, and materials compatible with the piping. and PE-AL-PE piping systems, testing with air shall be permitted where authorized by the manufacturer’s instructions 404.3 Potable Water. Potable water systems shall be iden- for the PEX, PP-R, PP-RCT, PEX-AL-PEX, PE-RT, and PE- tified with a green background with white lettering. The min- AL-PE pipe and fittings products, and air testing is not pro- imum size of the letters and length of the color field shall be hibited by applicable codes, laws, or regulations outside this in accordance with Table 404.3. code. 405.3 Flushing. TABLE 404.3 Heating and cooling sources, system pip- MINIMUM LENGTH OF COLOR FIELD AND SIZE OF LETTERS ing and tubing shall be flushed after installation with water or OUTSIDE DIAMETER OF MINIMUM LENGTH OF MINIMUM SIZE OF a cleaning solution. Cleaning and flushing of the heating and PIPE OR COVERING COLOR FIELD LETTERS cooling sources shall comply with the manufacturer’s instruc- (inches) (inches) (inches) tions. The cleaning solution shall be compatible with all sys- 1 1 1 ⁄2 to 1 ⁄4 8 ⁄2 tem components and shall be used in accordance with the 1 3 manufacturer’s instructions. 1 ⁄2 to 2 8 ⁄4 1 1 2 ⁄2 to 6 12 1 ⁄4 406.0 Pressure and Safety Devices. 1 2 8 to 10 24 2 ⁄ 406.1 General. 1 Each closed hydronic system shall be pro- Over 10 32 3 ⁄2 tected against pressures exceeding design limitations with not For SI units: 1 inch = 25.4 mm less than one pressure relief valve. Each closed section of the system containing a heat source shall have a relief valve located so that the heat source is not capable of being isolated 404.4 Nonpotable Water. Nonpotable water systems shall from a relief device. Pressure relief valves shall be installed have a yellow background with black uppercase lettering, with in accordance with their listing and the manufacturer’s instal- words “CAUTION: NONPOTABLE WATER, DO NOT lation instructions. DRINK.” Each nonpotable system shall be identified to des- 406.2 Discharge Piping. ignate the liquid being conveyed, and the direction of normal The discharge piping serving a flow shall be clearly shown. The minimum size of the letters temperature relief valve, pressure relief valve, or combina- and length of the color field shall comply with Table 404.3. tion of both shall be in accordance with Section 311.3. 404.5 Location of Piping Identification. The background color and required information shall be indicated 406.0 407.0 Heating Appliances and Equipment. every 20 feet (6096 mm) but not less than once per room, and 406.1 407.1 General. Heating appliances, equipment, safety shall be visible from the floor level. and operational controls shall be listed for their intended use 404.6 Flow Directions. Flow directions shall be indicated in a hydronic heating system and installed in accordance with on the system. the manufacturer’s installation instructions. 404.7 Heat Transfer Fluid. Solar thermal piping shall be 406.2 407.2 Boilers. Boilers and their controls systems shall identified with an orange background with black uppercase comply with the mechanical code. lettering, with the words “CAUTION: HEAT TRANSFER 406.2.1 407.2.1 Condensing Boilers. A condensing FLUID, DO NOT DRINK.” Each solar thermal system shall boiler, in which the heat exchanger and venting system be identified to designate the fluid being conveyed. The min- are designed to operate with condensing flue gases, shall imum size of the letters and length of the color field shall be permitted to be connected directly to the panel heat- comply with Table 404.3. ing system without a protective mixing device. Each outlet on the solar thermal piping system shall be 406.2.2 407.2.2 Noncondensing Boilers. Where the posted with black uppercase lettering as follows: heat exchanger and venting system are not designed to “CAUTION: HEAT TRANSFER FLUID, DO NOT operate with condensed flue gases, the boiler shall be per- DRINK.” mitted to connect directly to the panel heating system

26 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT HYDRONICS

where protected from flue gas condensation. The operat- of the system. Expansion tanks for systems designed to oper- ing temperature of the boiler shall be more than the fluid ate at more than 30 pounds-force per square inch (psi) (207 temperature in accordance with the manufacturer’s kPa) shall comply with ASME BPVC Section VIII. instructions. The minimum return-water temperature to 407.4 Open-Type Expansion Tanks. Open-type expan- the heat source shall comply with Section 401.5. sion tanks shall be located not less than 3 feet (914 mm) 406.3 407.3 Dual-Purpose Water Heaters. Water heaters above the highest point of the system. An overflow with a used for combined space- and water-heating applications shall diameter of not less than one-half the size of the supply or not be in accordance with the standards referenced in Table 403.2, less than 1 inch (25 mm) in diameter shall be installed at the and shall be installed in accordance with the manufacturer’s top of the tank. The overflow shall discharge through an air installation instructions. Water used as the heat transfer fluid gap into the drainage system. in the hydronic heating system shall be isolated from the 408.4 Sizing. Expansion tanks shall be sized to accept the potable water supply and distribution in accordance with Sec- design expansion volume of the fluid in the system. The min- tion 313.0, Section 314.0, and Section 402.2 402.0. imum capacity of a closed-type expansion tank shall be sized 406.3.1 407.3.1 Temperature Limitations. Where a in accordance with Section 605.4. combined space- and water-heating application requires water for space heating at temperatures exceeding 140°F 408.0 409.0 Materials. (60°C), a thermostatic mixing valve in accordance with 408.1 409.1 Pipe, Tube, Tubing, and Fittings. ASSE 1017 shall be installed to temper the water sup- Hydronic plied to the potable water distribution system to a tem- pipe and tubing shall comply with the applicable standards perature of 140°F (60°C) or less. referenced in Table 408.1 409.1 and shall be approved for use 406.4 407.4 Solar Heat Collector Systems. Solar water based on the intended purpose. Materials shall be rated for heating systems used in hydronic panel radiant heating sys- the operating temperature and pressure of the system and shall tems shall be installed in accordance with Chapter 5. be compatible with the type of heat transfer fluid. Pipe fittings and valves shall be approved for the installation with 407.5 Heat Pumps. Water source heat pumps shall comply the piping, materials to be installed and shall comply with the with AHRI/ASHRAE/ISO 13256-1 for water-to-air heat applicable standards referenced in Table 408.1 409.1. Where pumps and AHRI/ASHRAE/ISO 13256-2 for water-to-water required, exterior piping shall be protected against freezing, heat pumps. Air source heat pumps shall comply with AHRI UV radiation, corrosion and degradation. Embedded pipe or 210/240. Heat pumps shall be fitted with a means to indicate tubing shall comply with Section 417.2 418.2. that the compressor is locked out. 408.2 409.2 Expansion and Contraction. Pipe and tub- 407.0 408.0 Expansion Tanks. ing shall be so installed that it will not be subject to undue strains or stresses, and provisions shall be made for expan- 407.1 408.1 General. An expansion tank shall be installed sion, contraction, and structural settlement. in each closed hydronic system to control system pressure 408.3 409.3 Hangers and Supports. Pipe and tubing due to thermal expansion and contraction. Expansion tanks shall be supported in accordance with Section 317.0 and shall be of the closed or open type. Expansion tanks shall be Table 317.3. Equipment that is part of the piping system shall rated for the pressure of the system. be provided with additional support in accordance with this Exception: Drainback type solar thermal systems shall not code and manufacturer’s installation instructions. require a hydronic expansion tank. 405.4 409.4 Oxygen Diffusion Corrosion. PEX and PE- 407.2 408.2 Installation. Expansion tanks shall be accessi- RT tubing in closed hydronic systems shall contain an oxygen ble for maintenance and shall be installed in accordance with barrier with an oxygen permeation rate not to exceed 4.59 E- the manufacturer’s installation instructions. Each expansion 04 grains per square feet per day (0.32 mg/m2/day) at 104°F tank shall be equipped with a shutoff device that will remain (40°C). open during operation of the hydronic system. Valve handles Exception: Closed hydronic systems without ferrous com- shall be locked open or removed to prevent from being inad- ponents in contact with the hydronic fluid. vertently shut off. Where systems contain more than 5 gallons (19 L) of fluid, provisions shall be made for draining the tank 409.0 410.0 Joints and Connections. without emptying the system. Expansion tanks shall be securely fastened to the structure. Supports shall be capable of 409.1 410.1 General. Joints and connections shall be of an carrying twice the weight of the tank filled with water without approved type. Joints shall be gas and watertight and designed placing a strain on connecting piping. Hot-water-heating sys- for the pressure of the hydronic system. Changes in direction tems incorporating hot water tanks or fluid relief columns shall shall be made by the use of fittings or with pipe bends. Pipe be installed to prevent freezing under normal operating condi- bends shall have a radius of not less than six times the outside tions. diameter of the tubing or shall be in accordance with the man- 407.3 408.3 Closed-Type Expansion Tanks. Closed-type ufacturer’s installation instructions. Joints between pipe and expansion tanks shall be designed for a hydrostatic test pres- fittings shall be installed in accordance with the manufacturer’s sure of two and one-half times the allowable working pressure installation instructions.

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TABLE 408.1 409.1 MATERIALS FOR HYDRONICS AND SOLAR THERMAL SYSTEM, PIPING, TUBING, AND FITTINGS STANDARDS MATERIAL PIPING/TUBING FITTINGS Copper/Copper Alloy ASME B16.15, ASME B16.18, ASTM B42, ASTM B43, ASTM B75, ASME B16.22, ASME B16.23, ASME ASTM B88, ASTM B135, ASTM B251*, B16.24, ASME B16.26, ASME B16.29, ASTM B302, ASTM B447 ASME B16.51, ASSE 1061, ASTM F3226, IAPMO PS 117 Steel ASME B16.5, ASME B16.9, ASTM A53, ASTM A106, ASTMA254 ASME B16.11, ASTM A420, ASTM F3226, IAPMO PS 117 Gray Iron –– ASTM A126 Malleable Iron –– ASME B16.3 Chlorinated Polyvinyl Chloride (CPVC) ASSE 1061, ASTM D2846, ASTM F437, ASTM D2846, ASTM F441, ASTM F442, ASTM F438, ASTM F439, ASTM F1970, CSA B137.6 CSA B137.6 Polyethylene (PE) ASTM D1693, ASTM D2513, ASTM D2609, ASTM D2683, ASTM D2683, ASTM D2737, ASTM D3035, ASTM D3261, ASTM F1055, ASTM F2165, ASTM D3350, ASTM F714, ASTM F2165, CSA B137.1, NSF 358-1 AWWA C901, CSA B137.1, NSF 358-1 Cross-Linked Polyethylene (PEX) ASSE 1061, ASTM F877, ASTM F1055, ASTM F1807, ASTM F1960, ASTM F1961, ASTM F876, ASTM F2165, ASTM F3253, ASTM F2080, ASTM F2098, ASTM F2159, CSA B137.5, NSF 358-3 ASTM F2165, ASTM F2735, ASTM F3253, ASTM F3347, ASTM F3348, CSA B137.5, NSF 358-3 Polypropylene (PP) ASTM F2165, ASTM F2389, CSA B137.11, ASTM F2165, ASTM F2389, CSA B137.11, NSF 358-2 NSF 358-2 Polyvinyl Chloride (PVC) ASTM D2464, ASTM D2466, ASTM D1785, ASTM D2241, CSA B137.3 ASTM D2467, ASTM F1970, CSA B137.2, CSA B137.3 Raised Temperature Polyethylene (PE-RT) ASSE 1061, ASTM D3261, ASTM F1055, ASTM F2165, ASTM F2623, ASTM F2769, ASTM F1807, ASTM F2159, ASTM F2165, CSA B137.18 ASTM F2735, ASTM F2769, CSA B137.18 Cross-Linked Polyethylene/Aluminum/ ASTM F1281, ASTM F2165, ASTM F2262, ASTM F1281, ASTM F1974, ASTM F2165, Cross-Linked Polyethylene (PEX-AL-PEX) CSA B137.10 ASTM F2434, CSA B137.10 Polyethylene/Aluminum/Polyethylene (PE- ASTM F1282, ASTM F1974, ASTM F2165, ASTM F1282, ASTM F2165, CSA B137.9 AL-PE) CSA B137.9 Stainless Steel ASTM A269, ASTM A312, ASTM A554, ASTM F1476, ASTM F1548, ASTM A778 ASTM F3226, IAPMO PS 117 Chlorinated Polyvinyl Chloride/Aluminum/ Chlorinated Polyvinyl Chloride ASTM F2855 ASTM D2846 (CPVC/AL/CPVC) * Only Type K, L, or M shall be permitted to be installed.

409.2 410.2 Chlorinated Polyvinyl Chloride (CPVC) shall be orange in color. The primer shall be colored and Pipe. Joints between chlorinated polyvinyl chloride (CPVC) be in accordance with ASTM F656. Listed solvent pipe and fittings shall be installed in accordance with one of cement in accordance with ASTM F493 that does not the following methods: require the use of primers, yellow or red in color, shall be permitted for pipe and fittings manufactured in accor- (1) Mechanical joints shall include, but not be limited to, 1 dance with ASTM D2846, ⁄2 of an inch (15 mm) through flanged, grooved, and push fit fittings. Removable and 1 2 inches (50 mm) in diameter or ASTM F442, ⁄2 of an nonremovable push fit fittings with an elastomeric o-ring inch (15 mm) through 3 inches (80 mm) in diameter. that employ quick assembly push fit connectors shall be Apply primer where required inside the fitting and to the in accordance with ASSE 1061. depth of the fitting on pipe. Apply liberal coat of cement (2) Solvent cement joints for CPVC pipe and fittings shall be to the outside surface of pipe to depth of fitting and inside clean from dirt and moisture. Solvent cements in accor- of fitting. Place pipe inside fitting to forcefully bottom the dance with ASTM F493, requiring the use of a primer pipe in the socket and hold together until joint is set.

28 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT HYDRONICS

(3) Threaded joints for CPVC pipe shall be made with pipe (3) Mechanically formed tee fittings shall have extracted col- threads in accordance with ASME B1.20.1. A minimum of lars that shall be formed in a continuous operation consist- Schedule 80 shall be permitted to be threaded and the pres- ing of drilling a pilot hole and drawing out the pipe or tube sure rating shall be reduced by 50 percent. The use of surface to form a collar having a height not less than three molded fittings shall not result in a 50 percent reduction in times the thickness of the branch tube wall. The branch the pressure rating of the pipe provided that the molded pipe or tube shall be notched to conform to the inner curve fittings shall be fabricated so that the wall thickness of the of the run pipe or tube and shall have two dimple depth material is maintained at the threads. Thread sealant com- stops to ensure that penetration of the branch pipe or tube pound that is compatible with the pipe and fitting, insolu- into the collar is of a depth for brazing and that the branch ble in water, and nontoxic shall be applied to male threads. pipe or tube does not obstruct the flow in the main line pipe Caution shall be used during assembly to prevent over or tube. Dimple depth stops shall be in line with the run of 1 tightening of the CPVC components once the thread the pipe or tube. The second dimple shall be ⁄4 of an inch sealant has been applied. Female CPVC threaded fittings (6.4 mm) above the first and shall serve as a visual point of shall be used with plastic male threads only. inspection. Fittings and joints shall be made by brazing. 409.3 410.3 CPVC/AL/CPVC Plastic Pipe and Joints. Soldered joints shall not be permitted. Joints between chlorinated polyvinyl chloride/aluminum/ (4) Pressed fittings for copper or copper alloy pipe or tubing chlorinated polyvinyl chloride (CPVC/AL/CPVC) pipe or shall have an elastomeric o-ring that forms the joint. The and fittings shall be installed in accordance with one of the pipe or tubing shall be fully inserted into the fitting, and following methods: the pipe or tubing marked at the shoulder of the fitting. (1) Mechanical joints shall include, but not be limited to, Pipe or tubing shall be cut square, chamfered, and reamed flanged, grooved and push-fit fittings. to full inside diameter. The fitting alignment shall be checked against the mark on the pipe or tubing to ensure (2) Solvent cement joints for CPVC/AL/CPVC pipe and fit- the pipe or tubing is inserted into the fitting. The joint tings shall be clean from dirt and moisture. Solvent shall be pressed using the tool recommended by the man- cements in accordance with ASTM F493, requiring the ufacturer. use of a primer shall be orange in color. The primer shall be colored and be in accordance with ASTM F656. (5) Removable and nonremovable push fit fittings for copper Listed solvent cement in accordance with ASTM F493 or copper alloy tubing or pipe that employ quick assem- that does not require the use of primers, yellow in color, bly push fit connectors shall be in accordance with ASSE shall be permitted for pipe and fittings manufactured in 1061. Push fit fittings for copper or copper alloy pipe or 1 accordance with ASTM D2846, /2 inch (15 mm) through tubing shall have an approved elastomeric o-ring that 1 2 inches (50 mm) in diameter, /2 inch (15 mm) through forms the joint. Pipe or tubing shall be cut square, cham- 3 inches (80 mm) in diameter. Apply primer where fered, and reamed to full inside diameter. The tubing required inside the fitting and to the depth of the fitting shall be fully inserted into the fitting, and the tubing on pipe. Apply liberal coat of cement to the outside sur- marked at the shoulder of the fitting. The fitting align- face of pipe to depth of fitting and inside of fitting. Place ment shall be checked against the mark on the tubing to pipe inside fitting to forcefully bottom the pipe in the ensure the tubing is inserted into the fitting and gripping socket and hold together until joint is set. mechanism has engaged on the pipe. 409.4 410.4 Copper or Copper Alloy Pipe and Tub- (6) Soldered joints between copper or copper alloy pipe or tubing. Joints between copper or copper alloy pipe or tubing and ing and fittings shall be made in accordance with ASTM fittings shall be installed in accordance with one of the fol- B828. Pipe or tubing shall be cut square and reamed to the lowing methods: full inside diameter including the removal of burrs on the (1) Brazed joints between copper or copper alloy pipe or tub- outside of the pipe or tubing. Surfaces to be joined shall be ing and fittings shall be made with brazing alloys hav- cleaned bright by manual or mechanical means. Flux shall ing a liquid temperature above 1000°F (538°C). The joint be applied to pipe or tubing and fittings and shall be in surfaces to be brazed shall be cleaned bright by either accordance with ASTM B813, and shall become noncor- manual or mechanical means. Tubing shall be cut square rosive and nontoxic after soldering. Insert pipe or tubing and reamed to full inside diameter. Brazing flux shall be into the base of the fitting and remove excess flux. Pipe or applied to the joint surfaces where required by manufac- tubing and fitting shall be supported to ensure a uniform turer’s recommendation. Brazing filler metal in accor- capillary space around the joint. Solder in accordance with dance with AWS A5.8 shall be applied at the point where ASTM B32 shall be applied to the joint surfaces until cap- the pipe or tubing enters the socket of the fitting. illary action draws the molten solder into the cup. Joint sur- (2) Flared joints for soft copper or copper alloy tubing shall faces shall not be disturbed until cool and any remaining be made with fittings that are in accordance with the flux residue shall be cleaned. applicable standards referenced in Table 408.1 409.1. (7) Threaded joints for copper or copper alloy pipe shall be Pipe or tubing shall be cut square using an appropriate made with pipe threads in accordance with ASME tubing cutter. The tubing shall be reamed to full inside B1.20.1. Thread sealant tape or compound shall be diameter, resized to round, and expanded with a proper applied only on male threads, and such material shall be flaring tool. of approved types, insoluble in water, and nontoxic.

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409.5 410.5 Cross-Linked Polyethylene (PEX) Pipe. for insert fittings shall be made by cutting the pipe Joints between cross-linked polyethylene (PEX) pipe and fit- square, using a cutter designed for plastic piping, and tings shall be installed with fittings for PEX tubing that com- removal of sharp edges. Two stainless steel clamps shall ply with the applicable standards referenced in Table 408.1 be placed over the end of the pipe. Fittings shall be 409.1. PEX tubing labeled in accordance with ASTM F876 checked for proper size based on the diameter of the pipe. shall be marked with the applicable standard designation for The end of pipe shall be placed over the barbed insert fit- the fittings specified for use with the tubing. Mechanical ting, making contact with the fitting shoulder. Clamps joints shall be installed in accordance with the manufacturer’s shall be positioned equal to 180 degrees (3.14 rad) apart installation instructions. and shall be tightened to provide a leak tight joint. Com- 409.6 410.6 Cross-Linked Polyethylene/Aluminum/ pression type couplings and fittings shall be permitted Cross-Linked Polyethylene (PEX-AL-PEX) Pipe. for use in joining PE piping and tubing. Stiffeners that Joints between cross-linked polyethylene/aluminum/cross- extend beyond the clamp or nut shall be prohibited. linked polyethylene (PEX-AL-PEX) pipe and fittings shall Bends shall be not less than 30 pipe diameters, or the coil be installed in accordance with one of the following meth- radius where bending with the coil. Bends shall not be ods: permitted closer than 10 pipe diameters of a fitting or valve. Mechanical joints shall be designed for their (1) Mechanical joints between PEX-AL-PEX pipe and fit- intended use. tings shall include mechanical and compression type fit- 409.8 410.8 Polyethylene/Aluminum/Polyethylene (PE- tings and insert fittings with a crimping ring. Insert AL-PE). fittings utilizing a crimping ring shall be in accordance Joints between polyethylene/aluminum/polyethyl- with ASTM F1974 or ASTM F2434. Crimp joints for ene (PE-AL-PE) pipe and fittings shall be installed in crimp insert fittings shall be joined to PEX-AL-PEX pipe accordance with one of the following methods: by the compression of a crimp ring around the outer cir- (1) Mechanical joints for PE-AL-PE pipe or tubing and fit- cumference of the pipe, forcing the pipe material into tings shall be either of the metal insert fittings with a split annular spaces formed by ribs on the fitting. ring and compression nut or metal insert fittings with (2) Compression joints shall include compression insert fit- copper crimp rings. Metal insert fittings shall comply tings and shall be joined to PEX-AL-PEX pipe through with ASTM F1974. Crimp insert fittings shall be joined the compression of a split ring or compression nut around to the pipe by placing the copper crimp ring around the the outer circumference of the pipe, forcing the pipe outer circumference of the pipe, forcing the pipe material material into the annular space formed by the ribs on the into the space formed by the ribs on the fitting until the fitting. pipe contacts the shoulder of the fitting. The crimp ring 409.7 410.7 Polyethylene (PE) Plastic Pipe/Tubing. shall then be positioned on the pipe so the edge of the 1 1 8 4 Joints between polyethylene (PE) plastic pipe or tubing and crimp ring is ⁄ of an inch (3.2 mm) to ⁄ of an inch (6.4 fittings shall be installed in accordance with one of the fol- mm) from the end of the pipe. The jaws of the crimping lowing methods: tool shall be centered over the crimp ring and tool per- pendicular to the barb. The jaws shall be closed around (1) Butt-fusion joints shall be installed in accordance with the crimp ring and shall not be crimped more than once. ASTM F2620 and shall be made by heating the squared ends of two pipes, pipe and fitting, or two fittings by (2) Compression joints for PE-AL-PE pipe or tubing and fit- holding ends against a heated element. The heated ele- tings shall be joined through the compression of a split ment shall be removed where the proper melt is obtained ring, by a compression nut around the circumference of and joined ends shall be placed together with applied the pipe. The compression nut and split ring shall be force. placed around the pipe. The ribbed end of the fitting shall be inserted onto the pipe until the pipe contacts the shoul- (2) Electro-fusion joints shall be heated internally by a con- der of the fitting. Position and compress the split ring by ductor at the interface of the joint. Align and restrain fit- tightening the compression nut onto the insert fitting. ting to pipe to prevent movement and apply electric 409.9 410.9 Polyethylene of Raised Temperature (PE- current to the fitting. Turn off the current when the RT). proper time has elapsed to heat the joint. The joint shall Joints between polyethylene of raised temperature (PE- fuse together and remain undisturbed until cool. RT) tubing and fittings shall be installed with fittings for PE-RT tubing that comply with the applicable standards ref- (3) Socket-fusion joints shall be installed in accordance with erenced in Table 408.1 409.1. Metal insert fittings, metal ASTM F2620 and shall be made by simultaneously heating the outside surface of a pipe end and the inside of a fit- compression fittings, and plastic fittings shall be manufac- ting socket. Where the proper melt is obtained, the pipe tured to and marked in accordance with the standards for fit- and fitting shall be joined by inserting one into the other tings in Table 408.1 409.1. 409.10 410.10 Polypropylene (PP) Pipe. with applied force. The joint shall fuse together and Joints between remain undisturbed until cool. polypropylene pipe and fittings shall be installed in accor- (4) Mechanical joints between PE pipe or tubing and fittings dance with one of the following methods: shall include insert and mechanical compression fittings (1) Heat-fusion joints for polypropylene (PP) pipe shall be that provide a pressure seal resistance to pullout. Joints installed with socket-type heat-fused polypropylene fit-

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tings, butt-fusion polypropylene fittings or pipe, or elec- (2) Threaded joints shall be made with pipe threads that are tro-fusion polypropylene fittings. Joint surfaces shall be in accordance with ASME B1.20.1. Thread sealant tape clean and free from moisture. The joint shall be undis- or compound shall be applied only on male threads, and turbed until cool. Joints shall be made in accordance with such material shall be of approved types, insoluble in ASTM F2389 or CSA B137.11. water, and nontoxic. (2) Mechanical and compression sleeve joints shall be (3) Welded joints shall be made by electrical arc or oxy- installed in accordance with the manufacturer’s installa- gen/acetylene method. Joint surfaces shall be cleaned by tion instructions. Polypropylene pipe shall not be an approved procedure. Joints shall be welded by an threaded. Polypropylene transition fittings for connec- approved filler metal. tion to other piping materials shall only be threaded by (4) Pressed joints shall have an elastomeric o-ring that forms use of copper alloy or stainless steel inserts molded in the connection. The pipe or tubing shall be fully inserted the fitting. into the fitting, and the pipe or tubing marked at the shoul- 409.11 410.11 Polyvinyl Chloride (PVC) Pipe. Joints der of the fittings. Pipe or tubing shall be cut square, between polyvinyl chloride pipe and fittings shall be installed chamfered, and reamed to full inside diameter. The fit- in accordance with one of the following methods: ting alignment shall be checked against the mark on the pipe or tubing to ensure the pipe or tubing is fully inserted (1) Mechanical joints shall be designed to provide a perma- into the fitting. The joint shall be pressed using the tool nent seal and shall be of the mechanical or push-on joint. recommended by the manufacturer. The mechanical joint shall include a pipe spigot that has 409.13 410.13 Joints Between Different Materials. a wall thickness to withstand without deformation or col- lapse; the compressive force exerted where the fitting is Joints between different types of materials shall be installed in tightened. The push-on joint shall have a minimum wall accordance with the manufacturer’s installation instructions and shall comply with Section 409.13.1 410.13.1 and Section thickness of the bell at any point between the ring and 409.13.2 410.13.2. the pipe barrel. The elastomeric gasket shall comply with 409.13.1 410.13.1 Copper or Copper Alloy Pipe or ASTM D3139, and be of such size and shape as to pro- Tubing to Threaded Pipe Joints. vide a compressive force against the spigot and socket Joints from copper after assembly to provide a positive seal. or copper alloy pipe or tubing to threaded pipe shall be made by the use of copper alloy adapter, copper alloy nip- (2) Solvent cement joints for PVC pipe and fittings shall be ple [minimum 6 inches (152 mm)], dielectric fitting, or clean from dirt and moisture. Pipe shall be cut square and dielectric union in accordance with ASSE 1079. The joint pipe shall be deburred. Where surfaces to be joined are between the copper or copper alloy pipe or tubing and the cleaned and free of dirt, moisture, oil, and other foreign fitting shall be a soldered, brazed, flared, or pressed joint material, apply primer purple in color in accordance with and the connection between the threaded pipe and the fit- ASTM F656. Primer shall be applied until the surface of ting shall be made with a standard pipe size threaded joint. the pipe and fitting is softened. Solvent cements in accor- 409.13.2 410.13.2 Plastic Pipe to Other Materials. dance with ASTM D2564 shall be applied to all joint surfaces. Joints shall be made while both the inside socket Where connecting plastic pipe to other types of piping, surface and outside surface of pipe are wet with solvent approved types of adapter or transition fittings designed cement. Hold joint in place and undisturbed for 1 minute for the specific transition intended shall be used. after assembly. 410.0 411.0 System Controls. (3) Threads shall comply with ASME B1.20.1. A minimum of Schedule 80 shall be permitted to be threaded; how- 410.1 411.1 Water Temperature Controls. A heat source ever, the pressure rating shall be reduced by 50 percent. or system of commonly connected heat sources shall be pro- The use of molded fittings shall not result in a 50 per- tected by a water-temperature-activated operating control to cent reduction in the pressure rating of the pipe provided stop heat output of the heat source where the system water that the molded fittings shall be fabricated so that the reaches a pre-set operating temperature. wall thickness of the material is maintained at the 410.2 411.2 Operating Steam Controls. A steam heat threads. Thread sealant compound that is compatible source or system of commonly connected steam heat sources with the pipe and fitting, insoluble in water, and nontoxic shall be protected by a pressure-actuated control to shut off shall be applied to male threads. Caution shall be used the fuel supply where the system pressure reaches a pre-set during assembly to prevent over tightening of the PVC operating pressure. components once the thread sealant has been applied. 410.2.1 411.2.1 Water-Level Controls. A primary Female PVC threaded fittings shall be used with plastic water-level control shall be installed on a steam heat male threads only. source to control the water level in the heat source. The 409.12 410.12 Steel Pipe and Tubing. Joints between control shall be installed in accordance with the manu- steel pipe or tubing and fittings shall be installed in accordance facturer’s installation instructions. with one of the following methods: 410.3 411.3 Occupied Spaces. A temperature-sensing (1) Mechanical joints shall be made with an approved and device shall be installed in the occupied space to regulate the listed elastomeric gasket. operation of the hydronic system.

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410.5 411.4 Simultaneous Operation. Radiant heating 411.6 412.6 Air-Removal Device. Provision shall be made and cooling systems sharing a common space temperature for the removal of air from fluid in hydronic systems. Air- control shall be configured to prevent simultaneous heating removal devices shall be located in the areas of the hydronic and cooling. piping system where air is likely to accumulate. Air-removal 410.6 411.5Temperature Reading. A temperature gauge or devices shall be installed to facilitate their removal for exam- transmitter shall be installed for reading the fluid temperatures ination, repair, or replacement. in the panel system supply and heat source outlet. One temper- Exception: Drainback type solar thermal systems shall not ature gauge or transmitter shall be permitted where the temper- require an air-removal device. ature between the heat source outlet and panel system supply 411.7 412.7 Air-Separation Device. To assist with the are the same. removal of entrained air, an air-separation device shall be installed in hydronic systems. The device shall be located in 411.0 412.0 Pressure and Flow Controls. accordance with the manufacturer’s installation instructions or at the point of no mechanically-induced pressure change 411.1 412.1 Balancing. A means for balancing distribution within the hydronic system. loops, heat emitting devices, and multiple-boiler installations Exception: Air-separation devices shall not be required on shall be provided in accordance with the manufacturer’s solar thermal systems. instructions. A means for balancing and flow control shall 411.8 412.8 Secondary Loops. include the piping design, pumping equipment, or balancing Secondary loops that are isolated from the primary heat-distribution loop by a heat devices. 411.2 412.2 Low-Water Control. exchanger are closed-loop hydronic systems and shall have a Direct-fired heat sources pressure relief valve in accordance with Section 311.1, an within a closed heating system shall have a low-water fuel cut- expansion tank in accordance with Section 407.0 408.0, an air- off device, except as specified in Section 411.3 412.3. Where removal device in accordance with Section 411.6 412.6, and an a low-water control is integral with the heat source as part of air-separation device in accordance with Section 411.7 412.7. the appliance’s integrated control, and is listed for such use, a separate low-water control shall not be required. An external 412.0 413.0 Hydronic Space Heating. cut-off device shall be installed in accordance with the heat- 412.1 413.1 General. source manufacturer’s installation instructions. No valve shall Based on the system design, the heat- be located between the external low-water fuel cut-off and the distribution units shall be selected in accordance with the heat-source unit. Where a pumped condensate return is manufacturer’s specifications. installed, a second low-water cut-off shall be provided. 412.2 413.2 Installation. Heat-distribution units shall be 411.3 412.3 Flow-Sensing Devices. A direct-fired heat installed in accordance with the manufacturer’s installation source, requiring forced circulation to prevent overheating, instructions and this code. shall have a flow-sensing device installed with the appliance 412.3 413.3 Balancing. System loops shall be installed so or such device shall be integral with the appliance. A low- that the design flow rates are achieved within the system. water fuel cut-off device shall not be required. 412.4 413.4 Heat Transfer Fluid. The ignitable flash point 411.4 412.4 Automatic Makeup Fluid. Where an auto- of heat transfer fluid in a hydronic piping system shall be a matic makeup fluid supply fill device is used to maintain the minimum of 50°F (28°C) above the maximum system oper- fluid content of the heat-source unit, or any closed-loop in the ating temperature. The heat transfer fluid shall be compatible system, the makeup supply shall be located at the expansion with the makeup fluid supplied to the system. tank connection or other approved location. A pressure-reducing valve shall be installed on a makeup 413.0 414.0 Steam Systems. water feed line. The pressure of the feed line shall be set in 413.1 414.1 Steam Traps. For other than one-pipe steam accordance with the design of the system, and connections to systems, each heat-distribution unit shall be supplied with a potable water shall be in accordance with Section 402.0 to steam trap that is listed for the application. prevent contamination due to backflow. 413.2 414.2 Sloping for Two-Pipe System. Two-pipe 411.5 412.5 Differential Pressure Regulation. Provi- steam system piping and heat-distribution units shall be 1 sions shall be made to bypass excessive zone flows in excess sloped down at not less than ⁄8 inch per foot (10 mm/m) in the of design velocity in a multi-zone hydronic system where the direction of the steam flow. closing of some or all of the two-way zone valves is capable 413.3 414.3 Sloping for One-Pipe System. One-pipe of causes excess flow through the open zones or deadheading steam system piping and heat-distribution units shall be 1 of a fixed-speed circulator or pump. sloped down at not less than ⁄8 inch per foot (10 mm/m) 411.5.1 412.5.1 Differential Pressure Bypass towards the steam boiler, without trapping. Valve. Where a differential pressure bypass valve is used 413.4 414.4 Automatic Air Vents. Steam automatic air for the purpose specified in Section 411.5 412.5, it shall vents shall be installed to eliminate air pressure in heat-dis- be installed and adjusted to provide bypass of the distri- tribution units on gravity steam piping systems. Air vents bution system when most or all of the zones are closed. shall not be used on a vacuum system.

