1、AN AMERICAN NATIONAL STANDARDNECA 202-2013 Standard forInstalling and MaintainingIndustrial Heat Tracing SystemsPublished byNational Electrical Contractors AssociationTMStandard forInstalling and MaintainingIndustrial Heat Tracing SystemsNECA 202-2013An AmericanNational StandardPublished byNational
2、Electrical Contractors AssociationNOTICE OF COPYRIGHTThis document is copyrighted by NECAReproduction of these documents either in hard copy or soft (including posting on the web) is prohibited without copyright permission. For copyright permission to reproduce portions of this document, please cont
3、act NECA Standards & Safety at (301) 657-3110 ext. 549, or send a fax to (301) 215-4500.ORNational Electrical Contractors Association 3 Bethesda Metro Center, Suite 1100 Bethesda, Maryland 20814 (301) 657-3110Revision HistoryNECA 202-2001 07/2001 First publicationNECA 202-2006 09/2006 ReaffirmationN
4、ECA 202-2013 10/2013 Revisioni n1. ScopeForeword iii1. Scope 11.1 Products and Applications Included .11.2 Products and Applications Excluded 11.3 Related Construction Materials .11.4 Regulatory and Other Requirements 12. Definitions 33. Pre-Installation Checks . 43.1 Check the Pipe to be Heat Trace
5、d .43.2 Plan the Installation .43.3 Mark Location of Terminations 44. General Installation Practices . 54.1 Receiving, Storing, Protecting, and Delivering .54.2 Site Preparation 64.3 Unpacking and Handling Material64.4 Proper Type and Application .74.5 Coordination with Other Trades .74.6 Securing C
6、omponents in Place .74.7 Wiring Connections .75. Heating Cable Installation 95.1 Paying Out the Cable .95.2 Attaching the Heating Cable 105.3 Securing the Heating Cable .125.4 Wrapping Heat Sinks 145.5 Special Cautions .146. Heating Cable Connections 167. Thermostat Controls 187.1 General 187.2 Ambi
7、ent-Sensing Thermostats 187.3 Line-Sensing Thermostats .188. Thermal Insulation 198.1 Pre-Insulation Inspection .198.2 Insulation Installation 19Table of Contentsn iiNECA 202 Standard for Installing and Maintaining Industrial Heat Tracing Systems9. Power Supply and Electrical Protection 209.1 Voltag
8、e Rating .209.2 Electrical Loading .209.3 Ground-Fault Protection for Equipment (GFPE) 209.4 Disconnecting Means .2010. Commissioning . 2110.1 Pre-Commissioning .2110.2 Ambient-Sensing Controlled Systems .2110.3 Line-Sensing Controlled Systems 2110.4 Backup (Redundant) Systems 2111. Preventive Maint
9、enance 2211.1 Maintenance Procedures 2211.2 Maintenance Records .2211.3 Repairs .2211.4 Maintenance of Piping and Associated Equipment 2211.5 Special Cautions .2212. Heating Cable Testing . 2312.1 Insulation Resistance Testing 2413. Typical Troubleshooting Guide for Parallel Circuit Heaters . 2513.1
10、 Troubleshooting Flowchart 2513.2 Questions, Steps, and Corrective Actions .25Annex A: Recordkeeping . 33Annex B: Reference Standards 36iii n1. ScopeNational Electrical Installation Standards (NEIS) are designed to improve communication among specifiers, purchasers, and suppliers of electrical const
11、ruction services. They define a minimum baseline of quality and workmanship for installing electrical products and systems. NEIS are intended to be referenced in contract documents for electrical construction projects. The following language is recommended:Industrial heat tracing systems shall be in
12、stalled in accordance with NECA 202-2013, Standard for Installing and Maintaining Industrial Heat Tracing Systems (ANSI).Use of NEIS is voluntary, and the National Electrical Contractors Association (NECA) assumes no obligation or liability to users of this publication. Existence of a standard shall
13、 not preclude any member or non member of either organization from specifying or using alternate construction methods permitted by applicable regulations.This publication is intended to comply with the edition of the National Electrical Code (NEC) in effect at the time of publication. Because they a
14、re quality standards, NEIS may in some instances go beyond the minimum safety requirements of the NEC. It is the responsibility of users of this publication to comply with state and local electrical codes when installing electrical products and systems.Suggestions for revisions and improvements to t
15、his standard are welcome. They should be addressed to:NECA Standards & Safety 3 Bethesda Metro Center, Suite 1100 Bethesda, MD 20814 (301) 657-3110 (301) 215 4500 fax www.neca neis.org neisnecanet.orgTo purchase NEIS, contact the NECA Order Desk at (301) 215 4504 tel, (301) 215-4500 fax, or orderdes
16、k necanet.org. NEIS can also be purchased in .pdf download format at www.neca-neis.org/standards.Copyright 2013, National Electrical Contractors Association. All rights reserved. Unauthorized reproduction prohibited.National Electrical Installation Standards, NEIS, and the NEIS logo are trademarks o
17、f the National Electrical Contractors Association. National Electrical Code and NEC are registered trademarks of the National Fire Protection Association.Cover illustration courtesy of Tyco Thermal Controls Figures courtesy of Pentair Thermal ManagementForeword(This foreword is not a part of the sta
