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Heat Tracing ProductsOverview

Industrial Cable Applications

• Self Regulating

• Constant Wattage

• Mineral Insulated

Commercial Cable Applications

• Self Regulating FreezeProtection

• Self Regulating Roof & GutterDe-Icing

Heat tracing is used to counteract the heat lostfrom process equipment and piping throughits insulation. A heat tracing system is agroup of process equipment and piping whichis heat traced and controlled in a logical andeconomical manner.

There are many reasons for making up theheat loss of a system. With any heat loss,there is a corresponding drop in temperature.

In many cases, a drop in temperature bringsabout unacceptable consequences. Theseconsequences could be freezing of water incooling water lines, steam or condensatereturn lines, compressed air lines, fireprotection lines, storage tanks, valves, etc. Adrop in temperature of process fluids couldresult in solution precipitation, unacceptableviscosity increase or solidification of theproduct in the lines.

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Electric Heat Tracing Products

Chromalox heating cable line includes cablessuitable for most process maintenance, pipeand vessel freeze protection and roof andgutter de-icing applications.

Industrial Heating Cables are ideal for processmaintenance applications. Maintenancetemperatures up to 900°F can be achieved in avariety of hazardous and corrosive environ-ments. Industrial Cables include:

SRL — Self-Regulating, Low Temperature

SRM/E — Self-Regulating, Medium Tempera-ture Enhanced

CWM — Constant Wattage, Medium Tempera-ture

MI — Mineral Insulation, High Temperature.

Commercial Application Cables are designedto meet specific needs of winterizing applica-tions such as water line freeze protection andpreventing ice damage to building structures.Commercial Cables include:

SRF — Self-Regulating Freeze Protection

SRF-RG — Self-Regulating Roof and GutterFreeze Protection.

Industrial ProcessMaintenance Applications

When industrial process piping and vesselsmust be maintained above the ambient airtemperature, Chromalox has the heating cableto fit the application. Cables range in themaximum maintenance temperature from150°F for SRL to 900°F for MI cables.

• Petroleum Refineries — Maintain petroleumand by-products at process temperature

• Waste Water Treatment Facilities — Preventthe precipitation of NaOH from solutions

• Food Processing Plants — Maintainviscosity of products in processes such aschocolate, oils and tallow

• Instrument Lines

• Storage Tanks

• Div. 1 and Div. 2 Hazardous LocationApplications (Contact your Local ChromaloxSales office for Div. 1 applications)

• Freeze Protection of Steam Cleaned Lines

• Power Generating Plants — Trace steamcondensate lines and other chemical additivelines

• Asphalt Lines.

Commercial Applications

In a large number of regions in the world,buildings are susceptible to damage caused bywater freezing. Primarily, this damage involveseither the bursting of pipes or structuraldamage due to the weight of ice and snowbuilding up on the roof. Chromalox Commer-cial Application Cables are intended to preventthis damage.

• Cooling Tower Pipes

• Parking Garage Drain Lines

• Chiller Water Lines

• Exposed Pipe Traps

• Exposed Storm Water Pipes

• Sump Discharge Pipes and Equipment

• Wet Sprinkler Fire Systems, where approvedby Local Codes

• Outdoor Sports Facilities and Stadiums

• Roof and Gutter De-icing.

Heat Tracing ProductsApplications

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Heat Tracing Products — Section Outline

Heat Tracing ProductsIndustrial & Commercial Grade Cables

Industrial Cable Applications

Self-Regulating

Chromalox SRL and SRM/E Self RegulatingHeating Cables provide the most versatility inheat trace designs and applications. Con-structed of a semiconductive heater matrixextruded between parallel buss wires, a self-regulating cable adjusts its output to indepen-dently respond to temperatures all along itslength. As temperatures increase, the heater’sresistance increases which lowers the outputwattage. Conversely, as the temperaturedecreases, the resistance decreases and thecable produces more heat. The result — anenergy efficient heating cable.

Self-regulating cables are flexible, can becut-to-length in the field and can be singleoverlapped without fear of burnout in areaswhere complex piping and equipment requireadditional heat trace cable.

Chromalox manufactures low (SRL) andmedium (SRM/E) temperature self-regulatingheating cable for use on 120 and 208 to 277V.Equipped with a ground braid and optionalTPR or FEP jacket, Chromalox self-regulatingcables are third party tested and approved foruse in harsh corrosive and hazardousapplications.

Constant Wattage

Chromalox CWM Constant Wattage HeatingCables are ideally suited for applications wherea particular watt density is required at alltimes. The heater element consists of anichrome wire wrapped around parallel,insulated buss wires. At specific intervals, ashort section of insulation is removed fromalternating buss wires to create connection

nodes for the nichrome wire. The result is anetwork of parallel resistors along the entirelength of constant wattage cable.