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413.5 414.5 Condensate Flow. System piping shall be TABLE 414.4 415.4 MAXIMUM LOOP LENGTHS OF installed to allow condensate to flow to the condensate CONTINUOUS TUBING FOR RADIANT SYSTEMS receiver or steam boiler, either by gravity or pump-assisted. 413.6 414.6 Steam-Distribution Piping. NOMINAL TUBE SIZE MAXIMUM LOOP LENGTH Where multi- (inches) (feet) 1 row elements are installed in an enclosure, they shall be top ⁄4 125 fed and piped in parallel down to the steam trap. A single 5 ⁄16 200 steam trap for each row of heating elements shall be installed. 3 ⁄8 250 Where the size of the return header is increased by a mini- 1 ⁄2 300 mum of one pipe size, a single steam trap shall be permitted 5 ⁄8 400 to be installed for multiple rows. Where multiple steam unit 3 4 heaters are installed, an individual steam trap for each unit ⁄ 500 shall be installed. 1 750 For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm 414.0 415.0 Radiant Heating and Cooling. 414.5 415.5 Poured Floor Structural Concrete Slab 414.1 415.1 Installation. Radiant heating and cooling sys- Systems. tems shall be installed in accordance with the system design. Where tubing is embedded in a structural concrete 414.2 415.2 Radiant Floor Heating. Floor finished sur- slab, such tubes shall not be larger in outside dimension than face temperatures shall not exceed the following temperatures one-third of the overall thickness of the slab and shall be for space heating applications: spaced not less than three diameters on center except within 10 feet (3048 mm) of the distribution manifold. The top of (1) 85°F (29°C) in general occupied applications. the tubing shall be embedded in the slab not less than 2 inches (2) 90°F (32°C) in bathrooms, foyers, distribution areas such (51 mm) below the surface. as hallways and indoor swimming pools. 414.5.1 415.5.1 Slab Penetration Tube and Joint (3) 88°F (31°C) in industrial spaces. Protection. Where embedded in or installed under a (4) 95°F (35°C) in radiant panel perimeter areas, i.e., up to concrete slab, tubing shall be protected from damage at 2.5 feet (762 mm) from outside walls. penetrations of the slab with protective sleeving The radiant heating system temperature shall not exceed approved by the tubing manufacturer. The space between the maximum temperature rating of the materials used in its the tubing and sleeve shall be sealed with an approved construction. sealant compatible with the tubing. The tubing at the 414.3 415.3 Radiant Cooling Systems. location of an expansion joint in a concrete slab shall be Radiant cooling encased in protective pipe sleeving that covers the tubing systems shall be designed to minimize the potential for con- not less than 12 inches (305 mm) on either side of the densation. expansion joint or the tubing shall be installed below the To prevent condensation on any cooled radiant surface, slab. the supply water temperature for a radiant cooling system 414.5.2 415.5.2 Insulation. Where a poured concrete shall be not less than 3°F (1.7°C) above the anticipated space radiant floor system is installed in contact with the soil, dew point temperature, or in accordance with the manufac- insulation recommended by the manufacturer for such an turer’s recommendation. Chilled water piping, valves, and fit- application and with a minimum R-value of 5 shall be tings shall be insulated and vapor sealed to prevent surface placed between the soil and the concrete; extend to the condensation. outside edges of the concrete; and be placed on all slab 414.4 415.4 Tube Placement. Hydronic radiant system edges. tubing shall be installed in accordance with the manufac- 414.5.3 415.5.3 Types of Tube Fasteners. Tubing turer’s installation instructions and with the tube layout and that is embedded within concrete shall be fastened spacing in accordance with the system design. Except for dis- according to manufacturer’s instructions. Unless prohib- tribution mains, tube spacing and the individual loop lengths ited by the manufacturer, tube fasteners include the fol- shall be installed with a variance of not more than ±10 percent lowing: from the design. The maximum loop length of continuous (1) Ties made of wire, typically fastened to anchors tubing from a supply-and-return manifold shall not exceed such as rebar or wire mesh; the lengths specified by the manufacturer or, in the absence of manufacturer’s specifications, the lengths specified in Table (2) Plastic tube/cable ties, typically nylon, fastened to 414.4 415.4. Actual loop lengths shall be determined by spac- anchors such as rebar or wire mesh; ing, flow rate, and pressure drop requirements in accordance (3) Staples made of metal or plastic or combination with the system design. thereof, without sharp edges that would harm tube, For the purpose of system balancing, each individual fastened to insulation or subfloor; loop shall have a tag securely affixed to the manifold to indi- (4) Plastic rails with integrated tube holders intended cate the length of the loop, and the room(s) and area(s) served. for the specific type of tube;

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(5) Insulation sheets with integrated knobs for holding 414.9.1 415.9.1 Radiant Wall and Ceiling Panels. the specific type of tube and intended for this appli- Radiant panels attached to wood, steel, masonry, or con- cation. crete framing members shall be fastened by means of (6) Other fasteners recommended by the manufacturer. anchors, bolts, or approved screws of sufficient size and anchorage to support the loads applied. Panels shall be 414.5.4 415.5.4 Spacing of Tube Fasteners. The installed with corrosion-resistant fasteners. Piping sys- maximum spacing between tube fasteners within a concrete floor shall not exceed the spacing specified by the tems shall be designed for thermal expansion to prevent manufacturer or, in the absence of manufacturer’s spec- the load being transmitted to the panel. ifications, 2.5 feet (762 mm). 415.0 416.0 Indirect-Fired Domestic Hot-Water Stor- 414.6 415.6 Joist Systems and Subfloors. Where tub- age Tanks. ing is installed below a subfloor, the tube spacing shall be in accordance with the system design and joist space limitations. 415.1 416.1 General. Domestic hot-water heat exchangers, Where tubing is installed above or in the subfloor, the whether internal or external to the heating appliance, shall be tube spacing shall not exceed 12 inches (305 mm) center-to- permitted to be used to heat water in domestic hot-water stor- center for living areas. age tanks. Tanks used to store hot water shall be listed for the Where tubing is installed in the joist cavity, the cavity intended use and constructed in accordance with nationally shall be insulated with not less than R-12 material below the recognized standards. A pressure- and temperature-relief heated space. valve with a set pressure not exceeding 150 percent of the maximum operating pressure of the system, and at a temper- An air space of not less than 1 inch (25.4 mm) and not ature of 210°F (99°C), shall be installed on the storage tank. more than 3 inches (76 mm) shall be maintained between the top of the insulation and the underside of the floor unless a Where the normal operating temperature of the boiler or conductive plate is installed in accordance with manufac- dual-purpose water heater that provides heat input for domes- turer’s instructions. tic hot water exceeds 140°F (60°C), a thermostatically controlled mixing valve in accordance with Section 406.3.1 Where tubing is installed in panels above or in the sub- 407.3.1 shall be installed to limit the water supplied to the floor and not embedded in concrete, the floor assembly shall potable hot water system to a temperature of 140°F (60°C) be insulated with not less than R-5 material below the tubing or less. The potability of the water shall be maintained when installed over habitable space. throughout the system. 414.7 415.7 Wall and Ceiling Panels. Where piping is installed in the wall stud cavity or the ceiling joist cavity, the 416.0 417.0 Snow and Ice Melt Systems. cavity shall be insulated with material having an R-value of not less than R-12 material. The insulation shall be installed 417.1 Use of Chemical Additives and Corrosive Flu- in such a manner as to prevent heating or cooling from being ids. Where auxiliary systems contain chemical additives, cor- lost thermal energy loss from the space intended to be con- rosive fluids, or both, not intended or designed for use in the trolled. primary system, a heat exchanger shall be used in accordance An air space of not less than 1 inch (25.4 mm) and not with Section 313.0. The chemical additives in the auxiliary more than 3 inches (76 mm) shall be maintained between the systems shall be compatible with auxiliary system compo- insulation and the interior surface of the panel unless a con- nents and accepted for use by the heat exchanger manufac- ductive plate is installed. turer. 416.1 417.2 Snow and Ice Melt Controls. 414.8 415.8 Tubing Fasteners. Tubing that is installed An automatic within joist spaces and subfloor panel systems shall be fas- operating control device that controls the supply hydronic tened according to manufacturer’s instructions. Unless pro- fluid temperature to the snow and ice melt area shall be hibited by the manufacturer, tubing fasteners shall include the installed in the system. A means shall be provided to prevent following: low return hydronic solution temperature in accordance with (1) Heat transfer panel systems made of wood, aluminum or Section 410.4 401.5. Snow and ice melt systems shall be pro- other thermally conductive materials intended for this tected from freezing with a mixture of propylene glycol and application and the specific type of tube; water, or other approved fluid. Automotive antifreeze shall not be used. (2) Staples made of metal or plastic or combination thereof, 416.1.1 417.2.1 Tube Placement. without sharp edges that would harm tube, intended for Snow and ice melt this application and the specific type of tube fastened to tubing shall be installed in accordance with the manu- subfloor; and facturer’s installation instructions and with the tube layout and spacing in accordance with the system design. (3) Plastic rails with integrated tube holders intended for the Except for distribution mains, tube spacing and the indi- specific type of tube. vidual loop lengths shall be installed with a variance of (4) Other fasteners recommended by the manufacturer. not more than ±10 percent from the design. 414.9 415.9 Radiant Heating and Cooling Panels. The maximum loop length of continuous tubing Radiant heating and cooling panels shall be installed in accor- from a supply-and-return manifold arrangement shall not dance with the manufacturer’s installation instructions. exceed the lengths specified by the manufacturer or, in

34 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT HYDRONICS

the absence of manufacturer’s specifications, the lengths 416.1.5 417.2.5 Testing and Flushing. Testing of specified in Table 416.1.1 417.2.1. Actual loop lengths snow and ice melt systems shall be in accordance with shall be determined by spacing, flow rate, and pressure Section 405.2 and flushing shall be in accordance with drop in accordance with the system design. Section 405.3. 416.2 417.3 Types of Tube Fasteners. Tubing that is TABLE 416.1.1 417.2.1 embedded within concrete shall be fastened according to MAXIMUM LOOP LENGTHS FOR SNOW manufacturer’s instructions. Unless prohibited by the manu- AND ICE MELT SYSTEMS1, 2 facturer, tube fasteners include the following: NOMINAL MAXIMUM TOTAL TUBE SIZE ACTIVE LOOP LENGTH LOOP LENGTH (1) Ties made of wire, typically fastened to anchors such as (inches) (feet) (feet) rebar or wire mesh; PE-RT or and PEX Tubing (2) Plastic tube/cable ties, typically nylon, fastened to 1 ⁄2 115 140 anchors such as rebar or wire mesh; 5 ⁄8 225 250 (3) Staples made of metal or plastic or combination thereof, 3 ⁄4 300 325 without sharp edges that would harm tube, fastened to 1 450 475 insulation or subfloor; 3 Copper Tubing (4) Plastic rails with integrated tube holders intended for the 1 ⁄2 – 140 specific type of tube; 3 ⁄4 – 280 (5) Insulation sheets with integrated knobs for holding the For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm specific type of tube and intended for this application. Notes: 1 (6) Other fasteners recommended by the manufacturer. The total PE-RT or PEX loop lengths consist of two separate sections, the 416.3 417.4 Spacing of Tube Fasteners. active loop and the leader length. The active loop is installed within the The maximum heated slab. The leader length is the total distance to and from the man- spacing between tube fasteners within a concrete area shall ifold and heated slab, including vertical distances. not exceed the spacing specified by the manufacturer or, in 2 The manifolds shall be installed as close to the snow melts area as pos- the absence of manufacturer’s specifications, 2.5 feet (762 sible. mm). 3 In concrete use not less than Type L copper water tubing. In bituminous pavement use a Type K copper water tubing. 417.0 418.0 Piping Installation. 417.1 418.1 General. 416.1.2 417.2.2 Poured Structural Concrete Slab Piping, fittings, and connections shall Systems. be installed in accordance with the conditions of their Where tubes are embedded in a structural approval and manufacturer’s installation instructions. concrete slab, such tubes shall not be larger in outside 417.2 418.2 Embedded Piping Materials and Joints. dimension than one-third of the overall thickness of the Piping embedded in concrete shall be steel pipe, Type L cop- slab and shall be spaced not less than six diameters on per tubing or plastic pipe or tubing rated at not less than 100 center except within 10 feet (3048 mm) of the distribu- 80 psi at 180°F (689 552 kPa at 82°C). Joints of pipe or tub- tion manifold. The top of the tubing shall be embedded ing that are embedded in a portion of the building, such as in the slab not less than 2 inches (51 mm) below the sur- concrete or plaster, shall be installed in accordance with Sec- face of the finished concrete slab. 416.1.3 417.2.3 Slab Penetration Tube and Joint tion 417.2.1 418.2.1 through Section 417.2.3 418.2.3. 417.2.1 418.2.1 Steel Pipe. Steel pipe shall be welded Protection. Where embedded in or installed under a by electrical arc or oxygen/acetylene method. concrete slab, tubing shall be protected from damage at 417.2.2 418.2.2 Copper Tubing. penetrations of the slab with protective sleeving recom- Copper tubing shall mended by the tubing manufacturer. The space between be joined by brazing with filler metals having a melting the tubing and sleeve shall be sealed with a sealant rec- point not less than 1000°F (538°C). ommended by the tubing manufacturer as compatible 417.2.3 418.2.3 Plastics. Plastic pipe and tubing shall with the tubing. The tubing at the location of an expan- be installed in continuous lengths or shall be joined by sion joint in a concrete slab shall be encased in a protec- heat fusion methods, solvent cement joints, or other tive pipe sleeve that covers the tubing not less than 12 approved fittings in accordance with Table 408.1 409.1 inches (305 mm) on either side of the joint or the tubing and the manufacturer’s installation instructions. shall be installed below the slab. 417.3 418.3 Pressure Testing. Piping to be embedded in 416.1.4 417.2.4 Insulation. Where a poured concrete concrete shall be pressure tested in accordance with Section snow melt system is installed in contact with the soil, 405.2 prior to pouring concrete. During the pour, the pipe sys- insulation recommended by the manufacturer for such tem shall maintain the test pressure of not less than one and application and with a minimum R value of 5 shall be one-half times the hydronic system operating pressure and placed between the concrete and the grade and be not less than 100 psi (689 kPa). During freezing or the possi- extended as close as practicable to the outside edges of bility of freezing conditions, testing shall be done with air the concrete. where permitted by the manufacturer.

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417.4 418.4 System Drainage. Hydronic piping systems shall be installed to permit the system to be drained. The system shall drain by indirect waste in accordance with Section 316.3. Embedded piping underground or under floors is not required to be designed for draining the system. 418.5 Condensate Drainage. Condensate drains from dehumidifying coils shall be constructed and sloped for condensate removal. Such drains shall be installed in accordance with Section 308.0. 417.5 418.6 Clearance to Combustibles. Hydronic piping where the exterior temperature exceeds 250°F (121°C) shall have a clearance of not less 1 inch (25.4 mm) to combustible materials.

36 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT CHAPTER 5 SOLAR THERMAL SYSTEMS

501.0 General. 501.7 Drainback Systems. The circulating pump shall be 501.1 Applicability. The provisions of this chapter address sized to overcome the static head pressure height of the collec- the construction and installation of solar thermal systems, tor, pressure losses, and provide the required flow rate to the including components. The solar thermal system shall include collector. The drainback reservoir shall be located in a con- the solar collector, thermal storage, system piping and appur- ditioned space to prevent freezing. A sight glass, or other tenances. method of monitoring the level of fluid in the solar loop shall 501.2 Connections. Connections that are required for fill- be installed in the solar loop, or on the drainback reservoir. A ing, draining, and flushing shall be readily accessible. Solar drainback system shall be capable of being manually isolated thermal systems using liquid as a heat transfer medium shall and drained. 501.8 Water Heating Systems. have means for purging air. Solar water heating sys- 501.3 Stagnation Condition. The solar thermal assembly tems shall be in accordance with IAPMO S1001.1 or ICC shall be capable of withstanding stagnant conditions in accor- 900/SRCC 300. Where solar collectors are capable of being dance with the manufacturer’s instructions where high solar isolated from the remainder of the system, a suitable pressure flux and no flow occurs. relief valve shall be installed in the isolatable section. 501.8 501.9 Auxiliary Heating. 501.4 Draining. Solar thermal system piping shall be An auxiliary heating sys- installed to permit draining of the system. Drainback system tem shall be installed in conjunction with the solar thermal piping above the fluid level of the drainback reservoir shall system and shall be adequate to provide service in the absence 1 have a slope of not less than ⁄4 inch per foot (20.8 mm/m). of solar thermal energy input. Auxiliary heating that utilizes 501.5 Materials. electricity as the energy source shall be in accordance with Piping, tubing and fittings materials shall Section 315.0. Auxiliary heating that utilizes solid fuel or fuel comply with Table 408.1 409.1. Joining methods shall be in gas as the energy source shall be in accordance with the accordance with Section 409.0 410.0. Materials in contact mechanical code. with heat transfer medium shall be approved for such use. 501.9 501.10 Automatic Air Vents. Galvanized steel shall not be used for solar thermal piping Where installed, auto- systems containing antifreeze. Black steel shall not be used in matic air release vents shall be installed at high points of the systems with entrained air. Unions between dissimilar metals solar thermal system in accordance with the system design requirements and manufacturer’s installation instructions. shall comply with Section 305.2 and Section 409.13 410.13. 501.10 501.11 Waterproofing. The material used shall be capable of withstanding the max- Joints between structural imum temperature and pressure of the system. supports and buildings or dwellings, including penetrations made by bolts or other means of fastening, shall be made 501.5.1 Plastic. Plastic used in the construction of a watertight with approved materials. solar thermal system shall be installed in accordance with 501.11 501.12 Protection. the manufacturer’s installation instructions. Solar thermal systems shall be protected from excessive pressures, temperature, and vacuum 501.5.2 Combustible Materials. Combustible mate- in accordance with Section 311.0. Where required, freeze pro- rials shall not be located on or adjacent to construction tection shall be provided in accordance with Section 501.12 required to be of noncombustible materials or in fire 501.13. areas, unless approved by the Authority Having Juris- 501.12 501.13 Freeze Protection. diction. Unless designed for such conditions, solar thermal systems and components that 501.5.3 Adhesives. Adhesives used in a solar collector contain liquid as the heat transfer medium shall be protected shall not vaporize at the design temperature. 501.5.4 Potable Water. from freezing where the ambient temperature is less than Materials in contact with 46°F (8°C) by means of fail-safe in accordance with Section potable water shall comply with NSF 61. Piping in solar 501.12.1 501.13.1 through Section 501.12.5 501.13.5. systems designed to convey potable water shall be 501.12.1 501.13.1 Antifreeze. Antifreeze shall be used flushed and disinfected in accordance with the Uniform in accordance with the solar thermal system manufac- Plumbing Code. turer’s instructions. 501.5.5 Racks. Dissimilar metals used for racking shall 501.12.2 501.13.2 Drainback. Drainback systems shall be isolated to prevent galvanic corrosion. Paint shall not drain by gravity and shall be permitted to be installed in be used as a method of isolation. applications where the ambient temperature is not less 501.5.6 Fasteners. Mountings and fasteners shall be than -60°F (-51°C). made of corrosion-resistant materials. Carbon steel 501.12.3 501.13.3 Integral Collector Storage. Inte- mountings and fasteners shall be classified as noncorro- gral collector storage systems shall be permitted to be sive in accordance with ASME SA194. installed in applications where the ambient temperature is 501.6 Thermosiphon Systems. The storage tank in a ther- not less than 23°F (-5°C) and the duration of a below-freez- mosiphon system shall be installed above the collector. ing episode has not exceeded 18 hours. Exposed piping in

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a solar thermal system shall be protected with insulation 502.3 Flat Plate Collector Glass. Flat plate collector having a thermal resistance of not less than R-5.0. glass shall be tempered. 501.12.4 501.13.4 Indirect Thermosiphon. Indirect 502.4 Air Collectors. Materials exposed within air collec- thermosiphon systems shall be permitted to be installed tors shall be noncombustible or shall have a flame spread in applications where the ambient temperature is not less index not to exceed 25 and a smoke developed index not to than 23°F (-5°C). Exposed piping in a solar thermal sys- exceed 50 where tested as a composite product in accordance tem shall be protected with insulation having a thermal with ASTM E84 or UL 723. resistance of not less than R-5. 502.4.1 Testing. Materials used within an air collector 501.12.5 501.13.5 Air Heating Systems. Air solar shall not smoke, smolder, glow, or flame where tested in heating systems shall be permitted to be used in accor- accordance with ASTM C411 at temperatures exposed dance with the manufacturer’s instructions. to in service. In no case shall the test temperature be less 501.12.6 501.13.6 Labeling. A label indicating the than 250°F (121°C). method of freeze protection for the system shall be 502.5 Installation. Solar collectors shall be anchored to attached to the system in a visible location. roof structures or other surfaces in accordance with Section 501.12.7 501.13.7 Piping. Fittings, pipe slope, and col- 317.1. Collectors shall be mounted as to minimize the accu- lector shall be designed to allow for manual gravity mulation of debris. Connecting pipes shall not be used to pro- draining and air filling of solar thermal system compo- vide support for a solar collector. Collectors shall be installed nents and piping. Pipe slope for gravity draining shall be in accordance with the manufacturer’s installation instruc- 1 not less than ⁄4 inch per foot (20.8 mm/m) of horizontal tions. length. Collector header pipes or absorber plate riser 502.5.1 Roof Installations. Anchors secured to and tubes internal to the collector shall be sloped in accor- through a roofing material shall be made to maintain the dance with the manufacturer’s instructions. Where a water integrity of the roof covering. Roof drainage shall means to drain the system is provided a drain valve shall not be impaired by the installation of collectors. Solar be installed. collectors that are not an integral part of the roofing sys- 501.13 501.14 Circulators. Circulating pumps shall be tem shall be installed to preserve the integrity of the roof installed in accordance with Section 310.0. For drainback sys- surface. tems, the pump shall overcome the total head of the system 502.5.2 Above or on the Roof. Collectors located while maintaining the required collector flow rate. For other above or on roofs, and functioning as building compo- systems, the pump shall overcome the friction head of the sys- nents, shall not reduce the required fire-resistance and tem while maintaining the required collector flow rate. fire-retardance classification of the roof covering mate- 501.14 501.15 Protection Against Decay. Wood used in rials. the construction of collector or system mounting, and exposed Exceptions: to outdoor conditions shall be pressure-treated with preser- vative or shall be a naturally durable, decay resistant species (1) One- and two-family dwellings. of lumber. (2) Collectors located on buildings not exceeding three 2 501.15 501.16 Flash Points. The flash point of a heat-trans- stories in height, a 9000 square feet (836.13 m ) total fer medium shall be 50°F (28°C) or more above the design floor area; or both providing: maximum temperature. (a) The collectors are noncombustible. 501.16 501.17 Storage Tanks. Storage tanks shall comply (b) Collectors with plastic covers have noncom- with Chapter 6 and be installed in accordance with the man- bustible sides and bottoms, and the total area ufacturer’s installation instructions. Access ports and con- covered and the collector shall not exceed the nections shall be accessible. following: 1 1. Plastic CC1 – 33 ⁄3 percent of the roof area. 502.0 Solar Collectors. 2. Plastic CC2 – 25 percent of the roof area. 502.1 General. Frames and braces exposed to the weather (c) Collectors with plastic film covers having a shall be constructed of materials for exterior locations, and thickness of not more than 0.010 of an inch protected from corrosion or deterioration, in accordance with (0.25 mm) shall have noncombustible sides and the Authority Having Jurisdiction. bottoms, and the total area covered by the col- 1 502.1.1 Construction. Collectors shall be designed lector shall not exceed 33 ⁄3 percent of the roof and constructed as to prevent interior condensation, out- area. gassing, or other processes that will reduce the transmis- 502.5.3 Ground Installations. Solar collectors shall sion properties of the glazing, reduce the efficiency of terminate above finished grade to avoid being obstructed the insulation, or otherwise adversely affect the per- by vegetation, snow, or ice. The supporting columns formance of the collector. shall extend below the frost line. 502.2 Fire Safety Requirements. Collectors that func- 502.5.4 Wall Mounted. Solar collectors that are tion as building components shall be in accordance with the mounted on a wall shall be secured and fastened in an building code. approved manner in accordance with Section 317.0.

38 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT SOLAR THERMAL SYSTEMS

502.5.5 Access. Access shall be provided to collectors 503.4 Fittings. Fittings shall be insulated with mitered sec- and components in an approved manner. A work space tions, molded fittings, insulating cement, or flexible insula- adjacent to collectors for maintenance and repair shall be tion. provided in accordance with the Authority Having Juris- 503.5 Installation. Insulation shall be finished with a jacket diction. 502.5.6 Orientation. or facing with the laps sealed with adhesives or staples so as Collectors shall be located and to secure the insulation on the pipe. Insulation jacket seams oriented in accordance with the manufacturer’s installa- shall be on the underside of the piping and shall overlap in tion instructions. accordance with the manufacturer’s installation instructions. 502.6 Listing. Collectors that are manufactured as a com- Joints and seams shall be sealed with a sealant that is plete component shall be listed and labeled by an approved approved for both the material and environmental conditions. listing agency in accordance with ICC 901/SRCC 100, UL In lieu of jackets, molded insulation shall be permitted to be 1279, or equivalent standard. secured with 16 gauge galvanized wire ties not exceeding 9 inches (229 mm) on center. 503.0 Insulation. 503.5.1 Exterior Applications. Insulation for exte- 503.1 General. The temperature of surfaces within reach of rior applications shall be finished with an approved building occupants shall not exceed 140°F (60°C) unless they jacket or facing with the surfaces and laps sealed. Jack- are protected by insulation. Where sleeves are installed, the eting, facing, and tape used for exterior applications shall insulation shall continue full size through them. be designed for such use. Where flexible insulation is Coverings and insulation used for piping shall be of mate- used, it shall be wrapped and sealed against water pene- rial approved for the operating temperature of the system and tration. Insulation used for exterior applications shall be the installation environment. Where installed in a plenum, the resistant to extreme temperatures, UV exposure, and insulation, jackets and lap-seal adhesives, including pipe cov- moisture. erings and linings, shall have a flame spread index not to 503.6 Ducts. Circulating air ducts shall be insulated in exceed 25 and a smoke-developed index not to exceed 50 accordance with Table 503.6. where tested in accordance with ASTM E84 or UL 723. 503.2 Heat Loss. Insulation shall be installed on intercon- 504.0 Testing. necting solar and hot water piping. The final 5 feet (1524 mm) of the cold water supply line, or the entire length where less 504.1 Piping. The piping of the solar thermal system shall than 5 feet (1524 mm), shall be insulated. The insulation be tested with water, air, heat transfer liquid, or as recom- thickness shall be in accordance with Table 503.3(1) or Table mended by the manufacturer’s instructions, except that plas- 503.3(2), or the insulation installed shall have an R-value of tic pipe shall not be tested with air. The Authority Having not less than R-2.6 degree Fahrenheit hour square foot per 2 2 Jurisdiction shall be permitted to require the removal of plugs, British thermal unit (°F•h•ft /Btu)(R-0.46 m •K/W). Piping, etc., to ascertain where the pressure has reached all parts of storage tanks, and circulating air ductwork shall be insulated. the system. Ductwork and piping shall be permitted to not be insulated 504.2 System Requirements. where exposed in conditioned spaces, and the heat loss from Prior to the installation of such ducts or piping does not otherwise contribute to the heat- insulation and startup, a solar thermal system, including piping or cooling load within such space. ing, collectors, heat exchangers, and other related equipment, Exception: Low temperature, aboveground piping installed shall be tested and proved airtight. for swimming pools, spas, and hot tubs in accordance with 504.2.1 Direct (Open-Loop) Systems. Direct (open- the manufacturer’s installation instructions unless such piping loop) systems shall be tested under a water pressure not is located within a building. less than one and one-half times the maximum design 503.3 Piping. Pipe and fittings, other than unions, flanges, or operating pressure or 150 pounds-force per square inch valves, shall be insulated. Insulation material shall be approved (psi) (1034 kPa), whichever is more. Systems shall with- for continuous operating temperatures of not less than 220°F stand the test without leaking for a period of not less than (104°C). [See Table 503.3(1) through Table 503.3(4)]. 15 minutes.

TABLE 503.3(1) MINIMUM PIPE INSULATION

PIPE DIAMETER (inches) FLUID TEMPERATURE 1 AND LESS 1.25 – 2 2.5 – 4 5 – 6 8 AND LARGER RANGE (°F) R-VALUE 306 – 460 10 10 12 14 14 251 – 305 8 10 10 12 12 201 – 250 6 6 8 8 8 105 – 200 2 4 6 6 6 For SI units: 1 inch = 25.4 mm, °C = (°F-32)/1.8

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TABLE 503.3(1) PIPE INSULATION THICKNESS

INSULATION O.D. INSULATION (inches) NPS PIPE O.D. I.D. INSULATION NOMINAL THICKNESS (inches) (inches) (inches) (inches)* ½ ¾ 1 1.5 2 2.5 3 3.5 4 4.5 5

1 ⁄2 0.84 0.86 1.84 2.36 2.88 4.00 5.00 6.62 7.62 8.62 9.62 10.75 11.75 3 ⁄4 1.05 1.07 2.06 2.36 2.88 4.00 5.00 6.62 7.62 8.62 9.62 10.75 11.75 1 1.315 1.33 2.32 2.88 3.50 4.50 5.56 6.62 7.62 8.62 9.62 10.75 11.75 1 1 ⁄4 1.660 1.68 2.66 3.28 3.50 5.00 5.56 6.62 7.62 8.62 9.62 10.75 11.75 1 1 ⁄2 1.900 1.92 2.78 3.50 4.00 5.00 6.62 7.62 8.62 9.62 10.75 11.75 12.75 2 2.375 2.41 3.42 3.98 4.50 5.56 6.62 7.62 8.62 9.62 10.75 11.75 12.75 1 2 ⁄2 2.875 2.91 3.88 4.48 5.00 6.62 7.62 8.62 9.62 10.75 11.75 12.75 14.00 3 3.500 3.53 4.50 4.96 5.56 6.62 7.62 8.62 9.62 10.75 11.75 12.75 14.00 1 3 ⁄2 4.000 4.03 4.96 5.56 6.62 7.62 8.62 9.62 10.75 11.75 12.75 12.75 14.00 4 4.500 4.53 5.56 6.58 6.62 7.62 8.62 9.62 10.75 11.75 12.75 14.00 15.00 6 6.625 6.70 7.80 8.12 8.62 9.62 10.75 11.75 12.75 14.00 15.00 16.00 17.00 For SI units: 1 inch = 25 mm * Thickness values are applicable for calcium silicate, cellular foam plastics, cellular glass, mineral fiber, and perlite preformed insulation materials.

504.2.2 Indirect (Closed-Loop) Systems. Indirect 505.4 Corrosion Resistant. Glazed solar collectors made (closed-loop) systems shall be hydrostatically tested at of copper shall not be used for solar pool, spa, or hot tub heat- one-and-one-half times the maximum designed operating. ing pressure in accordance with the manufacturer’s Exception: Where a heat exchanger is provided between the installation instructions. Systems shall withstand the test collector circuit and the swimming pool, spa, or hot tub water. without leaking for a period of not less than 15 minutes.

505.0 Swimming Pools, Spas, and Hot Tubs. 505.1 Water Chemistry. Where water from a swimming pool, spa or hot tub is heated by way of circulation through solar collectors, the chemistry of such water shall comply with the requirements of Section 505.2, and shall be filtered in accordance with Section 505.3 and Section 505.3.1. 505.2 Parameters. Parameters for chemicals used within a swimming pool, spa, or hot tub shall be in accordance with Table 505.2.

TABLE 505.2 WATER CHEMISTRY PARAMETER ACCEPTABLE RANGE Calcium Hardness 200 – 400 parts per million (ppm) Langelier Saturation Index 0 (+ or - 0.3 acceptable) pH 7.2 – 7.8 TDS < 1500 ppm Total Alkalinity 80 – 120 ppm

505.3 Filter. A filter shall be provided to remove debris from the water entering the solar loop. Exception: A solar swimming pool, spa, or hot tub heating system with a heat exchanger. 505.3.1 Location. A filter shall be located upstream of a pump used to direct water to solar collectors.

40 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT SOLAR THERMAL SYSTEMS

TABLE 503.3(2) IRON PIPE AND COPPER TUBING INSULATION THICKNESS PIPE SIZE (inches) TEMP COPPER TUBING SIZE DIFF. INSULATION* IRON PIPE SIZE (DT)(°F) (nominal)

1⁄2 3⁄4 1 11⁄4 11⁄2 2 21⁄2 3 4 6 3⁄8 1⁄2 3⁄4 1 11⁄4 11⁄2 2 21⁄2 3 31⁄2 4 5 6

1 1 1 1 1 1 1 1 1 1 1 1 1 1 Calcium T 2 2 ⁄2 3 3 ⁄2 4 4 ⁄2 2 ⁄2 3 ⁄2 4 4 ⁄2 1 ⁄2 1 ⁄2 2 ⁄2 3 3 ⁄2 4 4 ⁄2 2 ⁄2 3 3 ⁄2 4 4 ⁄2 5 Silicate HL 25 25 25 25 25 25 40 38 39 40 23 25 25 24 24 25 25 39 40 40 38 40 40 240 1 1 1 1 1 1 1 1 Fibrous T 1 1 ⁄2 1 ⁄2 2 2 3 1 ⁄2 2 3 4 1 1 1 1 ⁄2 1 ⁄2 2 2 1 ⁄2 2 2 ⁄2 3 3 ⁄2 4 Glass HL 25 23 25 26 25 25 38 40 37 39 20 21 25 22 25 24 23 34 39 38 36 39 38 1 1 1 1 1 1 1 1 1 1 Calcium T 2 2 ⁄2 2 ⁄2 3 3 ⁄2 4 2 ⁄2 3 3 ⁄2 4 1 ⁄2 1 ⁄2 2 2 ⁄2 3 3 ⁄2 4 2 3 3 3 ⁄2 4 4 Silicate HL 23 24 25 25 25 25 39 40 40 40 21 23 24 24 25 24 23 40 38 40 39 38 40 230 1 1 1 1 1 1 1 1 1 1 1 1 1 Fibrous T 1 1 ⁄2 1 ⁄2 1 ⁄2 2 2 ⁄2 1 ⁄2 2 2 ⁄2 3 1 1 1 1 ⁄2 1 ⁄2 1 ⁄2 2 1 ⁄2 1 ⁄2 1 ⁄2 2 2 ⁄2 3 Glass HL 22 21 23 25 23 25 34 37 38 40 18 18 23 20 23 25 25 31 38 40 39 39 40 1 1 1 1 1 1 1 1 Calcium T 2 2 2 ⁄2 3 3 ⁄2 4 2 ⁄2 3 3 ⁄2 4 1 1 ⁄2 2 2 2 ⁄2 3 3 ⁄2 2 3 3 3 ⁄2 4 4 Silicate HL 23 25 24 24 24 24 37 39 40 40 25 22 23 25 25 25 25 38 37 39 40 38 40 220 1 1 1 1 1 1 1 1 1 1 1 1 1 Fibrous T 1 1 ⁄2 1 ⁄2 1 ⁄2 2 2 ⁄2 1 ⁄2 2 2 ⁄2 3 ⁄2 1 1 1 1 ⁄2 1 ⁄2 2 1 ⁄2 1 ⁄2 1 ⁄2 2 2 ⁄2 3 Glass HL 22 20 22 25 22 24 33 35 36 39 25 18 22 24 21 24 24 30 36 37 37 37 38 1 1 1 1 1 1 1 1 1 1 Calcium T 1 ⁄2 2 2 ⁄2 3 3 3 ⁄2 2 3 3 ⁄2 4 1 1 1 ⁄2 2 2 ⁄2 3 3 ⁄2 2 2 ⁄2 2 ⁄2 3 3 ⁄2 4 Silicate HL 24 25 24 22 25 25 40 39 38 40 24 24 25 24 25 24 25 36 38 40 40 38 40 210 1 1 1 1 1 1 1 1 1 1 1 1 1 Fibrous T 1 1 1 ⁄2 1 ⁄2 2 2 ⁄2 1 ⁄2 2 2 3 ⁄2 ⁄2 ⁄2 1 1 ⁄2 1 ⁄2 1 ⁄2 1 1 ⁄2 1 ⁄2 2 2 ⁄2 3 Glass HL 21 25 21 25 21 23 31 34 40 40 24 24 24 23 20 23 23 40 35 39 36 36 37 1 1 1 1 1 1 1 1 1 1 1 1 Calcium T 1 ⁄2 1 ⁄2 2 2 ⁄2 3 3 ⁄2 2 2 ⁄2 3 3 ⁄2 1 1 1 ⁄2 2 2 2 ⁄2 3 1 ⁄2 2 2 ⁄2 3 3 ⁄2 3 ⁄2 Silicate HL 23 24 25 25 23 25 38 38 40 40 23 23 24 23 25 25 25 39 40 39 38 38 40 200 1 1 1 1 1 1 1 1 1 1 1 1 1 Fibrous T 1 1 1 ⁄2 1 ⁄2 2 2 1 ⁄2 1 ⁄2 2 3 ⁄2 ⁄2 ⁄2 1 1 ⁄2 1 ⁄2 1 ⁄2 1 1 ⁄2 1 ⁄2 2 2 2 ⁄2 Glass HL 20 25 21 23 21 25 31 40 40 40 24 22 24 22 20 23 24 39 34 35 35 40 40 1 1 1 1 1 1 1 1 1 1 1 1 1 Fibrous T ⁄2 ⁄2 1 1 ⁄2 1 ⁄2 1 ⁄2 1 1 ⁄2 1 ⁄2 2 ⁄2 ⁄2 ⁄2 ⁄2 1 1 1 1 ⁄2 1 1 1 1 ⁄2 2 2 Glass HL 24 24 21 19 22 25 37 33 40 38 20 20 20 18 22 23 22 32 36 39 35 34 38 180 3 3 1 1 1 1 1 3 3 1 1 1 1 Flexible T ⁄4 ⁄4 1 1 ⁄2 2 2 1 1 ⁄2 2 2 ⁄2 ⁄2 ⁄2 ⁄4 ⁄4 1 1 ⁄2 2 1 1 1 ⁄2 2 2 ⁄2 2 ⁄2 Tubing HL 21 23 23 25 22 25 40 40 40 40 21 22 22 24 24 24 25 36 40 39 39 38 40 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Fibrous T ⁄2 ⁄2 1 1 ⁄2 1 ⁄2 1 ⁄2 1 1 ⁄2 1 ⁄2 2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 1 1 1 ⁄2 1 1 1 1 ⁄2 1 ⁄2 2 Glass HL 22 23 20 18 21 23 35 31 38 35 18 18 19 25 21 22 22 30 34 37 32 38 36 170 1 3 1 1 1 1 1 1 1 3 1 3 1 1 Flexible T ⁄2 ⁄4 1 1 ⁄2 1 ⁄2 2 1 1 ⁄2 2 2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄4 1 1 ⁄2 2 ⁄4 1 1 ⁄2 2 2 2 ⁄2 Tubing HL 25 22 22 24 25 24 38 39 40 40 20 20 25 22 23 24 23 39 37 36 36 40 40 1 1 1 1 1 1 1 1 1 1 1 Fibrous T ⁄2 ⁄2 1 1 1 ⁄2 1 ⁄2 1 1 1 ⁄2 2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 1 1 1 1 1 1 1 ⁄2 2 Glass HL 16 18 19 25 20 23 34 40 36 40 18 18 18 24 25 21 25 29 33 37 40 37 35 160 1 1 1 1 1 1 3 3 3 3 1 3 1 1 Flexible T ⁄2 ⁄2 1 1 ⁄2 1 ⁄2 1 1 1 ⁄2 2 2 ⁄2 ⁄8 ⁄8 ⁄8 ⁄4 1 1 1 ⁄2 ⁄4 1 1 1 ⁄2 2 2 ⁄2 Tubing HL 23 24 25 22 25 32 37 38 37 38 22 23 24 21 22 23 25 37 36 36 39 39 38 1 1 1 1 1 1 1 1 1 1 1 1 Fibrous T ⁄2 ⁄2 1 1 1 1 ⁄2 1 1 1 ⁄2 2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 1 1 ⁄2 1 1 1 1 ⁄2 1 ⁄2 Glass HL 20 21 18 23 24 21 32 38 34 38 17 18 19 23 23 20 24 40 31 33 37 35 40 150 1 3 3 1 3 1 3 3 3 1 3 3 3 3 1 1 Flexible T ⁄2 ⁄4 ⁄4 1 1 1 ⁄2 ⁄4 1 1 ⁄2 2 ⁄8 ⁄8 ⁄8 ⁄2 ⁄4 ⁄4 1 ⁄4 ⁄4 1 1 ⁄2 1 ⁄2 2 Tubing HL 24 18 23 24 25 24 40 39 40 40 20 21 22 23 24 24 25 34 39 31 38 40 40 1 1 1 1 1 1 1 1 1 1 1 Fibrous T ⁄2 ⁄2 1 1 1 1 1 1 1 ⁄2 2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 1 1 ⁄2 1 1 1 1 ⁄2 1 ⁄2 Glass HL 19 19 17 22 22 25 29 35 32 35 15 15 16 21 21 18 22 37 28 31 35 32 27 140 1 1 3 1 3 1 3 3 3 1 1 3 1 3 3 1 1 Flexible T ⁄2 ⁄2 ⁄4 1 1 1 ⁄2 ⁄4 1 1 ⁄2 2 ⁄8 ⁄8 ⁄8 ⁄2 ⁄2 ⁄4 1 ⁄2 ⁄4 ⁄4 1 ⁄2 1 ⁄2 2 Tubing HL 22 25 21 23 24 23 37 37 39 39 18 19 21 23 22 22 23 38 38 39 38 40 39 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Fibrous T ⁄2 ⁄2 ⁄2 ⁄2 1 1 1 1 1 1 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 1 ⁄2 ⁄2 1 1 1 1 ⁄2 Glass HL 17 17 23 25 20 23 26 31 38 40 14 14 14 19 21 24 20 33 38 25 31 37 34 130 3 3 1 3 1 3 3 3 3 1 3 3 1 3 3 1 Flexible T ⁄8 ⁄8 ⁄2 1 1 1 ⁄4 1 1 ⁄2 2 ⁄8 ⁄8 ⁄8 ⁄8 ⁄2 ⁄4 ⁄4 ⁄2 ⁄4 ⁄4 1 1 ⁄2 2 Tubing HL 21 24 25 21 22 25 35 35 40 37 17 18 19 20 21 21 25 36 36 37 34 39 37

UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT 41 SOLAR THERMAL SYSTEMS

TABLE 503.3(2) (continued) IRON PIPE AND COPPER TUBING INSULATION THICKNESS PIPE SIZE TEMP (inches) COPPER TUBING SIZE DIFF. INSULATION* IRON PIPE SIZE (DT)(°F) (nominal) 1⁄2 3⁄4 1 11⁄4 11⁄2 2 21⁄2 3 4 6 3⁄8 1⁄2 3⁄4 1 11⁄4 11⁄2 2 21⁄2 3 31⁄2 4 5 6

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Fibrous T ⁄2 ⁄2 ⁄2 ⁄2 1 1 ⁄2 1 1 1 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 1 ⁄2 ⁄2 ⁄2 1 1 1 Glass HL 16 16 21 23 18 21 38 29 35 37 13 13 14 17 18 23 18 31 35 40 29 35 40 120 3 3 3 1 3 3 3 1 3 3 3 3 3 1 3 1 1 3 1 1 Flexible T ⁄8 ⁄8 ⁄8 ⁄2 ⁄4 1 ⁄4 ⁄4 1 ⁄2 ⁄8 ⁄8 ⁄8 ⁄8 ⁄8 ⁄2 ⁄4 ⁄2 ⁄2 ⁄4 1 1 ⁄2 1 ⁄2 Tubing HL 19 22 23 25 23 23 32 39 38 40 16 16 17 19 24 24 23 33 38 34 32 38 40 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Fibrous T ⁄2 ⁄2 ⁄2 ⁄2 1 1 ⁄2 1 1 1 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 1 1 Glass HL 14 15 19 21 17 19 34 26 32 38 12 12 13 16 16 20 24 28 32 36 39 31 36 110 3 3 3 1 3 3 1 3 1 3 3 3 3 3 1 3 1 1 1 Flexible T ⁄8 ⁄8 ⁄8 ⁄2 ⁄4 ⁄4 ⁄2 ⁄4 1 1 ⁄2 ⁄8 ⁄8 ⁄8 ⁄8 ⁄8 ⁄2 ⁄4 ⁄2 ⁄2 ⁄2 1 1 1 Tubing HL 17 20 21 23 22 25 37 36 35 36 14 15 16 17 22 22 21 30 35 40 29 35 40 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Fibrous T ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 1 1 Glass HL 10 11 15 16 21 24 28 38 40 38 9 9 10 12 14 19 21 25 37 38 39 34 36 80 3 3 3 3 1 1 3 1 3 3 3 3 3 3 3 1 3 3 3 1 1 3 Flexible T ⁄8 ⁄8 ⁄8 ⁄8 ⁄2 ⁄2 ⁄8 ⁄2 ⁄4 1 ⁄8 ⁄8 ⁄8 ⁄8 ⁄8 ⁄8 ⁄2 ⁄8 ⁄8 ⁄8 ⁄2 ⁄2 ⁄4 Tubing HL 12 15 15 23 16 22 39 35 25 37 10 11 12 12 16 23 19 30 34 40 31 36 40 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Fibrous T ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 1 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 ⁄2 Glass HL 9 10 13 14 18 19 23 29 35 31 8 9 9 10 12 16 18 22 27 32 34 41 50 70 3 3 3 3 1 1 3 1 1 3 3 3 3 3 3 3 3 3 3 3 1 1 3 Flexible T ⁄8 ⁄8 ⁄8 ⁄8 ⁄2 ⁄2 ⁄8 ⁄2 ⁄2 ⁄4 ⁄8 ⁄8 ⁄8 ⁄8 ⁄8 ⁄8 ⁄8 ⁄8 ⁄8 ⁄8 ⁄2 ⁄2 ⁄4 Tubing HL 11 13 13 21 14 20 37 33 39 40 9 10 11 11 14 21 23 26 29 37 29 34 38 For SI units: 1 inch = 25.4 mm, °C = °F(0.5555556), 1000 British thermal units per hour = 0.293kW *T = Thickness (inches), HL = Heat loss (Btu/h)

TABLE 503.3(2) STANDARD TUBING INSULATION THICKNESS

INSULATION O.D. TUBE INSULATION (inches) TUBE O.D. SIZE I.D. INSULATION NOMINAL THICKNESS (inches) (inches) (inches) (inches)* 1 1.5 2 2.5 3 3.5 4 4.5 5

3 ⁄8 0.500 0.52 2.38 3.50 4.50 5.56 6.62 - - - - 1 ⁄2 0.625 0.64 2.88 3.50 4.50 5.56 6.62 - - - - 3 ⁄4 0.875 0.89 2.88 4.00 5.00 6.62 7.62 8.62 9.62 10.75 11.75 1 1.125 1.14 2.88 4.00 5.00 6.62 7.62 8.62 9.62 10.75 11.75 1 1 ⁄4 1.375 1.39 3.50 4.50 5.56 6.62 7.62 8.62 9.62 10.75 11.75 1 1 ⁄2 1.625 1.64 3.50 4.50 5.56 6.62 7.62 8,62 9.62 10.75 11.75 2 2.125 2.16 4.00 5.00 6.62 7.62 8.62 9.62 10.75 11.75 12.75 1 2 ⁄2 2.625 2.66 4.50 5.56 6.62 7.62 8.62 9.62 10.75 11.75 12.75 3 3.125 3.16 5.00 6.61 7.62 8.62 9.62 10.75 11.75 12.75 14.00 1 3 ⁄2 3.625 3.66 5.56 6.62 7.62 8.62 9.62 10.75 11.75 12.75 14.00 4 4.125 4.16 6.62 7.62 8.62 9.62 10.75 11.75 12.75 14.00 15.00 5 5.125 5.16 7.62 8.62 9.62 10.75 11.75 12.75 14.00 15.00 16.00 6 6.125 6.20 8.62 9.62 10.75 11.75 12.75 14.00 15.00 16.00 17.00 For SI units: 1 inch = 25 mm * Thickness values are applicable for calcium silicate, cellular foam plastics, cellular glass, mineral fiber, and perlite preformed insulation materials.

