W A T L O W Table of Contents Introduction Electric Heaters Resistance Temperature Detectors (RTDs). 49 This Application Guide is to assist you Thermistors . 52 in understanding the principles of electric thermal systems and compo- Non-Contact Temperature nents as they apply to various heating Sensor Basics . 54 tasks. Its purpose is to give you Defining an Application and theory, general calculations and Determining a Solution . 60 engineering data along with examples Reference Data . 61 for solving heating problems. This Thermocouple and Resistance Application Guide is not a how-to Wire RTD Initial Calibration manual or a substitute for specific Tolerances . 61 information related to complex RTD Resistance vs. Temperature and/or critical applications. Watlow Tables (Standard Thermistors) . 63 engineers are available to provide you detailed information on engineering RTD Resistance vs. Temperature Tables (DIN Platinum RTDs). 70 approaches not included in this guide. When designing any thermal system, caution must always be exercised to Temperature Controllers comply with safety requirements, local Product Overview . 7 and/or national electrical codes, Power Calculations . 15 agency standards, considerations for Power Evaluation. 19 use in toxic or explosive environments Review of Heater and sound engineering practices. Application Factors. 20 Integrity and suitability of any Select Heater . 22 thermal system design/specification is ultimately the responsibility of those Reference Data . 24 selecting and approving system Heat Loss Factors and Graphs . 26 components. Quick Estimates of This Application Guide is organized Wattage Requirements . 30 into sections dealing with the basic facets of an electric thermal system: Temperature Sensors the electric heaters, temperature sensors and temperature and power controllers. Information about wiring practices along with reference data and examples are also provided. Product Overview . 74 As always, Watlow Electric Manufac- Thermal Control Principles . 81 turing Company stands ready to Control Output Types . 88 provide you advice or engineering Control Output Comparison. 90 expertise to design and produce components to meet your electric Limit Control Protection for Temperature Process . 93 heating requirements. Agency Recognition for Controllers . 94 Customer Assistance Control System Tuning. 94 Product Overview . 34 Typical Thermal Control System Manufacturing Facilities . 3 Contact Temperature Sensors Chart Recordings . 97 Sales Offices . 4 Types and Comparisons. 36 Controller Overview . 99 Thermocouples . 37 Data Communications. 100 1 Table of Contents Power Controllers Reference Data Glossary Celsius to Fahrenheit / Definitions of Commonly Used Fahrenheit to Celsius . 127 Terms Used in Heating, Sensing Ratings of Listed Heater Voltages and Controlling . 188 Operated on Other Voltages. 129 Conversion Factors. 130 Watlow Products and Commonly Used Geometric Technical Support Areas and Volume. 133 Delivered Worldwide Physical Properties of Solids, Liquids and Gases . 134 Product Overview . 101 Watlow’s worldwide sales and Properties of Non-Metallic distributor network Five Basic Types . 102 Solids . 134 If you don’t find what you need in this Theory of SCR Power Controllers . 108 Properties of Metals . 137 Application Guide, call the Watlow Methods of Firing SCRs . 109 Properties of Metals in office nearest you listed on the Enclosure Guidelines . 112 Liquid State . 139 following One phone call Heater Life and Selection of Power Properties of Liquids. 140 gives you instant access to expert technical advice, application Handling Device . 113 Properties of Gases . 143 assistance and after-the-sale service. SCR Protective Devices . 114 Properties of Air . 143 In addition, more than 150 authorized Corrosion Guide . 144 distributors are located in the U.S. Wiring Practices Examples of Applications. 156 and 42 other countries. Cabinet Freeze Protection . 156 For up-to-date information on Watlow’s new products or services, Heating a Steel Mold . 158 see Watlow’s home page on the Melting of Aluminum. 164 Internet at http://www.watlow.com. Heating Liquid in a Tank. 174 Heating a Flowing Liquid . 178 Air Duct Heater . 182 Drying a Moving Web of Cloth . 186 Electrical Noise . 116 Helpful Wiring Guidelines. 118 Input Power Wiring . 120 Output Wiring . 122 SCR Wiring – Tips and Special Considerations . 