Enclosed Bus Assemblies ME- Building Group s1

Enclosed Bus Assemblies ME- Building Group

SECTION 262500 – ENCLOSED BUS ASSEMBLIES

PART 1 - GENERAL

0.1 RELATED DOCUMENTS

A. Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 01 Specification Sections, apply to this Section.

0.2 SUMMARY

A. This Section includes busway systems complete with fittings, hangers and accessories, and plug-in devices.

0.3 SUBMITTALS

A. Product Data: Include electrical ratings, dimensions, mounting position, mounting method, vertical supports, and materials for each busway type and component.

B. Shop Drawings: Detail fabrication and installation of busway, including component details, and attachments to other construction elements. Detail supports and connections to building.

C. “Busway Installation Torque/Megger Data Sheet” for record of test results.

0.4 QUALITY ASSURANCE

A. Busway, Devices, and Accessories: Listed and labeled as defined in NFPA 70, Article 100, by a testing agency acceptable to authorities having jurisdiction.

B. Comply with NFPA 70 for components.

C. Comply with NEMA BU 1, "Busways."

D. Before start of Field Tests, provide to the Owner a table of acceptable megger readings for each Utility and Welding busway. 1. Base the tables on the contract drawings, installation drawings, and the actual feeder cable lengths as installed.

0.5 DELIVERY, STORAGE, AND HANDLING

A. Package busway components in bundles on pallets or equivalent, shrink-wrapped; protected from weather.

B. Ship the bundles on a flatbed truck or trailer such they can be unloaded by forklift from either side of the truck and not requiring the use of a truck dock or dock leveler.

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C. Provide a list of expected maximum weights of pallets to be unloaded on site.

PART 2 - PRODUCTS

0.1 MANUFACTURERS

A. Manufacturers: Unless otherwise directed by the Owner, provide products by one of the following: 1. Cutler-Hammer. 2. General Electric Co.; Electrical Distribution & Control Division. 3. Square D Co. 4. Siemens

0.2 BUSWAY

A. Plug-in Bus Assemblies: NEMA BU 1, low-impedance bus assemblies in nonventilated housing, single-bolt joints, ratings as indicated. 1. Voltage: 480 V, 3 phase, with voltage drop not greater than 3 Volts/100 ft. 2. 100 percent ground capacity. 3. Short-Circuit Withstand a. Utility Bus: 65,000 symmetrical amperes (minimum). b. Welding Bus: 125,000 symmetrical amperes (minimum). 4. Temperature Rise: 55 deg C above 40 deg C ambient maximum. 5. Bus Materials: Copper conductors, fully insulated (NEMA Class B) with Class 130C insulation except tin plated surface at stabs and joints. 6. Enclosure: Steel or aluminum with manufacturer’s standard enamel finish, plug-in openings 24 inches on center, and hinged covers over unused openings. 7. Torque-Indicating Joint: Positive joint torque indication fittings which indicate that the bolt has been properly torqued during installation by means of double-headed bolts, or equivalent, such that one head will shear off at proper torque.

B. Busway fittings 1. Provide busway fittings such as horizontal and vertical elbows, end caps, tap boxes and hangers to form a complete system. 2. Quantities and dimension information is indicated on the Busway Isometric Drawing.

0.3 PLUG-IN DEVICES

A. Fusible Switches 1. Provide totally enclosed, quick-make, quick-break plug-in type fusible switch units with Class R fuse clips and which comply with applicable requirements of NEMA KS 1 and UL 98. 2. Provide plug-in type units with means for locking in the “off” position utilizing up to three heavy duty padlocks. 3. Provide plug-in units with door interlock which prevents door from being opened in the “on” position. 4. Provide bypass means to allow authorized personnel to defeat the door interlock feature. Page 2 of 4 Revision Date: 01/21/14 Project & Bid Package File name: 00576b1e8713a6dc1c7f55d6c612efb0.doc

5. Provide plug-in units capable of hook-stick or chain operation. 6. Provide plug-in units mechanically interlocked with busway housing to prevent installation or removal of plug-in units while the switch is in the “on” position. 7. Provide plug-in unit enclosures that make a positive ground connection to the busway housing before contact with phase bus bars is made. 8. Provide indication for “on” and “off” positions. 9. Maximum size of busway plug-in units is 400 amp, electrical loads requiring power feeds larger than 400 amps are to be fed directly from a substation feeder breaker.

PART 3 - EXECUTION

0.1 INSTALLATION

A. Install busway level and plumb and according to manufacturer's written instructions, Shop Drawings, and referenced standards. Document megger and torque values measured during installation on owner provided “Busway Installation Torque/Megger Data Sheet”.

B. Support busway independent of supports for other elements such as pipe, conduit, ceilings, and ducts as indicated and as follows: 1. Design each fastener and support to carry 200 lbs or four times the supported weight of busway, whichever is greater. 2. Support busway to prevent twisting from eccentric loading. 3. Support busway with not less than 3/8-inch steel rods. Install side bracing to prevent swaying or movement of busway. Modify supports after completion to eliminate strains and stresses on bus bars and housings. 4. Fasten supports securely to building structure.

C. Install expansion fittings at locations indicated where busway crosses building expansion joints. Install so distance between expansion fittings does not exceed 90 percent of manufacturer's recommended distance between fittings.

D. Coordinate busway terminations to ensure proper phasing, connection, and closure. Provide cable termination lugs for feeder cables at end and center tap boxes. Verify line size and quantity with power riser diagrams.

E. Tighten each busway joint with torque wrench and document the torque value at which the first head of the double headed joint bolt shears off.

F. Perform insulation resistance test on each busway section, piece, and/or offset prior to installation. Document test results.

G. Perform insulation resistance test on busway after each busway section, piece, and/or offset is added during installation. Document test results.

H. Install busway plug-in units. 1. Install the operating handle on the front or sides of the plug-in unit. Do not install the operating handle on the top or the bottom of the unit. Page 3 of 4 Revision Date: 01/21/14 Project & Bid Package File name: 00576b1e8713a6dc1c7f55d6c612efb0.doc

2. Make conduit connections from above only, entering the top of the plug-in unit. Do not enter the front, back or sides of the plug-in unit. 3. Support conduit independent of plug-in unit.

I. Install fuses in each fusible plug-in unit.

0.2 FIELD QUALITY CONTROL

A. Perform insulation resistance test on completed busway, phase to phase, phase to ground, and phase to neutral (if applicable). Document results.

B. Verify proper phasing relationship between busway and associated equipment.

C. Before energizing busway, re-tighten each busway joint to proper torque. Document torque values.

D. Re-tighten each busway joint to proper torque after busway has been energized for six months. Document torque values for each joint.

0.3 ADJUSTING

A. Align busway runs vertically and horizontally to eliminate sags and twists. Provide additional stiffeners if required to restrict excessive movement.

END OF SECTION

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