42 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT SOLAR THERMAL SYSTEMS

TABLE 503.3(3) UNIVERSAL PIPE INSULATION THICKNESS BASED ON RADIUS AND IRON PIPE SIZE (IPS)

1 3 1 Pipe ⁄2 INCH THICK* ⁄4 INCH THICK* 1 INCH THICK* 1 ⁄2 INCHES THICK* 2 INCHES THICK* IPS Diameter r * r r r r r (inches) 1 2 2 2 2 2 (inches) r2 •ln A r2 r2 •ln A r2 r2 •ln A r2 r2 •ln A r2 r2 •ln A r2 r1 r1 r1 r1 r1 1 ⁄2 0.840 0.420 0.72 0.48 0.92 1.21 0.62 1.18 1.77 0.75 1.44 3.12 1.05 2.00 4.46 1.31 2.50 3 ⁄4 1.050 0.525 0.69 0.54 1.03 0.96 0.62 1.18 1.44 0.75 1.44 2.67 1.05 2.00 3.90 1.31 2.50 1 1.315 0.657 0.65 0.61 1.16 1.11 0.75 1.44 1.71 0.92 1.75 2.77 1.18 2.25 4.01 1.46 2.78 1 1 ⁄4 1.660 0.830 0.63 0.70 1.33 1.29 0.86 1.64 1.31 0.92 1.75 2.76 1.31 2.50 3.36 1.46 2.78 1 1 ⁄2 1.990 0.950 0.53 0.63 1.39 1.06 0.92 1.75 1.49 1.05 2.00 2.42 1.31 2.50 2.98 1.46 2.78 2 2.375 1.187 0.62 0.90 1.71 1.02 1.04 1.99 1.43 1.18 2.25 2.37 1.46 2.78 3.39 1.73 3.31 1 2 ⁄2 2.875 1.437 0.58 1.02 1.94 0.99 1.17 2.24 1.38 1.31 2.50 1.84 1.46 2.78 2.76 1.73 3.31 3 3.500 1.750 0.56 1.18 2.25 0.87 1.29 2.48 1.29 1.46 2.78 2.11 1.73 3.31 2.96 2.00 3.81 1 3 ⁄2 4.000 2.000 0.52 1.29 2.48 0.89 1.46 2.78 1.67 1.73 3.31 1.67 1.73 3.31 2.46 2.00 3.81 4 4.500 2.250 0.59 1.46 2.78 1.25 1.72 3.29 1.28 1.73 3.31 2.01 2.00 3.81 2.80 2.26 4.31 6 6.625 3.312 0.64 2.05 3.90 0.83 2.13 4.06 1.13 2.26 4.31 1.79 2.52 4.81 2.60 2.82 5.38 For SI units: 1 inch = 25.4 mm, 1 square inch = 0.000645 m2 * A = Area (square inches), r1 = Inside radius (inches), r2 = Outside radius (inches)

UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT 43 SOLAR THERMAL SYSTEMS

TABLE 503.3(4) DESIGN VALUES FOR THERMAL CONDUCTIVITY (k) OF INDUSTRIAL INSULATION1, 3, 4, 5 ACCEPTED TYPICAL TYPICAL THERMAL CONDUCTIVITY (k) AT MEAN TEMP (°F) MAX TEMP 3 DENSITY FORM MATERIAL COMPOSITION FOR USE (lb/ft3) (°F)1 -100 -75 -50 -25 0 25 50 75 100 200 300 500 700 BLOCKS, BOARDS & PIPE INSULATION ASBESTOS Laminated asbestos paper 700 30 –– –– –– –– –– –– –– –– 0.40 0.45 0.50 0.60 –– Corrugated & laminated asbestos paper 4-ply 300 11-13 –– –– –– –– –– –– –– 0.54 0.57 0.68 –– –– –– 6-ply 300 15-17 –– –– –– –– –– –– –– 0.49 0.51 0.59 –– –– –– 6-ply 300 18-20 –– –– –– –– –– –– –– 0.47 0.49 0.57 –– –– –– MOLDED AMOSITE & BINDER 1500 15-18 –– –– –– –– –– –– –– –– 0.32 0.37 0.42 0.52 0.62 85 PERCENT MAGNESIA 600 11-12 –– –– –– –– –– –– –– –– 0.35 0.38 0.42 –– –– 1200 11-13 –– –– –– –– –– –– –– –– 0.38 0.41 0.44 0.52 0.62 CALCIUM SILICATE 1800 12-15 –– –– –– –– –– –– –– –– –– –– –– 0.63 0.74 CELLULAR GLASS 800 9 –– –– 0.32 0.33 0.35 0.36 0.38 0.40 0.42 0.48 0.55 –– –– 1600 21-22 –– –– –– –– –– –– –– –– –– –– –– 0.64 0.68 DIATOMACEOUS SILICA 1900 23-25 –– –– –– –– –– –– –– –– –– –– –– 0.70 0.75 MINERAL FIBER Glass, Organic bonded, block and 400 3-10 0.16 0.17 0.18 0.19 0.20 0.22 0.24 0.25 0.26 0.33 0.40 –– –– boards Nonpunking binder 1000 3-10 –– –– –– –– –– –– –– –– 0.26 0.31 0.38 0.52 –– 350 3-4 –– –– –– –– 0.20 0.21 0.22 0.23 0.24 0.29 –– –– –– Pipe insulation, slag or glass 500 3-10 –– –– –– –– 0.20 0.22 0.24 0.25 0.26 0.33 0.40 –– –– 1000 10-15 –– –– –– –– –– –– –– –– 0.33 0.38 0.45 0.55 –– Inorganic bonded-block 1800 15-24 –– –– –– –– –– –– –– –– 0.32 0.37 0.42 0.52 0.62 Pipe insulation, slag or glass 1000 10-15 –– –– –– –– –– –– –– –– 0.33 0.38 0.45 0.55 –– MINERAL FIBER Resin binder –– 15 –– –– 0.23 0.24 0.25 0.26 0.28 0.29 –– –– –– –– –– RIGID POLYSTYRENE Extruded, Refrigerant 12 exp 170 3.5 0.16 0.16 0.15 0.16 0.16 0.17 0.18 0.19 0.20 –– –– –– –– Extruded, Refrigerant 12 exp 170 2.2 0.16 0.16 0.17 0.16 0.17 0.18 0.19 0.20 –– –– –– –– –– Extruded 170 1.8 0.17 0.18 0.19 0.20 0.21 0.23 0.24 0.25 0.27 –– –– –– –– Molded beads 170 1 0.18 0.20 0.21 0.23 0.24 0.25 0.26 0.28 –– –– –– –– –– POLYURETHANE2, 4 Refrigerant 11 exp 210 1.5-2.5 0.16 0.17 0.18 0.18 0.18 0.17 0.16 0.16 0.17 –– –– –– –– RUBBER, Rigid Foamed 150 4.5 –– –– –– –– –– 0.20 0.21 0.22 0.23 –– –– –– –– VEGETABLE & ANIMAL FIBER Wool felt (pipe insulation) 180 20 –– –– –– –– –– 0.28 0.30 0.31 0.33 –– –– –– –– INSULATING CEMENTS MINERAL FIBER (Rock, slag, or glass) With colloidal clay binder 1800 24-30 –– –– –– –– –– –– –– –– 0.49 0.55 0.61 0.73 0.85 With hydraulic setting binder 1200 30-40 –– –– –– –– –– –– –– –– 0.75 0.80 0.85 0.95 –– LOOSE FILL Cellulose insulation (milled pulver- –– 2.5-3 –– –– –– –– –– –– 0.26 0.27 0.29 –– –– –– –– ized paper or wood pulp) Mineral fiber, slag, rock, or glass –– 2-5 –– –– 0.19 0.21 0.23 0.25 0.26 0.28 0.31 –– –– –– –– Perlite (expanded) –– 5-8 0.25 0.27 0.29 0.30 0.34 0.35 0.37 0.39 –– –– –– –– –– Silica aerogel –– 7.6 –– –– 0.13 0.14 0.15 0.15 0.16 0.17 0.18 –– –– –– –– –– 7-8.2 –– –– 0.39 0.40 0.42 0.44 0.45 0.47 0.49 –– –– –– –– Vermiculite (expanded) –– 4-6 –– –– 0.34 0.35 0.38 0.40 0.42 0.44 0.46 –– –– –– –– For SI units: °C = (°F-32)/1.8, 1 pound per cubic foot = 16.01846 kg/m3, 1 inch = 25.4 mm, 1 British thermal unit inch per hour square foot degree Fahrenheit = 0.1 [W/(m•K)] Notes: 1 These temperatures are generally accepted as maximum. Where operating temperature approaches these limits, follow the manufacturer’s recommendations. 2 Values are for aged board stock. 3 Representative values for dry materials as selected by ASHRAE TC 4.4, Insulation and Moisture Barriers. They are intended as design (not specification values for materials of building construction for normal use). For thermal resistance of a particular product, use the value supplied by the manufacturer or by unbiased tests. 4 Some polyurethane foams are formed by means that produce a stable product (with respect to k), but most are blown with refrigerant and will change with time. 5 Thermal conductivity (k) of industrial insulation shall be expressed in British thermal unit inch per hour square foot degree Fahrenheit [Btu•in/(h•ft2•°F)] [W/(m•K)].

44 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT SOLAR THERMAL SYSTEMS

TABLE 503.6 INSULATION OF DUCTS5 INSULATION TYPES MECHANI- INSULATION TYPES HEATING DUCT LOCATION HEATING ZONES1 CALLY COOLED4 ONLY4 I A and W On roof or on exterior of building C, V2 and W II B and W III C and W I A Attics, and garages and crawl A and V2 II A spaces III B 3 I A In walls, within floor-ceiling A and V2 II A spaces3 III B Within the conditioned space, or in basements; return ducts in air None required –– None required plenums Cement slab or within ground None required –– None required Notes: 1 Heating Degree Days: (a) Zone I – below 4500 Degree Days (b) Zone II – 4501 Degree Days to 8000 Degree Days (c) Zone III – exceeds 8000 Degree Days 2 Vapor barriers shall be installed on supply ducts in spaces vented to the outside in geographic areas where the average July, August, and September mean dew point temperature exceeds 60°F (16°C). 3 Insulation shall be permitted to be omitted on that portion of a duct that is located within a wall or a floor-ceiling space where: (a) Both sides of the space are exposed to conditioned air. (b) The space is not ventilated. (c) The space is not used as a return plenum. (d) The space is not exposed to unconditioned air. Ceilings that form plenums need not be insulated. 4 The examples of materials listed under each type of insulation is not meant to limit other available thickness and density combinations with the equivalent installed conductance or resistance based on the insulation only. Insulation Types: A = Materials with an installed conductance of 0.48 or the equivalent thermal resistance of 2.1. Examples of materials capable of meeting the above requirements: (a) One inch (25.4 mm), 0.60 pounds per cubic feet (lb/ft3) (9.61 kg/m3) mineral fiber (rock, slag, or glass) blanket. (b) One-half inch (12.7 mm), 1.5 lb/ft3 to 3 lb/ft3 (24 kg/m3 to 48 kg/m3) mineral fiber blanket duct liner. (c) One-half inch (12.7 mm), 3 lb/ft3 to 10 lb/ft3 (48 kg/m3 to 160 kg/m3) mineral fiber board. B = Materials with an installed conductance of 0.24 or the equivalent thermal resistance of 4.2. Examples of materials meeting the above requirements: Two inch (51 mm), 0.60 lb/ft3 (9.61 kg/m3) mineral fiber blanket. One inch (25.4 mm), 1.5 lb/ft3 to 3 lb/ft3 (24 kg/m3 to 48 kg/m3) mineral fiber blanket duct liner. One inch (25.4 mm), 3 lb/ft3 to 10 lb/ft3 (48 kg/m3 to 160 kg/m3) mineral fiber board. C = Materials with an installed conductance 0.16 or the equivalent thermal resistance 6.3. Examples of materials meeting the above requirements: Three inch (76 mm), 0.60 lb/ft3 (9.61 kg/m3) mineral fiber blanket. One-and-one-half inch (38 mm), 1.5 lb/ft3 to 3 lb/ft3 (24 kg/m3 to 48 kg/m3) mineral blanket duct liner. One-and-one-half inch (38 mm), 3 lb/ft3 to 10 lb/ft3 (48 kg/m3 to 160 kg/m3) mineral fiber board. V = Vapor barrier: Material with a perm rating not exceeding 0.5 perm [2.9 E-11 kg/(Pa•s•m2)]. Joints shall be sealed. W = Approved weatherproof barrier. 5 Where ducts are used for both heating and cooling, the minimum insulation shall be as required for the most restrictive condition.

UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT 45 46 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT CHAPTER 6 THERMAL STORAGE

601.0 General. 603.0 Storage Tanks. 601.1 Applicability. This chapter shall govern the construc- 603.1 Plans. Plans for tanks shall be submitted to the tion, design, location, and installations a thermal storage. Ther- Authority Having Jurisdiction for approval, unless listed by mal storage includes storage tanks with or without heat an approved listing agency. Such plans shall show dimen- exchangers and expansion tanks. sions, reinforcing, structural calculations, and such other per- 601.2 Test Pressure for Storage Tanks. The test pressure tinent data as required. for storage tanks that are subject to water pressure from utility 603.2 Atmospheric Tanks. Atmospheric storage tanks shall mains (with or without a pressure reducing valve) shall be two be vented to the atmosphere and installed in accordance with times the working pressure but not less than 300 psi (2068 kPa). the manufacturer’s installation instructions. 601.2.1 Pressure Type. Pressure-type storage tanks 603.2.1 Overflow. Gravity tanks shall be installed with exceeding 15 pounds-force per square inch (psi) (103 an overflow opening of not less than 2 inches (50 mm) in kPa) shall be tested in accordance with ASME BPVC diameter. The openings shall be aboveground and Section VIII. Pressure-type storage tanks not exceeding installed with a screened return bend. 15 psi (103 kPa) shall be hydrostatically tested at one and 603.2.2 Makeup Water. Makeup water from a potable one-half times the maximum design operating pressure. water system to an atmospheric tank shall be protected by 601.2.2 Atmospheric-Type. Atmospheric-type ther- an air gap. mal storage tanks shall be tested by filling with water for 603.2.3 Draining. An overflow shall be provided for an a period of 24 hours prior to inspection and shall with- atmospheric tank. The overflow shall be provided with a stand the test without leaking. No thermal storage tank or means of drainage in accordance with Section 316.0. The portion thereof shall be covered or concealed prior to overflow for an atmospheric tank containing nonpotable approval. water shall be emptied into an approved container. 601.3 Storage Tank Connectors. Flexible metallic stor- 603.3 Prefabricated Tanks. Prefabricated tanks shall be age tank connectors or reinforced flexible storage tank con- listed and labeled. nectors connecting a storage tank to the piping system shall 603.4 Separate Storage Tanks. For installations with sep- be in accordance with the applicable standards referenced in arate storage tanks, a pressure relief valve and temperature Table 901.1. Copper or stainless steel flexible connectors relief valve or combination thereof shall be installed on both shall not exceed 24 inches (610 mm) in length. PEX, PEX- the main storage and auxiliary storage tank. AL-PEX, PE-AL-PE, or PE-RT tubing shall not be installed 603.4.1 Isolation. within the first 18 inches (457 mm) of piping connected to a Storage tanks shall be provided with storage tank. isolation valves for servicing. 603.5 Underground Tanks. Tanks shall be permitted to be 602.0 Insulation. buried underground where designed and constructed for such installation. 602.1 Thickness. Tank insulation shall have a thermal resist- 603.6 Pressure Vessels. A pressure-type storage tank ance not less than as shown in Table 602.1. The temperature exceeding an operating pressure of 15 pounds-force per square difference shall be calculated as the difference between the inch (psi) (103 kPa) shall be constructed in accordance with design operating temperature of the tank and the temperature ASME BPVC Section VIII. Fiber-reinforced plastic storage of the surrounding air, or soil where the tank is installed under- tanks shall be constructed in accordance with ASME BPVC ground. Where such data is not available, a temperature dif- Section X. ference of 50°F (28°C) shall be used. 603.7 Devices. TABLE 602.1 Devices attached to or within a tank shall be MINIMUM TANK INSULATION* accessible for repair and replacement. 603.7.1 Safety Devices. THERMAL RESISTANCE Pressure-type thermal storage TEMPERATURE DIFFERENCE(°F) (R)[°F•h•ft2 /(Btu)] tanks shall be installed with a listed combination temper- 50 6 ature and pressure relief valve in accordance with Section 311.1. The temperature setting shall not exceed 210°F 100 12 (99°C) and the pressure setting shall not exceed 150 per- 150 18 cent of the maximum designed operating pressure of the 200 24 system, or 150 percent of the established normal operat- 250 30 ing pressure of the piping materials, or the labeled maxi- For SI units: °C = °F(0.5555556), 1 degree Fahrenheit hour square foot per mum operating pressure of a pressure-type storage tank, British thermal unit = [0.176 (m2•K)/W], 1 degree Fahrenheit hour square foot per British thermal unit inch = [6.9 (m•K)/W] whichever is less. The pressure and temperature setting * Based on thermal conductivity (k) of 0.20 [(Btu•inch)/(°F•h•ft2)] shall not exceed the pressure and temperature rating of the tank or as recommended by the tank manufacturer.

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Storage tanks and bottom fed tanks connected to a 605.3 Closed-Type Systems. Closed-type systems shall water heater shall be designed to withstand vacuum have an airtight tank or other approved air cushion that will induced pressure, or shall be provided with a vacuum be consistent with the volume and capacity of the system, and relief in accordance with Section 311.4. The vacuum shall be designed for a hydrostatic test pressure of two and relief valve shall be installed at the top of the tank and one-half times the allowable working pressure of the system. shall have an operating pressure not to exceed 200 psi Expansion tanks for systems designed to operate at more than (1379 kPa) and a temperature rating not to exceed 250°F 30 pounds-force per square inch (psi) (207 kPa) shall comply (121°C). The size of such vacuum relief valves shall have with ASME BPVC Section VIII. Provisions shall be made for a minimum rated capacity for the equipment served. This draining the tank without emptying the system. section shall not apply to pressurized captive air 605.4 Minimum Capacity of Closed-Type Tank. diaphragm or bladder tanks. The minimum capacity for a gravity-type hot water system expansion 603.8 Tank Covers. Tank covers shall be structurally designed to withstand anticipated loads and pressures in accordance with tank shall be in accordance with Table 605.4(1). The minimum the manufacturer’s instructions. capacity for a forced-type hot water system expansion tank shall be in accordance with Table 605.4(2) or Equation 605.4. 604.0 Materials. 604.1 General. Tanks shall be constructed in accordance with (0.00041t-0.0466)V (Equation 605.4) Section 604.2 through Section 604.5. V = s t P P 604.2 Construction. Tanks shall be constructed of durable a – a materials not subject to excessive corrosion or decay and shall ( Pf Po ) be watertight. Each such tank shall be structurally designed to withstand anticipated loads and pressures and shall be installed level and on a solid bed. Where: 604.3 Concrete. The walls and floor of each poured-in-place, Vt = Minimum volume of expansion tank, gallons. concrete tank shall be monolithic. The exterior walls shall be V = Volume of system, not including expansion tank, gallons. double-formed so as to provide exposure of the exterior walls s during the required water test. The compressive strength of a t = Average operating temperature, °F. concrete tank wall, top and covers, or floor shall be not less than P = Atmospheric pressure, feet H2O absolute. 2 2 a 2500 pounds per square inch (lb/in ) (1.7577 E+06 kg/m ). P = Fill pressure, feet H O absolute. Where required by the Authority Having Jurisdiction, the con- f 2 crete shall be sulfate resistant (Type V Portland Cement). Po = Maximum operating pressure, feet H2O absolute. 604.4 Metal Tanks. Metal tanks shall be welded, riveted and caulked, brazed, bolted, or constructed by use of a combination TABLE 605.4(1) of these methods. EXPANSION TANK CAPACITIES FOR GRAVITY 604.5 Filler Metal. Filler metal used in brazing shall be non- HOT WATER SYSTEMS1 ferrous metal or an alloy having a melting point above 1000°F INSTALLED EQUIVALENT TANK CAPACITY DIRECT RADIATION2 (538°C) and below that of the metal joined. (gallons) (square feet) 605.0 Expansion Tanks. Up to 350 18 605.1 Where Required. An expansion tank shall be Up to 450 21 installed in a water heating system as a means for controlling Up to 650 24 increased pressure caused by thermal expansion. Expansion Up to 900 30 tanks shall be of the closed or open type and securely fastened Up to 1100 35 to the structure. Tanks shall be rated for the pressure of the Up to 1400 40 system. Supports shall be capable of carrying twice the Up to 1600 2 to 30 weight of the tank filled with water without placing strain on Up to 1800 2 to 30 the connecting piping. Up to 2000 2 to 35 Water-heating systems incorporating hot water tanks or Up to 2400 2 to 40 fluid relief columns shall be installed to prevent freezing For SI units: 1 gallon = 3.785 L, 1 square foot = 0.0929 m2 under normal operating conditions. Notes: 605.2 Systems with Open Type Expansion Tanks. Open 1 Based on a two-pipe system with an average operating water temperature type expansion tanks shall be located not less than 3 feet (914 of 170°F (77°C), using cast-iron column radiation with a heat emission mm) above the highest point of the system. Such tanks shall rate of 150 British thermal units per square foot hour [Btu/(ft2•h)] (473 2 be sized based on the capacity of the system. An overflow W/m ) equivalent direct radiation. 2 2 with a diameter of not less than one-half the size of the water For systems exceeding 2400 square feet (222.9 m ) of installed equiva- supply or not less than 1 inch (25 mm) in diameter shall be lent direct water radiation, the required capacity of the cushion tank shall be increased on the basis of 1 gallon (4 L) tank capacity per 33 square feet installed at the top of the tank. The overflow shall discharge 2 (3.1 m ) of additional equivalent direct radiation. through an air gap into the drainage system.

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TABLE 605.4(2) EXPANSION TANK CAPACITIES FOR FORCED WATER SYSTEMS1 TANK CAPACITY SYSTEM VOLUME2 TANK CAPACITY DIAPHRAGM TYPE (gallons) (gallons) (gallons) 100 9 15 200 17 30 300 25 45 400 33 60 500 42 75 1000 83 150 2000 165 300 For SI units: 1 gallon = 3.785 L Notes: 1 Based on an average operating water temperature of 195°F (91°C), a fill pressure of 12 psig (83 kPa), and an operating pressure of not more than 30 psig (207 kPa). 2 Includes volume of water in boiler, radiation, and piping, not including expansion tank.

606.0 Dry Storage Systems. 606.1 Waterproofing. The containment structure for dry thermal storage systems shall be constructed in an approved manner to prevent the infiltration of water or moisture. 606.2 Detecting Water Intrusion. The containment structure shall be capable of fully containing spillage or moisture accumulation that occurs. The structure shall have a means, such as a sight glass, to detect spillage or moisture accumulation, and shall be fitted with a drainage device to eliminate spillage. 606.3 Rock as Storage Material. Systems utilizing rock as the thermal storage material shall use clean, washed rock, and free of organic material. 606.4 Odor and Particulate Control. Thermal storage materials and containment structures, including an interior protective coating, shall not impart toxic elements, particulate matter, or odor to areas of human occupancy. 606.5 Combustibles Within Ducts or Plenums. Mate- rials exposed within ducts or plenums shall be noncombustible or shall have a flame spread index not to exceed 25 and a smoke developed index not to exceed 50 where tested as a composite product in accordance with ASTM E84 or UL 723.

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Part I - General. loads and stresses, including the effects of buoyancy, during the occurrence of flooding to the design flood elevation. 701.0 General. 701.8 Pipe Support. Pipe shall be supported in accordance 701.1 Applicability. Part I of tThis chapter applies shall with Section 317.1. apply to geothermal energy systems such as, but not limited 701.9 Velocities. Ground source heat pump ground-loop to, building systems coupled with a ground-heat exchanger, systems shall be designed so that the flow velocities do not submerged heat exchanger using water-based fluid as a heat exceed the maximum flow velocity recommended by the pipe transfer medium, or groundwater (well). The regulations of and fittings manufacturer. Flow velocities shall be controlled this chapter shall govern the construction, location and instal- to reduce the possibility of water hammer. lation of geothermal energy systems. 701.10 Chemical Compatibility. Antifreeze and other Indoor piping, fittings, and accessories that are part of materials used in the system shall be chemically compatible the groundwater system shall be in accordance with Section with the pipe, tubing, fittings, and mechanical systems. 703.5 and Chapter 4. 701.11 Transfer Fluid. The transfer fluid shall be compati- 701.1.1 Prior to Construction. Documents for per- ble with the makeup water supplied to the system. mits shall be submitted prior to the construction of a building system, ground heat exchanger, submerged heat exchanger, or water well. Permits shall be issued by the 702.0 Groundwater Systems. Authority Having Jurisdiction. 702.1 General. 701.1.2 Equipment, Accessories, Components, The potable water supply connected to a and Materials. groundwater system shall be protected with an approved The mechanical equipment, accessories, backflow prevention device. The connection of a discharge components, and materials used shall be of the type and line to the sanitary or storm sewer system, or private sewage rating approved for the specific use. 701.2 Construction Documents. disposal system, shall be in accordance with the plumbing The construction docu- code or in accordance with the Authority Having Jurisdiction. ments for the building system portion of the geothermal energy system shall be submitted to the Authority Having Jurisdiction. 703.0 Design of Systems. 701.3 Site Survey. A site survey shall be conducted prior to 703.1 Ground-Heat Exchanger Design. The ground- designing the geothermal system. The requirements for con- heat exchanger design shall be provided by a licensed pro- struction documents shall be defined by the Authority Having fessional or a designer with the appropriate certifications or Jurisdiction. Where no guidance is provided, the following credentials as defined by the Authority Having Jurisdiction. information shall be provided: 703.2 Piping and Tubing Materials Standards. For (1) Ground heat exchanger dimensions. water-based systems, ground source heat pump ground-loop (2) Grout or sealing specifications, as applicable. pipe and tubing shall comply with the standards listed in (3) Dimensions from building to water well, ground heat Table 703.2. Piping and tubing used for DX systems shall be exchanger, or submerged heat exchanger. of copper in accordance with Section 715.3. (4) Operating temperatures and pressures. 701.4 Used Materials. The installation of used pipe, fit- TABLE 703.2 tings, valves, and other materials shall not be permitted. PLASTIC GROUND SOURCE LOOP PIPING MATERIAL STANDARD 701.5 Contact with Building Material. A ground source heat pump ground-loop piping system shall not be in direct Cross-Linked Polyethylene ASTM F876, ASTM F3253, contact with building materials that cause the piping or fit- (PEX) CSA B137.5, CSA C448, ting material to degrade or corrode, or that interferes with the NSF 358-3 operation of the system. High Density Polyethylene ASTM D2737, ASTM D3035, 701.6 Strains and Stresses. Piping shall be installed so as (HDPE) ASTM F714, AWWA C901, to prevent detrimental strains and stresses in the pipe. Provi- CSA B137.1, CSA 448, sions shall be made to protect piping from damage resulting NSF 358-1 from expansion, contraction, and structural settlement. Pip- Polypropylene (PP) ASTM F2389, ing shall be installed so as to avoid structural stresses or CSA B137.11, NSF 358-2 strains within building components. Polyethylene Raised Tempera- ASTM F2623, ASTM F2769, ture (PE-RT) CSA B137.18, CSA C448, 701.7 Flood Hazard. Piping located in a flood hazard area NSF 358-4 shall be capable of resisting hydrostatic and hydrodynamic

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703.3 Fittings. For water-based systems, fittings for ground 703.5.1.1 703.4.1.1 Joining Methods for Poly- source heat pump systems shall be recommended by the man- ethylene Pipe or Tubing. Joints between high ufacturer for installation with the piping materials to be installed, density polyethylene (HDPE) plastic pipe or tubing and shall comply with the standards listed in Table 703.3. Fit- and fittings shall be installed in accordance with the tings for use in DX systems shall comply with Section 715.3. manufacturer’s installation instructions, the appropriate standards listed in accordance with Table TABLE 703.3 703.3, and one of the following heat fusion meth- GROUND SOURCE LOOP PIPE FITTINGS ods: MATERIAL STANDARD (1) Butt-fusion joints shall be made in accordance Cross-Linked Polyethylene ASTM F877, ASTM F1055, with ASTM F2620 by heating the squared ends (PEX) ASTM F1807, ASTM F1960, of two pipes, pipe and fitting, or two fittings by ASTM F2080, ASTM F2159, holding ends against a heated element. The ASTM F2434, ASTM F3253, heated element shall be removed where the ASTM F3347, ASTM F3348, proper melt is obtained, and joined ends shall CSA B137.5, CSA C448, be placed together with applied force. NSF 358-3 High Density Polyethylene ASTM D2683, ASTM D3261, (2) Socket-fusion joints shall be made in accor- (HDPE) ASTM F1055, CSA B137.1, dance with ASTM F2620, by simultaneously CSA C448, NSF 358-1 heating the outside surface of a pipe end and the Polypropylene (PP) ASTM F2389, CSA B137.11, inside of a fitting socket. Where the proper melt NSF 358-2 is obtained, the pipe and fitting shall be joined Polyethylene Raised Tempera- ASTM D3261, ASTM F1055, by inserting one into the other with applied ture (PE-RT) ASTM F1807, ASTM F2080, force. The joint shall fuse together and remain ASTM F2159, ASTM F2769, undisturbed until cool. CSA B137.18, CSA C448, (3) Electrofusion joints shall be heated internally NSF 358-4 by a conductor at the interface of the joint. Align and restrain fitting to pipe to prevent 703.5 703.4 Underground Piping and Submerged movement and apply electric current to the fit- Materials. ting. Turn off the current when the proper time Underground and submerged piping for a ground- has elapsed to heat the joint. The joint shall fuse heat exchanger shall be polyethylene (PE) pipe or tubing in together and remain undisturbed until cool accordance with Section 703.5.1 703.4.1 and Section made in accordance with ASTM F1055. 703.5.1.1 703.4.1.1, or cross-linked polyethylene (PEX) pipe 703.5.2 703.4.2 Cross-Linked Polyethylene or tubing in accordance with Section 703.5.2 703.4.2 and Sec- (PEX). tion 703.5.2.1 703.4.2.1. Cross-linked polyethylene pipe shall be manufactured to outside diameters, wall thickness, and respec- 703.5.1 703.4.1 Polyethylene (PE). Polyethylene tive tolerances in accordance with ASTM F876 or CSA pipe or tubing shall be manufactured to outside diame- B137.5 the standards listed in Table 703.2. Pipe or tub- ters, wall thickness, and respective tolerances in accor- ing shall have a dimension ratio of 9 PEX shall have a dance with ASTM D3035, ASTM D3350, ASTM F714 minimum tubing material designation code of PEX 1206 or CSA B137.1 in accordance with the standards listed in and shall have a minimum pressure rating of not less than Table 703.2. Pipe or tubing shall have a maximum 160 psi (1103 kPa) at 73°F (23°C). dimension ratio of 11 minimum wall thickness equal to SDR-11 and shall have a minimum pressure rating of not Fittings shall be manufactured to dimensional spec- less than 160 psi (1103 kPa) at 73°F (23°C). ifications and requirements in accordance with ASTM F1055 for electrofusion fittings, and ASTM F1960, Fittings shall be manufactured to dimensional spec- ASTM F2080, or CSA B137.5 for cold-expansion com- ifications and requirements in accordance with ASTM pression sleeve fittings. D2683 for socket fusion fittings, ASTM D3261 for 703.5.2.1 703.4.2.1 Joining Methods for butt/sidewall fusion fittings, or ASTM F1055 for elec- Cross-Linked Polyethylene Pipe or Tubing. trofusion fittings Polyethylene pipe or tubing shall be manufactured from a PE compound that has a pipe mate- Joints between cross-linked polyethylene (PEX) rial designation code of PE 3608, PE 3708, PE 3710, PE pipe or tubing and fittings shall be installed in accor- 4608, PE 4708, or PE 4710 as defined in the applicable dance with the manufacturer’s installation instruc- standards referenced in Table 703.2, with a cell classifi- tions and the appropriate standards in accordance cation in accordance with ASTM D3350 appropriate for with Table 703.3. and one of the following methods: the material designation code, and a color and ultravio- (1) Electrofusion joints shall be heated internally let stabilizer code of C or E. Code E compounds shall be by a conductor at the interface of the joint. stabilized against deterioration from unprotected expo- Align and restrain fitting to pipe to prevent sure to ultraviolet rays for not less than 3 years in accor- movement and apply electric current to the fit- dance with the test criteria specified in ASTM D2513. ting. Turn off the current when the proper time