Constant wattage cables are flexible, can becut-to-length in the field, and are manufac-tured for use on voltages from 120 to 480V.Although not suited for overlapping, itsconstant output makes it an ideal choice forhigher temperature applications where higherwatt densities are required. Equipped with aground braid and optional FEP jacket,Chromalox constant wattage cables are thirdparty tested and approved for use in harsh,corrosive and hazardous areas. Contact yourLocal Chromalox Sales office for hazardousarea designs.

Mineral Insulated

Chromalox MI Mineral Insulated HeatingCables are the most rugged heating cable inChromalox's product line. Constructed of asolid series resistor element embedded inhighly compacted mineral insulation, MIcables are built to handle high temperature,high wattage applications. The series resistorand mineral insulation are encased in ametallic jacket of Alloy 825 for high tempera-ture or corrosive applications.

Mineral insulated cables are factory assembledand tested, ensuring the highest qualityproduct. Since the units consist of a seriesresistor, virtually any wattage/voltage/lengthcable configuration can be produced within thecable's physical operating limits. Chromaloxmineral insulated cables are available for useup to 600V and are tested and approved foruse in corrosive and hazardous areas. Optionalaccessories include pulling eyes and reverseglands. Other special features are alsoavailable.

Commercial Cable Applications

Self-Regulating Freeze Protection

Chromalox SRF Self Regulating FreezeProtection Heating Cable is a self-regulatingcable designed for the freeze protection ofwater lines. The self-regulating matrix allowsfor overlapping and easy field installation. SRFalso lowers its output and energy consump-tion as the temperature increases thuslowering energy costs. The 16 AWG busswires provide for long circuits which reducethe number of accessories required.

A braided and braided with overjacketconstruction is available. Braided cable shouldbe used on dry pipes and dry locations. Theoverjacket construction is suitable for wetlocations where occasional exposure tomoisture is expected.

SRF heating cable is not for use in hazardouslocations. Consult the Industrial CableProducts in this section for cables suitable forhazardous locations.

Self-Regulating Roof & GutterDe-Icing

SRF-RG Heating Cable is specifically designedfor roof and gutter de-icing applications.SRF-RG features a self-regulating matrix thatreduces output as snow melt requirementsdecrease or when warm weather is present.

The braided and overjacketed constructionprovides reliable moisture protection. The 16AWG buss wires allow ample circuit lengthsand rugged design. Accessories are availablefor mounting to roofs and gutters.

EL Series Standard RT-JBC, RT-RST, G-39Connection Accessories RT-TST, RT-RES,

RT-TESGeneral Application Accessories G-42HL Hazardous Locations HL-PC, HL-ES G-43Connection Kits HL-S, HL-TB100/E100 Freeze G-45Protection ThermostatsEL Series Standard G-45Temperature ControlsRBF Heat Trace or G-47Pipe SensorDL Series Integrated RTAS G-48Temperature Controls RTBC G-50

RTSS G-51Electronic Controls & Controls Panels G-52

Industrial - Application Guidelines G-4Self-Regulating

Low Temperature SRL G-8Medium Temperature SRM/E G-11

Constant Wattage CWM G-14Mineral Insulated MI G-17Hazardous Location

Low Temperature HSRL G-21Medium Temperature HSRM G-24

Commercial - Application Guidelines G-29Self-Regulating

Freeze Protection SRF G-27Roof & Gutter SRF-RG G-32

Connection Accessories G-34DL Series Integrated RTPC, RTST, RTES G-35Connection Accessories RTPC G-36

RTST G-37RTES G-38

Type Model PageType Model Page

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Industrial Commercial

Features SRL SRM/E CWM Alloy 825 MI SRF SRF-RG

Heat Tracing ProductsApplication & SelectionGuidelines

General Product Summary

This section is designed to assist you indetermining the appropriate cable for use inyour application.

Step 1 — Collect Required Application Dataand Determine Heat Loss

Step 2 — Choose the cable that best meetsyour specific application parameters based onthe summary. Consideration of applicationtemperature, exposure temperature, applica-tion requirements and environmental ratingsshould be made.

Step 3 — Select Heating Cable Wattage Rating

Step 4 — Determine Total Cable Required

Step 5 — Determine Circuits and CircuitProtection

Step 6 — Select Appropriate Accessories

Step 1 — Collect RequiredApplication Data & DetermineHeat Loss

Application data required can be split into twocategories. The first is the heat loss data. Thisincludes:

• Maintenance Temperature

• Minimum Ambient Temperature

• Pipe Size

• Insulation Type (or K factor)

• Insulation Thickness

• Indoor/Outdoor Installation

• Maximum Expected Wind Speed

• Required Safety Factor.