18、ndard)n ivNECA 202 Standard for Installing and Maintaining Industrial Heat Tracing Systems1 n1. Scope1.1 Products and Applications IncludedThis standard describes procedures for the installation, testing, and documentation of electrical freeze protection and process heat tracing systems. Heat tracin
19、g cable types covered by this publication include: self-regulating, constant wattage, and zone heating cables and mineral insulated (MI) heating cables (see Figures 1.1(a)-1.1(e) below and on the following page).System components used with these types of heat tracing cables included power transforme
20、rs, control panels, temperature sensors, temperature controllers, contactors, circuit breakers, enclosures, conduit, wire, and all necessary auxiliary equipment and controls.1.2 Products and Applications ExcludedThe following types of heat tracing systems are specifically excluded from this publicat
21、ion:1. Skin effect heating systems 2. Impedance heating systems 3. Inductance heating systemsNOTE: ANSI/IEEE 844-2000, Recommended Practice for Electrical Impedance, Induction, and Skin Effect Heating of Pipelines and Vessels provides information about installing the above mentioned systems in list
22、items 1, 2, and 3.1.3 Related Construction MaterialsIn addition to the electrical heat tracing components described in 1.1, this publication includes related construction materials including labels, adhesive tapes, attachment wire and components, and thermal insulation and cladding.1.4 Regulatory an
23、d Other Requirements a) All information in this publication is intended to conform to the National Electrical Code (ANSI/NFPA 70), and, in general, the typical recommendations of electrical heat tracing manufacturers. All work shall be performed using safety-related work practices in accordance with
24、 NFPA 70E, Standard for Electrical Safety in the Workplace. Installers should always follow the NEC, applicable state and local codes, manufacturers instructions when installing electrical heat tracing. Articles 427 (ordinary areas) and 500 through 516 (Classified areas) of the NEC govern the instal
25、lation of electrical heat tracing systems. IEEE 515 and 515.1 are accepted industry standards that also contain useful information about installing electrical heat tracing systems.b) Only qualified persons familiar with the construction and installation of electrical heat tracing systems should inst
26、all heat-tracing systems. 1. ScopeSeriesHeatingCircuitParallelHeatingCircuitZoneHeatingCircuitFigure 1.1(a)Types of electrical heatingn 2NECA 202 Standard for Installing and Maintaining Industrial Heat Tracing SystemsAdministrative functions and other tasks can be performed under the supervision of
27、a qualified person. All work should be performed in accordance with NFPA 70E, Standard for Electrical Safety in the Workplace.c) General requirements for installing electrical products and systems are described in NECA 1, Standard for Good Workmanship in Electrical Construction (ANSI). Other Nationa
28、l Electrical Installation Standards provide additional guidance for installing particular types of electrical products and systems. A complete list of NEIS is provided in Annex B.Figure 1.1(b)Self-regulating conductive polymer heating cableFigure 1.1(c)Zone heaters polymeric heating cableFigure 1.1(
29、d)Series resistance cablesResistance wireMetal sheath(Note: May be either one or two conductors)Dielectric insulationFigure 1.1(e)Mineral insulated (MI) cablePrimary electrical insulationOuterjacket(optional)BraidNodeResistancewireZone(1.5 ft to 6 ft)Bus wiresOuter polymeric jacket (optional)Dielect
30、ric insulationNode connectionNichromeheating elementBuswireBraidSelf-regulating heating cable coreResistance wirePlastic dielectric insulationBraidOuter polymeric jacket (optional)3 n1. Scope2. DefinitionsGround-Fault A system intended to provide Protection of protection of equipment from Equipment
31、(GFPE) damaging line-to-ground- fault currents by operating to cause a disconnecting means to open all ungrounded conductors of the faulted circuit. This protection is provided at current levels less than those required to protect conductors from damage through the operation of a supply circuit over
32、current device.Piping System A length or lengths of pipe including pumps, valves, flanges, control devices, strainers, and/or similar equipment for conveying fluids.Resistance A heating element applied Heaters to a pipeline or vessel, externally or internally. Heating cable, heating tape, heating bl
33、ankets, MI cable, self-regulating cable, and zone constant wattage cables are examples of resistance heaters.Vessel A container such as a barrel, drum, or tank for holding fluids or other material.Electrical Heat Information used to instruct Tracing Design designers and installers on Specification r