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has elapsed to heat the joint. The joint shall fuse (10) Means for flow balancing for the building loop shall be together and remain undisturbed until cool. provided. (2) Cold-expansion joints that are in accordance with (11)Supply and return header temperatures and pressures ASTM F2080 shall be made, and fittings shall be shall be marked. joined to the pipe by expanding the end of the 707.3 704.2 Circulating Pumps. The circulating pump pipe with the expander tool, inserting the cold- shall be sized for the operating conditions and the heat trans- expansion fitting into expanded pipe, then pulling fer fluid properties. the compression-sleeve over the PEX pipe and the fitting, compressing the pipe between compression-sleeve and the fitting. Cold-expansion 705.0 Valves. joints shall be permitted to be buried with the 705.1 Where Required. Shutoff valves shall be installed manufacturer’s approved corrosion covering. in ground source-loop piping systems in the locations indi- (3) Cold-expansion joints that are in accordance cated in Section 705.2 through Section 705.8. with ASTM F1960 shall be made by applying 705.2 Heat Exchangers. Shutoff valves shall be installed an expansion ring on the pipe end; the pipe shall on the supply and return side of a heat exchanger. be expanded using an expander tool and inserting the cold-expansion fitting into the expanded Exception: Where a heat exchanger is an integral part of a pipe. The pipe shall retract over the fitting, cre- boiler or is a part of a manufactured boiler and heat exchanger ating the seal. Buried pipes shall comply with packaged unit, and is capable of being isolated from the the manufacturer’s instructions. hydronic system by supply and return valves. 705.3 Central Systems. 703.7 703.5 Indoor Piping. Indoor piping, fittings, and Shutoff valves shall be installed accessories that are part of the groundwater system shall be in on the building supply and return of a central utility system. accordance with Chapter 4. Such materials shall be rated for 705.4 Pressure Vessels. Shutoff valves shall be installed the operating temperature and pressures of the system and on the connection to a pressure vessel. shall be compatible with the type of transfer medium. For DX 705.5 Pressure-Reducing Valves. Shutoff valves shall systems, joints shall be purged with an inert gas and brazed be installed on both sides of a pressure-reducing valve. with a brazing alloy having 15 percent silver content in accor- 705.6 Equipment and Appliances. dance with AWS A5.8. Shutoff valves shall be installed on connections to mechanical equipment and 707.0 704.0 Heat Pump and Distribution System appliances. 705.7 Expansion Tanks. Design. Shutoff valves shall be installed at connections to nondiaphragm-type expansion tanks. 707.2 704.1 Heat Pump Distribution System. The heat 705.8 Reduced Pressure. A pressure relief valve shall be pump distribution system shall be designed as follows: installed on the low-pressure side of a hydronic piping system (1) Individual heat pumps shall have the capacity to handle that has been reduced in pressure. The relief valve shall be the peak load for each zone at its peak hour. set at the maximum pressure of the system design. (2) Distribution piping and fittings shall be insulated to prevent condensation inside the building. 705.0 706.0 Specific System Components Design. (3) An isolation valve shall be installed on both supply and 707.1 706.1 General. return of each unit. Ground coupled and water source heat pumps shall be certified listed in accordance with (4) Condensate drains on heat pumps shall be installed in AHRI/ASHRAE/ISO 13256-1 for water-to-air heat pumps accordance with the manufacturer’s installation instruc- and AHRI/ASHRAE/ISO 13256-2 for water-to water heat tions. pumps. DX heat pumps shall be certified listed in accordance (5) Air filters shall be installed for heat pump units. with ASHRAE 194. All heat Ppump equipment used in DX (6) Drain valves shall be installed at the base of each supply systems shall comply with AHRI 870. Heat pumps shall be and return pipe riser for system flushing. fitted with a means to indicate that the compressor is locked (7) Piping shall be supported in accordance with Section out. 317.0 and provisions for vibration, expansion or con- 705.1 706.2 Heat Exchangers. Heat exchangers used for traction shall be provided. heat transfer or heat recovery shall protect the potable water (8) Specifications for each heat pump, the heating and cool- system from being contaminated by the heat transfer medium. ing capacity, the fluid flow rate, the airflow rate, and the Single-wall heat exchangers shall comply with Section 313.1. external pressure or head shall be provided on the con- Double-wall heat exchangers shall separate the potable water struction documents. from the heat transfer medium by providing a space between (9) Manually controlled air vents shall be installed at the the two walls that are vented to the atmosphere. 705.2 706.3 Heat-Transfer Medium. high points in the system and drains at the low points. The heat-transfer Where the heat-transfer fluid is a salt or alcohol, auto- medium shall be compatible with components with which it matic air vents shall not be installed. comes into contact. Where antifreeze or corrosion inhibitors

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are used, such solutions shall be approved by the Authority 703.2 707.6 Ground Heat-Exchanger Installation Prac- Having Jurisdiction. The heat-transfer fluid flash point shall tices. A ground-heat exchanger system shall be installed as be not less than 50°F (28°C) above the maximum system follows: operating temperature. For DX systems, the heat transfer (1) Outside piping or tubing located within 5 feet (1524 mm) medium shall be a refrigerant listed in ASHRAE 34 or the of any wall or structure shall be continuously insulated mechanical code. with insulation that has a minimum R-5 value. Such pipe 705.4 706.4 Insulation. The temperature of surfaces within or tubing installed under the slab or basement floors shall reach of building occupants shall not exceed 140°F (60°C) be insulated within 5 feet (1524 mm) from the structure unless they are protected by insulation. Where sleeves are to the exterior point of exit from the slab. installed, the sleeve insulation shall retain its full size over (2) Freeze protection shall be provided where the design of the length of the material being protected. the ground heat exchanger system would permit the heat- transfer medium to freeze. 704.0 707.0 Installation Practices. (3) Horizontal piping shall be installed not less than 12 707.1 Prior to Construction. Documents for permits shall inches (305 mm) below the frost line. be submitted prior to the construction of a building system, or (4) Submerged heat exchangers shall be protected from dam- water well. Permits shall be issued by the Authority Having age and shall be securely fastened to the bottom of the Jurisdiction. lake or pond, or other approved submerged structure. 707.2 Equipment, Accessories, Components, and Materials. (5) A minimum separation distance shall be maintained The mechanical equipment, accessories, compo- between the potable water intake and the submerged heat nents, and materials used shall be recommended by the man- exchanger system in accordance with the Authority Hav- ufacturer for the specific use. ing Jurisdiction. 707.3 Construction Documents. The construction docu- (6) Vertical and horizontal ground-heat exchangers shall ments for the building system portion of the geothermal maintain the following setbacks: energy system shall be submitted to the Authority Having Jurisdiction. (a) Ten feet (3048 mm) horizontally from a pressure- tested sewer lateral into a building. 707.4 Site Survey Requirements. The site survey shall identify the physical limitations of the land area, including its (b) Twenty feet (6096 mm) horizontally from a non- extent, structures, existing wells of all types, proximity of pressure tested sewer lateral into a building. other existing ground source heat pump systems, pavements, (c) Three feet (914 mm) horizontally from buried utili- trees, grading, ponds, waterways, easements, overhead and ties such as electrical, gas, or water. underground services, septic systems, any identified septic (d) Fifty feet (15 240 mm) from a water well. repair areas, utility of rights of way, and any other elements that could affect an open-loop configuration. (e) Fifty feet (15 240 mm) from a septic tank and 100 feet (30 480 mm) from a subsurface sewage leach- Permission shall be obtained from any adjoining prop- ing field. erty owner(s), as evidenced by the registration and approval of a formal easement that meets requirements of the Author- (f) One hundred feet (30 480 mm) from a spring; or at ity Having Jurisdiction. It shall be received prior to the instal- distances specified by the Authority Having Juris- lation of any open-loop system that will extend into, cross, or diction. interfere with the equipment or rights-of-way of utilities, (7) Wells and boreholes shall be sealed in accordance with jurisdictions, and other property owners. the Authority Having Jurisdiction. Where grout is The site survey shall include a subsurface investigation required, it shall be applied in a single continuous oper- that meets the requirements for an open-loop heat exchanger. ation from the bottom of the borehole by pumping 707.5 Subsurface Investigation. A subsurface investiga- through a tremie pipe. 704.1 707.7 Trenching, Excavation, and Backfill. tion shall be performed in accordance with Section 707.5.1 Prior as determined by the registered design professional or certi- to excavation, trenching, or drilling, buried utilities, drainage, fied person conducting the site survey. water, and irrigation systems shall be located. Prior to exca- 707.5.1 Subsurface Conditions. The water well logs vation, trenching, or drilling, the contractor, and owner shall and other geological records shall be used to anticipate agree in writing to site restoration requirements and submit to the subsurface conditions of the aquifer and its potential the Authority Having Jurisdiction for approval. Prior to any supply of fresh water, multiple aquifers, saltwater intru- excavation, trenching, or drilling, all buried utilities including sions, contaminated soils and groundwater, hazardous drainage and irrigation systems shall be located and flagged gases, and any interference with neighboring water wells by the appropriate utility and ground source heat pump sys- and ground source heat exchangers. tem contractor representative. 704.2 707.8 Trenches, Tunneling, and Driving. Geological issues such as permafrost conditions and building stability shall be considered when reviewing Trenches shall comply with Section 320.1. Tunneling and available records. driving shall comply with Section 320.2.

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704.3 707.9 Excavations and Open Trenches. Excava- 707.17.8, and in accordance with requirements of the Author- tions required to be made for the installation of piping or tub- ity Having Jurisdiction. Prior to any excavation, trenching, or ing shall be in accordance with Section 320.3. Piping or drilling, all buried utilities including drainage and irrigation tubing shall be supported to maintain its alignment and pre- systems shall be located and flagged by the appropriate utility vent sagging. Piping in the ground shall be laid on a firm bed and ground source heat pump system contractor representative. for its entire length; where other support is otherwise pro- 707.17.1 Trenches. Trenches for underground piping vided, it shall be approved in accordance with Section 302.0. or tubing shall be excavated in accordance with the set- Piping or tubing shall be backfilled after an inspection in back requirements in Section 712.4. accordance with Section 320.4. 707.17.2 Buried Systems. 704.4 707.10 Protection of Piping, Materials, and Buried open-loop system piping, shall be installed not less than 3.3 feet (1006 mm) Structures. Piping and tubing passing under or through below the finished grade. walls shall be protected from breakage in accordance with 707.17.3 Pipe Installation. Piping in horizontal Section 318.1. Piping and tubing shall be installed in accor- trenches shall be embedded with not less than 6 inches dance with Section 318.2 to provide for expansion, contrac- (152 mm) of inert granular material above and below, or tion, and structural settlement. An electrically continuous in accordance with the Authority Having Jurisdiction and corrosion-resistant tracer wire (not less than AWG 14) or tape project specifications. shall be buried with the plastic pipe to facilitate locating. One end shall be brought aboveground at a building wall or riser. Horizontal piping trenching shall be backfilled with 704.5 707.11 Sleeves. approved material and shall be compacted. In exterior walls, annular space 707.17.4 Separation. between sleeves and pipes shall be sealed and made watertight The horizontal piping shall be and shall not be subject to a load from building construction in separated from fluid-based on-site service systems to pre- accordance with Section 318.6 through Section 318.6.2. vent excessive short-circuiting heat transfer between 704.6 707.12 Steel Nail Plates. such systems. Steel nail plates shall be 707.17.5 Insulation. installed for plastic and copper piping penetrating framing Insulation shall be provided on the members to within 1 inch (25.4 mm) of the exposed framing piping where there is close proximity of all site services in accordance with Section 318.5. to prevent thermal interference between fluid-based on- 705.3 707.13 On Site Storage. site service systems. Exterior piping shall be fit- 707.17.6 Pipe Bends. ted with end caps and protected from freezing, UV radiation, Sharp bending of pipe shall be corrosion, and degradation. For DX systems, copper piping prevented or approved elbow fitting shall be used with a and fittings shall be stored to prevent physical damage, con- bend-radius in accordance with the manufacturer’s tamination, and each pipe or tubing shall be pressurized with installation instructions. 707.17.7 Closed Cell Insulation. an inert gas and sealed with a cap. Buried horizontal 707.4 707.14 Heat Pump and Distribution System open-loop system pipes passing parallel within 5 feet Installation. The heat pump and distribution system shall (1524 mm) of a wall, structure, or water pipe shall be be installed in accordance with the system’s design, with this insulated with R-2 minimum closed cell insulation. code, and the manufacturer’s installation instructions. 707.17.8 Tracer Markings. Means shall be provided for 707.15 Pressurizing During Installation. Ground source underground detection or utility location of the buried pipe heat pump ground loop piping to be embedded in concrete system. This shall include, but is not limited to, metallic shall be pressure tested prior to pouring concrete. During detectable tape, with a thickness of not less than 11/64 of pouring, the pipe shall be maintained at the proposed operat- an inch (4.4 mm) and width of 6 inches (152 mm). ing pressure. This warning marking shall be permanent, conspic- 707.16 Horizontal Geothermal Piping - Materials and uous and resistant to the environmental conditions and Methods. Horizontal geothermal piping shall be in accor- shall be placed within 1 foot to 2 feet (305 mm to 610 dance with Section 707.16.1 through Section 707.17.8. mm) on top of the horizontal piping of the heat exchanger installation. 707.16.1 Piping Material. Piping materials and joining methods for horizontal piping from the ground heat- exchanger shall be in accordance with Section 703.2 708.0 System Start-Up. through Section 703.5. 708.1 General. The following requirements shall be veri- 707.16.2 Dissimilar Materials. Transition fittings fied prior to system start-up.: between dissimilar materials shall be inside or accessible. (1) Piping shall be cleaned, flushed, and purged. 707.16.3 Protection of Piping. Pipes passing through (2) DX systems shall be pressurized using nitrogen for not walls shall be sleeved and sealed in accordance with Sec- less than 1 hour. There shall be no allowable variance to tion 318.0. the test pressure after being corrected for ambient tem- 707.17 Trenches, Excavation, and Backfilled. Excava- perature changes during the test. The test pressure shall tion for horizontal piping shall comply with Section 707.7 not exceed 150 psig (1034 kPa) when pressure testing through Section 707.10, Section 707.17.1 through Section the compressor unit and indoor system components.

UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT 55 (32) The ground heat exchanger and building piping shall be 708.7 System Start-Up. System startup shall be in accor- cleaned, flushed, and, where required, shall be filled with dance with CSA C448.1, CSA C448.2, and Section 708.0. the heat transfer fluid medium. The ground loop system 708.8 Contaminants. Particulate contaminants shall be shall be tested at the design flow rate(s) and differential removed from the indoor piping system prior to initial start-up. pressure(s) recorded. Where the actual pressure change at design flow is more than +/- ± 10 percent of the design 701.4 709.0 Decommissioning and Abandonment. flow pressure drop, the cause shall be identified and cor- 709.1 General. rective action taken. Prior to the abandonment or decommis- (43) A method for the removal of air and a method for adding sioning of a ground-heat exchanger, submerged heat heat transfer fluid (where necessary) shall be provided. exchanger or ground water (well) the owner shall obtain the necessary permits from the Authority Having Jurisdiction. (54)The heat pumps shall be operational and adjustments Decommissioning of geothermal systems shall comply with shall be made in accordance with the manufacturer’s CSA C448. Prior to the abandonment or decommissioning of installation instructions. geothermal systems, the owner shall obtain the necessary per- (65)All necessary additional flow tests of the ground heat mits from the Authority Having Jurisdiction. exchanger shall be completed prior to heat pump start-up. (76) Ground heat exchanger and building piping, valves, and Part II – Closed-Loop Systems. operating controls, shall be set, adjusted, and operating as required. 710.0 General. (87) The system shall be labeled at the loop charging valves 710.1 Applicability. with a permanent-type label, indicating the type of heat Part II of this chapter shall apply to transfer fluid used. Where antifreeze is used, the labels geothermal energy systems such as, but not limited to, build- shall indicate the antifreeze type and concentration. ing systems coupled with a closed-loop system using water- based fluid as a heat transfer medium. (9) DX systems shall have permanent type labels installed 710.2 Piping and Tubing. and affixed on the compressor unit with the refrigerant Piping and tubing for closed- type and quantity. loop systems shall be in accordance Section 703.2 and Table 703.2. (108) Supply and return lines, as well as associated isolation 710.3 Borehole Piping and Tubing. valves from individual boreholes or water wells, shall be Borehole piping or identified and tagged. tubing for vertical and horizontally drilled closed-loop systems, shall have a minimum wall thickness equal to SDR-11 (11) For DX systems, refrigerant liquid and vapor lines from and shall have a minimum pressure rating of not less than 160 the loop system shall be identified and tagged. psi (1103 kPa) at 73°F (23°C). (129) Supply and return lines on submerged systems shall be 710.4 Underground Fittings. Underground fittings for identified in an approved manner, at the point of entry to closed-loop systems shall be in accordance with Section a surface water resource. 703.3 and Table 703.3. 708.2 Operation and Maintenance Manual. An operation 703.3 710.5 Verification. For closed-loop systems, the sys- and maintenance manual for the geothermal system shall be pro- tem shall be flushed of debris and purged of air after com- vided to the owner. The manual shall include information on pletion of the entire ground-heat exchanger. Flow rates and required testing and maintenance of the system. Training shall pressure drops shall be compared to calculated values to be provided on the system’s operation, maintenance require- assure no blockage or kinking of the pipe. A report shall be ments, and on the content of the operation and maintenance submitted to the owner to confirm that the loop flow is in manual. The operation and maintenance manual shall contain a accordance with the construction documents. layout of the ground-heat exchanger and building loop. For direct exchange (DX) systems, each u-bend shall be 708.3 Labeling and Marking. Ground source heat pump tested and proved tight with an inert gas at not less than 315 ground-loop system piping shall be marked with tape, metal psi (2172 kPA) and maintained for 15 minutes without pres- tags, or other methods where it enters a building. The mark- sure drop. The pressure reading after tremie grouting of the ing shall indicate the following words: “GROUND SOURCE boreholes shall be maintained in the ground heat exchanger HEAT PUMP-LOOP SYSTEM.” The marking shall indicate for not less than 2 hours, in accordance with CSA C448. antifreeze used in the system by name and concentration. 703.4 710.6 Vertical Bores. Vertical bores shall be drilled 708.4 Documentation. The ground source heat pump sys- to a depth to provide complete insertion of the u-bend pipe to tem as-built installation drawings and instructions shall be its specified depth. The borehole diameter shall be sized for provided to the building owner or designated agent. the installation and placement of the heat exchange u-bend and the tremie used to place the grouting material. CSA C448 708.5 Maintenance. The periodic maintenance required, shall be used for vertical loop depth and borehole diameter in accordance with the design requirements, shall be provided sizing guidance. The u-bend joint and pipe shall be visually and be made available to the owner or designated agent. inspected for integrity in accordance with the manufacturer’s 708.6 Records. The ground source heat pump system con- installation instructions. The u-bend joint and pipe shall be struction documents shall be provided to the owner. pressurized to not less than 100 psi (689 kPa), not to exceed

56 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT GEOTHERMAL ENERGY SYSTEMS

the pressure rating of the pipe at the test temperature, for 1 711.2 Individual Loop Pressure Testing. Individual loop hour to check for leaks before insertion into the borehole. testing shall be performed as required by the Authority Hav- 703.4.1 710.6.1 Backfill. Bentonite grout and ther- ing Jurisdiction. mally-enhanced bentonite grout, where used to seal and 711.3 Field Pressure Testing – Final. The ground heat . backfill each borehole, shall comply with NSF 60 Bore- exchanger and building piping shall be cleaned, flushed, and, holes shall be backfilled in accordance with the Author- where required, shall be filled with the heat transfer fluid ity Having Jurisdiction. medium. The ground loop system shall be tested at the design 703.4.2 710.6.2 U-Bends and Headers. Headers, u- flow rate(s) and differential pressure(s) recorded. Where the bends and ground loop pipes shall be pressure-tested in actual pressure change at design flow is more than +/- 10 per- accordance with CSA C448, or as required by the cent of the design flow pressure drop, the cause shall be iden- Authority Having Jurisdiction. Before testing, heat fusion tified, and corrective action taken. joints shall be cooled to ambient temperature. Mechani- 711.4 Field Flow Testing - Final. Final field flow testing cal joints shall be completely assembled. Flushing and shall be performed as required by the Authority Having Juris- purging to remove air and debris shall be completed diction. before testing. The assembly shall be filled with water (or water/antifreeze solution) and purged at a minimum Part III – Open-Loop Systems. flow rate of 2 feet per second (0.6 m/s) to remove air, but not more than the maximum flow velocity recommended by the pipe and fittings manufacturer to remove debris. 712.0 General. 703.4.2.1 710.6.2.1 Test Pressure. The maxi- 712.1 Applicability. Part III of this chapter shall apply to mum test pressure shall be 1.5 times the system geothermal energy systems such as, but not limited to, build- design pressure, as determined by Section 703.4.2.3 ing systems coupled with a groundwater (well) or surface 710.6.2.3, or Section 703.4.2.4 710.6.2.4, not to water open-loop using water-based fluid as a heat transfer exceed 100 psi (689 kPa). Components or devices medium. The regulations of this chapter shall govern the con- with lower pressure-ratings than the pipe shall be struction, location and installation of geothermal energy sys- protected from excessive pressure during testing by tems. removing or isolating from the test section. Indoor piping, fittings, and accessories that are part of Exception: Where lower pressure-rated components or devices cannot be removed or isolated from the the groundwater system shall be in accordance with Section test section, the maximum test pressure shall not 703.5 and Chapter 4. 702.1.1 712.2 Test Wells. exceed the pressure rating of the component or Test wells drilled to investigate device. subsurface conditions shall provide details of the groundwa- 703.4.2.2 710.6.2.2Testing Procedure. The test ter location, chemical and physical characteristics, rock strata, section and the test liquid shall be at the same tem- and temperature profiles. The number of test wells shall be perature. The test section shall be filled with liquid determined in accordance with the Authority Having Juris- and purged of air. The test section shall be brought diction. Each test well shall be tested for flow rate for a period to the specified test pressure. Test pressure shall be of not less than 24 hours. Water samples shall be collected in maintained for 4 hours, with make-up fluid added as accordance with the NGWA-01 from each well to establish needed. The test pressure shall be reduced by 10 psi existing water quality levels are approved for groundwater (69 kPa) and monitored for 1 hour with no addition system use. Water samples shall be analyzed for standard of pressure or make-up fluid. A passing test is indi- drinking water, fecal and coliform content, bacterial iron, cated where after a period of 1 hour no visual leak- nitrate, dissolved minerals, pH, hardness, and other com- age is observed, and pressure remains equal to or pounds in accordance with NGWA-01 or in accordance with greater than 95 percent of the original pressure. the Authority Having Jurisdiction. Wells shall be tested for 703.4.2.3 710.6.2.3 Calculation of Static water production and recovery. Monitoring wells shall be pro- Pressure (Water). For water, the static pressure tected, and marked to allow for monitoring of ground tem- applied shall be equivalent to 0.43 psig (2.96 kPa) perature, groundwater levels, and groundwater quality. 702.1.2 712.3 Installation of Water Wells. per foot (305 mm) of elevation. Water supply, 703.4.2.4 710.6.2.4 Calculation of Static recharge wells, and pumping equipment shall be hydrauli- Pressure (Other Fluids). For fluids of different cally tested, sealed, and grouted in accordance with approved density, the static pressure shall be calculated using well construction practices and submitted to the Authority the density of the system fluid. Having Jurisdiction for approval. Wells shall be tested for water production and recovery, water quality before final sys- 706.0 711.0 Ground-Heat Exchanger Testing. tem design. Wells shall be disinfected upon completion in accordance with NGWA-01 or in accordance with the 706.1 711.1 Testing. Pressure-testing of the ground-heat Authority Having Jurisdiction. A copy of the water quality exchanger shall be performed in accordance with the testing test results and the log of well construction in accordance with method in Section 703.4 710.6. NGWA-01 shall be provided to the owner.

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712.4 Setbacks. Open-loop ground-heat exchangers shall (7) Pressure gauges shall be provided to aid in start-up and maintain the following minimum setbacks or at distances monitoring of the system during operation. specified by the Authority Having Jurisdiction: (8) The ability to switch over operation of supply and return (a) Ten feet (3048 mm) horizontally from a pressure-tested wells for 100 percent standby, redevelopment, cleaning sewer lateral into a building. of wells, and the thermal balancing of the ground and (b) Twenty feet (6096 mm) horizontally from a non-pressure aquifer shall be provided. tested sewer lateral into a building. (9) There shall be no adverse effects on the quality and quan- (c) Three feet (914 mm) horizontally from buried utilities tity of offsite existing or future users of groundwater, in such as electrical, gas, or water. accordance with the requirements of the Authority Hav- ing Jurisdiction. (d) Fifty feet (15 240 mm) from a water well. 713.4 Water Wells and Injection Wells. Water wells and (e) Fifty feet (15 240 mm) from a septic tank and 100 feet injection wells for groundwater heat pump systems shall be (30 480 mm) from a subsurface sewage leaching field. installed by a registered professional who is qualified to drill (f) One hundred feet (30 480 mm) from a spring. wells that comply with the requirements of the Authority Having Jurisdiction. 713.0 Open Ground Water Systems. Water supply wells and injection wells shall be devel- 713.1 General. The installation and use of water wells shall oped in accordance with NGWA-01. be in accordance with the Authority Having Jurisdiction. The 713.5 Testing and Sampling. Pumping tests and water water well records shall include well logs, pumping tests, and sampling shall be done as required by the registered design aquifer information. professional or certified person. 713.6 Disinfection. 713.2 Open-Loop Water Well Drilling Logs. The water Water wells shall be disinfected upon well drilling logs shall include the following: completion in accordance with requirements of the Authority (1) The subsurface stratigraphy. Having Jurisdiction and NGWA-01. (2) The aquifer type and conditions such as, but not limited to, confined, unconfined, flowing and depth. 714.0 Testing and Verification. 714.1 Pumping Test. (3) The drilling method used and the penetration speed. Water supply wells and injection (4) The presence of substances known to have a potential wells shall undergo a stop and start pumping test to demon- risk to health and safety shall be documented in the drill strate the sand-free yield. 714.2 Retesting. logs and the property owner shall be advised of the Where sediment is present, the problem potential risk to health and safety. shall be corrected, and the test shall be repeated until accept- 713.3 Design Considerations. A groundwater heat pump able results are obtained. 714.3 Variable Rate Pump Test. system shall be designed by a registered design professional The operating conditions or certified person. Due design consideration shall be given to of the water supply wells and injection wells shall be evalu- the following: ated and verified with variable rate pumping. 714.4 Constant Rate Pump Test. (1) Where multiple heat pumps or fan coils are connected to The sustainable well a common water loop, a diversified building design load yield, aquifer coefficients, and zones of influences on the shall be used to design a ground water heat pump. groundwater flow requirements shall be confirmed with a constant rate-pumping test. The constant rate-pumping test (2) The water supply well(s) and injection wells, or water shall be done on the water supply and injection wells at rates discharge system, shall be capable of being operated at and durations as specified by the registered design profes- sustainable pumping rates that exceed the maximum sional or certified person. daily requirements without causing an adverse impact to 714.5 Water Level Monitoring. existing or future offsite uses of groundwater or surface Water levels shall be mon- water bodies. itored in the pumping well and observation wells during pumping and recovery periods. The monitoring time intervals (3) The water temperature and the quality and chemical shall be as specified by the registered design professional or composition of the water resource are in accordance with certified person. the system manufacturer’s recommendations. 714.6 Injection Wells. Injection testing shall be performed (4) The groundwater and surface water resources shall be pro- on water wells that are designated to be used as injection tected by returning water to the source aquifer or an aquifer wells at rates specified by the registered design professional with the same water quality, or a surface water body. or certified person. The results of the drilling and pumping (5) The return capacity of the injection, or surface water body tests shall be provided to the owner or the owner’s represen- discharge system, shall be suitable under winter conditions. tative and provided in accordance with requirements of the (6) The temperature of the return water shall have no adverse Authority Having Jurisdiction. thermal impacts on offsite existing or future uses of 714.7 Re-Injected Water. The water quality of re-injected groundwater, or on surface water bodies, in accordance water into the earth shall comply with the requirements of the with the requirements of the Authority Having Jurisdiction. Authority Having Jurisdiction.

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Part IV – Direct Exchange (DX) Systems. 715.8 DX Piping. DX piping shall be installed in accordance with approved plans and specifications, including pro- 715.0 Direct Exchange (DX) Systems. visions for cathodic protection. 715.1 General. The installation and use of Direct Exchange (DX) wells shall be in accordance with the Authority Having Jurisdiction. The DX well records shall include well logs, pressure tests, and aquifer information. 715.2 Applicability. Part IV of this chapter shall apply to geothermal energy systems such as, but not limited to, building systems coupled with a DX closed-loop using refrigerant as a heat transfer medium. The regulations of this Chapter shall govern the construction, location and installation of geothermal energy systems. Indoor piping, fittings, and accessories that are part of the ground source system shall be in accordance with Section 703.5 and Chapter 4. 703.6 715.3 DX Systems. Copper pipe and tubing installed for DX systems shall be manufactured in accordance with ASTM B280 and copper fittings in accordance with ASME B16.22. Joints shall be purged with an inert gas and brazed with a brazing alloy having 15 percent silver content in accordance with AWS A5.8. Underground piping and tubing shall have a cathodic protection system installed. 706.2 715.4 DX System Testing. For DX systems, each loop shall be tested with an inert gas at not less than 315 psi (2172 kPa) for not less than 15 minutes without pressure drop. The pressure reading after grouting of the boreholes shall be maintained in the ground-heat exchanger for not less than 2 hours. For direct exchange (DX) systems, each refrigerant u- bend shall be tested and proved tight with an inert gas at not less than 315 psi (2172 kPa) and maintained for 15 minutes without pressure drop. The pressure reading after tremie grouting of the boreholes shall be maintained in the ground heat exchanger for not less than 2 hours, in accordance with CSA C448. 715.5 Indoor Piping. For DX systems, joints shall be purged with an inert gas and brazed with a brazing alloy having 15 percent silver content in accordance with AWS A5.8. 715.6 On Site Storage. For DX systems, copper piping and fittings shall be stored to prevent physical damage, contamination, and each pipe or tubing shall be pressurized with an inert gas and sealed with a cap. 715.7 System Start-Up. DX system start-up shall be in accordance with Section 708.0 and the following: (1) DX systems shall be pressurized using nitrogen for not less than 1 hour. There shall be no allowable variance to the test pressure after being corrected for ambient temperature changes during the test. The test pressure shall not exceed 150 psig (1034 kPa) when pressure testing the compressor unit and indoor system components. (2) DX systems shall have permanent type labels installed and affixed on the compressor unit with the refrigerant type and quantity. (3) For DX systems, refrigerant liquid and vapor lines from the loop system shall be identified and tagged.

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Part I – General.

801.0 General. 801.1 Electrical Wiring and Equipment. Electrical wiring and equipment shall comply with the requirements of NFPA 70, National Electrical Code (NEC), or local ordinances. This chapter does not provide all electrical information necessary for the installation of a photovoltaic (PV) system. Resort shall be had to the edition of NFPA 70 adopted by the Authority Having Jurisdiction. 801.2 Applicability. This chapter applies to solar PV systems, other than those covered by Section 832.0, including the array circuit(s), inverter(s), and controller(s) for such systems [see Figure 801.2(1) and Figure 801.2(2)]. The systems covered by this chapter may be interactive with other electrical power production sources or stand-alone or both, and may or may not be connected to energy storage systems such as batteries. These PV systems may have ac or dc output for utilization. [NFPA 70:690.1]

Notes: 1 These diagrams are intended to be a means of identification for PV system components, circuits, and connections. 2 The PV system disconnect in these diagrams separates the PV system from all other systems. 3 Not all disconnecting means required by Section 810.0 through Section Notes: 811.1.4 are shown. 1 These diagrams are intended to be a means of identification for PV power 4 System grounding and equipment grounding are not shown. See Section source components, circuits, and connections that make up the PV power 816.0 through Section 822.1. source. 5 Custom designs occur in each configuration, and some components are 2 Custom PV power source designs occur, and some components are optional. optional. FIGURE 801.2(2) FIGURE 801.2(1) IDENTIFICATION OF PV SYSTEM COMPONENTS IDENTIFICATION OF PV POWER SOURCE COMPONENTS IN COMMON CONFIGURATIONS [NFPA 70: FIGURE 690.1(a)] [NFPA 70: FIGURE 690.1(b)]

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802.0 General Requirements. 802.5 Locations Not Permitted. PV system equipment 802.1 Photovoltaic Systems. Photovoltaic systems shall and disconnecting means shall not be installed in bathrooms. be permitted to supply a building or other structure in addition [NFPA 70:690.4(E)] to any other electrical supply system(s). [NFPA 70:690.4(A)] 802.6 Photovoltaic Modules/Panels/Shingles. Photo- 802.2 Equipment. Inverters, motor generators, PV mod- voltaic modules/panels/shingles shall comply with UL 1703 ules, PV panels, ac modules, dc combiners, dc-to-dc con- and shall be installed in accordance with the manufacturer’s verters, and charge controllers intended for use in PV systems installation instructions and the building code. shall be listed or field labeled for the PV application. [NFPA 70:690.4(B)] 803.0 Alternating-Current (ac) Modules. 802.2.1 Listing Requirements. Equipment used in 803.1 Photovoltaic Source Circuits. The requirements PV power systems shall be listed or field labeled in of this chapter pertaining to PV source circuits shall not apply accordance with Table 802.2.1. to ac modules. The PV source circuit, conductors, and invert- TABLE 802.2.1 ers shall be considered as internal wiring of an ac module. STANDARDS FOR PV EQUIPMENT [NFPA 70:690.6(A)] EQUIPMENT STANDARDS 803.2 Inverter Output Circuit. The output of an ac mod- Building-Integrated PV UL 1703 or UL 61730-11, ule shall be considered an inverter output circuit. [NFPA Modules and Panels UL 61730-21 70:690.6(B)] Building-Integrated PV UL 2703 Mounting Systems Part II – Circuit Requirements. Charge Controllers UL 1741 Combiner Boxes UL 1741 804.0 Circuit Requirements. Concentrator PV Modules UL 8703 804.1 Maximum Voltage. DC-to-DC Converters UL 1741 or UL 62109-1 The maximum voltage of PV Flat-Plate PV modules UL 1703 or UL 61730-11, system dc circuits shall be the highest voltage between any UL 61730-21 two circuit conductors or any conductor and ground. PV sys- Inverters UL 1741 or UL 62109-1 tem dc circuits on or in one- and two-family dwellings shall PV AC Modules UL 17032, UL 17412 or be permitted to have a maximum voltage of 600 volts or less. UL 61730-11, UL 61730-21 PV system dc circuits on or in other types of buildings shall be permitted to have a maximum voltage of 1000 volts or less. PV Modules and Panels 1 UL 1703 or UL 61730-1 , Where not located on or in buildings, listed dc PV equipment, UL 61730-21 rated at a maximum voltage of 1500 volts or less, shall not be PV DC Arc Fault Circuit UL 1699B required to comply with Parts II and III of Article 490 of Interrupters NFPA 70. [NFPA 70:690.7] PV DC Connectors UL 6703 804.1.1 Photovoltaic Source and Output Circuits. PV Solar Trackers UL 3703 In a dc PV source circuit or output circuit, the maximum PV Wire UL 4703 PV system voltage for that circuit shall be calculated in Rack Mounting Systems UL 2703 accordance with one of the following methods: Rapid Shutdown Equipment UL 1741 and Systems (1) Instructions in listing or labeling of the module: The sum of the PV module–rated open-circuit voltage of Notes: the series-connected modules corrected for the low- 1 UL 61730-1 shall be used in conjunction with UL 61730-2. 2 est expected ambient temperature using the open- UL 1703 shall be used in conjunction with UL 1741. circuit voltage temperature coefficients in accordance with the instructions included in the list- 802.3 Qualified Personnel. The installation of equipment ing or labeling of the module. and all associated wiring and interconnections shall be per- (2) Crystalline and multicrystalline modules: For crys- formed only by qualified persons. [NFPA 70:690.4(C)] For talline and multicrystalline silicon modules, the sum purposes of this chapter a qualified person is defined as one of the PV module–rated open-circuit voltage of the who has skills and knowledge related to the construction and series-connected modules corrected for the lowest operation of the electrical equipment and installations and has expected ambient temperature using the correction received safety training to recognize and avoid the hazards factor provided in Table 804.1.1. involved. [NFPA 70:100] (3) PV systems of 100 kW or larger – For PV systems 802.4 Multiple PV Systems. Multiple PV systems shall be with a generating capacity of 100 kW or greater, a permitted to be installed in or on a single building or structure. documented and stamped PV system design, using Where the PV systems are remotely located from each other, a an industry standard method and provided by a directory in accordance with Section 823.1 shall be provided at licensed professional electrical engineer, shall be each PV system disconnecting means. [NFPA 70:690.4(D)] permitted.