Refer to the Technical section of this catalog,“Determining Heat Energy Requirements —

Pipe & Tank Tracing” for details onperforming heat loss calculations. ForCommercial Freeze Protection, please seeCable Selection Tables in this section.

The second category of data required is theapplication and environmental conditions. Thisincludes:

• Maximum Exposure Temperature(Power Off Condition)

• Circuit Length Considerations

• Available Voltage

• Hazardous Area Requirements

• Type of Pipe (Plastic or Metal)

• Chemical Exposure

• Fire Resistance.

Step 2 — Select the Cable

Choose the cable that best fits your specificapplication parameters and wattage require-ments.

Heat Tracing Product Features

Max. Maintenance Temp. (°F) 150 302 320 900 100 50Max. Exposure Temp. (°F) Power Off 185 420 400 1,100 185 185Max. W/Ft. 10 20 12 50 8 12Max. Circuit Length (Ft.) 95 - 660 150 - 600 225 - 900 330 - 1,000+ 180 - 660 135-540Buss Wire Size 16 14 12 N/A 16 16Voltages 120, 208-277 120, 208-277 120, 208-277, 480 Up to 600 120, 208-277 120, 208-277Hazardous Ratings Yes Yes Yes Yes No NoUsable on Plastic Pipe Yes No No No Yes YesCut-to-Length in Field Yes Yes Yes No Yes YesField Splicable Yes Yes Yes No Yes YesCan be Overlapped Yes Yes No No Yes YesOutput Varies with Temp. Yes Yes No No Yes YesVaries Output Along Length Yes Yes No No Yes YesDesign of System Simple Simple Simple Involved Simple SimpleInstallation of System Easiest Easiest Simple Involved Easiest EasiestFire Resistance Fair Fair Fair Excellent Fair FairChemical Resistance See Corrosion Guide, next pageSize (Max. In.) 0.435 x 0.185 0.5 x 0.2 0.435 x 0.235 0.4 0.435 x 0.185 0.435 x 0.185Accessories DL/EL DL DL/EL DL/EL RG AccessoriesMonitor Wire Available Yes Contact Factory Contact Factory No No NoApplications FL,PL FL,FH,PL,PH FL,FH,PL,PH FL,FH,PL,PH FL RG

FL = Freeze ProtectionFH = Freeze Protection, High Exposure TemperaturePL = Process Maintenance, Low TemperaturePH = Process Maintenance, High TemperatureRG = Roof and Gutter De-icing

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UL CSA FM

Heat Tracing ProductsApplication & SelectionGuidelines (cont’d.)Agency Approvals

SRL-C � � � � � � � �SRL-CT � � � � � � � �SRL-CR � � � � � � � �

SRM/E-C � � � � � � � �SRM/E-CT � � � � � � � �

CWM-C � � � � � �CWM-CT � � � � � �

MI* � � � � � � � � � � � �

SRF-C � � �SRF-CR � � �SRF-RG � � �

For T ratings, refer to individual product pages.For more specific information, refer to individual product pages.CF=Contact Factory*Class I, Division I, Groups B,C & D - UL, CSA, FM - Contact your Local Chromalox Sales office for design assistance.

Class I Class II Class I Class II Class I Class II Div. 2 Div. 2 Div. 2 Div. 2 Div. 2 Div. 2

Ordinary Groups Groups Class III Ordinary Groups Groups Class III Ordinary Groups Groups Class IIICable Area B, C, D F, G Div. 2 Area A, B, C, D F, G Div. 2 Area B, C, D F, G Div. 2

Corrosion Guide to Select Proper Cable Construction

Moisture C, CR, CT C, CT C, CT Yes C, CR YesAqueous Solutions of CR, CT CT CT No No NoInorganic CompoundsLiquids Organic CT CT CT Yes No NoChemicalsAcids or Bases CT CT CT No No NoNote — This is a recommendation guide. Chromalox cannot warrant any Electric Heat Trace against failure by sheath degradation if such failure

is the result of operating conditions beyond the control of the heater manufacturer. It is the responsibility of the purchaser to make theultimate choice of sheath material based on knowledge of the chemical composition of the corrosive solution, character of materialsentering the solution, and controls which maintains the process.

Industrial Commercial

Exposure To SRL SRM/E CWM Alloy 825 MI SRF SRF-RG

More Information is Available Onlineon Heat Trace.

Bookmark Your Browser towww.chromalox.comand Select Manuals.