34、equired parts and construction methods for installing electrical heat tracing systems.n 41. Scope3.1 Check the Pipe to be Heat Traceda) Verify that the pipe has been pressure-tested, and that all equipment and supports are installed.b) Verify that any paint or coatings used on the pipe are dry.c) Wa
35、lk the pipe system and plan the routing of the heating cable on the pipe. Note the accessibility of all parts of the line, including power locations.d) Verify construction welding has been completed in the area.e) Remove any sharp edges or burrs that could damage the heating cable.3.2 Plan the Insta
36、llationCompare design drawings with the actual pipe and note any differences in: Pipe length and pipe sizes Number of valves, indicator gauges, flanges, and other components Number of pipe supports NOTE: These may not be marked on the design drawing, but there should be a note indicating the amount
37、of heating cable designed into each circuit for pipe supports.Ensure that the heat tracing system meets minimum requirements of NEC Article 427 in addition to the specific requirements for hazardous (classified) locations as specified Articles 500 through 516. 3.3 Mark Location of Terminationsa) Whi
38、le walking the pipe, mark the location of power connections, splices, and tees on the pipe with a vivid-color spray paint or a marker.b) In cases where the connection kit cannot be mounted on the pipe, construct brackets or other supports.3. Pre-Installation Checks5 n1. Scope4.1 Receiving, Storing,
39、Protecting, and Delivering4.1.1 Receiving material on sitea) Unload carefully, observing all packing label warnings.b) Use forklifts or other loading equipment only for palletized and large reel shipment.c) Leaving protective coverings in place as much as possible, open and inspect the heating cable
40、 and components for in-transit damage completely and, as quickly as possible, initiate recovery of loss due to shipping damage. Undamaged materials should be carefully re-packed unless intended for immediate installation. NOTE: Depending on specifications, company policy, or project circumstances, i
41、t may be necessary to receive, unpack and check all material at the company shop or other staging area, in which case careful repackaging is essential.d) Verify receipt of manufacturers installation instruction literature on electrical heat tracing systems and the maintenance of the systems.e) Verif
42、y the heating cable catalog number and quantity against the bill of materials. The heating cable catalog number is typically printed on the cable insulation or over jacket for parallel cables shown in Figures 1.1(b) and 1.1(c) or on a permanent label for series cables shown in Figures 1.1(d) and 1.1
43、(e). See Figure 4.1.1(e).f) For braided heating cable, measure the cable insulation resistance for each reel by using the procedure outlined in 12.1.2.4.1.2 Cable reel or carton marking requirementsThe carton, container, spool, or reel in or on which the heating device is delivered should be marked
44、with 4. General Installation PracticesFigure 4.1.1(e). Typical cable marking information required on jacketMinimum power output at ratedvoltage on a 50 F pipe (watts/ft)Outer jacket specNominal voltage rating1 (100 V to 130 V)2 (200 V to 277 V)Heating cable familyn 6NECA 202 Standard for Installing
45、and Maintaining Industrial Heat Tracing Systemsthe following information:a) The manufacturers name, trademark, or other recognized symbol or identification.b) The catalog number, reference number, or model.c) The rated voltage.d) The rated power output in watts per unit length at rated voltage, and
46、at a stated reference temperature for cables that change output with temperature.e) The statement, “Refer to installation instructions and any other warnings or notices.”f) Product certification (Listing) markings.g) Location or area classification markings (if applicable).h) Temperature class or ma
47、ximum surface temperature (if applicable).4.1.3 Storage and protectiona) Store material in a clean, dry location at temperatures between -40C and 60C (-40F and 140F). Especially avoid areas where water accumulate or where significant airborne dust or dirt is present. If a clean, dry location is not
48、available, store material on pallets or other means to raise above floor and possible water levels, and wrap in protective plastic sheeting.b) Stack or otherwise store equipment carefully to prevent damage. Observe warnings and stacking instructions on packaging or shipping materials.c) Do not stack
49、 boxes that are partially crushed, even if the products are intact.d) Should any event occur, such as a water leak, which could damage stored material, immediately re-inspect it and obtain replacements for damaged products.e) Protect the ends of all heat tracing cables to prevent water entrance and migration in the heating cable.4.1.4 Moving material on sitea) In general, move heat tracing cable reels and other materials as few times as possible.b) Move material by hand, dolly, or other device in a manner so as not to damage mat