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The maximum voltage shall be used to determine the 805.0 Circuit Sizing and Current. voltage rating of conductors, cables, disconnects, overcur- 805.1 Calculation of Maximum Circuit Current. The rent devices, and other equipment. [NFPA 70:690.7(A)] maximum current for the specific circuit shall be calculated TABLE 804.1.1 in accordance with Section 805.1.1 through Section 805.1.6. VOLTAGE CORRECTION FACTORS FOR CRYSTALLINE Where the requirements of Section 805.1.1 and Section AND MULTICRYSTALLINE SILICON MODULES 805.2.1 are both applied, the resulting multiplication factor [NFPA 70: TABLE 690.7(A)]1, 2 is 156 percent. [NFPA 70:690.8(A)] AMBIENT 805.1.1 Photovoltaic Source Circuit Currents. FACTOR The TEMPERATURE (°F) maximum current shall be calculated by one of the fol- 76 to 68 1.02 lowing methods: 67 to 59 1.04 (1) The sum of parallel-connected PV module-rated 58 to 50 1.06 short-circuit currents multiplied by 125 percent. 49 to 41 1.08 (2) For PV systems with a generating capacity of 100 40 to 32 1.10 kW or greater, a documented and stamped PV sys- 31 to 23 1.12 tem design, using an industry standard method and 22 to 14 1.14 provided by a licensed professional electrical engi- 13 to 5 1.16 neer, shall be permitted. The calculated maximum 4 to -4 1.18 current value shall be based on the highest 3-hour -5 to -13 1.20 current average resulting from the simulated local -14 to -22 1.21 irradiance on the PV array accounting for elevation -23 to -31 1.23 and orientation. The current value used by this -32 to -40 1.25 method shall not be less than 70 percent of the value For SI units: °C = (°F-32)/1.8 calculated using Section 805.1.1(1). [NFPA Notes: 70:690.8(A)(1)] 1 Correction factors for ambient temperatures below 77°F (25°C). 805.1.2 Photovoltaic Output Circuit Currents. The 2 Multiply the rated open circuit voltage by the appropriate correction fac- maximum current shall be the sum of parallel source cir- tor shown above. cuit maximum currents as calculated in Section 805.1.1. [NFPA 70:690.8(A)(2)] 804.1.2 DC-to-DC Converter Source and Output 805.1.3 Inverter Output Circuit Current. The max- Circuits. In a dc-to-dc converter source and output cir- imum current shall be the inverter continuous output cur- cuit, the maximum voltage shall be calculated in accor- rent rating. [NFPA 70:690.8(A)(3)] dance with Section 804.1.2.1 or Section 804.1.2.2. 805.1.4 Stand-Alone Inverter Input Circuit Cur- [NFPA 70:690.7(B)] rent. 804.1.2.1 Single DC-to-DC Converter. The maximum current shall be the stand-alone con- For cir- tinuous inverter input current rating when the inverter is cuits connected to the output of a single dc-to-dc producing rated power at the lowest input voltage. converter, the maximum voltage shall be the maxi- [NFPA 70:690.8(A)(4)] mum rated voltage output of the dc-to-dc converter. 805.1.5 DC-to-DC Converter Source Circuit Cur- [NFPA 70:690.7(B)(1)] rent. 804.1.2.2 Two or More Series Connected DC- The maximum current shall be the dc-to-dc con- to-DC Converters. For circuits connected to the verter continuous output current rating. [NFPA output of two or more series connected dc-to-dc con- 70:690.8(A)(5)] verters, the maximum voltage shall be determined 805.1.6 DC-to-DC Converter Output Circuit Cur- in accordance with the instructions included in the rent. The maximum current shall be the sum of parallel listing or labeling of the dc-to-dc converter. If these connected dc-to-dc converter source circuit currents as instructions do not state the rated voltage of series- calculated in Section 805.1.5. [NFPA 70:690.8(A)(6)] connected dc-to-dc converters, the maximum volt- 805.2 Conductor Ampacity. PV system currents shall be age shall be the sum of the maximum rated voltage considered to be continuous. Circuit conductors shall be sized output of the dc-to-dc converters in series. [NFPA to carry not less than the larger of Section 805.2.1 or Section 70:690.7(B)(2)] 804.2 Bipolar Source and Output Circuits. 805.2.2 or where protected by a listed adjustable electronic For two- overcurrent protective device in accordance with Section wire dc circuits connected to bipolar PV arrays, the maximum 806.2(3), not less than the current in Section 805.2.3. [NFPA voltage shall be the highest voltage between the two -wire cir- 70:690.8(B)] cuit conductors where one conductor of the two-wire circuit 805.2.1 Before Application of Adjustment and Cor- is connected to the functional ground reference (center tap). rection Factors. To prevent overvoltage in the event of a ground-fault or arc- One hundred twenty-five percent of the fault, the array shall be isolated from the ground reference maximum currents as calculated in Section 805.1 before and isolated into two two-wire circuits. [NFPA 70:690.7(C)] the application of adjustment and correction factors.

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Exception: Circuits containing an assembly, together not meeting the requirements of Section 805.5.3, shall be with its overcurrent device(s), that is listed for continu- the maximum setting possible. [NFPA 70:240.6(B)] ous operation at 100 percent of its rating shall be per- 805.5.3 Restricted Access Adjustable-Trip Cir- mitted to be used at 100 percent of its rating. [NFPA cuit Breakers. A circuit breaker(s) that has restricted 70:690.8(B)(1)] access to the adjusting means shall be permitted to have 805.2.2 After Application of Adjustment and Cor- an ampere rating(s) that is equal to the adjusted current rection Factors. The maximum currents calculated in setting (long-time pickup setting). Restricted access shall accordance with Section 805.1 after the application of be defined as located behind one of the following: adjustment and correction factors. [NFPA (1) Removable and sealable covers over the adjusting 70:690.8(B)(2)] means 805.2.3 Adjustable Electronic Overcurrent Pro- (2) Bolted equipment enclosure doors tective Device. The rating or setting of an adjustable (3) Locked doors accessible only to qualified personnel electronic overcurrent protective device installed in [NFPA 70:240.6(C)] accordance with Section 805.5. [NFPA 70:690.8(B)(3)] 805.3 Systems with Multiple Direct-Current Voltages. 806.0 Overcurrent Protection. For a PV power source that has multiple output circuit volt- 806.1 Circuits and Equipment. PV system dc circuit and ages and employs a common-return conductor, the ampacity inverter output conductors and equipment shall be protected of the common-return conductor shall be not less than the sum against overcurrent. Overcurrent protective devices shall not be of the ampere ratings of the overcurrent devices of the indi- required for circuits with sufficient ampacity for the highest vidual output circuits. [NFPA 70:690.8(C)] available current. Circuits connected to current limited supplies 805.4 Sizing of Module Interconnection Conductors. (e.g., PV modules, dc-to-dc converters, interactive inverter out- Where a single overcurrent device is used to protect a set of put circuits) and also connected to sources having higher current two or more parallel-connected module circuits, the ampac- availability (e.g., parallel strings of modules, utility power) shall ity of each of the module interconnection conductors shall be be protected at the higher current source connection. not less than the sum of the rating of the single overcurrent Exception: An overcurrent device shall not be required for device plus 125 percent of the short-circuit current from the PV modules or PV source circuit or dc-to-dc converters other parallel-connected modules. [NFPA 70:690.8(D)] source circuit conductors sized in accordance with Section 805.5 Standard Ampere Ratings. Standard ampere rat- 805.2 where one of the following applies: ings shall be in accordance with Section 805.5.1 through Sec- (1) There are no external sources such as parallel-connected tion 805.5.3. source circuits, batteries, or backfeed from inverters. 805.5.1 Fuses and Fixed-Trip Circuit Breakers. (2) The short-circuit currents from all sources do not exceed The standard ampere ratings for fuses and inverse time the ampacity of the conductors and the maximum over- circuit breakers shall be considered as shown in Table current protective device size rating specified for the PV 805.5.1. Additional standard ampere ratings for fuses module or dc-to-dc converter. [NFPA 70:690.9(A)] shall be 1, 3, 6, 10, and 601. The use of fuses and inverse 806.2 Overcurrent Device Ratings. Overcurrent devices time circuit breakers with nonstandard ampere ratings used in PV system dc circuits shall be listed for use in PV shall be permitted. [NFPA 70:240.6(A)] systems. Overcurrent devices, where required, shall be rated in accordance with one of the following:

TABLE 805.5.1 (1) Not less than 125 percent of the maximum currents cal- STANDARD AMPERE RATINGS FOR FUSES culated in accordance with Section 805.1. AND INVERSE TIME CIRCUIT BREAKERS (2) An assembly, together with its overcurrent device(s), that [NFPA 70:TABLE 240.6(A)] is listed for continuous operation at 100 percent of its rat- STANDARD AMPERE RATINGS ing shall be permitted to be used at 100 percent of its rat- 15 20 25 30 35 ing. 40 45 50 60 70 (3) Adjustable electronic overcurrent protective devices 80 90 100 110 125 rated or set in accordance with Section 805.5. [NFPA 150 175 200 225 250 70:690.9(B)] 300 350 400 450 500 806.3 Photovoltaic Source and Output Circuits. A 600 700 800 1000 1200 single overcurrent protective device, where required, shall be 1600 2000 2500 3000 4000 permitted to protect the PV modules and conductors of each 5000 6000 — — — source circuit or the conductors of each output circuit. Where single overcurrent protection devices are used to protect PV source or output circuits, all overcurrent devices shall be 805.5.2 Adjustable-Trip Circuit Breakers. The rating placed in the same polarity for all circuits within a PV system. of adjustable-trip circuit breakers having external means The overcurrent devices shall be accessible but shall not be for adjusting the current setting (long-time pickup setting), required to be readily accessible. [NFPA 70:690.9(C)]

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806.4 Power Transformers. Overcurrent protection for a 807.2.5 Back-Fed Circuit Breakers. Plug-in type transformer with a source(s) on each side shall be provided in back-fed circuit breakers connected to an interconnected accordance with Section 450.3 of NFPA 70 by considering supply shall be secured in accordance with Section first one side of the transformer, then the other side of the 807.2.5.1. Circuit breakers marked “line” and “load” transformer, as the primary. shall not be back-fed. [NFPA 70:710.15(E)] 807.2.5.1 Back-Fed Devices. Exception: A power transformer with a current rating on the Plug-in-type over- side connected toward the interactive inverter output, not less current protection devices or plug-in type main lug assemblies that are back-fed and used to terminate than the rated continuous output current of the inverter, shall field-installed ungrounded supply conductors shall be be permitted without overcurrent protection from the inverter. secured in place by an additional fastener that requires [NFPA 70:690.9(D)] other than a pull to release the device from the mounting means on the panel. [NFPA 70:408.36(D)] 807.0 Stand-Alone Systems. 807.2.6 Voltage and Frequency Control. The stand- 807.1 General. The wiring system connected to a stand- alone supply shall be controlled so that voltage and fre- alone system shall be installed in accordance with Section quency remain within suitable limits for the connected 807.2. [NFPA 70:690.10] loads. [NFPA 70:710.15(F)] 807.2 Wiring System. Premises wiring systems shall be 808.0 Arc-Fault Circuit Protection (Direct Current). adequate to meet the requirements of this chapter and NFPA 808.1 Arc-Fault Circuit Protection. 70 for similar installations supplied by a feeder or service. Photovoltaic systems The wiring on the supply side of the building or structure dis- operating at 80 volts dc or greater between any two conduc- connecting means shall comply with the requirements of this tors shall be protected by a listed PV arc-fault circuit inter- chapter and NFPA 70, except as modified by Section 807.2.1 rupter or other system components listed to provide through Section 807.2.6. [NFPA 70:710.15] equivalent protection. The system shall detect and interrupt 807.2.1 Supply Output. arcing faults resulting from a failure in the intended continu- Power supply to premises ity of a conductor, connection, module, or other system com- wiring systems shall be permitted to have less capacity ponent in the PV system dc circuits. than the calculated load. The capacity of the stand-alone Exception: For PV systems not installed on or in buildings, supply shall be equal to or greater than the load posed by PV output circuits and dc-to-dc converter output circuits that the largest single utilization equipment connected to the are direct buried, installed in metallic raceways, or installed system. Calculated general lighting loads shall not be in enclosed metallic cable trays are permitted without arc- considered as a single load. [NFPA 70:710.15(A)] fault circuit protection. Detached structures whose sole pur- 807.2.2 Sizing and Protection. The circuit conduc- pose is to house PV system equipment shall not be considered tors between a stand-alone source and a building or struc- buildings according to this exception. [NFPA 70:690.11] ture disconnecting means shall be sized based on the sum of the output rating of the stand-alone sources. [NFPA 809.0 Rapid Shutdown of PV Systems on Buildings. 70:710.15(B)] 809.1 Reduce Shock Hazard. PV system circuits installed 807.2.3 Single 120-Volt Supply. Stand-alone systems on or in buildings shall include a rapid shutdown function to shall be permitted to supply 120 volts to single-phase, reduce shock hazard for emergency responders in accordance three-wire, 120/240-volt service equipment or distribu- with Section 809.1.1 through Section 809.1.4. tion panels where there are no 240-volt outlets and where Exception: Ground mounted PV system circuits that enter there are no multiwire branch circuits. In all installations, buildings, of which the sole purpose is to house PV system the sum of the ratings of the power sources shall be less equipment, shall not be required to comply with Section than the rating of the neutral bus in the service equip- 809.1. [NFPA 70:690.12] ment. This equipment shall be marked with the follow- 809.1.1 Controlled Conductors. Requirements for ing words or equivalent: controlled conductors shall apply to PV circuits supplied by the PV system. [NFPA 70:690.12(A)] 809.1.2 Controlled Limits. WARNING The use of the term array boundary in this section is defined as 1 foot (305 mm) SINGLE 120-VOLT SUPPLY. DO NOT CONNECT from the array in all directions. Controlled conductors MULTIWIRE BRANCH CIRCUITS! outside the array boundary shall comply with Section 809.1.2.1 and inside the array boundary shall comply with Section 809.1.2.2. [NFPA 70:690.12(B)] The warning sign(s) or label(s) shall comply with 809.1.2.1 Outside the Array Boundary. Con- Section 810.1.2.1. [NFPA 70:710.15(C)] 807.2.4 Energy Storage or Backup Power System trolled conductors located outside the boundary or more than 3 feet (914 mm) from the point of entry Requirements. Energy storage or backup power sup- inside a building shall be limited to not more than plies are not required. [NFPA 70:710.15(D)] 30 volts within 30 seconds of rapid shutdown initi-

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ation. Voltage shall be measured between any two Part III – Disconnecting Means. conductors and between any conductor and ground. [NFPA 70:690.12(B)(1)] 810.0 Disconnecting Means. 809.1.2.2 Inside the Array Boundary. The PV 810.1 Photovoltaic System Disconnecting Means. system shall comply with one of the following: Means shall be provided to disconnect the PV system from all (1) The PV array shall be listed or field labeled as wiring systems including power systems, energy storage sys- a rapid shutdown PV array. Such a PV array tems, and utilization equipment and its associated premises shall be installed and used in accordance with wiring. [NFPA 70:690.13] the instructions included with the rapid shut- 810.1.1 Location. down PV array listing or field labeling. The PV system disconnecting means shall be installed at a readily accessible location. [NFPA (2) Controlled conductors located inside the bound- 70:690.13(A)] ary or not more than 3 feet (914 mm) from the 810.1.2 Markings. point of penetration of the surface of the build- Each PV system disconnecting ing shall be limited to not more than 80 volts means shall plainly indicate whether in the open (off) or within 30 seconds of rapid shutdown initiation. closed (on) position and be permanently marked “PV Voltage shall be measured between any two SYSTEM DISCONNECT” or equivalent. Additional conductors and between any conductor and markings shall be permitted based upon the specific sys- ground. tem configuration. For PV system disconnecting means where the line and load terminals may be energized in (3) PV arrays with no exposed wiring methods, no the open position, the device shall be marked with the exposed conductive parts, and installed more following words or equivalent: than 8 feet (2438 mm) from exposed grounded conductive parts or ground shall not be required to comply with Section 809.1.2.2. WARNING The requirement of Section 809.1.2.2 shall ELECTRIC SHOCK HAZARD become effective January 1, 2019. [NFPA TERMINALS ON THE LINE AND LOAD 70:690.12(B)(2)] SIDES MAY BE 809.1.3 Initiation Device. The initiation device(s) shall initiate the rapid shutdown function of the PV sys- ENERGIZED IN THE OPEN POSITION tem. The device “off” position shall indicate that the The warning sign(s) or label(s) shall comply with rapid shutdown function has been initiated for all PV sys- Section 810.1.2.1. [NFPA 70:690.13(B)] tems connected to that device. For one-family and two- 810.1.2.1 Field-Applied Hazard Markings. family dwellings, an initiation device(s) shall be located Where caution, warning, or danger signs or labels at a readily accessible location outside the building. are required by this chapter, the labels shall comply The rapid shutdown initiation device(s) shall consist with the following requirements: of at least one of the following: (1) The marking shall warn of the hazards using (1) Service disconnecting means effective words, colors, symbols, or any com- (2) PV system disconnecting means bination thereof. (3) Readily accessible switch that plainly indicates (2) The label shall be permanently affixed to the whether it is in the “off” or “on” position equipment or wiring method and shall not be hand written. Where multiple PV systems are installed with rapid shutdown functions on a single service, the initiation Exception: Portions of labels or markings that device(s) shall consist of not more than six switches or are variable, or that could be subject to changes, six sets of circuit breakers, or a combination of not more shall be permitted to be hand written and shall than six switches and sets of circuit breakers, mounted be legible. in a single enclosure, or in a group of separate enclosures. (3) The label shall be of sufficient durability to These initiation device(s) shall initiate the rapid shut- withstand the environment involved. [NFPA down of all PV systems with rapid shutdown functions 70:110.21(B)] on that service. Where auxiliary initiation devices are 810.1.3 Suitable for Use. If the PV system is con- installed, these auxiliary devices shall control all PV sys- nected to the supply side of the service disconnecting tems with rapid shutdown functions on that service. means as permitted in Article 230.82(6) of NFPA 70, the [NFPA 70:690.12(C)] PV system disconnecting means shall be listed as suit- 809.1.4 Equipment. Equipment that performs the rapid able for use as service equipment. [NFPA 70:690.13(C)] shutdown functions, other than initiation devices such as 810.1.4 Maximum Number of Disconnects. Each listed disconnect switches, circuit breakers, or control PV system disconnecting means shall consist of not more switches, shall be listed for providing rapid shutdown than six switches or six sets of circuit breakers or a com- protection. [NFPA 70:690.12(D)] bination of not more than six switches and sets of circuit

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breakers, mounted in a single enclosure or in a group of 811.1.2 Interrupting Rating. An equipment discon- separate enclosures. A single PV system disconnecting necting means shall have an interrupting rating sufficient means shall be permitted for the combined ac output of for the maximum short-circuit current and voltage that one or more inverters or ac modules in an interactive sys- is available at the terminals of the equipment. An isolat- tem. [NFPA 70:690.13(D)] ing device shall not be required to have an interrupting 810.1.5 Rating. The PV system disconnecting means rating. [NFPA 70:690.15(B)] shall have ratings sufficient for the maximum circuit cur- 811.1.3 Isolating Device. An isolating device shall not rent available short-circuit current, and voltage that is be required to simultaneously disconnect all current-car- available at the terminals of the PV system disconnect. rying conductors of a circuit. The isolating device shall [NFPA 70:690.13(E)] be one of the following: 810.1.6 Type of Disconnect. The type(s) of discon- (1) A connector meeting the requirements of Section nect shall be in accordance with the Section 810.1.6.1 814.1 and listed and identified for use with specific through Section 810.1.6.3. equipment 810.1.6.1 Simultaneous Disconnection. The (2) A finger safe fuse holder PV system disconnecting means shall simultane- (3) An isolating switch that requires a tool to open ously disconnect the PV system conductors of the (4) An isolating device listed for the intended application circuit from all conductors of other wiring systems. The PV system disconnecting means shall be an An isolating device shall be rated to open the maxi- externally operable general-use switch or circuit mum circuit current under load or be marked “Do Not breaker, or other approved means. A dc PV system Disconnect Under Load” or “Not for Current Interrupt- disconnecting means shall be marked for use in PV ing.” [NFPA 70:690.15(C)] systems or be suitable for backfeed operation. 811.1.4 Equipment Disconnecting Means. An [NFPA 70:690.13(F)(1)] equipment disconnecting means shall simultaneously 810.1.6.2 Devices Marked “Line” and “Load.” disconnect all current carrying conductors that are not Devices marked with “line” and “load” shall not be solidly grounded of the circuit to which it is connected. permitted for backfeed or reverse current. [NFPA An equipment disconnecting means shall be externally 70:690.13(F)(2)] operable without exposing the operator to contact with 810.1.6.3 DC-Rated Enclosed Switches, energized parts, shall indicate whether in the open (off) Open-Type Switches, and Low-Voltage or closed (on) position, and shall be lockable in accordance with Section 110.25 of NFPA 70. An equipment Power Circuit Breakers. DC-rated, enclosed disconnecting means shall be one of the following switches, open-type switches, and low-voltage devices: power circuit breakers shall be permitted for backfeed operation. [NFPA 70:690.13(F)(3)] (1) A manually operable switch or circuit breaker (2) A connector meeting the requirements of Section 811.0 Disconnection of Photovoltaic Equipment. 814.1.5(1) (3) A load break fused pull out switch 811.1 Isolating Devices. Isolating devices shall be provided to isolate PV modules, ac PV modules, fuses, dc-to-dc (4) A remote-controlled circuit breaker that is operable converters inverters, and charge controllers from all conduc- locally and opens automatically when control power tors that are not solidly grounded. An equipment disconnect- is interrupted ing means or a PV system disconnecting means shall be For equipment disconnecting means, other than permitted in place of an isolating device. Where the maxi- those complying with Section 814.1, where the line and mum circuit current is greater than 30 amperes for the output load terminals can be energized in the open position, the circuit of a dc combiner or the input circuit of a charge con- device shall be marked in accordance with the warning in troller or inverter, an equipment disconnecting means shall Section 810.1.2. [NFPA 70:690.15(D)] be provided for isolation. Where a charge controller or inverter has multiple input circuits, a single equipment dis- Part IV – Wiring Methods. connecting means shall be permitted to isolate the equipment from the input circuits. [NFPA 70:690.15] 812.0 Wiring Methods Permitted. 811.1.1 Location. Isolating devices or equipment dis- 812.1 Wiring Systems. connecting means shall be installed in circuits connected All raceway and cable wiring to equipment at a location within the equipment, or methods included in NFPA 70, other wiring systems and fit- within sight and within 10 feet (3048 mm) of the equip- tings specifically listed for use on PV arrays, and wiring as ment. An equipment disconnecting means shall be per- part of a listed system shall be permitted. Where wiring mitted to be remote from the equipment where the devices with integral enclosures are used, sufficient length of equipment disconnecting means can be remotely oper- cable shall be provided to facilitate replacement. ated from within 10 feet (3048 mm) of the equipment. Where PV source and output circuits operating at volt- [NFPA 70:690.15(A)] ages greater than 30 volts are installed in readily accessible

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locations, circuit conductors shall be guarded or installed in as photovoltaic (PV) wire shall be permitted in exposed out- Type MC cable or in raceway. For ambient temperatures door locations in PV source circuits for PV within the PV exceeding 86°F (30°C), conductor ampacities shall be cor- array. PV wire shall be installed in accordance with Section rected in accordance with Table 812.1. [NFPA 70:690.31(A)] 338.10(B)(4)(b) of NFPA 70 and Section 334.30 of NFPA 70. [NFPA 70:690.31(C)(1)] TABLE 812.1 812.3.1 Cable Tray. CORRECTION FACTORS PV source circuits and PV output [NFPA 70: TABLE 690.31(A)] circuits using single-conductor cable listed and identified as photovoltaic (PV) wire of all sizes, with or with- TEMPERATURE RATING OF CONDUCTOR out a cable tray marking/rating, shall be permitted in cable trays installed in outdoor locations, provided that AMBIENT TEMPERATURE (°F) 140°F 167°F 194°F 221°F the cables are supported at intervals not to exceed 12 inches (305 mm) and secured at intervals not to exceed 86 1.00 1.00 1.00 1.00 1 4 ⁄2 feet (1372 mm). [NFPA 70:690.31(C)(2)] 87–95 0.91 0.94 0.96 0.97 812.4 Multiconductor Cable. Jacketed multiconductor cable 96–104 0.82 0.88 0.91 0.93 assemblies listed and identified for the application shall be per- 105–113 0.71 0.82 0.87 0.89 mitted in outdoor locations. The cable shall be secured at inter- 114–122 0.58 0.75 0.82 0.86 vals not exceeding 6 feet (1829 mm). [NFPA 70:690.31(D)] 123–131 0.41 0.67 0.76 0.82 812.5 Flexible Cords and Cables. Flexible cords and 132–140 — 0.58 0.71 0.77 flexible cables, where connected to the moving parts of track- 141–158 — 0.33 0.58 0.68 ing PV arrays, shall comply with Article 400 of NFPA 70 and 159–176 — — 0.41 0.58 shall be of a type identified as a hard service cord or portable For SI units: °C = (°F - 32)/1.8 power cable; they shall be suitable for extra-hard usage, listed for outdoor use, water resistant, and sunlight resistant. Allow- able ampacities shall be in accordance with Section 400.5 of 812.2 Identification and Grouping. PV source circuits NFPA 70. Stranded copper PV wire shall be permitted to be and PV output circuits shall not be contained in the same race- connected to moving parts of tracking PV arrays in accor- way, cable tray, cable, outlet box, junction box, or similar fit- dance with the minimum number of strands specified in Table ting as conductors, feeders, branch circuits of other non-PV 812.5. [NFPA 70:690.31(E)] systems, or inverter output circuits, unless the conductors of the different systems are separated by a partition. PV system TABLE 812.5 circuit conductors shall be identified and grouped as required MINIMUM PV WIRE STRANDS by Section 812.2.1 through Section 812.2.2. The means of [NFPA 70: TABLE 690.31(E)] identification shall be permitted by separate color coding, PV WIRE AWG MINIMUM STRANDS marking tape, tagging, or other approved means. [NFPA 18 17 70:690.31(B)] 16 – 10 19 812.2.1 Identification. PV system circuit conductors shall be identified at all accessible points of termination, 8 – 4 49 connection, and splices. 2 130 The means of identification shall be permitted by sep- 1 AWG – 1000 MCM 259 arate color coding, marking tape, tagging, or other approved means. Only solidly grounded PV system cir- 812.6 Small-Conductor Cables. cuit conductors, in accordance with Section 816.1(5), shall Single-conductor cables be marked in accordance with Section 200.6 of NFPA 70. listed for outdoor use that are sunlight resistant and moisture resistant in sizes 16 AWG and 18 AWG shall be permitted for Exception: Where the identification of the conductors is module interconnections where such cables meet the ampacity evident by spacing or arrangement, further identification requirements of Section 400.5 of NFPA 70. Section 310.15 of shall not be required. [NFPA 70:690.31(B)(1)] NFPA 70 shall be used to determine the cable ampacity adjust- 812.2.2 Grouping. Where the conductors of more than ment and correction factors. [NFPA 70:690.31(F)] one PV system occupy the same junction box or raceway 812.7 Photovoltaic System Direct-Current Circuits with a removable cover(s), the ac and dc conductors of on or in a Building. Where PV system dc circuits run each system shall be grouped separately by cable ties or inside a building, they shall be contained in metal raceways, similar means at least once and shall then be grouped at Type MC metal-clad cable that is in accordance with Section intervals not to exceed 6 feet (1829 mm). 812.7.5(10), or metal enclosures from the point of penetra- Exception: The requirement for grouping shall not apply tion of the surface of the building to the first readily accessi- where the circuit enters from a cable or raceway unique ble disconnecting means. The disconnecting means shall to the circuit that makes the grouping obvious. [NFPA comply with Section 810.1.2, Section 810.1.3, Section 70:690.31(B)(2)] 811.1.1 and Section 811.1.2. The wiring methods shall com- 812.3 Single-Conductor Cable. Single-conductor cable ply with the additional installation requirements in Section Type USE-2 and single-conductor cable listed and identified 812.7.1 through Section 812.7.4. [NFPA 70:690.31(G)]

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812.7.1 Embedded in Building Surfaces. Where (a) The conduit is terminated in listed fittings. circuits are embedded in built-up, laminate, or membrane (b) The circuit conductors contained in the conduit roofing materials in roof areas not covered by PV mod- are protected by overcurrent devices rated at 20 ules and associated equipment, the location of circuits amperes or less. shall be clearly marked using a marking protocol that is (c) The size of the conduit does not exceed trade 1 approved as being suitable for continuous exposure to size 1 ⁄4 (35 metric designator). sunlight and weather. [NFPA 70:690.31(G)(1)] (d) The combined length of flexible metal conduit 812.7.2 Flexible Wiring Methods. Where flexible 3 and flexible metallic tubing and liquidtight flex- metal conduit (FMC) smaller than the trade size ⁄4 (met- ible metal conduit in the same ground-fault cur- ric designator 21) or Type MC cable less than 1 inch (25 rent path does not exceed 6 feet (1829 mm). mm) in diameter containing PV power circuit conductors (e) If used to connect equipment where flexibility is installed across ceilings or floors joists, the raceway or is necessary to minimize the transmission of cable shall be protected by substantial guard strips that are vibration from equipment or to provide flexi- at least as high as the raceway or cable. Where run bility for equipment that requires movement exposed, other than within 6 feet (1829 mm) of their con- after installation, an equipment grounding connection to equipment, these wiring methods shall closely ductor shall be installed. follow the building surface or be protected from physical (6) Listed liquidtight flexible metal conduit meeting the damage by an approved means. [NFPA 70:690.31(G)(2)] following conditions: 812.7.3 Marking and Labeling Required. The fol- (a) The conduit is terminated in listed fittings. lowing wiring methods and enclosures that contain PV 3 1 8 2 system dc circuit conductors shall be marked with the (b) For trade sizes ⁄ through ⁄ (12 through 16 metric designator), the circuit conductors con- wording “WARNING: Photovoltaic Power Source” by tained in the conduit are protected by overcur- means of permanently affixed labels or other approved rent devices rated at 20 amperes or less. permanent markings: 3 1 (c) For trade sizes ⁄4 through 1 ⁄4 (21 through 35 (1) Exposed raceways, cable trays, and other wiring metric designator), the circuit conductors con- methods. tained in the conduit are protected by overcur- (2) Covers or enclosures of pull boxes and junction rent devices rated not more than 60 amperes and boxes. there is no flexible metal conduit, flexible metallic tubing, or liquidtight flexible metal (3) Conduit bodies in which any of the available con- 3 1 duit openings are unused. [NFPA 70:690.31(G)(3)] conduit in trade sizes ⁄8 through ⁄2 (12 through 812.7.4 Markings and Labeling Methods and 16 metric designator) in the ground-fault current path. Locations. The labels or markings shall be visible after installation. The labels shall be reflective, and all letters (d) The combined length of flexible metal conduit shall be capitalized and shall be a minimum height of not and flexible metallic tubing and liquidtight flex- 3 ible metal conduit in the same ground-fault cur- less than ⁄8 of an inch (9.5 mm) in white on a red back- rent path shall not exceed 6 feet (1829 mm). ground. PV system dc circuit labels shall appear on every section of the wiring system that is separated by enclo- (e) If used to connect equipment where flexibility sures, walls, partitions, ceilings, or floors. Spacing is necessary to minimize the transmission of between labels or markings, or between a label and a vibration from equipment or to provide flexi- marking, shall not be more than 10 feet (3048 mm). Labels bility for equipment that requires movement required by this section shall be suitable for the environ- after installation, an equipment grounding con- ment where they are installed. [NFPA 70:690.31(G)(4)] ductor shall be installed. 812.7.5 Types of Equipment Grounding Conduc- (7) Flexible metallic tubing where the tubing is terminated in listed fittings and meeting the following tors. The equipment grounding conductor installed with conditions: or enclosing the circuit conductors shall be one or more or a combination of the following: (a) The circuit conductors contained in the tubing are protected by overcurrent devices rated at 20 (1) A copper, aluminum, or copper-clad aluminum con- amperes or less. ductor. This conductor shall be solid or stranded; insulated, covered, or bare; and in the form of a wire (b) The combined length of flexible metal conduit or a busbar of any shape. and flexible metallic tubing and liquidtight flexible metal conduit in the same ground-fault cur- (2) Rigid metal conduit. rent path shall not exceed 6 feet (1829 mm). (3) Intermediate metal conduit. (8) Armor of Type AC cable in accordance with Sec- (4) Electrical metallic tubing. tion 320.108 of NFPA 70. (5) Listed flexible metal conduit meeting all the fol- (9) The copper sheath of mineral-insulated, metal- lowing conditions: sheathed cable Type MI.

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(10)Type MC cable that provides an effective ground- 814.0 Connectors. fault current path in accordance with one or more of 814.1 General. Connectors, other than those covered by the following: Section 813.1, shall comply with Section 814.1.1 through (a) It contains an insulated or uninsulated equip- Section 814.1.5. [NFPA 70:690.33] ment grounding conductor in accordance with 814.1.1 Configuration. The connectors shall be polar- Section 812.7.5(1). ized and shall have a configuration that is noninter- (b) The combined metallic sheath and uninsulated changeable with receptacles in other electrical systems equipment grounding/bonding conductor of on the premises. [NFPA 70:690.33(A)] interlocked metal tape-type MC cable that is 814.1.2 Guarding. The connectors shall be constructed listed and identified as an equipment grounding and installed so as to guard against inadvertent contact conductor. with live parts by persons. [NFPA 70:690.33(B)] (c) The metallic sheath or the combined metallic 814.1.3 Type. The connectors shall be of the latching or sheath and equipment grounding conductors of locking type. Connectors that are readily accessible and the smooth or corrugated tube-type MC cable that are used in circuits operating at over 30 volts dc or that is listed and identified as an equipment 15 volts ac shall require a tool for opening. [NFPA grounding conductor. 70:690.33(C)] (11)Cable trays in accordance with Section 392.10 of 814.1.4 Grounding Member. The grounding member NFPA 70 and Section 392.60 of NFPA 70. shall be the first to make and the last to break contact (12)Cablebus framework in accordance with Section with the mating connector. [NFPA 70:690.33(D)] 370.60(1) of NFPA 70. 814.1.5 Interruption of Circuit. Connectors shall be (13) Other listed electrically continuous metal raceways either Section 814.1.5(1) or Section 814.1.5(2): and listed auxiliary gutters. (1) Be rated for interrupting current without hazard to (14) Surface metal raceways listed for grounding. [NFPA the operator. 70:250.118] 812.8 Flexible, Fine-Stranded Cables. (2) Be a type that requires the use of a tool to open and Flexible, fine- marked “Do Not Disconnect Under Load” or “Not stranded cables shall be terminated only with terminals, lugs, for Current Interrupting.” [NFPA 70:690.33(E)] devices, or connectors in accordance with Section 110.14 of NFPA 70. [NFPA 70:690.31(H)] 815.0 Access to Boxes. 812.9 Bipolar PV Systems. Where the sum, without con- 815.1 Junction, Pull, and Outlet Boxes. sideration of polarity, of the voltages of the two monopole Junction, pull, subarrays exceeds the rating of the conductors and connected and outlet boxes located behind modules or panels shall be equipment, monopole subarrays in a bipolar PV system shall so installed that the wiring contained in them can be rendered be physically separated, and the electrical output circuits from accessible directly or by displacement of a module(s) or each monopole subarray shall be installed in separate race- panel(s) secured by removable fasteners and connected by a ways until connected to the inverter. The disconnecting flexible wiring system. [NFPA 70:690.34] means and overcurrent protective devices for each monopole subarray output shall be in separate enclosures. All conduc- Part V – Grounding and Bonding. tors from each separate monopole subarray shall be routed in the same raceway. Solidly grounded bipolar PV systems shall be clearly marked with a permanent, legible warning notice 816.0 Grounding and Bonding. indicating that the disconnection of the grounded conductor(s) 816.1 PV System Grounding Configurations. One or may result in overvoltage on the equipment. more of the following system grounding configurations shall Exception: Listed switchgear rated for the maximum volt- be employed: age between circuits and containing a physical barrier sepa- (1) 2-wire PV arrays with one functional grounded conduc- rating the disconnecting means for each monopole subarray tor. shall be permitted to be used instead of disconnecting means in separate enclosures. [NFPA 70:690.31(I)] (2) Bipolar PV arrays according to Section 804.2 with a functional ground reference (center tap). 813.0 Component Interconnections. (3) PV arrays not isolated from the grounded inverter output circuit. 813.1 Concealed Fittings and Connectors. Fittings and connectors that are intended to be concealed at the time of on- (4) Ungrounded PV arrays. site assembly, where listed for such use, shall be permitted for (5) Solidly grounded PV arrays as permitted in Section 816.2 on-site interconnection of modules or other array components. (Exception). Such fittings and connectors shall be equal to the wiring (6) PV systems that use other methods that accomplish method employed in insulation, temperature rise, and fault-cur- equivalent system protection in accordance with Section rent withstand, and shall be capable of resisting the effects of 816.1.1 through Section 816.1.5 with equipment listed the environment in which they are used. [NFPA 70:690.32] and identified for the use. [NFPA 70:690.41(A)]

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816.1.1 Electrical System Grounding. Electrical 817.0 Point of System Grounding Connection. systems that are grounded shall be connected to earth in 817.1 Grounding Connection. Systems with a ground- a manner that will limit the voltage imposed by lightning, fault protection device in accordance with Section 816.2 shall line surges, or unintentional contact with higher-voltage have any current-carrying conductor-to-ground connection lines and that will stabilize the voltage to earth during made by the ground-fault protective device. For solidly normal operation. [NFPA 70:250.4(A)(1)] 816.1.2 Grounding of Electrical Equipment. grounded PV systems, the dc circuit grounding connection Nor- shall be made at any single point on the PV output circuit. mally non-current-carrying conductive materials enclos- [NFPA 70:690.42] ing electrical conductors or equipment, or forming part of such equipment, shall be connected to earth so as to limit 818.0 Equipment Grounding and Bonding. the voltage to ground on these materials. [NFPA 70:250.4(A)(2)] 818.1 General. Exposed non-current-carrying metal parts 816.1.3 Bonding of Electrical Equipment. Normally of PV module frames, electrical equipment, and conductor non-current-carrying conductive materials enclosing elec- enclosures shall be grounded in accordance with Section trical conductors or equipment, or forming part of such 818.2 or Section 818.4, regardless of voltage. Equipment equipment, shall be connected together and to the electri- grounding conductors and devices shall comply with Section cal supply source in a manner that establishes an effec- 818.1.1 through Section 818.1.3. [NFPA 70:690.43] tive ground-fault current path. [NFPA 70:250.4(A)(3)] 818.1.1 Photovoltaic Mounting Systems and 816.1.4 Bonding of Electrically Conductive Mate- Devices. Devices and systems used for mounting PV rials and Other Equipment. Normally non-current- modules that are also used for bonding module frames carrying electrically conductive materials that are likely shall be listed, labeled, and identified for bonding PV to become energized shall be connected together and to modules. Devices that mount adjacent PV modules shall the electrical supply source in a manner that establishes be permitted to bond adjacent PV modules. [NFPA an effective ground-fault current path. [NFPA 70:690.43(A)] 70:250.4(A)(4)] 818.1.2 Equipment Secured to Grounded Metal 816.1.5 Effective Ground-Fault Current Path. Elec- Supports. Devices listed, labeled, and identified for trical equipment and wiring and other electrically conduc- bonding and grounding the metal parts of PV systems tive material likely to become energized shall be installed shall be permitted to bond the equipment to grounded in a manner that creates a low-impedance circuit facilitat- metal supports. Metallic support structures shall have ing the operation of the overcurrent device or ground detec- identified bonding jumpers connected between separate tor for high-impedance grounded systems. It shall be metallic sections or shall be identified for equipment capable of safely carrying the maximum ground-fault current likely to be imposed on it from any point on the wiring bonding and shall be connected to the equipment ground- system where a ground fault may occur to the electrical ing conductor. [NFPA 70:690.43(B)] 818.1.3 With Circuit Conductors. supply source. The earth shall not be considered as an Equipment effective ground-fault current path. [NFPA 70:250.4(A)(5)] grounding conductors for the PV array and support struc- 816.2 Ground-Fault Protection. DC PV arrays shall be pro- ture (where installed) shall be contained within the same vided with dc ground-fault protection meeting the requirements raceway, cable, or otherwise run with the PV array circuit of Section 816.3 and Section 816.4 to reduce fire hazards. conductors when those circuit conductors leave the vicinity of the PV array. [NFPA 70:690.43(C)] Exception: PV arrays with not more than two PV source cir- 818.2 Equipment Fastened in Place or Connected by cuits and with all PV system dc circuits not on or in build- Permanent Wiring Methods (Fixed) — Grounding. ings shall be permitted without ground-fault protection where solidly grounded. [NFPA 70:690.41(B)] Unless grounded by connection to the grounded circuit con- 816.3 Ground-Fault Detection. The ground fault protec- ductor as permitted by Section 250.32, Section 250.140 and tive device or system shall detect ground fault(s) in the PV Section 250.142 of NFPA 70, non-current-carrying metal array dc current-carrying conductors and components, includ- parts of equipment, raceways, and other enclosures, if ing any functional grounded conductors, and be listed for pro- grounded, shall be connected to an equipment grounding con- viding PV ground-fault protection. [NFPA 70:690.41(B)(1)] ductor by one of the methods specified in Section 818.2.1 or 816.4 Isolating Faulted Circuits. The faulted circuits Section 818.2.2. [NFPA 70:250.134] shall be isolated by one of the following methods: 818.2.1 Equipment Grounding Conductor Types. (1) The current-carrying conductors of the faulted circuit By connecting to any of the equipment grounding con- shall be automatically disconnected. ductors in accordance with Section 812.7.5. [NFPA (2) The inverter or charge controller fed by the faulted circuit 70:250.134(A)] 818.2.2 With Circuit Conductors. shall automatically cease to supply power to output cir- By connecting to cuits and isolate the PV system dc circuits from the an equipment grounding conductor contained within the ground reference in a functional grounded system. same raceway, cable, or otherwise run with the circuit [NFPA 70:690.41(B)(2)] conductors.