124 2 W A T L O W Customer Assistance Watlow Manufacturing Hannibal, Missouri Winona, Minnesota - Controls Facilities Watlow Hannibal Watlow Winona, Inc. Manufactures: Manufactures: United States Manufacturing • Circulation Heaters • Custom Electronic Controllers Facilities • Duct Heaters • Power Controls Anaheim, California • Immersion Heaters • Safety and Limit Controls Watlow AOV, Inc. • Multicell Heaters • Single Loop Controls Manufactures: • Tubular Heaters 1241 Bundy Boulevard, P.O. Box 5580 • Silicone Rubber Heaters • Thick Film Heaters Winona, MN 55987-5580 1400 North Kellogg Drive, Suite A #6 Industrial Loop Road Phone: 507-454-5300 Anaheim, CA 92807 P.O. Box 975 FAX: 507-452-4507 Phone: 714-779-2252 Hannibal, MO 63401 FAX: 714-777-9626 Phone: 573-221-2816 Winona, Minnesota - Polymer Watlow Polymer Technologies, Inc. Batavia, Illinois FAX: Tubular/Process/Multicell 573-221-3723 Manufactures: Watlow Batavia • Polymer Heaters Manufactures: FAX: Thick Film 1265 East Sanborn Street • Cast-In Heaters 573-221-7578 Winona, MN 55987 1310 Kingsland Drive Richmond, Illinois Phone: 507-457-9797 Batavia, IL 60510 Watlow Richmond FAX: 507-457-9736 Phone: 630-879-2696 Manufactures: FAX #1: 630-879-1101 • RTDs, Thermocouples, Thermistors Wright City, Missouri FAX #2: 630-482-2042 • Thermocouple Wire and Cable 4/1/02 (formerly Troy, MO) • Temperature Measurement Devices Watlow Process Systems Columbia, Missouri 5710 Kenosha Street, P.O. Box 500 Manufactures: Watlow Columbia/Ceramic Fiber Richmond, IL 60071 • Process Heating Systems Manufactures: #10 Cooperative Way • Ceramic Fiber Heaters Phone: 815-678-2211 FAX: 815-678-3961 Wright City, Missouri 63390 2407 Big Bear Court Phone: 636-745-7575 Columbia, MO 65202 St. Louis, Missouri FAX: 636-745-0537 Phone: 573-443-8817 World Headquarters and FAX: 573-443-8818 Watlow St. Louis Asian Manufacturing Facilities Manufactures: Singapore Watlow Columbia/Flexible • Band Heaters Manufactures: • Cable Heaters Watlow Singapore Pte. Ltd. • Flexible Heaters • FIREROD® Heaters Manufactures: ® 2101 Pennsylvania Drive • Radiant Heaters • FIREROD Heaters Columbia, MO 65202 • Special Heaters • Thermocouples Phone: 573-474-9402 • Strip Heaters 55 Ayer Rajah Crescent, #03-23 FAX: 573-474-5859 12001 Lackland Road Singapore 139949 St. Louis, MO 63146 Phone: 65-67780323 Fenton, Missouri Phone: 314-878-4600 FAX: 65-67739488 Single Iteration FAX: 314-878-6814 A Consulting Services Division European Manufacturing Facilities of Watlow Watsonville, California France 909 Horan Drive Watlow Anafaze Watlow France, S.A.R.L. (Sales Office) Fenton, MO 63026 Manufactures: Immeuble Ampère Phone: 866-449-6846 • Multi-loop Controls Z.I. Rue Ampere FAX: 636-349-5352 • High Level Software 95307 Cergy Pontoise Cedex, France Phone: 507-454-5300 Phone: 33-1-3073-2425 FAX: 507-452-4507 FAX: 33-1-3073-2875 3 Customer Assistance Watlow Manufacturing Italy Latin American Manufacturing Facilities Watlow Italy, S.r.l. Facilities Manufactures: Mexico European Manufacturing Facilities • Thermocouples Watlow de Mexico, S.A. de C.V. (con’t.) Via Meucci 14 Manufactures: Germany 20094 Corsico - MI, Italy • FIREROD Heaters Watlow GmbH Phone: 39-02-4588841 (Cartridge and Metric) Manufactures: FAX: 39-02-45869954 • Ceramic Knuckle Heaters • Cable Heaters • THINBAND® Heaters • Cartridge Heaters United Kingdom • HV Band Heaters (FIREROD, EB Cartridge and Watlow Limited • Silicone Rubber Heaters Metric FIREROD) Manufactures: • Tubular Heaters • Silicone Rubber Heaters • Band Heaters • Cable Heaters • K-RING® Heaters • Cartridge Heaters Av. Epigmenio Gonzalez No. 5 • Pump Line Heaters • FIREROD Heaters • Electronic Assemblies • Flexible Heaters Col. Parques Industriales Queretaro C.P. 76130 Lauchwasenstr. 1 • Thermocouples Queretaro, Mexico Postfach 1165 Robey Close D 76709 Kronau, Germany Linby Industrial Estate Phone: 52-442-217-62-35 Fax: 52-442-217-64-03 Phone: 49-7253-94-00-0 Linby, Nottingham, England NG15 8AA FAX: 49-7253-94-00-44 Phone: 44-0-115-964-0777 FAX: 44-0-115-964-0071 Sales Support United States Sales Offices Chicago Denver 1320 Chase Street, Suite 2 5945 West Sumac Avenue Atlanta Algonquin, IL 60102-9668 Littleton, CO 80123-0886 1320 Highland Lake Drive Phone: 847-458-1500 Phone: 303-798-7778 Lawrenceville, GA 30045-8225 Fax: 847-458-1515 Fax: 303-798-7775 Phone: 770-972-4948 Fax: 770-972-5138 Cincinnati Detroit 4700 Duke Drive, Suite 125 155 Romeo Road, Suite 600 Austin Mason, OH 45040-9163 Rochester, MI 48307 12343 Hymeadow, Suite 2L Phone: 513-398-5500 Phone: 248-651-0500 Austin, TX 78750-1830 Fax: 513-398-7575 Fax: 248-651-6164 Phone: 512-249-1900 Fax: 512-249-0082 Cleveland Houston 28 West Aurora 3403 Chapel Square Drive Birmingham Northfield, OH 44067-2063 Spring, TX 77388 308 Honeysuckle Lane Phone: 330-467-1423 Phone: 281-440-3074 Chelsea, AL 35043-9669 Fax: 330-467-1659 Fax: 281-440-6873 Phone: 205-678-2358 Fax: 205-678-2567 Dallas Indianapolis PO Box 704011 160 W. Carmel Drive, Suite 204 Charlotte Dallas, TX 75370-4011 Carmel, IN 46032-4745 10915 Tara Oaks Drive Phone: 972-620-6030 Phone: 317-575-8932 Charlotte, NC 28227-5493 Fax: 972-620-8680 Fax: 317-575-9478 Phone: 704-573-8446