Required Jacket Material

Select the appropriate jacket configuration forthe desired level of mechanical and corrosivechemical protection. The CR over-jacket optioncan be used when additional mechanicalprotection is desired. The CR over-jacketoption is required when the cable can be

exposed to aqueous inorganic chemicals. TheCT over-jacket option is required when thecable can be exposed to organic chemicals orstrong corrosives. Use Corrosion Guide aboveto determine the correct jacket material optionfor the cable type selected.

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Step 3 — Select HeatingCable Wattage Rating

After calculating the heat lossin the pipe and adjusting for anyapplication deviations, you maydetermine which cable ratingto use. If you have selected aself-regulating cable you mustadjust the output based onmaintenance temperatures,using the Thermal OutputRating Graphs shown on theindividual product pages, selectthe lowest cable rating that willprovide the pipe maintenancetemperature. For Example: A15 W/Ft. SRM/E cable @ 150°Fwill output approximately10 W/Ft. Multiple passes or runsof cable may be required to provide sufficient output perfoot calculated in Step 1. This isaccomplished with parallel runsof cable or spiraling. Contactyour Local Chromalox Sales office.

Heat Tracing ProductsApplication & SelectionGuidelines (cont’d.)

Cable Output vs. Temperature

Step 5 — Determine Circuits &Circuit Protection

Circuit protection depends on the breakersize being used and the start-up temperature.The National Electric Code (NEC 1996)requires the use of ground fault protectionbreakers for heating cable. Refer to thespecific data of the individual heat trace cableto determine maximum circuit lengths. Todetermine the number of circuits required foreach pipe, divide the total cable length foundin Step 4 by the maximum circuit length foundin the individual cable data charts. Round upto the next higher number.

Number of Circuits = Cable LengthMaximum Circuit Length

Step 4 — Determine Total Length ofCable Required

The total amount of heating cable isdetermined by adding the total footage ofpipe to be traced and adding for allowancesfor the components such as flanges, valves,pipe supports; then, multiply by the totalnumber of runs or Wrap Factor determined inStep 3.

(Total Feet of Traced Pipe + Cable Allowancefor Components) x # of Runs = Total CableLength)

Pipe Component Cable Allowance Estimation

Flange Pair 1.5 xPipe Support 2.0 xButterfly Valve 2.5 xBall Valve 2.7 xGlobe Valve 4.0 xGate Valve 5.0 x

Example: Pipe: 150 feetValves: 1 globe valvePipe Supports: 2Flanges: 2Total Cable Length = [150 + (1 x 4) + (2 x 2) + (2 x 1.5)] x 2 runs

= 161 feet x 2 runs= 322 feet

Component Cable Allowance Factor (Ft.) x # Components Total Additional Cable

(°F)

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t.)

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4

12

16

20

24

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30 50 70 90 110 130 150 170 190 210 230 250 270 290 300

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Heat Tracing ProductsApplication & SelectionGuidelines (cont’d.)

Step 6 — Select Controls & GeneralApplication Accessories

Chromalox took a long hard look at the hiddencosts that occur in a heat trace project. Indeedthis is the labor involved in the installation.Being an innovator, we set out to design aproduct that went above and beyond what thecompetition offered while reducing overallinstallation time and number of parts. TheIntegrated Connection Accessories (DL) aredesigned to combine power connections andthermostats in one integrated box. Further-more, the design offers ease of maintenanceand expandability for the future. Of course weoffer the standard connection accessories,common to the heat trace industry, whichoffer lower up front purchase pricing.

Heating Cable

Design of Multiple Runs when Heat RequirementsExceed Cable Output Ratings

Multiple Straight Runs

Spiral Run

Sensors

Insulation

Controls

DL — Duraline Integrated ConnectionAccessories

• Integrated Design — Allows for quickinstallation with fewer parts

• Lower Man Hours for Installation andMaintenance

• Ease of Maintenance — No replacementof component when doing routinemaintenance checks

• Easy to Troubleshoot — Boxes easilyopen for access to wiring and for takingdiagnostic measurements

• Integrated Power Connection andThermostat — No separate powerconnection and thermostat box required,resulting in faster installations

• Allows for Future Expansion of System —Because junction, splice and thermostatboxes have multiple cable exits, futurecable runs are easily added.

EL — Standard Connection Accessories

• Lower Cost — For use in competitivedesign and bid installations

• Rugged Cast Junction Box

• Easy to Use Heat Shrink Tubing Kits

• Typical Industry Design — Meets mostspecifications.

General Application Accessories

For application tape, straps and conduit hubs,refer to the DL & EL General ApplicationAccessories at the end of this section.

For HL kits information, see Product DataSheet PJ932.

More Information is Available Onlineon Heat Trace.

Bookmark Your Browser towww.chromalox.comand Select Manuals.

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