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Exceptions: (6) For ungrounded systems, the grounding terminal bar within (1) As provided in Section 818.3, the equipment the service equipment enclosure. [NFPA 70:250.130(C)] grounding conductor shall be permitted to be run 818.4 Equipment Secured to Grounded Metal Sup- separately from the circuit conductors. ports. Electrical equipment secured to and in electrical contact (2) For dc circuits, the equipment grounding conductor with a metal rack or structure provided for its support and con- shall be permitted to be run separately from the cir- nected to an equipment grounding conductor by one of the cuit conductors. [NFPA 70:250.134(B)] means indicated in Section 818.2. The structural metal frame of 818.3 Nongrounding Receptacle Replacement or a building shall not be used as the required equipment ground- Branch Circuit Extensions. The equipment grounding con- ing conductor for ac equipment. [NFPA 70:250.136(A)] ductor of a grounding-type receptacle or a branch-circuit extension shall be permitted to be connected to any of the following: 819.0 Size of Equipment Grounding Conductors. (1) Any accessible point on the grounding electrode system 819.1 General. Equipment grounding conductors for PV in accordance with Section 250.50 of NFPA 70. source and PV output circuits shall be sized in accordance (2) Any accessible point on the grounding electrode con- with Section 250.122 of NFPA 70. Where no overcurrent pro- ductor. tective device is used in the circuit, an assumed overcurrent (3) The equipment grounding terminal bar within the enclo- device rated in accordance with Section 806.2 shall be used sure where the branch circuit for the receptacle or branch when applying Table 819.1. Increases in equipment ground- circuit originates. ing conductor size to address voltage drop considerations (4) An equipment grounding conductor that is part of shall not be required. An equipment grounding conductor another branch circuit that originates from the enclosure shall not be less than 14 AWG. [NFPA 70:690.45] where the branch circuit for the receptacle or branch cir- 819.1.1 Equipment Grounding Conductor Instal- cuit originates. lation. An equipment grounding conductor shall be (5) For grounded systems, the grounded service conductor installed in accordance with Section 819.1.2, Section within the service equipment enclosure. 819.1.3, and Section 819.1.4. [NFPA 70:250.120] TABLE 819.1 MINIMUM SIZE EQUIPMENT GROUNDING CONDUCTORS FOR GROUNDING RACEWAY AND EQUIPMENT1 [NFPA 70: TABLE 250.122]

RATING OR SETTING OF AUTOMATIC OVERCURRENT SIZE (AWG or kcmil) DEVICE IN CIRCUIT AHEAD OF EQUIPMENT, CONDUIT, ALUMINUM OR COPPER COPPER ETC., NOT EXCEEDING (AMPERES) CLAD ALUMINUM2 15 14 12 20 12 10 60 10 8 100 8 6 200 6 4 300 4 2 400 3 1 500 2 1/0 600 1 2/0 800 1/0 3/0 1000 2/0 4/0 1200 3/0 250 1600 4/0 350 2000 250 400 2500 350 600 3000 400 600 4000 500 750 5000 700 1200 6000 800 1200 Notes: 1 Where necessary to comply with Section 816.1.5 of this chapter or 250.4(B)(4) of NFPA 70, the equipment grounding conductor shall be sized larger than given in this table. 2 See installation restrictions in Section 819.1.1.

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819.1.2 Raceway, Cable Trays, Cable Armor, a grounding electrode system by means of a grounding elec- Cablebus, or Cable Sheaths. Where it consists of a trode conductor sized in accordance with Section 821.2.1 raceway, cable tray, cable armor, cablebus framework, through Section 821.2.6. [NFPA 70:690.47(A)] or cable sheath or where it is a wire within a raceway or 821.2.1 Size of the Direct-Current Grounding cable, it shall be installed in accordance with the appli- Electrode Conductor. The size of the grounding elec- cable provisions of NFPA 70 using fittings for joints and trode conductor for a dc system shall be as specified in terminations approved for use with the type raceway or Section 821.2.2 and Section 821.2.3, except as permit- cable used. All connections, joints, and fittings shall be ted by Section 821.2.4 through Section 821.2.6. The made tight using suitable tools. [NFPA 70:250.120(A)] grounding electrode conductor for a dc system shall meet 819.1.3 Aluminum and Copper-Clad Aluminum the sizing requirements in this section but shall not be Conductors. Equipment grounding conductors of bare required to be larger than 3/0 copper or 250 kcmil alu- or insulated aluminum or copper-clad aluminum shall be minum. [NFPA 70:250.166] permitted. Bare conductors shall not come in direct con- 821.2.2 Not Smaller Than the Neutral Conductor. tact with masonry or the earth or where subject to corro- Where the dc system consists of a three-wire balancer set sive conditions. Aluminum or copper-clad aluminum or balancer winding with overcurrent protection in accor- conductors shall not be terminated within 18 inches (457 dance with Section 445.12(D) of NFPA 70, the ground- mm) of the earth. [NFPA 70:250.120(B)] ing electrode conductor shall not be smaller than the 819.1.4 Equipment Grounding Conductors neutral conductor and not smaller than 8 AWG copper Smaller Than 6 AWG. Where not routed with circuit or 6 AWG aluminum. [NFPA 70:250.166(A)] conductors as permitted in Section 818.3 and Section 821.2.3 Not Smaller Than the Largest Conductor. 818.2.2 (Exception 2), equipment grounding conductors Where the dc system is other than as in Section 821.2.2, less than 6 AWG shall be protected from physical dam- the grounding electrode conductor shall not be smaller age by an identified raceway or cable armor unless than the largest conductor supplied by the system, and installed within hollow spaces of the framing members of be not smaller than 8 AWG copper or 6 AWG aluminum. buildings or structures and where not subject to physical [NFPA 70:250.166(B)] damage. [NFPA 70:250.120(C)] 821.2.4 Connected to Rod, Pipe, or Plate Elec- trodes. Where connected to rod, pipe, or plate elec- 820.0 Array Equipment Grounding Conductors. trodes as in Section 821.3.5 or Section 821.3.7, that 820.1 PV Modules. portion of the grounding electrode conductor that is the For PV modules, equipment ground- sole connection to the grounding electrode shall not be ing conductors smaller than 6 AWG shall comply with Sec- required to be larger than 6 AWG copper wire or 4 AWG tion 819.1.4. Where installed in raceways, equipment aluminum wire. [NFPA 70:250.166(C)] grounding conductors and grounding electrode conductors 821.2.5 Connected to a Concrete-Encased Elec- not more than 6 AWG shall be permitted to be solid. [NFPA trode. Where connected to a concrete-encased electrode 70:690.46] in accordance with Section 821.3.3, that portion of the grounding electrode conductor that is the sole connec- 821.0 Grounding Electrode System. tion to the grounding electrode shall not be required to be 821.1 Electrode System. Grounding of electrode systems more than 4 AWG copper wire. [NFPA 70:250.166(D)] shall comply with Section 821.2 and Section 821.3. 821.2.6 Connected to a Ground Ring. Where con- 821.2 Buildings or Structures Supporting a PV Array. nected to a ground ring as in Section 821.3.4, that portion A building or structure supporting a PV array shall have a of the grounding electrode conductor that is the sole con- grounding electrode system installed in accordance with Part nection to the grounding electrode shall not be required III of Article 250 of NFPA 70. to be larger than the conductor used for the ground ring. [NFPA 70:250.166(E)] PV array equipment grounding conductors shall be con- 821.3 Additional Auxiliary Electrodes for Array nected to the grounding electrode system of the building or Grounding. structure supporting the PV array in accordance with Part VII Grounding electrodes shall be permitted to be of Article 250 of NFPA 70. This connection shall be in addi- installed in accordance with Section 250.54 of NFPA 70 and tion to any other equipment grounding conductor require- Section 821.3.1 through Section 821.3.9 at the location of ments in Section 818.1.3. The PV array equipment grounding ground- and roof-mounted PV arrays. The electrodes shall be conductors shall be sized in accordance with Section 819.1. permitted to be connected directly to the array frame(s) or structure. The grounding electrode conductor shall be sized For PV systems that are not solidly grounded, the equip- according to Section 250.66 of NFPA 70. The structure of a ment grounding conductor for the output of the PV system, ground-mounted PV array shall be permitted to be considered connected to associated distribution equipment, shall be per- a grounding electrode if it meets the requirements of Section mitted to be the connection to ground for ground-fault pro- 821.3.1 through Section 821.3.9. Roof-mounted PV arrays tection and equipment grounding of the PV array. shall be permitted to use the metal frame of a building or For solidly grounded PV systems, as permitted in Sec- structure if the requirements of Section 821.3.2 are met. tion 816.1(5), the grounded conductor shall be connected to [NFPA 70:690.47(B)]

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821.3.1 Metal Underground Water Pipe. A metal 821.3.6 Other Listed Electrodes. Other listed underground water pipe in direct contact with the earth grounding electrodes shall be permitted. [NFPA for 10 feet (3048 mm) or more (including any metal well 70:250.52(A)(6)] casing bonded to the pipe) and electrically continuous 821.3.7 Plate Electrodes. Each plate electrode shall (or made electrically continuous by bonding around insu- expose not less than 2 square feet (0.2 m2) of surface to lating joints or insulating pipe) to the points of connec- exterior soil. Electrodes of bare or electrically conduc- 1 tion of the grounding electrode conductor and the tive coated iron or steel plates shall be at least ⁄4 of an bonding conductor(s) or jumper(s), if installed. [NFPA inch (6.4 mm) in thickness. Solid, uncoated electrodes 70:250.52(A)(1)] of nonferrous metal shall be at least 0.06 of an inch (1.52 821.3.2 Metal In-Ground Support Structure(s). mm) in thickness. [NFPA 70:250.52(A)(7)] One or more metal in-ground support structure(s) in 821.3.8 Other Local Metal Underground Systems direct contact with the earth vertically for 10 feet (3048 or Structures. Other local metal underground systems mm) or more, with or without concrete encasement. If or structures such as piping systems, underground tanks, multiple metal in-ground support structures are present at and underground metal well casings that are not bonded a building or a structure, it shall be permissible to bond to a metal water pipe. [NFPA 70:250.52(A)(8)] only one into the grounding electrode system. [NFPA 821.3.9 Not Permitted for Use as Grounding 70:250.52(A)(2)] Electrodes. 821.3.3 Concrete-Encased Electrode. The following systems and materials shall A concrete- not be used as grounding electrodes: encased electrode shall consist of at least 20 feet (6096 mm) of one of the following: (1) Metal underground gas piping systems. (1) One or more bare or zinc galvanized or other elec- (2) Aluminum. trically conductive coated steel reinforcing bars or (3) The structures and structural reinforcing steel 1 rods of not less than ⁄2 of an inch (12.7 mm) in described in Section 680.26(B)(1) of NFPA 70 and diameter, installed in one continuous 20 foot (6096 Section 680.26(B)(2) of NFPA 70. [NFPA mm) length, or if in multiple pieces connected 70:250.52(B)] together by the usual steel tie wires, exothermic welding, welding, or other effective means to create 822.0 Equipment Bonding Jumpers. a 20 foot (6096 mm) or greater length; or 822.1 Bonding Jumpers. Equipment bonding jumpers, if (2) Bare copper conductor not less than 4 AWG. used, shall comply with Section 819.1.4. [NFPA 70:690.50] Metallic components shall be encased by at least 2 inches (51 mm) of concrete and shall be located hori- Part VI – Marking. zontally within that portion of a concrete foundation or footing that is in direct contact with the earth or within vertical foundations or structural components or mem- 823.0 Marking. bers that are in direct contact with the earth. If multiple 823.1 Directory. concrete-encased electrodes are present at a building or A permanent plaque or directory denoting structure, it shall be permissible to bond only one into the location of all electrical power source disconnecting means the grounding electrode system. on or in the premises shall be installed at each service equipment location and at location(s) of the system disconnect(s) for Concrete installed with insulation, vapor barriers, all electric power production sources capable of being inter- films or similar items separating the concrete from the connected. The marking shall comply with Section 810.1.2.1. earth is not considered to be in “direct contact” with the earth. [NFPA 70:250.52(A)(3)] Exception: Installations with large numbers of power production sources shall be permitted to be designated by groups. 821.3.4 Ground Ring. A ground ring encircling the [NFPA 70:705.10] building or structure, in direct contact with the earth, con- 823.2 Modules. sisting of not less than 20 feet (6096 mm) of bare copper Modules shall be marked with identifica- conductor not less than 2 AWG. [NFPA 70:250.52(A)(4)] tion of terminals or leads as to polarity, maximum overcurrent 821.3.5 Rod and Pipe Electrodes. Rod and pipe device rating for module protection, and with the following electrodes shall not be less than 8 feet (2438 mm) in ratings: length and shall consist of the following materials: (1) Open-circuit voltage (1) Grounding electrodes of pipe or conduit shall not be (2) Operating voltage 3 smaller than trade size ⁄4 (21 metric designator) and, (3) Maximum permissible system voltage where of steel, shall have the outer surface galvanized (4) Operating current or otherwise metal-coated for corrosion protection. (5) Short-circuit current (2) Rod-type grounding electrodes of stainless steel and 5 copper or zinc coated steel shall be not less than ⁄8 (6) Maximum power [NFPA 70:690.51] of an inch (15.9 mm) in diameter, unless listed. 823.3 Format. The marking requirements in Section 810.1.2.1 [NFPA 70:250.52(A)(5)] shall be provided in accordance with the following:

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(1) Red background 827.2 Facilities with Utility Services and Photovoltaic Systems. (2) White lettering Plaques or directories shall be installed in accor- 3 dance with Section 823.1. [NFPA 70:690.56(B)] (3) Not less than ⁄8 of an inch (9.5 mm) letter height 827.3 Buildings with Rapid Shutdown. Buildings with (4) Capital letters PV systems shall have permanent labels as described in Sec- (5) Made of reflective weather-resistant material tion 827.3.1 through Section 827.3.3. [NFPA 70:690.56(C)] 827.3.1 Rapid Shutdown Type. The type of PV sys- 824.0 Alternating-Current Photovoltaic Modules. tem rapid shutdown shall be labeled as described in Sec- 824.1 Identification. Alternating-current modules shall be tion 827.3.1(1) or Section 827.3.1(2): marked with identification of terminals or leads and with (1) For PV systems that shut down the array and con- identification of the following ratings: ductors leaving the array: (1) Nominal operating ac voltage. (2) Nominal operating ac frequency. SOLAR PV SYSTEM IS EQUIPPED (3) Maximum ac power. WITH RAPID SHUTDOWN. (4) Maximum ac current. TURN RAPID SHUTDOWN SWITCH TO THE “OFF” POSITION TO SHUT DOWN PV SYSTEM (5) Maximum overcurrent device rating for ac module pro- AND REDUCE SHOCK HAZARD IN ARRAY. tection. [NFPA 70:690.52]

825.0 Direct-Current Photovoltaic Power Source. The title “SOLAR PV SYSTEM IS EQUIPPED WITH RAPID SHUTDOWN” shall utilize capitalized 825.1 Labeling. 3 A permanent label for the dc PV power characters with a minimum height of ⁄8 of an inch (9.5 source indicating the information specified in Section mm) in black on yellow background, and the remaining 825.1(1) through Section 825.1(3) shall be provided by the characters shall be capitalized with a minimum height of 3 installer at dc PV system disconnecting means and at each dc ⁄16 of an inch (4.8 mm) in black on white background. equipment disconnecting means required by Section 811.1. [see Figure 827.3.1(1)] Where a disconnecting means has more than one dc PV power source, the values in Section 825.1(1) through Section 825.1(3) shall be specified for each source. (1) Maximum voltage. (see Section 804.1 for voltage) (2) Maximum circuit current. (see Section 805.1 for calculation of maximum circuit current) (3) Maximum rated output current of the charge controller or dc-to-dc converter (if installed). [NFPA 70:690.53] 825.2 Interactive System Point of Interconnection. All interactive system(s) points of interconnection with other sources shall be marked at an accessible location at the disconnecting means as a power source and with the rated ac output current and the nominal operating ac voltage. [NFPA 70:690.54]

826.0 Photovoltaic Systems Connected to Energy FIGURE 827.3.1(1) Storage Systems. LABEL FOR PV SYSTEMS THAT SHUT DOWN THE 826.1 Marking. The PV system output circuit conductors ARRAY AND THE CONDUCTORS LEAVING THE ARRAY shall be marked to indicate the polarity where connected to [NFPA 70: FIGURE 690.56(C)(1)(a)] energy storage systems. [NFPA 70:690.55] (2) For PV systems that only shut down conductors 827.0 Facilities with Stand-Alone Systems. leaving the array: 827.1 General. Any structure or building with a PV power system that is not connected to a utility service source and is SOLAR PV SYSTEM IS EQUIPPED WITH a stand-alone system shall have a permanent plaque or direc- RAPID SHUTDOWN tory installed on the exterior of the building or structure at a TURN RAPID SHUTDOWN SWITCH TO THE readily visible location. The plaque or directory shall indicate “OFF” POSITION TO SHUT DOWN the location of system disconnecting means and that the struc- CONDUCTORS OUTSIDE THE ARRAY. ture contains a stand-alone electrical power system. [NFPA CONDUCTORS IN ARRAY REMAIN 70:690.56(A)] ENERGIZED IN SUNLIGHT.

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The title “SOLAR PV SYSTEM IS EQUIPPED Part VII – Connection to Other Sources. WITH RAPID SHUTDOWN” shall utilize capitalized 3 characters with a minimum height of ⁄8 of an inch (9.5 828.0 Connection to Other Sources. mm) in white on red background, and the remaining 828.1 PV Systems. characters shall be capitalized with a minimum height of PV systems connected to other sources 3 ⁄16 of an inch (4.8 mm) in black on white background. shall be installed in accordance with Parts I and II of Article [see Figure 827.3.1(2)] 705 of NFPA 70. [NFPA 70:690.59]

Part VIII – Energy Storage Systems.

829.0 Energy Storage Systems. 829.1 General. An energy storage system connected to a PV system shall be installed in accordance with Article 706 of NFPA 70. [NFPA 70:690.71]

830.0 Batteries. 830.1 Battery Locations. Battery locations shall comply with the following: (1) Battery rooms shall be provided with an exhaust rate of not less than 1 cubic foot per minute per square foot [(ft3/min)/ft2] [0.005 (m3/s)/m2] of floor area of the room FIGURE 827.3.1(2) LABEL FOR PV SYSTEMS THAT SHUT DOWN THE to prevent the accumulation of flammable vapors. Such CONDUCTORS LEAVING THE ARRAY ONLY exhaust shall discharge directly to an approved location [NFPA 70: FIGURE 690.56(C)(1)(b)] at the exterior of the building. (2) Makeup air shall be provided at a rate equal to the rate that air is exhausted by the exhaust system. Makeup air The labels in Section 827.3.1(1) and Section intakes shall be located so as to avoid recirculation of 827.3.1(2) shall include a simple diagram of a building contaminated air. with a roof. The diagram shall have sections in red to signify sections of the PV system that are not shut down (3) Batteries shall be protected against physical damage. when the rapid shutdown switch is operated. (4) Batteries shall not be located in areas where open use, The rapid shutdown label in Section 827.3.1 shall be handling or dispensing of combustible, flammable, or located on or not more than 3 feet (914 mm) from the explosive materials occurs. service disconnecting means to which the PV systems (5) Batteries shall not be located near combustible material are connected and shall indicate the location of all iden- to constitute a fire hazard and shall have a clearance of tified rapid shutdown switches if not at the same loca- not less than 12 inches (305 mm) from combustible tion. [NFPA 70:690.56(C)(1)] material. 827.3.2 Buildings with More Than One Rapid Shutdown Type. For buildings that have PV systems 831.0 Self-Regulating Charge Control. with both rapid shutdown types or a PV system with a 831.1 General. rapid shutdown type and a PV system with no rapid shut- The PV source circuit shall be considered down, a detailed plan view diagram of the roof shall be to comply with the requirements of Section 831.1.1 through provided showing each different PV system and a dotted Section 831.1.5 if: line around areas that remain energized after the rapid (1) The PV source circuit is matched to the voltage rating shutdown switch is operated. [NFPA 70:690.56(C)(2)] and charge current requirements of the interconnected 827.3.3 Rapid Shutdown Switch. A rapid shutdown battery cells and, switch shall have a label located on or no more than 3 (2) The maximum charging current multiplied by 1 hour is feet (914 mm) from the switch that includes the follow- less than 3 percent of the rated battery capacity expressed ing wording: in ampere-hours or as recommended by the battery manufacturer. [NFPA 70:690.72] RAPID SHUTDOWN SWITCH FOR A charging controller shall comply with UL 1741. SOLAR PV SYSTEM 831.1.1 Charge Control. Provisions shall be provided to control the charging process of the Energy Storage The label shall be reflective, with all letters capitalized System (ESS). All adjustable means for control of the 3 and having a minimum height of ⁄8 of an inch (9.5 mm), in charging process shall be accessible only to qualified per- white on red background. [NFPA 70:690.56(C)(3)] sons. [NFPA 70:706.23(A)]

76 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT SOLAR PHOTOVOLTAIC SYSTEMS

831.1.2 Diversion Charge Controller, Sole Means 832.2 Special Requirements for Large-Scale PV of Regulating Charging. An ESS employing a diver- Electric Supply Stations. Large-scale PV electric supply sion charge controller as the sole means of regulating stations shall be accessible only to authorized personnel and charging shall be equipped with a second independent comply with the following: means to prevent overcharging of the storage device. (1) Electrical circuits and equipment shall be maintained and [NFPA 70:706.23(B)(1)] operated only by qualified personnel. 831.1.3 Diversion Charge Controller, Circuits with Diversion Charge Controller and Diversion (2) Access to PV electric supply stations shall be restricted by Load. fencing or other adequate means in accordance with Sec- Circuits containing a diversion charge controller tion 110.31 of NFPA 70. Field-applied hazard markings and a diversion load shall comply with the following: shall be applied in accordance with Section 810.1.2.1. (1) The current rating of the diversion load shall be less (3) The connection between the PV electric supply station than or equal to the current rating of the diversion and the system operated by a utility for the transfer of load charge controller. The voltage rating of the electrical energy shall be through medium- or high volt- diversion load shall be greater than the maximum age switch gear, substation, switch yard, or similar meth- ESS voltage. The power rating of the diversion load ods whose sole purpose shall be to safely and effectively shall be at least 150 percent of the power rating of interconnect the two systems. the charging source. (4) The electrical loads within the PV electric supply station (2) The conductor ampacity and the rating of the over- shall only be used to power auxiliary equipment for the current device for this circuit shall be at least 150 generation of the PV power. percent of the maximum current rating of the diversion charge controller. [NFPA 70:706.23(B)(2)] (5) Large-scale PV electric supply stations shall not be 831.1.4 Energy Storage Systems Using Utility- installed on buildings. [NFPA 70:691.4] 832.3 Equipment Approval. Interactive Inverters. Systems using utility-interactive All electrical equipment shall inverters to control energy storage state-of-charge by be approved for installation by one of the following: diverting excess power into the utility system shall com- (1) Listing and labeling ply with Section 831.1.4(1) and Section 831.1.4(2). (2) Field labeling (1) These systems shall not be required to comply with (3) Where products complying with Section 832.3(1) or Sec- Section 831.1.3. tion 832.3(2) are not available, by engineering review (2) These systems shall have a second, independent validating that the electrical equipment is tested to rele- means of controlling the ESS charging process for vant standards or industry practice [NFPA 70:691.5] use when the utility is not present or when the pri- 832.4 Engineered Design. Documentation of the electri- mary charge controller fails or is disabled. [NFPA cal portion of the engineered design of the electric supply sta- 70:706.23(B)(3)] tion shall be stamped and provided upon request of the 831.1.5 Charge Controllers and DC-to-DC Con- Authority Having Jurisdiction. Additional stamped inde- verters. Where charge controllers and other DC-to-DC pendent engineering reports detailing compliance of the power converters that increase or decrease the output cur- design with applicable electrical standards and industry prac- rent or output voltage with respect to the input current or tice shall be provided upon request of the AHJ. The inde- input voltage are installed, all of the following shall pendent engineer shall be a licensed professional electrical apply: engineer retained by the system owner or installer. This doc- (1) The ampacity of the conductors in output circuits umentation shall include details of conformance of the design shall be based on the maximum rated continuous with this chapter, and any alternative methods to this chapter, output current of the charge controller or converter or other articles of NFPA 70. [NFPA 70:691.6] for the selected output voltage range. 832.5 Conformance of Construction to Engineered Design. (2) The voltage rating of the output circuits shall be Documentation that the construction of the electric based on the maximum voltage output of the charge supply station conforms to the electrical engineered design controller or converter for the selected output volt- shall be provided upon request of the Authority Having Juris- age range. [NFPA 70:706.23(C)] diction. Additional stamped independent engineering reports detailing the construction conforms with this chapter, appli- Part IX – Large-Scale Photovoltaic (PV) Electric cable standards and industry practice shall be provided upon Power Production Facility. request of the Authority Having Jurisdiction. The independent engineer shall be a licensed professional electrical engineer retained by the system owner or installer. This 832.0 Large-Scale Photovoltaic (PV) Electric Power documentation, where requested, shall be available prior to Production Facility. commercial operation of the station. [NFPA 70:691.7] 832.1 Scope. Section 832.2 through Section 832.9 covers 832.6 Direct Current Operating Voltage. For large-scale the installation of large-scale PV electric power production PV electric supply stations, calculations shall be included in facilities with a generating capacity of no less than 5000 kW, the documentation required in Section 832.4. [NFPA and not under exclusive utility control. [NFPA 70:691.1] 70:691.8]

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832.7 Disconnection of Photovoltaic Equipment. Iso- lating devices shall be permitted to be more than 6 feet (1829 mm) from the equipment where written safety procedures and conditions of maintenance and supervision ensure that only qualified persons service the equipment. Buildings whose sole purpose is to house and protect supply station equipment shall not be required to comply with Section 809.1. Written standard operating procedures shall be available at the site detailing necessary shutdown procedures in the event of an emergency. [NFPA 70:691.9] 832.8 Arc-Fault Mitigation. PV systems that do not comply with the requirements of Section 808.1 shall include details of fire mitigation plans to address dc arc-faults in the documentation required in Section 832.4. [NFPA 70:691.10] 832.9 Fence Grounding. Fence grounding requirements and details shall be included in the documentation required in Section 832.4. [NFPA 70:691.11]

78 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT CHAPTER 9 REFERENCED STANDARDS Note: Referenced sections in Table 901.1 will be updated before publishing.

901.0 General. date, the title, application and the section(s) of this code that 901.1 Standards. The standards listed in Table 901.1 are reference the standard. The application of the referenced stan- referenced in various sections of this code and shall be con- dard(s) shall be as specified in Section 302.1.2. The promul- sidered part of the requirements of this document. The stan- gating agency acronyms referred to in Table 901.1 are defined dards are listed herein by the standard number and effective in a list found at the end of the chapter.

TABLE 901.1 REFERENCED STANDARDS REFERENCED STANDARD NUMBER STANDARD TITLE APPLICATION SECTIONS AHRI 210/240-2017 Performance Rating of Unitary Air-conditioning & Air- Air-Source Heat 407.5 source Heat Pump Equipment Pumps AHRI 870-2016 Performance Rating of Direct Geoexchange Heat Pumps Equipment 707.1 706.1 AHRI/ASHRAE/ISO Water-Source Heat Pumps – Testing and Rating for Perform- Water-Source Heat 407.5, 707.1 706.1 13256-1-1998 (R2012) ance – Part 1: Water-to-Air and Brine-to-Air Heat Pumps Pumps AHRI/ASHRAE/ISO Water-Source Heat Pumps – Testing and Rating for Perform- Water-Source Heat 407.5, 707.1 706.1 13256-2-1998 (R2012) ance – Part 2: Water-to-Water and Brine-to-Water Heat Pumps Pumps ASHRAE 34-2016 Designation and Safety Classification of Refrigerants Refrigerant Classifica- 705.2 706.3 tions ASHRAE 194-2012 2017 Method of Test for Direct-Expansion Ground-Source Heat Ground-Source Heat 707.1 706.1 Pumps Pumps ASME B1.20.1-2013 Pipe Threads, General Purpose (Inch) Joints 409.2(3) 410.2(3), (R2018) 409.4(7) 410.4(7), 409.11(3) 410.11(3), 409.12(2) 410.12(2) ASME B16.3-2016 Malleable Iron Threaded Fittings: Classes 150 and 300 Fittings Table 408.1 409.1 1 ASME B16.5-2013 2017 Pipe Flanges and Flanged Fittings: NPS ⁄2 tThrough NPS 24 Fittings Table 408.1 409.1 Metric/Inch ASME B16.9-2012 2018 Factory-Made Wrought Buttwelding Fittings Fittings Table 408.1 409.1 ASME B16.11-2016 Forged Fittings, Socket-Welding and Threaded Fittings Table 408.1 409.1 ASME B16.15-2013 2018 Cast Copper Alloy Threaded Fittings: Classes 125 and 250 Fittings Table 408.1 409.1 ASME B16.18-2012 2018 Cast Copper Alloy Solder Joint Pressure Fittings Fittings Table 408.1 409.1 ASME B16.22-2013 2018 Wrought Copper and Copper Alloy Solder-Joint Pressure Fit- Fittings 703.6 715.3, tings Table 408.1 409.1 ASME B16.23-2016 Cast Copper Alloy Solder Joint Drainage Fittings: DWV Fittings Table 408.1 409.1 ASME B16.24-2016 Cast Copper Alloy Pipe Flanges, Flanged Fittings, and Fittings Table 408.1 409.1 Valves: Classes 150, 300, 600, 900, 1500, and 2500 ASME B16.26-2013 2018 Cast Copper Alloy Fittings for Flared Copper Tubes Fittings Table 408.1 409.1 ASME B16.29-2012 2017 Wrought Copper and Wrought Copper Alloy Solder-Joint Fittings Table 408.1 409.1 Drainage Fittings – DWV ASME B16.51-2013 2018 Copper and Copper Alloy Press-Connect Pressure Fittings Fittings Table 408.1 409.1 ASME BPVC Section Rules for Construction of Pressure Vessels Division 1 Miscellaneous 407.3 408.3, 601.2.1, VIII.1-2015 2017 603.6, 605.3 ASME BPVC Section X- Fiber-Reinforced Plastic Pressure Vessels Pressure Vessel 603.6 2015 2017 Construction, Pressure Vessels ASME SA194-2015 Carbon and Alloy Steel Nuts for Bolts for High Pressure or Mounting 501.5.6 High Temperature Service, or Both

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TABLE 901.1 (continued) REFERENCED STANDARDS REFERENCED STANDARD NUMBER STANDARD TITLE APPLICATION SECTIONS ASSE 1013-2011 Reduced Pressure Principle Backflow Preventers and Backflow Prevention 402.2 Reduced Pressure Principle Fire Protection Backflow Pre- venters ASSE 1017-2009 Temperature Actuated Mixing Valves for Hot Water Distri- Valves 311.5, 406.3.1 407.3.1 bution Systems ASSE 1061-2015 Push-Fit Fittings Fittings 409.2(1) 410.2(1), 409.4(5) 410.4(5), Table 408.1 409.1 ASSE 1079-2012 Dielectric Pipe Unions Fittings 409.13.1 410.13.1 ASTM A53/A53M-2012 Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Piping Table 408.1 409.1 2018 Seamless ASTM A106/A106M-2015 Seamless Carbon Steel Pipe for High-Temperature Service Piping Table 408.1 409.1 2018 ASTM A126-2004 Gray Iron Castings for Valves, Flanges, and Pipe Fittings Piping Table 408.1 409.1 (R2014) ASTM A254/A254M-2012 Copper-Brazed Steel Tubing Piping Table 408.1 409.1 ASTM A269/A269M- Seamless and Welded Austenitic Stainless Steel Tubing for Piping Table 408.1 409.1 2015a General Service ASTM A312/A312M-2017 Seamless, Welded, and Heavily Cold Worked Austenitic Piping Table 408.1 409.1 2018a Stainless Steel Pipes ASTM A420/A420M-2016 Piping Fittings of Wrought Carbon Steel and Alloy Steel for Fittings Table 408.1 409.1 Low-Temperature Service ASTM A554-2016 Welded Stainless Steel Mechanical Tubing Piping Table 409.1 ASTM A778/A778M-2016 Welded, Unannealed Austenitic Stainless Steel Tubular Piping Table 409.1 Products ASTM B32-2008 (R2014) Solder Metal Joints 409.4(6) 410.4(6) ASTM B42-2015a Seamless Copper Pipe, Standard Sizes Piping Table 408.1 409.1 ASTM B43-2015 Seamless Red Brass Pipe, Standard Sizes Piping Table 408.1 409.1 ASTM B75/B75M-2011 Seamless Copper Tube Piping Table 408.1 409.1 ASTM B88-2016 Seamless Copper Water Tube Piping Table 408.1 409.1 ASTM B135/B135M-2010 Seamless Brass Tube Piping Table 408.1 409.1 2017 ASTM B251/B251M-2010 General Requirements for Wrought Seamless Copper and Piping Table 408.1 409.1 2017 Copper-Alloy Tube ASTM B280-2016 2018 Seamless Copper Tube for Air Conditioning and Refrigera- Piping 703.6 715.3 tion Field Service ASTM B302-2012 2017 Threadless Copper Pipe, Standard Sizes Piping Table 408.1 409.1 ASTM B447-2012a Welded Copper Tube Piping Table 408.1 409.1 ASTM B813-2010 2016 Liquid and Paste Fluxes for Soldering of Copper and Copper Joints 409.4(6) 410.4(6) Alloy Tube ASTM B828-2016 Making Capillary Joints by Soldering of Copper and Copper Joints 409.4(6) 410.4(6) Alloy Tube and Fittings ASTM C411-2011 2019 Hot-Surface Performance of High-Temperature Thermal Duct Coverings and 502.4.1 Insulation Linings ASTM D1693-2015 Environmental Stress-Cracking of Ethylene Plastics Piping Table 408.1 409.1 ASTM D1785-2015 2015e1 Poly(Vinyl Chloride) (PVC) Plastic Pipe, Schedules 40, 80, Piping Table 408.1 409.1 and 120 ASTM D2241-2015 Poly(Vinyl Chloride) (PVC) Pressure-Rated Pipe (SDR Piping Table 408.1 409.1 Series)

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TABLE 901.1 (continued) REFERENCED STANDARDS REFERENCED STANDARD NUMBER STANDARD TITLE APPLICATION SECTIONS ASTM D2464-2015 Threaded Poly(Vinyl Chloride) (PVC) Plastic Pipe Fittings, Fittings Table 408.1 409.1 Schedule 80 ASTM D2466-2015 2017 Poly(Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule Fittings Table 408.1 409.1 40 ASTM D2467-2015 Poly(Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule Fittings Table 408.1 409.1 80 ASTM D2513-2016a Polyethylene (PE) Gas Pressure Pipe, Tubing, and Fittings Piping 703.4.1, Table 408.1 2018a 409.1 ASTM D2564-2012 Solvent Cements for Poly(Vinyl Chloride) (PVC) Plastic Joints 409.11(2) 410.11(2) (R2018) Piping Systems ASTM D2609-2015 Plastic Insert Fittings for Polyethylene (PE) Plastic Pipe Fittings Table 408.1 409.1

ASTM D2683-2014 Socket-Type Polyethylene Fittings for Outside Diameter- Fittings 703.5.1, Table 408.1 Controlled Polyethylene Pipe and Tubing 409.1, Table 703.3 ASTM D2737-2012a Polyethylene (PE) Plastic Tubing Piping Table 408.1 409.1, Table 703.2 ASTM D2846/D2846M- Chlorinated Poly(Vinyl Chloride) (CPVC) Plastic Hot- and Piping 409.2(2) 410.2(2), 2014 2019a Cold-Water Distribution Systems 409.3(2) 410.3(2), Table 408.1 409.1 ASTM D3035-2015 Polyethylene (PE) Plastic Pipe (DR-PR) Based on Controlled Piping 703.5.1, Table 408.1 Outside Diameter 409.1, Table 703.2 ASTM D3139-1998 Joints for Plastic Pressure Pipes Using Flexible Elastomeric Joints 409.11(1) 410.11(1) (R2011) Seals ASTM D3261-2016 Butt Heat Fusion Polyethylene (PE) Plastic Fittings for Poly- Fittings 703.5.1, Table 408.1 ethylene (PE) Plastic Pipe and Tubing 409.1, Table 703.3 ASTM D3350-2014 Polyethylene Plastics Pipe and Fittings Materials Piping 703.5.1, Table 408.1 409.1, 703.4.1 ASTM E84-2016 2019a Surface Burning Characteristics of Building Materials Miscellaneous 401.2, 502.4, 503.1, 606.5 ASTM F437-2015 Threaded Chlorinated Poly (Vinyl Chloride) (CPVC) Plastic Fittings Table 408.1 409.1 Pipe Fittings, Schedule 80 ASTM F438-2015 2017 Socket-Type Chlorinated Poly (Vinyl Chloride) (CPVC) Fittings Table 408.1 409.1 Plastic Pipe Fittings, Schedule 40 ASTM F439-2013 Chlorinated Poly (Vinyl Chloride) (CPVC) Plastic Pipe Fit- Fittings Table 408.1 409.1 tings, Schedule 80 ASTM F441/F441M-2015 Chlorinated Poly (Vinyl Chloride) (CPVC) Plastic Pipe, Piping Table 408.1 409.1 Schedules 40 and 80 ASTM F442/F442M- Chlorinated Poly (Vinyl Chloride) (CPVC) Plastic Pipe Piping, Plastic 409.2(2) 410.2(2), 2013e1 (SDR-PR) Table 408.1 409.1 ASTM F493-2014 Solvent Cements for Chlorinated Poly (Vinyl Chloride) Joints 409.2(2) 410.2(2), (CPVC) Plastic Pipe and Fittings 409.3(2) 410.3(2) ASTM F656-2015 Primers for Use in Solvent Cement Joints of Poly (Vinyl Joints 409.2(2) 410.2(2), Chloride) (PVC) Plastic Pipe and Fittings 409.3(2) 410.3(2), 409.11(2) 410.11(2) ASTM F714-2013 Polyethylene (PE) Plastic Pipe (DR-PR) Based on Outside Piping 703.5.1, Table 408.1 Diameter 409.1, Table 703.2 ASTM F876-2015a 2017 Crosslinked Polyethylene (PEX) Tubing Piping 409.5 410.5, 703.5.2, Table 408.1 409.1, Table 703.2 ASTM F877-2011a 2018a Crosslinked Polyethylene (PEX) Hot- and Cold-Water Dis- Piping Table 408.1 409.1, tribution Systems Table 703.3 ASTM F1055-2016a Electrofusion Type Polyethylene Fittings for Outside Diame- Fittings 703.4.1.1(3)703.5.1, ter Controlled Polyethylene and Crosslinked Polyethylene 703.5.2, Table 408.1 (PEX) Pipe and Tubing 409.1, Table 703.3

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TABLE 901.1 (continued) REFERENCED STANDARDS REFERENCED STANDARD NUMBER STANDARD TITLE APPLICATION SECTIONS ASTM F1281-2011 2017 Crosslinked Polyethylene/ Aluminum/Crosslinked Polyethyl- Piping Table 408.1 409.1 ene (PEX-AL-PEX) Pressure Pipe ASTM F1282-2017 Polyethylene/Aluminum/Polyethylene (PE-AL-PE) Compo- Piping Table 408.1 409.1 site Pressure Pipe ASTM F1476-2007 Performance of Gasketed Mechanical Couplings Fittings Table 409.1 (R2013) for Use in Piping Applications ASTM F1548-2001 Performance of Fittings for Use with Gasketed Mechanical Fittings Table 409.1 (R2018) Couplings Used in Piping Applications ASTM F1807-2017 2019 Metal Insert Fittings Utilizing a Copper Crimp Ring, or Fittings Table 408.1 409.1, Alternate Stainless Steel Clamps, for SDR9 Cross-linked Table 703.3 Polyethylene (PEX) Tubing and SDR9 Polyethylene of Raised Temperature (PE-RT) Tubing ASTM F1960-2015 2018a Cold Expansion Fittings with PEX Reinforcing Rings for Fittings 703.5.2, 703.5.2.1(3), Use with Cross-linked Polyethylene (PEX) and Polyethylene Table 408.1 409.1, of Raised Temperature (PE-RT) Tubing Table 703.3 ASTM F1961-2009 Metal Mechanical Cold Flare Compression Fittings with Fittings Table 408.1 Disc Spring for Crosslinked Polyethylene (PEX) Tubing ASTM F1970-2012e1 Special Engineered Fittings, Appurtenances or Valves for Piping Table 408.1 409.1 Use in Poly (Vinyl Chloride) (PVC) or Chlorinated Poly (Vinyl Chloride) (CPVC) Systems ASTM F1974-2009 Metal Insert Fittings for Polyethylene/Aluminum/Polyethyl- Fittings 409.6(1) 410.6(1), (R2015) ene and Crosslinked Polyethylene/Aluminum/Crosslinked 409.8(1) 410.8(1), Polyethylene Composite Pressure Pipe Table 408.1 409.1 ASTM F2080-2016 2018 Cold-Expansion Fittings with Metal Compression-Sleeves Fittings 703.5.2, 703.5.2.1(2), for Cross-linked Polyethylene (PEX) Pipe and SDR9 Poly- Table 408.1 409.1, ethylene of Raised Temperature (PE-RT) Pipe Table 703.3 ASTM F2098-2015 2018 Stainless Steel Clamps for Securing SDR9 Cross-linked Fittings Table 408.1 409.1 Polyethylene (PEX) Tubing and SDR9 Polyethylene of Raised Temperature (PE-RT) to Metal Insert and Plastic Insert Fittings ASTM F2159-2014 2019 Plastic Insert Fittings Utilizing a Copper Crimp Ring, or Fittings Table 408.1 409.1, Alternate Stainless Steel Clamps for SDR9 Cross-linked Table 703.3 Polyethylene (PEX) Tubing and SDR9 Polyethylene of Raised Temperature (PE-RT) Tubing ASTM F2165-2019 Flexible Pre-Insulated Plastic Piping Fittings, Piping and Table 409.1 Tubing ASTM F2262-2009 Crosslinked Polyethylene/ Aluminum/ Crosslinked Polyeth- Piping, Plastic Table 408.1 ylene Tubing OD Controlled SDR9 ASTM F2389-2017a Pressure-Rated Polypropylene (PP) Piping Systems Piping 409.10(1) 410.10(1), Table 408.1 409.1, Table 703.2, Table 703.3 ASTM F2434-2014 2018 Metal Insert Fittings Utilizing a Copper Crimp Ring for Pipe Fittings 409.6(1) 410.6(1), SDR9 Cross-linked Polyethylene (PEX) Tubing and SDR9 Table 408.1 409.1, Cross-linked Polyethylene/Aluminum/Cross-linked Polyeth- Table 703.3 ylene (PEX-AL-PEX) Tubing ASTM F2620-2013 Standard Practice for Heat Fusion Joining of Polyethylene Joints 409.7(1) 410.7(1), Pipe and Fittings 409.7(3) 410.7(3), 703.5.1.1(1) 703.4.1.1(1), 703.5.1.1(2) 703.4.1.1(2)

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TABLE 901.1 (continued) REFERENCED STANDARDS REFERENCED STANDARD NUMBER STANDARD TITLE APPLICATION SECTIONS ASTM F2623-2014 Polyethylene of Raised Temperature (PE-RT) SDR9 Tubing Piping Table 408.1 409.1, Table 703.2 ASTM F2735-2009 Plastic Insert Fittings for SDR9 Cross-linked Polyethylene Fittings Table 408.1 409.1 (R2016) 2018 (PEX) and Polyethylene of Raised Temperature (PE-RT) Tubing ASTM F2769-2016 2018 Polyethylene of Raised Temperature (PE-RT) Plastic Hot Piping, Fitting Table 408.1 409.1, and Cold-Water Tubing and Distribution Systems Table 703.2, Table 703.3 ASTM F2855-2012 Specification for Chlorinated Poly (Vinyl Chloride)/Alu- Piping, Plastic Table 408.1 409.1 minum/Chlorinated Poly (Vinyl Chloride) (CPVC-AL- CPVC) Composite Pressure Tubing ASTM F3226/F3226M- Metallic Press-Connect Fittings for Piping and Tubing Sys- Fittings Table 409.1 2016e1 tems ASTM F3253-2018 Crosslinked Polyethylene (PEX) Tubing with Oxygen Bar- Piping, Fittings Table 409.1, Table rier for Hot- and Cold-Water Hydronic Distribution Systems 703.2, Table 703.3 ASTM F3347-2019 Metal Press Insert Fittings with Factory Assembled Stainless Fittings Table 409.1, Table Steel Press Sleeve for SDR9 Cross-linked Polyethylene 703.3 (PEX) Tubing ASTM F3348-2019 Plastic Press Insert Fittings with Factory Assembled Stain- Fittings Table 409.1, Table less Steel Press Sleeve for SDR9 Cross-linked Polyethylene 703.3 (PEX) Tubing AWS A5.8M/A5.8-2011- Filler Metals for Brazing and Braze Welding (with revisions Joints 409.4(1) 410.4(1), AMD 1 through November 30, 2012) 703.6, 703.7 715.3, 715.5 3 AWWA C901-2017 Polyethylene (PE) Pressure Pipe and Tubing, ⁄4 In. (19 mm) Piping Table 408.1 409.1, Through 3 In. (76 mm), for Water Service Table 703.2 CSA B137.1-2017 Polyethylene (PE) Pipe, Tubing, and Fittings for Cold-Water Piping 703.5.1, Table 408.1 Pressure Services 409.1, Table 703.2, Table 703.3 CSA B137.2-2017 Polyvinylchloride (PVC) Injection-Moulded Gasketed Fit- Fittings Table 408.1 409.1 tings for Pressure Applications CSA B137.3-2017 Rigid Polyvinylchloride (PVC) Pipe and Fittings for Pressure Piping, Fittings Table 408.1 409.1 Applications CSA B137.5-2017 Crosslinked Polyethylene (PEX) Tubing Systems for Pres- Piping 703.5.2, Table 408.1 sure Applications 409.1, Table 703.2, Table 703.3 CSA B137.6-2017 Chlorinated Polyvinylchloride (CPVC) Pipe, Tubing, and Piping, Fittings Table 408.1 409.1 Fittings for Hot- and Cold-Water Distribution Systems CSA B137.9-2017 Polyethylene/Aluminum/Polyethylene (PE-AL-PE) Compos- Piping Table 408.1 409.1 ite Pressure-Pipe Systems CSA B137.10-2017 Crosslinked Polyethylene/Aluminum/Crosslinked Polyethyl- Piping Table 408.1 409.1 ene (PEX-AL-PEX) Composite Pressure-Pipe Systems CSA B137.11-2017 Polypropylene (PP-R) Pipe and Fittings for Pressure Appli- Piping 409.10(1) 410.10(1), cations Table 409.1, Table 703.2, Table 703.3 CSA B137.18-2017 Polyethylene of Raised Temperature Resistance (PE-RT) Piping, Fittings Table 408.1 409.1, Tubing Systems for Pressure Applications Table 703.2, Table 703.3 CSA C448.1-2016 Design and Installation of Ground Source Heat Pump Sys- Ground-Source Heat 708.7 tems for Commercial and Institutional Buildings Pumps CSA C448.2-2016 Design and Installation of Ground Source Heat Pump Ground-Source Heat 708.7 Systems for Residential and Other Small Buildings Pumps

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TABLE 901.1 (continued) REFERENCED STANDARDS REFERENCED STANDARD NUMBER STANDARD TITLE APPLICATION SECTIONS CSA/IGSHPA C448-2016 Design and Installation of Ground Source Heat Pump Sys- Miscellaneous 703.3, 703.4, 703.4.2, tems for Commercial and Residential Buildings 709.1, 710.6, 710.6.2, 715.4, Table 703.2, Table 703.3 CSA Z21.10.1-2014 2017 Gas Water Heaters, Volume I, Storage Water Heaters with Fuel Gas, Appliances Table 403.2 Input Ratings of 75,000 Btu Per Hour or Less (same as CSA 4.1) CSA Z21.10.3-2015 2017 Gas-Fired Water Heaters, Volume III, Storage Water Heaters Fuel Gas, Appliances Table 403.2 with Input Ratings Above 75,000 Btu Per Hour, Circulating and Instantaneous (same as CSA 4.3) IAPMO PS 117-2018 Press and Nail Connections Fittings Table 409.1 IAPMO S1001.1-2013 Design and Installation of Solar Water Heating Systems Solar Thermal Systems 501.8

ICC 900/SRCC 300-2015 Solar Thermal System Standard Solar Thermal Systems 501.8

ICC 901/SRCC 100-2015 Solar Thermal Collector Standard Collectors 502.6 NFPA 70-2014 2017 National Electrical Code Miscellaneous 315.1, 801.1, 804.1, 806.4, 807.2, 810.1.3, 811.1.4, 812.1, 812.2.1, 812.3, 812.5, 812.6, 812.7.5(8), 812.7.5(11), 812.7.5(12), 812.8, 818.2, 818.3(1), 819.1, 819.1.2, 821.2, 821.2.2, 821.3, 821.3.9(3), 828.1, 829.1, 832.2(2), 832.4, B 104.1, C 101.9(7) NGWA-01-2014 Water Well Construction Standard Geothermal 702.1.1, 702.1.2 712.2, 712.3 NSF 60-2016 2017 Drinking Water Treatment Chemicals-Health Effects Backfill 703.4.1 710.6.1 NSF 61-2016 2018 Drinking Water System Components - Health Effects Miscellaneous 501.5.4 NSF 358-1-2017 Polyethylene Pipe and Fittings for Water-Based Ground- Piping, Fittings Table 408.1 409.1, Source “Geothermal” Heat Pump Systems Table 703.2, Table 703.3 NSF 358-2-2012 2017 Polypropylene Pipe and Fittings for Water-Based Ground- Piping, Fittings Table 408.1 409.1, Source “Geothermal” Heat Pump Systems Table 703.2, Table 703.3 NSF 358-3-2016 Cross-Linked Polyethylene (PEX) Pipe and Fittings for Piping, Fittings Table 408.1 409.1, Water-Based Ground-Source (Geothermal) Heat Pump Sys- Table 703.2, Table tems 703.3 NSF 358-4-2018 Polyethylene of Raised Temperature (PE-RT) Tubing and Piping, Fittings Table 703.2, Table Fittings for Water-Based Ground-Source (Geothermal) Heat 703.3 Pump Systems UL 723-2008 2018 Test for Surface Burning Characteristics of Building Materi- Miscellaneous 401.2, 502.4, 503.1, als (with revisions through August 12, 2013) 606.5 UL 778-2016 Motor-Operated Water Pumps (with revisions February 22, Pumps 310.1 308.1.1 2017 January 17, 2019) UL 834-2004 Heating, Water Supply, and Power Boilers – Electric (with Appliances Table 403.2 revisions through December 9, 2013 September 24, 2018) UL 1279-2010 Outline of Investigation for Solar Collectors Electrical 502.6

84 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT REFERENCED STANDARDS

TABLE 901.1 (continued) REFERENCED STANDARDS REFERENCED STANDARD NUMBER STANDARD TITLE APPLICATION SECTIONS UL 1703-2002 Flat-Plate Photovoltaic Modules and Panels (with revisions Electrical 802.6, Table 802.2.1 through March 10, 2017 September 26, 2018) UL 1741-2010 Inverters, Converters, Controllers and Interconnection Sys- Electrical 831.1, Table 802.2.1 tem Equipment for Use With Distributed Energy Resources (with revisions through September 7, 2016 February 15, 2018) UL 1699B-2018 Photovoltaic (PV) DC Arc-Fault Circuit Protection Electrical Table 802.2.1 UL 2703-2015 Mounting Systems, Mounting Devices, Clamping/Retention Electrical Table 802.2.1 Devices, and Ground Lugs for Use with Flat-Plate Photovoltaic Modules and Panels UL 2523-2009 Solid Fuel-Fired Hydronic Heating Appliances, Water Heaters, Fuel Gas, Appliances Table 403.2 and Boilers (with revisions through February 8, 2013 March 16, 2018) UL 3703-2015 Solar Trackers Electrical Table 802.2.1 UL 4703-2014 Photovoltaic Wire Electrical Table 802.2.1 UL 6703-2014 Connectors for Use in Photovoltaic Systems (with revisions Electrical Table 802.2.1 through December 22, 2017) UL 8703-2011 Outline of Investigation for Concentrator Photovoltaic Mod- Electrical Table 802.2.1 ules and Assemblies UL 61730-1-2017 Photovoltaic (PV) Module Safety Qualification - Part 1: Electrical Table 802.2.1 Requirements for Construction UL 61730-2-2017 Photovoltaic (PV) Module Safety Qualification - Part 2: Electrical Table 802.2.1 Requirements for Testing UL 62109-1-2014 Safety of Power Converters for Use in Photovoltaic Power Sys- Electrical Table 802.2.1 tems - Part 1: General Requirements

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901.2 Standards, Publications, Practices, and cations, practices and guides shall be as specified in Section Guides. The standards, publications, practices and guides 302.1.2. The promulgating agency acronyms are found at the listed in Table 901.2 are not referenced in other sections of end of the table. this code. The application of the referenced standards, publi-

TABLE 901.2 STANDARDS, PUBLICATIONS, PRACTICES, AND GUIDES

DOCUMENT NUMBER DOCUMENT TITLE APPLICATION

ASHRAE 90.1-2013 2016 Energy Standard for Buildings Except Low-Rise Residential Buildings Energy ASHRAE 93-2010 Methods of Testing to Determine the Thermal Performance of Solar Collectors Testing (RA2014) ASHRAE 95-1981 Methods of Testing to Determine the Thermal Performance of Solar Domestic Testing (RA1987) Water Heating Systems ASHRAE 96-1980 Thermal Performance of Unglazed Flat-Plate Liquid-Type Solar Collectors Testing, Collector (RA1989) ASME A13.1-2015 Scheme for the Identification of Piping Systems Piping ASME B16.21-2016 Nonmetallic Flat Gaskets for Pipe Flanges Joints ASME B16.34-2013 2017 Valves - Flanged, Threaded, and Welding End Valves ASME B16.47-2011 2017 Large Diameter Steel Flanges: NPS 26 Through NPS 60 Metric/Inch Fittings ASME BPVC Section IV- Rules for Construction of Heating Boilers Miscellaneous 2015 2017 ASME BPVC Section IX- Welding, Brazing, and Fusing Qualifications Certification 2015 2017 ASSE 1010-2004 Water Hammer Arresters Water Supply Component ASTM A377-2003 (R2014) Ductile- Iron Pressure Pipe Piping, Ferrous 2018 ASTM A733-2016 Welded and Seamless Carbon Steel and Austenitic Stainless Steel Pipe Nipples Piping, Ferrous ASTM D56-2016a Flash Point by the Tag Closed Cup Tester Testing ASTM D93-2016a 2018 Flash Point by Pensky-Martens Closed Cup Tester Testing ASTM D635-2014 2018 Rate of Burning and/or Extent and Time of Burning of Plastics in a Horizontal Testing Position ASTM D2235-2004 Solvent Cement for Acrylonitrile-Butadiene-Styrene (ABS) Plastic Pipe and Joints (R2016) Fittings ASTM D2672-2014 Joints for IPS PVC Pipe Using Solvent Cement Joints ASTM D2855-2015 Two-Step (Primer and Solvent Cement) Method of Joining Poly (Vinyl Chlo- Joints ride) (PVC) or Chlorinated Poly (Vinyl Chloride) (CPVC) Pipe and Piping Components with Tapered Sockets ASTM D3278-1996 Flash Point of Liquids by Small Scale Closed-Cup Apparatus Testing (R2011) ASTM E136-2016a Behavior of Materials in a Vertical Tube Furnace at 750°C Furnace ASTM F480-2014 Thermoplastic Well Casing Pipe and Couplings Made in Standard Dimension Piping, Plastic Ratios (SDR), SCH 40 and SCH 80 ASTM F891-2016 Coextruded Poly(Vinyl Chloride) (PVC) Plastic Pipe with a Cellular Core Piping, Plastic AWS B2.2/B2.2M-2016 Brazing Procedure and Performance Qualification Certification AWWA C507-2015 2018 Ball Valves, 6 iIn. through 60 iIn. (150 mm tThrough 1,500 mm) Valves BS EN 12975-1-2006 Thermal Solar Systems and Components – Solar Collectors – Part 1: General Collector (R2010) Requirements BS EN 12976-1-2017 Thermal Solar Systems and Components – Factory Made Systems – Part 1: Solar Thermal Systems General Requirements BS EN 12976-2-2017 Thermal Solar Systems and Components – Factory Made Systems – Part 2: Solar Thermal Systems Test Methods BS EN 12975-2-2006 ISO Thermal Solar Systems and Components – Solar Collectors – Part 2: Test Collector 9806-2017 Methods Solar Energy – Solar Thermal Collectors – Test Methods

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TABLE 901.2 STANDARDS, PUBLICATIONS, PRACTICES, AND GUIDES

DOCUMENT NUMBER DOCUMENT TITLE APPLICATION

BS EN ISO 9488-2000 Solar Energy – Vocabulary Miscellaneous CSA Z21.22-2015 Relief Valves for Hot Water Supply Systems (same as CSA 4.4) Valves CSA Z21.24-2015 Connectors for Gas Appliances (same as CSA 6.10) Fuel Gas IAPMO PS-117-2016 Press and Nail Connections Fittings ICC 900/SRCC 300-2015 Solar Thermal System Standard Solar System IEEE 937-2007 Installation and Maintenance of Lead-Acid Batteries for Photovoltaic (PV) Installation and Mainte- Systems nance, Photovoltaic IEEE 1013-2007 Sizing Lead-Acid Batteries for Stand-Alone Photovoltaic (PV) Systems Photovoltaic, Sizing IEEE 1361-2014 Selecting, Charging, Testing, and Evaluating Lead-Acid Batteries Used in Testing, Evaluation Stand-Alone Photovoltaic (PV) Systems IEEE 1526-2003 Testing the Performance of Stand-Alone Photovoltaic Systems Testing, Photovoltaic IEEE 1547-2003 2018 Interconnecting Interconnection and Interoperability of Distributed Energy Connections, Photovoltaic Resources with Associated Electric Power Systems Interfaces IEEE 1562-2007 Array and Battery Sizing in Stand-Alone Photovoltaic (PV) Systems Array, Battery, Photo- voltaic IEEE 1661-2007 Test and Evaluation of Lead-Acid Batteries Used in Photovoltaic (PV) Hybrid Testing and Evaluation, Power Systems Photovoltaic MSS SP-58-2009 2018 Pipe Hangers and Supports – Materials, Design, Manufacture, Selection, Fuel Gas Application, and Installation MSS SP-80-2013 Bronze Gate, Globe, Angle, and Check Valves Valves NFPA 54/Z223.1-2015 2018 National Fuel Gas Code Fuel Gas NFPA 274-2013 2018 Test Method to Evaluate Fire Performance Characteristics of Pipe Insulation Pipe Insulation NSF 14-2016a 2018 Plastic Piping System Components and Related Materials Piping, Plastic UL 174-2004 Household Electric Storage Tank Water Heaters (with revisions through Appliances December 15, 2016) UL 873-2007 Temperature-Indicating and -Regulating Equipment (with revisions through Electrical February 6, 2015) UL 916-2015 Energy Management Equipment Electrical UL 1453-2016 Electric Booster and Commercial Storage Tank Water Heaters (with revisions Appliances through March 9, 2017 May 18, 2018) UL 4703-2014 Photovoltaic Wire Electrical UL 6703-2014 Connectors for Use in Photovoltaic Systems (with revisions through March 2, Electrical 2017) UL 8703-2011 Outline of Investigation for Concentrator Photovoltaic Modules and Assem- Electrical blies UL 60730-1 2016 Automatic Electrical Controls – Part 1: General Requirements Electrical

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ABBREVIATIONS IN TABLE 901.1 AND TABLE 901.2

AHRI Air-Conditioning, Heating, and Refrigeration Institute, 2111 Wilson Boulevard, Suite 500,Arlington, VA22201. ANSI American National Standards Institute, Inc., 25 W. 43rd Street, 4th Floor, New York, NY 10036. ASHRAE American Society of Heating, Refrigerating and Air Conditioning Engineers, Inc., 1791 Tullie Circle, NE, Atlanta, GA 30329-2305. ASME American Society of Mechanical Engineers, Two Park Avenue, New York, NY 10016-5990. ASSE American Society of Sanitary Engineering, 18927 Hickory Creek Drive, Suite 220, Mokena, IL 60448. ASTM ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. AWS American Welding Society, 8669 NW 36 Street, # 130, Miami, FL 33166-6672. AWWA American Water Works Association, 6666 W. Quincy Avenue, Denver, CO 80235. BSI (BS EN) British Standard International, 389 Chiswick High Road, London, W4 4AL United Kingdom. CSA Canadian Standards Association, 178 Rexdale Blvd., Toronto, ON, Canada M9W 1R3. e1 An editorial change since the last revision or reapproval. IAPMO International Association of Plumbing and Mechanical Officials, 4755 E. Philadelphia Street, Ontario, CA 91761. ICC International Code Council, 500 New Jersey Avenue, NW, 6th Floor, Washington, DC 20001. IEEE The Institute of Electrical and Electronics Engineers, Inc., 445 Hoes Lane, Piscataway, NJ 08854. MSS Manufacturers Standardization Society of the Valve and Fittings Industry, 127 Park Street NE, Vienna, VA 22180. NFPA National Fire Protection Association, 1 Batterymarch Park, Quincy, MA 02169-7471. NGWA National Ground Water Association, 601 Dempsey Road, Westerville, OH 43081. NSF NSF International, 789 N. Dixboro Road, Ann Arbor, MI 48105. SRCC Solar Rating and Certification Corporation, 400 High Point Drive, Suite 400, Cocoa, FL 32926. UL Underwriters Laboratories, Inc., 333 Pfingsten Road, Northbrook, IL 60062.

88 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT APPENDICES

The appendices are intended to supplement the provisions of the installation requirements of this code. The definitions in Chapter 2 are also applicable to the appendices.

TABLE OF CONTENTS

Page Appendix A Engineered Solar Energy Systems ...... 91

Appendix B Solar Photovoltaic System Installation Guidelines ...... 93

Appendix C Supplemental Checklist for Solar Photovoltaic Systems ...... 99

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A 101.0 General. (2) The pressure of the heat-transfer medium is maintained A 101.1 Applicability. The provisions of this appendix shall at less than the average minimum operating pressure of apply to the design, installation, and inspection of an engineered the potable water system. solar energy system, alternate materials, and equipment not Exception: Steam complying with Section A 103.2(1). specifically covered in other parts of the code. (3) The equipment is permanently labeled to indicate that A 101.2 Authority Having Jurisdiction. The Authority only additives recognized as safe by the FDA shall be Having Jurisdiction has the right to require descriptive details of used in the heat-transfer medium. an engineered solar energy system, alternate material, or equip- A 103.3 Other Designs. Other heat exchanger designs shall ment including pertinent technical data to be filed. be permitted where approved by the Authority Having Juris- A 101.3 Conformance. Components, materials, and equip- diction. ment shall comply with standards and specifications listed in Table 901.1 of this code and other national consensus standards applicable to solar energy systems and materials. A 101.4 Alternate Materials and Equipment. Where such standards and specifications are not available, alternate materials and equipment shall be approved in accordance with Sec- tion 302.2 of this code.

A 102.0 Engineered Solar Energy Systems. A 102.1 Definition. For purposes of this appendix, the following definition shall apply: Engineered Solar Energy System. A system designed for a specific building project with drawings and specifications indicating materials to be installed, all as prepared by a person registered or licensed to perform solar energy system design work. A 102.2 Inspection and Installation. In other than one- and two-family dwellings, the designer of the system shall provide periodic inspection of the installation on a schedule found suitable to the Authority Having Jurisdiction. Prior to the final approval, the designer shall verify to the Authority Having Juris- diction that the installation is in compliance with the approved plans, specifications, and data and such amendments thereto. The designer shall also certify to the Authority Having Juris- diction that the installation is in compliance with the applicable engineered design criteria. A 102.3 Owner Information. The designer of the system shall provide the building owner with information concerning the system, considerations applicable for subsequent modifications to the system, and maintenance requirements.

A 103.0 Water Heat Exchangers. A 103.1 Protection of Potable Water System. Heat exchangers used for heat transfer, heat recovery, or other solar thermal purposes shall protect the potable water system from being contaminated by the heat-transfer medium. A 103.2Where Permitted. Single-wall heat exchangers shall be permitted where they satisfy the following requirements: (1) The heat-transfer medium is either potable water or contains nontoxic fluids recognized as safe by the Food and Drug Administration (FDA) as food grade.

UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT 91 92 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT APPENDIX B SOLAR PHOTOVOLTAIC SYSTEM INSTALLATION GUIDELINES

B 101.0 General. (1) Marking content: B 101.1 Applicability. Provisions contained in these guide- CAUTION: lines shall not apply unless specifically adopted by local ordi- SOLAR CIRCUIT nance in accordance with Section 102.8. (2) Red background These guidelines shall not apply to non-habitable struc- (3) White lettering tures (e.g., parking shade structures, solar trellises, etc.). 3 (4) Minimum ⁄8 of an inch (9.5 mm) letter height B 101.2 Alternate Materials and Methods. Alternate materials and methods shall be approved in accordance with (5) Capital letters Section 302.2. (6) Arial or similar font, non-bold (7) Reflective, weather-resistant material (durable adhe- B 102.0 Marking. sive materials shall meet this requirement) B 102.4 Inverters. B 102.1 General. Photovoltaic (PV) systems shall be Markings shall not be required for the marked. Materials used for marking shall be weather resistant inverter. in accordance with Part VI of Chapter 8. B 103.0 Access, Pathways, and Smoke Ventilation. B 102.2 Main Service Disconnect. For residential applications, the marking shall be permitted to be placed within B 103.1 General. Access and spacing of PV modules shall the main service disconnect. Where the main service discon- comply with Section B 103.2 through Section B 103.3.3. nect is operable with the service panel closed, the marking B 103.2 Residential Systems—Single and Two-Unit shall be placed on the outside cover. Residential Dwellings. Plan review shall be required For commercial applications, the marking shall be placed where a system is installed on more than 50 percent of the adjacent to the main service disconnect in a location visible roof area of a residential building. See Figure B 103.2(1) from where the lever is operated. through Figure B 103.2(4). B 102.2.1 Marking Content and Format. Marking B 103.2.1 Access or Pathways. Access or pathways content and format for main service disconnects shall on the roof shall be provided in accordance with the fol- comply with the following: lowing: (1) Marking content: (1) Modules, on a hip roof, shall be located in a manner CAUTION: that provides one 3 foot (914 mm) wide clear access pathway from the eave to the ridge on each roof SOLAR ELECTRIC SYSTEM slope where modules are located. The access path- CONNECTED way shall be located over structural members. (2) Red background (2) Modules, on a roof with a single ridge, shall be (3) White lettering located in a manner that provides two 3 foot (914 3 (4) Minimum ⁄8 of an inch (9.5 mm) letter height mm) wide access pathways from the eave to the ridge on each roof slope where modules are located. (5) Capital letters (3) Modules, adjacent to hips and valleys, shall be (6) Arial or similar font, non-bold located not less than 18 inches (457 mm) from a hip (7) Reflective, weather-resistant material (durable adhe- or a valley where modules are to be placed on both sive materials shall meet this requirement) sides of a hip or valley. Where modules are to be B 102.3 Marking for Direct Current Conduit, Race- located on one side of a hip or valley that is of equal ways, Enclosures, Cable Assemblies, and Junction length, modules shall be permitted to be placed Boxes. Markings shall be required on interior and exterior dc directly adjacent to the hip or valley. conduit, raceways, enclosures, cable assemblies, and junction B 103.2.2 Smoke Ventilation. Smoke ventilation boxes. Markings shall be placed on interior and exterior dc shall be provided by locating modules not more than 3 conduit, raceways, enclosures, and cable assemblies every 10 feet (914 mm) from the lowest level of the ridge. feet (3048 mm), at turns; on both sides of a penetration; and B 103.3 Commercial Buildings and Residential at dc combiner and junction boxes. Housing Comprised of Three or More Units. Where B 102.3.1 Marking Content and Format. Marking the Authority Having Jurisdiction determines that the roof content and format for direct current conduit, raceways, configuration is similar to residential (such as in the case of enclosures, cable assemblies, and junction boxes shall townhouses, condominiums, or single family attached build- comply with the following: ings), the access and ventilation requirements of Section B

UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT 93 APPENDIX B

103.2 through Section B 103.2.2 shall be permitted. See Fig- ing and shall be ran along the bottom of structural members. ure B 103.3(1) through Figure B 103.3(4). B 105.0 Ground Mounted Photovoltaic Arrays. B 103.3.1 Access. There shall be not less than a 6 feet B 105.1 General. Setback requirements shall not apply to (1829 mm) wide clear perimeter around the edges of the ground-mounted and freestanding photovoltaic arrays. A roof. Where either axis of the building is 250 feet (76 clearance of not less than 10 feet (3048 mm) shall be required 200 mm) or less, there shall be not less than a 4 feet around ground-mounted photovoltaic arrays. (1219 mm) wide clear perimeter around the edges of the roof. B 103.3.2 Pathways. Pathways shall be established in the design of the solar installation. Pathways shall be provided in accordance with the following: (1) Pathways shall be located over structural members. (2) Centerline axis pathways shall be provided in both axis of the roof. Centerline axis pathways shall run on structural members or over the next closest structural member nearest to the center lines of the roof. (3) Shall be a straight line not less than 4 feet (1219 mm) clear to skylights, ventilation hatches, or both. (4) Shall be a straight line not less than 4 feet (1219 mm) clear to roof standpipes. (5) There shall be not less than a 4 foot (1219 mm) clearance around roof access hatches, skylights, ventilation hatches, roof standpipes, and similar obstructions. (6) There shall be not less than one 4 foot (1219 mm) clear pathway to parapets or roof edges. B 103.3.3 Smoke Ventilation. Smoke ventilation shall be provided in accordance with the following: (1) Arrays shall not exceed 150 feet (45 720 mm) by 150 feet (45 720 mm) in distance in either axis. (2) Ventilation between array sections shall be provided with one of the following: (a) A pathway 8 feet (2438 mm) or greater in width. (b) A pathway 4 feet (1219 mm) or greater in width that borders existing roof skylights or ventilation hatches. (c) A pathway 4 feet (1219 mm) or greater in width that borders 4 feet (1219 mm) by 8 feet (2438 mm) venting cutouts every 20 feet (6096 mm) on alternating sides of the pathway.

B 104.0 Location of Direct Current (dc) Conductors. B 104.1 General. Conduit, wiring systems, and raceways for photovoltaic circuits shall comply with NFPA 70 and be located as close as possible to a ridge, hip, or valley; and from the hip or valley as directly as possible to an outside wall. Conduit runs between subarrays and dc combiner boxes shall be the shortest path from the array to the dc combiner box. The dc combiner boxes shall be located such that conduit runs are minimized in the pathways between arrays. Direct Current (dc) wiring shall be ran in metallic conduit or raceways where located within enclosed spaces in a build-

94 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT APPENDIX B

3 feet

For SI units: 1 foot = 304.8 mm FIGURE B 103.2(1) SOLAR SYSTEM ON CROSS GABLE ROOF–SINGLE AND TWO–UNIT RESIDENTIAL BUILDING

3 feet

3 feet 3 feet

3 feet

For SI units: 1 foot = 304.8 mm FIGURE B 103.2(2) SOLAR SYSTEM ON CROSS GABLE ROOF WITH VALLEY–SINGLE AND TWO-UNIT RESIDENTIAL BUILDING

UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT 95 APPENDIX B

3 feet 3 feet 3 feet

3 feet

For SI units: 1 foot = 304.8 mm FIGURE B 103.2(3) SOLAR SYSTEM ON FULL GABLE ROOF SINGLE AND TWO-UNIT RESIDENTIAL BUILDING

3 feet

For SI units: 1 foot = 304.8 mm FIGURE B 103.2(4) SOLAR SYSTEM ON FULL HIP ROOF–SINGLE AND TWO-UNIT RESIDENTIAL BUILDING

96 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT APPENDIX B

478 feet 150 feet Skylight (typical)

6 feet 8 feet 4 feet 6 feet 6 feet

Roof hatch 150 feet

8 feet

324 feet Structural member

Structural member Structural member

For SI units: 1 foot = 304.8 mm FIGURE B 103.3(1) SOLAR ARRAY INSTALLATION ON LARGE COMMERCIAL BUILDINGS WITH 8 FOOT WALKWAYS

478 feet

150 feet Skylight (typical)

6 feet 6 feet 6 feet

Roof hatch 150 feet

300 feet Structural member

Structural member Structural member

For SI units: 1 foot = 304.8 mm FIGURE B 103.3(2) SOLAR ARRAY INSTALLATION ON LARGE COMMERCIAL BUILDINGS WITH 4 FOOT WIDE WALKWAYS WITH 8 FOOT BY 4 FOOT VENTING CUTOUTS EVERY 20 FOOT LENGTH

UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT 97 APPENDIX B

200 feet 4 feet Structural member 19 feet 2 inches 4 feet

4 feet

100 feet

4 feet 5 feet 3 inches

Structural member 8 feet 3 inches

For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm FIGURE B 103.3(3) SOLAR ARRAY INSTALLATION ON SMALL COMMERCIAL BUILDINGS WITH 4 FOOT WIDE WALKWAYS WITH 8 FOOT BY 4 FOOT VENTING CUTOUTS EVERY 20 FOOT LENGTH

200 feet 4 feet Structural member 8 feet

4 feet

100 feet

8 feet

Structural member

For SI units: 1 foot = 304.8 mm FIGURE B 103.3(4) SOLAR ARRAY INSTALLATION ON SMALL COMMERCIAL BUILDINGS WITH 8 FOOT WIDE WALKWAYS

98 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT APPENDIX C SUPPLEMENTAL CHECKLIST FOR SOLAR PHOTOVOLTAIC SYSTEMS

C 101.0 Plan Details. able series backfeed fuse protection rating, and installa- C 101.1 General. The following shall be provided with the tion instructions. plan details of a photovoltaic (PV) system: (11) The manufacturer’s instructions shall be provided for (1) Scope of the project, including the system kW•h (J) rat- inverters, converters, charge controllers, and ac modules, ing. indicating the following ratings: (2) Complete single line diagram and utility interconnect. (a) Maximum input ac and dc voltage, and the range of operating voltage(s). (3) Site plan, including location of system components. (b) Nominal ac output voltage. (4) Type of system (i.e. alternating-current modules, bipolar, grounded, ungrounded, hybrid, isolated, interactive, (c) Nominal dc voltage and operating range for utility stand-alone, etc). interactive or stand-alone systems with charge controller. (5) Utility service operating voltage or class. (d) Maximum input ac and dc current, and maximum (6) Information on the size, type, and insulation ratings (volt- input short circuit current. age, temperature, etc) of conductors and associated wiring components of the direct current (dc) and alter- (e) Maximum inverter output short circuit current and nating current (ac) side of the PV system. duration. (7) Type, size, and material of raceway(s). (f) Maximum utility source backfeed current, short or open circuit, for utility interactive system with or (8) Roof plan, including roof access and roof mounted without charge controller. equipment. (g) Maximum continuous ac output current and power. (9) The following information shall be provided for the dc side of the PV system: (h) Normal operation temperature range. (a) Number of series connected modules for each PV (12) Information indicating where the inverter(s) or charge source circuit. controller(s) contains current limiting devices that limits the output circuit current to the maximum inverter input (b) Number of parallel connected module or panel PV dc current rating. source circuits for each array or PV power source. (13) The manufacturer’s wiring details shall be provided for (c) Number of combiner boxes, control boxes, or PV power centers for each array, subarray, or PV power combiner boxes, control boxes, or PV power centers. It source. shall contain the manufacturer’s name, model designation, and listing. (d) Number of PV output circuits. (14) The manufacturer’s instructions shall be provided for (e) PV source circuit module or panel connection each connector indicating configuration, construction, arrangements. type, grounding member, and circuit current interruption (f) Operating and open-circuit voltage for each module capability and method. or panel. (15) Where the PV system uses a diversion charge controller (g) Operating voltage for each array or PV power as the sole means of regulating the charging of a battery. source. (16) Methods of access to the junction, pull, or outlet boxes (h) Operating current for each PV source circuit. behind the modules or panels. (i) Operating current for each array. C 101.2 Circuits. Circuit requirements shall be indicated in (j) Maximum array, panel, or module system voltage. the detail plans in accordance with the following: (k) Short circuit current of modules or panels. (1) Circuit conductors and overcurrent protective devices (l) Short circuit current of array and subarrays. shall be sized to carry not less than 125 percent of the maximum current in accordance with Section 805.1.1. (m) Short circuit current of battery system. (2) Overcurrent protection of output circuits with internal (n) Disconnecting means electrical ratings. current limiting devices shall be not less than 125 percent (o) Disconnecting means wiring diagram. of the maximum limited current of the output circuit. The (p) Disconnecting means rated short-circuit current per conductors in such an output circuit shall be sized in pole. accordance with Section 805.1.1. (10) The manufacturer’s instructions shall be provided for the (3) Common-return conductor of systems with multiple volt- PV modules or panels. The manufacturer’s instructions ages shall not be smaller than the sum of the ampere rat- shall include the manufacturer’s name, catalog numbers, ings of the overcurrent devices of the individual output complete electrical information, required marked accept- circuits.

UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT 99 APPENDIX C

(4) Where a single overcurrent device is used to protect a set (2) The voltage rating of a battery circuit cable shall not be of two or more parallel-connected module circuits, the smaller than the charging or equalizing condition of the ampacity of each of the module interconnection conduc- battery system. tors shall be not less than the sum of the fuse rating and C 101.9 Calculations. Calculations shall be provided for 125 percent of the short-circuit from the other parallel- solar PV systems in accordance with the following: connected modules. C 101.3 Overcurrent Protection. (1) The maximum system voltage calculation shall be based Circuits connected to on the expected ambient temperature. more than one electrical source shall have overcurrent pro- (2) The maximum system open-voltage calculation shall be tective devices that provide overcurrent protection from based on manufacturer’s instructions for PV power sources indicated on the plan details. C 101.4 Disconnecting Means. source modules made of materials other than crystalline Disconnecting means or multi-crystalline silicon. shall be provided in the plan details for the following: (3) The maximum dc circuit current calculation for each PV (1) PV source circuits (isolating switches) source circuit. (2) Overcurrent devices (4) The maximum dc current calculation for each PV output (3) Blocking diodes circuit. (4) Inverters (5) The fault current calculation from the utility side to the (5) Batteries ac disconnect(s) and inverter(s). (6) Charge controllers (6) Calculations to determine the minimum overcurrent protection device rating for the dc side. Photovoltaic system The PV disconnecting means shall be grouped together currents shall be considered as continuous. and the number of disconnects shall not exceed six. C 101.5 Wiring Method. (7) Where conductors are exposed to direct sunlight, the Wires used in a PV system shall ampacities shall be derated by the correction factors in be in accordance with Section 812.0. Ungrounded source and accordance with NFPA 70. output circuits shall be installed with disconnects, overcurrent protection, ground-fault protection, and inverter or (8) Calculations showing the size of equipment-grounding charge controllers and shall be listed for such purpose. conductor for the PV source and PV output circuit size Ungrounded sources and circuit conductors shall consist of shall be not less than 125 percent of the short circuit cur- sheathed multi-conductor cable or shall be located in an rent from the PV source. approved raceway. (9) Calculations showing the required maximum charging current of the interconnected battery cells. C 101.6 Grounding. Grounding shall be indicated in the plan details as follows: (10) Calculations for the ampacity of the neutral conductor of a two-wire inverter output connected to the ungrounded (1) Where components of the system are negatively or pos- conductors of a three-wire or a three-phase, four-wire itively grounded. system. (2) The dc circuit grounding shall be made at a single point (11) Calculations showing that the total dc leakage current in on the PV output circuit. the dc ground or dc grounded circuits in non-isolated PV (3) The equipment-grounding conductor for a PV source and systems do not exceed the equipment ground-fault pro- PV output circuits for a roof-mounted dc PV array in tective device leakage current trip setting. dwellings shall be sized in accordance with Section 819.0. (12) Calculations showing the required current and voltage (4) Grounding electrode system used for the ac, dc, or com- ratings of dc diversion charge controllers and diversion bined ac/dc systems. loads in a circuit. (5) The method used to ensure the removal of equipment (13) Calculations showing the required conductor ampacity from the system that shall not disconnect the bonding and overcurrent protective device rating for circuits con- connection between the grounding electrode conductors taining dc diversion charge controllers and diversion and exposed conducting surfaces. loads. (6) The method used to ensure the removal of a utility-inter- (14) Calculations showing where expansion fittings are not active inverter or other equipment that shall not discon- required for the roof mounted raceways due to thermal nect the bonding connection between the grounding expansion or building expansion joints where the race- electrode conductor and the PV source and the output cir- way is used as an equipment grounding conductor. cuit grounded conductor, or both. C 101.7 Ground Fault Protection. Direct current ground- fault protection for dwellings with roof mounted dc-PV arrays shall be provided on the plan details. C 101.8 Systems Over 1000 Volts. Plan details for PV systems over 1000 volts shall indicate the following: (1) The PV system is in accordance with Section 804.0, and other applicable installation requirements.

100 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT USEFUL TABLES

UNIT CONVERSIONS

Note: The information contained in these tables are not part of this American National Standard (ANS) and have not been processed in accordance with ANSI’s requirements for an ANS. As such, these tables may contain material that has not been subjected to public review or a consensus process. In addition, they do not contain requirements necessary for conformance to the standard.

ACCELERATION PRESSURE 1 ft/s2 = 0.3048 m/s2 1 lbf/in2 = 6.894757 kPa 1 ft of water (39.2°F) = 2.98898 kPa (at 4°C) AREA 1 in of water (39.2°F) = 0.249082 kPa (at 4°C) 1 square foot = 0.09290304 m2 1 in mercury (32°F) = 3.38638 kPa (at 0°C) 1 square inch = 6.4516 E-04 m2 SOLAR RADIATION DENSITY 1 langley = 4.184 E+04 J/m2 1 lb/ft3 = 16.01846 kg/m3

ENERGY SPECIFIC VOLUME 1 ft•lbf = 1.355818 J 1 ft3/lb = 0.06242796 m3/kg 1 Btu = 1055.056 J TEMPERATURE FORCE °C = (°F - 32)/1.8 1 lbf = 4.448222 N VELOCITY HEAT TRANSFER 1 ft/s = 0.3048 m/s 1 [Btu•in(h•ft2•°F)] = 0.1442279 [W/(m•K)] 1 ft/m = 0.00508 m/s 1 [Btu/(ft2•h)] = 3.154591 W/m2 VOLUME LENGTH 1 cubic foot = 0.02831685 m3 1 foot = 0.3048 m 1 cubic inch = 1.638706 E-05 m3 1 inch = 0.0254 m 1 gallon = 3.785412 L

MASS VOLUME FLOW RATE 1 lb = 0.4535924 kg 1 ft3/min = 4.719474 E-04 m3/s 1 ounce = 28.34952 g 1 ft3/s = 0.02831685 m3/s 1 gallon/min = 3.785412 E-03 m3/min MASS FLOW RATE 1 gallon/min = 0.06309020 L/s 1 lb/s = 0.4535924 kg/s 1 lb/m = 7.559873 E-03 kg/s 1 lb/h = 1.259979 E-04 kg/s

PLANE ANGLE 1 degree = 0.01745329 radians

POWER 1 Btu/h = 2.930711 E-04 kW

UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT 101 USEFUL TABLES

SYMBOLS

The following is a list of symbols commonly utilized in solar energy applications and are provided herein for the convenience of the users of this code. This list is based on ASHRAE 93. a, b, a’, b’ = constants used in incident angle modifier equa- K1 = incident angle modifier for biaxial collector, tion, dimensionless dimensionless 2 2 A = cross-sectional area, ft (m ) K2 = incident angle modifier for biaxial collector, dimensionless Aa = transparent frontal area for a nonconcentrating collector or the aperture area of a concentrating Lloc = longitude, degrees west collector, ft2 (m2) Lst = standard meridian for local time zone, degrees Ag = gross collector area, ft2 (m2) west Ar = absorbing area of a nonconcentrating collector LST = local standard time, decimal hours or the receiving area of a concentrating collector, LSTM = local standard time meridian, degrees west ft2 (m2) AST = apparent solar time, decimal hours bo = constant used in incident angle modifier equation, dimensionless m = air mass, dimensionless · B = effective angle for determining the equation of m = mass flow rate of the heat-transfer fluid, lbm/h time, degrees (kg/s) CA = effective heat capacity of the solar collector, · me = downstream air mass flow rate, lbm/h (kg/s) Btu/(lbm•°F) [J/(kg•K)] · m = upstream air mass flow rate, lbm/h (kg/s) cp = specific heat of the heat transfer fluid, i Btu/(lbm•°F) [J/(kg.•K)] · mL = leakage air mass flow rate, lbm/h (kg/s) E = equation of time, minutes n = day of year, beginning with January 1 = 1 Eλi = solar spectral irradiance averaged over ∆λ cen- ηr = collector efficiency based upon absorber area 2. tered at λi at air mass 1.5 W/(m μm) and inlet temperature,% [Btu/(ft2•h•μm)] P = optical property, dimensionless F’ = absorber plate efficiency factor, dimensionless Pf,e = static pressure of heat-transfer fluid at the outlet FR = solar collector heat removal factor, dimension- to the solar collector, lbf/in2 (Pa) less 2 2 P = static pressure of heat-transfer fluid at the inlet to G = solar irradiance, Btu/(ft •h) (W/m ) f,i the solar collector, lbf/in2 (Pa) Gbp = direct solar irradiance component in the aperture 2 plane, Btu/(ft2•h) (W/m2) ∆P = pressure drop across the collector, lbf/in (Pa) G = direct normal solar irradiance, Btu/(ft2•h) (W/m2) Qmi = measured volumetric airflow rate at the collector DN inlet, ft3/min (m3/s) Gd = diffuse solar irradiance incident upon the aper- 2 2 Q = airflow rate corrected to standard conditions, ture plane of collector, Btu/(ft •h) (W/m ) s 3 3 2 2 ft /min (m /s) Gsc = solar constant, 429.2 Btu/(ft •h) (1353 W/m ) qu = rate of useful energy extraction from the collec- Gt = global solar irradiance incident upon the aperture plane of collector, Btu/(ft2•h) (W/m2) tor, Btu/h (W) t = ambient air temperature, °F (°C) ha = enthalpy of the ambient air-water vapor mixture, a Btu/lbm (J/kg) tf = (tf,i + tf,e)/2, average fluid temperature, °F (°C) hf,e = enthalpy of the air-water vapor mixture at the tf,e = temperature of the heat-transfer fluid leaving exit of the air collector, Btu/lbm (J/kg) the collector, °F (°C) hf,i = enthalpy of the air-water vapor mixture at the tf,eT = temperature of the heat-transfer fluid leaving inlet of the air collector, Btu/lbm (J/kg) the collector at a specified time, °F (°C) hL = enthalpy of the leaking air-water vapor mixture, tf,e,initial = temperature leaving the collector at the begin- Btu/lbm (J/kg) ning of time constant test period, °F (°C) K = factor defined by ASHRAE 93, dimensionless tf,i = temperature of the heat-transfer fluid entering Kατ = incident angle modifier, dimensionless the collector, °F (°C) Kd = diffuse irradiance incident angle modifier, tp = average temperature of the absorbing surface dimensionless for a nonconcentrating collector, °F (°C)

102 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT USEFUL TABLES

tr = average temperature of the absorbing surface for a concentrating collector, °F (°C) t- = effective temperature defined by ASHRAE 93, °F (°C) - tHHL = effective temperature for a given header heat loss test flow rate, °F (°C) T = time, decimal hours or seconds T1, T2 = time at the beginning and end of a test period, decimal hours or seconds ∆t = temperature difference, °F (°C) ∆tss = temperature difference, of inlet and outlet transfer fluid at steady state, °F (°C) UL = solar collector heat-transfer loss coefficient, Btu/(h•ft2•F) [W/(m2•K)] Wn = humidity ratio at the nozzle, lbm H2O/lbm dry air (kg H2O/kg dry air) α = absorptance of the collector absorber surface for solar radiation, dimensionless γ = fraction of specularly reflected radiation from the reflector or refracted radiation that is inter- cepted by the solar collector receiving area, dimensionless θ = angle of incidence between director solar rays and the normal, to the collector surface or to the aperture, degrees β = solar altitude angle, degrees ϕ = solar azimuth angle, degrees ηg = collector efficiency based upon gross collector area and inlet temperature, percent λ = wavelength, μm λi = specific wavelength, μm ∆λi = wavelength interval, μm ρ = reflectance of a reflecting surface for solar radiation, dimensionless ρλ = spectral reflectance of a reflecting surface for solar energy, dimensionless τ = transmittance of the solar collector cover plate, dimensionless (τα)e = effective transmittance-absorptance product, dimensionless (τα)e,n = effective transmittance-absorptance product at normal incidence, dimensionless Σ = collector tilt from the horizontal, degrees

UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT 103 104 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT INDEX Note: Contents and Section numbers will be updated before publishing. © 2018 International Association of Plumbing and Mechanical Officials. All rights reserved. The copyright in this index is separate and distinct from the copyright in the document that it indexes. The licensing provisions set forth for the document are not applicable to this index. This index may not be reproduced in whole or in part by any means without the express written permission of IAPMO.

– A – ALTERNATING-CURRENT ABSORBER MODULES ...... [see Solar Definition ...... 203.0 photovoltaic (PV) system, ABSORPTION UNITS Alternating-current (ac) module] Labeling ...... 307.4 ANCHORING OF ACCEPTED ENGINEERING Collectors ...... 502.5, 502.5.1 PRACTICE ...... 203.0, 306.1 Equipment and appliances ...... 305.8 ACCESS TO APPEALS ...... 107.0 Appliances ...... 304.1 APPLIANCES Appliances on roof ...... 304.2, 304.4 Access to ...... 304.0 Appliances in attics Clearances ...... 305.1 and under floor spaces ...... 304.3 Definition ...... 203.0 Circuit breakers ...... 805.5.3 Electric cooling ...... 307.3 Connections ...... 501.2 Electric heating ...... 307.2 Connectors, photovoltaic systems ...... 814.0 In attics ...... 304.3 – 304.3.3 Fullway or shutoff valves ...... 312.14 In garages ...... 309.2 Live parts ...... 814.1.2 In under-floor spaces ...... 304.3 – 304.3.3 Overcurrent devices ...... 806.3 Labeling of ...... 307.0 Photovoltaic disconnecting means ...... 810.1.1 Listed ...... 302.1, 305.1 ACCESSIBILITY APPROVED Access or pathways, Definition ...... 203.0 photovoltaic systems ...... B 103.2.1, B 103.3, APPROVED TESTING AGENCY B 103.3.1, B 103.3.2 Definition ...... 203.0 ACCESSIBILITY FOR ARC-FAULT CIRCUIT PROTECTION ...... 808.1 Inspections ...... 105.1 ATTIC INSTALLATIONS Service ...... 304.0 Appliances ...... 304.3 – 304.3.3 ACCESSIBLE AUTHORITY HAVING JURISDICTION Definition ...... 203.0 Condemn equipment ...... 106.6 Readily, definition ...... 203.0 Connection approval ...... 105.4 ADMINISTRATION ...... Chapter 1 Cooperation of other AIR officials and officers ...... 103.1 Collector ...... 502.4, 502.4.1 Definition ...... 203.0 Gap ...... 203.0, 311.3 Deputies ...... 103.1 Heating Systems ...... 501.12.5 Disconnect utilities in Mass ...... 203.0 emergencies, to ...... 106.5 Test ...... 405.2, 417.3, 504.1 Inspections ...... 105.0 ALTERNATE ENGINEERING DESIGN Issues permits ...... 104.4 Design approval ...... 302.4.4 Liability ...... 103.2 Design document ...... 302.4.3 Limitations of authority ...... 107.2 Design review ...... 302.4.5 Powers and duties ...... 103.0 Inspection and testing ...... 302.4.6 Right of entry ...... 103.4 Permit application ...... 302.4.1 Stop orders ...... 106.4 Technical data ...... 302.4.2 Temporary connection ...... 105.4 ALTERNATE MATERIALS AND Testing ...... 105.3, 302.2.1 METHODS CONSTRUCTION AUTOMATIC EQUIVALENCY ...... 302.2 Air vent ...... 501.9

UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT 105 INDEX

AUXILIARY From air conditioning appliances . . .308.1, 308.2, 308.5 Electric heating, definition ...... 207.0 From air cooling coils ...... 308.1, 308.3 Energy system, definition ...... 203.0 Heat pumps, geothermal ...... 707.2(4) Heating, solar thermal ...... 501.8 Insulation required ...... 305.6 Snow and ice melt Point of discharge ...... 308.5 systems, hydronics ...... 416.0 Pumps ...... 308.1.1 Waste pipe sizing ...... 308.3, Table 308.3 – B – CONFLICTS BETWEEN CODES ...... 102.1 BACKFLOW CONNECTORS Definition ...... 204.0 Flexible connectors ...... 401.7, 601.3 BALANCING VALVES Storage tank connectors ...... 601.3 Definition ...... 204.0 CONTROL VALVES ...... 312.9 Where required ...... 312.8 COPPER OR COPPER BATTERIES ...... 830.0 ALLOY PIPE AND TUBING ...... 409.4 BIPOLAR CROSS-CONNECTION Photovoltaic array ...... 204.0 Definition ...... 205.0 Photovoltaic (PV) system ...... 804.2, 812.9, CROSS-LINKED POLYETHYLENE (PEX) 816.1 PIPING OR TUBING BOARD OF APPEALS ...... 107.0 Definition ...... 218.0 BONDING Ground-heat exchanger, Jumpers ...... 818.1.2, 822.0 geothermal ...... 703.5.2 Of electrically conductive Hydronics ...... 408.1, Table 408.1, materials and other equipment ...... 816.1.4 Table 416.1.1 Of equipment ...... 816.1.3, 818.0, 822.0 Joining and connections ...... (see Joints BRACES ...... 502.1 and connections) BRAZED JOINTS ...... (see Joints Oxygen diffusion ...... 405.4 and connections) CROSS-LINKED POLYETHYLENE-ALUMINUM- CROSS-LINKED POLYETHYLENE – C – (PEX-AL-PEX) PIPING OR TUBING CALCIUM HARDNESS Definition ...... 218.0 Definition ...... 205.0 Hydronics ...... 408.1, Table 408.1 CHANGE IN DIRECTION ...... 305.4, 409.1 Joining and connections ...... (see Joints CHLORINATED POLYVINYL and connections) CHLORIDE (CPVC) PIPE OR TUBING Hydronics ...... 408.1, Table 408.1 – D – Joining and connections ...... (see Joints and connections) DEFINITIONS ...... Chapter 2 CIRCULATORS DELETERIOUS WASTE ...... 316.1 (CIRCULATING PUMP) ...... 205.0, 310.0, DESIGN FLOOD ELEVATION 501.13, 707.3 Definition ...... 206.0 CLOSED LOOP SYSTEM ...... 205.0, DEVELOPED LENGTH 312.12, 504.2.2 Definition ...... 206.0 CONCRETE INSTALLATIONS DOUBLE-WALL HEAT EXCHANGERS ...... 313.1, 705.1 Auxiliary systems, tubing ...... 414.5 – 414.5.2, DRAINAGE PANS ...... 305.7, 308.2 416.1.2 – 416.1.4 DRAINBACK SYSTEMS ...... 501.7 Concrete-encased electrode ...... 821.2.5, 821.3.3 Circulators ...... 310.4, 501.7, 501.13 Embedded piping materials and joints . . . .417.2 – 417.3 Definition ...... 206.0 Piping or tubing ...... 318.2, 318.6, 318.6.1 Freeze protection ...... 401.8, 501.12.2 Radiant heating Piping slope ...... 501.4 or cooling tubing ...... 414.5 – 414.5.2 DRAINDOWN CONDENSATE Definition ...... 206.0 Cleanouts for condensate drain ...... 308.3.1 DUCTS Control ...... 308.2 Definition ...... 206.0 Definition ...... 205.0 Systems ...... 322.2

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– E – – H – ELECTRICAL ...... 315.0 HANGERS AND SUPPORTS Auxiliary heating ...... 207.0, 501.8 Appliances ...... 305.8 Controls ...... 315.2 Hydronics system piping ...... 408.3 Power ...... 304.4.5 In ground ...... 317.5 Solar photovoltaic (PV) systems ...... Chapter 8 Piping and tubing ...... 317.0, Table 317.3 Wiring ...... 315.1 HAZARDOUS ENERGY STORAGE SYSTEMS ...... 829.0 HEAT-TRANSFER MEDIUM ...... 309.3 EQUIPMENT HEAT EXCHANGER ...... 210.0, 313.0 Definition ...... 207.0 HEAT TRANSFER MEDIUM ...... 210.0, 309.3, Improper location ...... 305.5 404.7, 501.15 On roofs ...... 304.2, 304.4 HEATING DEGREE DAY Protection against flood damage ...... 302.3 Definition ...... 210.0 Service and access ...... 304.0 HYDRONIC SPACE HEATING ...... 412.0 EXISTING BUILDINGS ...... 302.1.3 HYDRONICS ...... Chapter 4 EXISTING SYSTEMS ...... 102.2 Appliances and equipment ...... 406.0 EXPANSION TANKS Boilers ...... 406.2, 406.2.1, 406.2.2 Closed-type ...... 407.3, 605.3 Circulators ...... 310.0 Installation ...... 407.2 Clearance ...... 417.5 Minimum capacity ...... 605.4, Table 605.4(1), Definition ...... 210.0 Table 605.4(2) Embedded piping materials and joints ...... 417.2 Open-type ...... 407.4, 605.2 Expansion tanks ...... 407.0 Where required ...... 407.1, 605.1 Hangers and supports ...... 408.3 Heat emitters ...... 401.5 – F – Heat sources ...... 403.1 FEES ...... 104.5 Heat transfer medium ...... 412.4 For investigations ...... 104.5.1, 104.5.2 Identification of piping ...... 404.0 For permits ...... 104.5, Table 104.5 Installation ...... 405.0, 417.0 For plan review ...... 104.3.2 Insulation ...... 401.2, 414.5.2, 416.1.4 For reinspection ...... 105.2.6 Joints and connections ...... 409.0 Refunds ...... 104.5.3 Materials ...... 408.0, Table 408.1 FILTERS Protection of potable Swimming pool, water supply ...... 402.0 spa or hot tubs ...... 505.3, 505.3.1 FITTINGS Radiant heating and cooling ...... 414.0 Geothermal piping ...... 703.5.1 – 703.7 Safety devices ...... 311.0 Hydronic piping ...... 408.1, Table 408.1 Snow and Ice melt systems ...... 416.1, 416.1.1, Solar thermal piping ...... 501.5, 501.12.7, 416.1.5, Table 416.1.1 503.3, 503.4 Steam systems ...... 413.0 FLASH POINT ...... 208.0, 501.15 Testing ...... 405.2, 416.1.5, 417.3 FLOOD RESISTANT CONSTRUCTION Water heaters ...... 403.2, 403.3, Coastal high hazard area ...... 205.0, 302.3.1 406.3, Table 403.2 Design flood elevation ...... 206.0 Flood hazard area ...... 208.0 – I – Flood hazard resistance ...... 302.3 INSPECTIONS FULLWAY VALVE ...... 312.13, 312.14 Reinspections ...... 105.2.6 FUSES ...... 805.5.1, Table 805.5.1 Requests ...... 105.2.3 INSTALLATIONS OF – G – Equipment and appliances ...... 305.0 GALVANIZED STEEL Equipment in garages ...... 309.2 Where prohibited ...... 501.5 INSULATION OF GLASS COLLECTORS ...... 502.3 Ducts ...... 503.6, Table 503.6 GROUNDING ...... 816.0 Hydronic systems ...... 401.2

UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT 107 INDEX

Solar thermal systems ...... 503.0, – M – Table 503.3(1) – Table 503.3(4) MARKINGS ...... 302.1.1 INTERACTIVE SYSTEM ...... 211.0, 810.1.4, 825.2 MATERIALS INVERTER INPUT CIRCUIT ...... 211.0 Alternate ...... 302.2 INVERTER OUTPUT CIRCUIT ...... 211.0, 803.2, 806.1 For piping, tubing INVERTERS ...... 211.0, 802.2, 806.1, B 102.4 and fittings (geothermal) ...... 703.5 INVERTERS, UTILITY For piping, tubing INTERACTIVE ...... 831.1.4 and fittings (hydronics) ...... 408.0, Table 408.1 IRRADIATION, INSTANTANEOUS For piping, tubing Definition ...... 211.0 and fittings (solar thermal) ...... 501.5 – 501.5.6 IRRADIATION, INTEGRATED AVERAGE MECHANICAL JOINTS ...... (see Joints Definition ...... 211.0 and connections) MINIMUM REQUIREMENTS – J – Purpose of code ...... 101.3 JOINTS AND CONNECTIONS ...... 409.0 MINIMUM STANDARDS ...... 302.1 Brazed joint ...... 212.0, 409.4 MONOPOLE SUBARRAY ...... 215.0, 812.9 Copper or copper alloy pipe or tubing ...... 409.4, 409.13.1, 703.6 – N – CPVC piping ...... 409.2 NONCOMBUSTIBLE MATERIAL CPVC/AL/CPVC Plastic Pipe and Joints ...... 409.3 Definition ...... 216.0 Different materials ...... 409.13 NONPOTABLE WATER ...... 316.4, 404.4 Embedded piping materials and joints ...... 417.2 Flared ...... 212.0, 409.4 – O – Mechanical joint ...... 212.0, 409.5, OPEN LOOP SYSTEM ...... 217.0, 504.2.1 409.6, 409.7, 409.8, OVERCURRENT 409.11, 409.12 PROTECTION ...... 805.2.3, 806.0, 807.2.5.1, PE pipe or tubing ...... 409.7, 703.5.1.1 C 101.2, C 101.3, C 101.5, PE-AL-PE pipe or tubing ...... 409.8 C 101.9(6) PE-RT piping or tubing ...... 409.9 PEX pipe or tubing ...... 409.5, 703.5.2.1 – P – PEX-AL-PEX pipe or tubing ...... 409.6 PASSIVE SOLAR SYSTEMS Plastic piping, joints, and fittings ...... 409.13.2 Definition ...... 218.0 PP piping or tubing ...... 409.10 PENALTIES ...... 106.2, 106.3 PVC piping ...... 409.11 PERMITS Soldered joint ...... 212.0 Application ...... 103.3, 104.3, 302.4.1 Solvent cement plastic pipe ...... 409.2, 409.11 Construction documents ...... 104.3.1 Steel pipe or tubing ...... 409.12 Exempt ...... 104.2 Threaded joint ...... 409.2, 409.12 Expiration ...... 104.4.3 Welded joint ...... 212.0, 409.12 Fees ...... 104.5, Table 104.5 For alteration ...... 104.1 – L – Inspection ...... 105.0 LABELED Investigation fees ...... 104.5.2 Definition ...... 214.0 Issuance ...... 104.4 LABELS AND INSTRUCTIONS Retention of plans ...... 104.4.6 For appliances ...... 307.0 Suspension or revocation of ...... 104.4.5 For heating appliances ...... 307.0 Validity ...... 104.4.2 For hydronic piping systems ...... 404.0 Work without ...... 104.5.1 LISTED PERMITS AND INSPECTIONS ...... 104.0, 105.0, Definition ...... 214.0 302.4.1, 302.4.6 LISTING AGENCY PHOTOLYSIS Definition ...... 214.0 Definition ...... 218.0 LOCATION OF PHOTOSYNTHESIS Equipment in garages ...... 309.2 Definition ...... 218.0

108 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT INDEX

PHOTOVOLTAIC (PV) PRESSURE SYSTEM ...... [see Solar photovoltaic Design, definition ...... 206.0 (PV) System] Limiting devices, definition ...... 218.0 PIPING Storage tanks ...... 601.2.1 Geothermal energy ...... 703.5 – 703.7 Test, definition ...... 218.0 Hangers and supports ...... 317.0, 408.3, Vessel ...... 311.2, 603.6 Table 317.3 PRESSURE-RELIEF VALVE Hydronics ...... 408.0, Table 408.1 Definition ...... 224.0 Identification ...... 404.0 Discharge ...... 311.3 Joints and connections ...... (see Joints Hydronics ...... 311.1 – 311.3 and connections) Pressure vessels ...... 311.2, 603.7.1 Protection of ...... 318.0 PYRANOMETER Trenching, excavation, Definition ...... 218.0 and backfill ...... 320.0, 704.1 – 704.3 PYRHELIOMETER PLANS Definition ...... 218.0 Approval by Authority Having Jurisdiction ...... 104.3 – Q – Retention of ...... 104.4.6 QUASI-STEADY STATE Review fees ...... 104.3.2 Definition ...... 219.0 PLENUMS QUICK-ACTING VALVE Definition ...... 218.0 Definition ...... 219.0 PLUMBING CODE Definition ...... 218.0 – R – POLYETHYLENE (PE) PIPE OR TUBING RADIANT HEATER Definition ...... 218.0 Definition ...... 220.0 Ground-heat exchanger, RADIANT HEATING AND COOLING ...... 414.0 geothermal ...... 703.5, 703.5.1 REFERENCED STANDARDS ...... Chapter 9 Hydronics ...... 408.0, Table 408.1 RELIEF VALVE, VACUUM ...... 220.0, 311.4 Joining and connections ...... (see Joints ROCK AS STORAGE MATERIAL ...... 606.3 and connections) ROCK STORAGE POLYETHYLENE-ALUMINUM-POLYETHYLENE Definition ...... 220.0 (PE-AL-PE) PIPE OR TUBING RODENTPROOFING ...... 318.9 Definition ...... 218.0 Hydronics ...... 408.0, Table 408.1 – S – Joining and connections ...... (see Joints SAFETY DEVICES ...... 311.0 and connections) SHINGLES ...... 802.6 POLYETHYLENE OF RAISED SINGLE-WALL HEAT TEMPERATURE (PE-RT) EXCHANGER ...... 313.1, A 103.2 PIPE OR TUBING SNOW AND ICE MELT SYSTEMS ...... 416.1, 416.1.1, Definition ...... 218.0 416.1.4, 416.1.5, Hydronics ...... 408.0, Table 408.1, Table 416.1.1 Table 416.1.1 SOLAR CELL Joining and connections ...... (see Joints Definition ...... 221.0 and connections) SOLAR COLLECTORS ...... 221.0, 502.0 Oxygen diffusion ...... 405.4 Absorber, definition ...... 203.0 POLYPROPYLENE (PP) Adhesives used ...... 501.5.3 PIPE OR TUBING Air collectors ...... 502.4 Hydronics ...... 408.0, Table 408.1 Aperture area, definition ...... 203.0 Joining and connections . .(see Joints and connections) Balancing valves required ...... 312.8.1 POLYVINYL CHLORIDE (PVC) Collector tilt, definition ...... 205.0 PIPE OR TUBING Concentrator, definition ...... 205.0 Definition ...... 218.0 Construction ...... 502.1.1 Hydronics ...... 408.0, Table 408.1 Cover, definition ...... 205.0

UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT 109 INDEX

Definition ...... 221.0 SOLAR THERMAL SYSTEMS Discharge ...... 309.4 Auxiliary heating ...... 501.8 Flat plate, definition ...... 208.0 Circulators ...... 205.0, 310.0, 501.13 Glass ...... 502.3 Definition ...... 221.0 Gross area, definition ...... 203.0 Drainback systems ...... 310.4, 501.7 Installation ...... 502.5 – 502.5.6 Draining ...... 501.4 Integral collector storage ...... 211.0, 501.12.3 Electrical (auxiliary) heating, definition ...... 207.0 Listing ...... 502.6 External auxiliary heating, definition ...... 207.0 Protection against decay ...... 501.14 Freeze protection ...... 401.8, 501.12 System, definition ...... 205.0 Heat exchanger ...... 313.0, A 103.0 Testing ...... 502.4.1 Heat transfer medium ...... 309.3, 501.15 Venetian blind collectors, definition ...... 224.0 Insulation ...... 503.0 Material ...... 501.5 SOLAR PHOTOVOLTAIC (PV) SYSTEM ...... Chapter 8 Protection ...... 501.11, 501.14 Access, pathways and smoke ventilation ...... B 103.0 Solar collectors ...... 502.0 Stagnation condition ...... 501.3 Alternating-current (ac) module ...... 203.0, 803.0, 824.0 Swimming pools, spas and hot tubs ...... 505.0 Bipolar systems ...... 804.2, 812.9 Testing ...... 504.0 Thermosiphon systems ...... 501.6 Circuit breakers ...... 805.5.1, 805.5.2, 805.5.3, STAGNATION CONDITION ...... 501.3 807.2.5, 809.1.3(3), 810.1.4, STAND-ALONE SYSTEMS ...... 221.0, 807.0 810.1.6.3, Table 805.5.1 STANDARDS Circuit requirements ...... 804.0 Definition ...... 221.0 Circuit sizing and current ...... 805.0 General ...... 302.1.2 Connection to other sources ...... 828.0 Hydronics ...... Table 408.1 Disconnecting means ...... 810.0, 811.0 Referenced ...... Chapter 9 Energy storage systems ...... 829.0 STORAGE TANKS ...... 221.0, 321.2, Chapter 6 Engineered systems ...... Appendix A STORAGE TEMPERATURE Fuses ...... 805.5.1, Table 805.5.1 Definition ...... 221.0 Ground-fault protection ...... 816.2 STORED ENERGY Grounding and bonding ...... 816.0 Definition ...... 221.0 Installation guidelines ...... Appendix B STRUCTURAL DESIGN LOADS ...... 305.9 Interactive inverters ...... 831.1.4 SUBARRAY ...... 221.0, 812.9 Interactive systems ...... 211.0, 810.1.4, 825.2 SWIMMING POOLS, SPAS, Inverters ...... 211.0, 802.2, 806.1 AND HOT TUBS ...... 505.0 Markings ...... 807.2.3, 810.1.2, 810.1.2.1, 812.7.3, 812.7.4, 823.0, – T – 823.3, B 102.0 TANKLESS WATER HEATER ...... 403.3 Modules, panels, and shingles ...... 802.6 TANKS Multiple systems ...... 802.4 Atmospheric type ...... 601.2.2, 603.2 Concrete ...... 604.3 Overcurrent protection ...... 805.2, 805.2.3, 806.0 Construction ...... 604.2 807.2.5.1 Covers ...... 603.8 Panel, Photovoltaic, definition ...... 218.0 Expansion tanks ...... (see Expansion tanks) Photovoltaic, definition ...... 218.0 Insulation of ...... 602.0, Table 602.1 Photovoltaic Output Circuit, definition ...... 218.0 Prefabricated ...... 603.3 Photovoltaic Power Source, definition ...... 218.0 Pressure type ...... 601.2.1, 603.6 Photovoltaic Source Circuit, definition ...... 218.0 Test pressure ...... 601.2, 601.2.1, 601.2.2 Photovoltaic System DC Circuit, definition ...... 218.0 Underground ...... 321.2, 603.5 Stand-alone systems ...... 221.0, 807.0 TEMPERATURE Subarray ...... 221.0, 812.9 RELIEF VALVE ...... 311.1, 603.4, 603.7.1 Supplemental checklist ...... Appendix C TESTING Systems over 1000 volts ...... 804.1, C 101.8 Of hydronic systems ...... 405.2, 417.3 Wiring methods permitted ...... 812.0 Of insulating materials ...... 401.2

110 UNIFORM SOLAR, HYDRONICS AND GEOTHERMAL CODE - PREPRINT INDEX

Of pressure vessels ...... 601.2.1 WATERPROOFING ...... 318.4, 501.10, 606.1 Of solar thermal systems ...... 504.0 WELD Of thermal storage ...... 601.2, 601.2.1, 601.2.2 Joints ...... 212.0, 409.12 Required by the Authority Welder ...... 309.1 Having Jurisdiction ...... 302.2.1 WORKMANSHIP ...... 306.0 THERMAL STORAGE ...... 222.0, Chapter 6 TOTAL ALKALINITY ...... 222.0, Table 505.2 TUBE FASTENERS Types ...... 414.5.3, 416.2 Spacing ...... 416.3

– U – UNCONSTITUTIONAL ...... 101.4 UNDER-FLOOR SPACE ...... 304.3 UNGROUNDED Conductors ...... 807.2.5.1 Photovoltaic (PV) power systems ...... 816.1(4), C 101.5

UNIVERSAL PIPE INSULATION THICKNESS ...... Table 503.3(3)

– V – VALVES Accessible ...... 312.14 Compatibility ...... 312.1 Rating ...... 312.1 Where required ...... 312.2, 401.4, 603.4.1, 707.2(3), 707.2(6) VALVE TYPES Balancing ...... 204.0, 312.8, 312.8.1 Check ...... 310.5 Combination temperature and pressure-relief ...... 205.0, 311.3, 603.7.1 Pressure relief ...... 224.0, 311.1, 311.2, 603.7.1 Quick-acting ...... 219.0 Safety or relief ...... 311.0, 603.7.1 Shutoff ...... 312.14 Temperature relief ...... 311.1, 311.3, 603.7.1 Thermostatic mixing ...... 311.5, 406.3.1 Vacuum relief ...... 220.0, 311.4, 603.7.1

– W – WATER CHEMISTRY ...... 505.1, Table 505.2 WATER HAMMER ...... 401.3 WATER HEATERS Accepted standards ...... 403.2, Table 403.2 Drain pans ...... 305.7 Dual purpose ...... 403.2, 406.3, Table 403.2 For space heating and cooling ...... 403.2, Table 403.2 Tankless ...... 403.3

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