Electric heat-tracing cables · Self-regulating, constant-wattage or mineral-insulated, maintain and exposure temperatures, voltage, circuit length and ground-fault protection
A heating cable (heat-trace cable) is laid along pipes, valves and tanks under thermal insulation to replace heat lost to the surroundings, either to prevent freezing or to hold a process temperature. Settle three things before ordering: the cable type for the temperatures involved — the temperature to maintain and the highest the cable will see, for example during steam-out — the supply voltage and circuit lengths, and the protection, control and hazardous-area approvals the plant requires.
Self-regulating, constant-wattage (zone) and mineral-insulated series heat-tracing cables for pipe and vessel freeze protection and process temperature maintenance, with their power connections and end seals. Floor heating mats, roof and gutter de-icing kits, cartridge and band heaters, and controllers sold alone are outside this page; heater bands and temperature controllers have their own pages.
01
Chromalox's SRL self-regulating cable, built with 16 AWG bus wires and a tinned copper braid, is listed for freeze protection and process maintenance to 150 °F (65 °C), with maximum continuous exposure of 185 °F (85 °C) power off, on metal and plastic pipes. The maker says that because it is self-regulating it uses less energy when less heat is needed and over-temperature conditions are minimized. [1]
Its CWM constant-wattage cable has a nichrome element wrapped around parallel insulated bus wires, giving a set watt density along its length. Chromalox lists 392 °F (200 °C) fluoropolymer insulation, maximum power-off exposure of 200 °C, 120, 208–277 and 480 V versions, and use on metallic pipes (factory consultation for plastic). [2]
Its mineral-insulated (MI) cables use a series resistance wire in compacted magnesium oxide inside an Alloy 825 or stainless-steel sheath. They maintain process temperatures up to 1,100 °F (593 °C), withstand up to 1,200 °F (648 °C) power off and insulate voltages up to 600 V. At lower temperatures they can be designed for watt densities up to 50 W/ft, with a 4 ft (1.2 m) cold lead as standard. [3]
Editorial note: the exposure rating must cover the highest pipe temperature the cable will meet, including steam cleaning or upset conditions, not only the maintain temperature; that is what separates the three types in Chromalox's ratings.
Give the supplier the pipe or vessel sizes and materials, insulation type and thickness, minimum ambient and wind, temperature to maintain, highest exposure temperature, supply voltage, circuit lengths and power points, hazardous-area classification, control and monitoring method, and approvals required.
02
Chromalox offers SRL at 120 and 208–277 V from stock and CWM at 120, 208–277 and 480 V. It says that from a single power point "you can easily configure and install a heat tracing system as short as several feet or as long as 780 feet right in the field." [1] [2]
On all three product pages Chromalox states that the US National Electrical Code requires a ground-fault protection device to reduce the risk of fire if the cable is damaged or wrongly installed, and recommends a minimum trip level of 30 mA to avoid nuisance tripping. [1] [2] [3]
Editorial calculation: 50 W/ft is about 164 W/m (50 ÷ 0.3048), and 780 ft is about 238 m. Maintain temperatures of 65 °C and 593 °C bracket the self-regulating and MI ranges published here. [3] [2] [1]
Linked suppliers list self-regulating, constant-power and mineral-insulated heating cables, heat-tracing for oil storage tanks and skin-effect heat tracing. [4] [5]
03
Suppliers linked to this page list heating cables; each card links to the page reviewed.
The listings reviewed range from self-regulating and constant-power heat-tracing cables to MI and floor-heating cables alongside tubular and cartridge heaters; ask each for power output at your pipe temperature, exposure ratings, maximum circuit length per breaker size and hazardous-area certificates.
04
This is a functional reference built from the sources cited; it is not one maker's specification.
| Part | Role | Fix in the order |
|---|---|---|
| Bus wires | Carry supply along parallel cables. [1] [2] | Gauge; circuit length. |
| Heating element | Self-regulating core, nichrome or series wire. [1] [2] [3] | Type; output. |
| Insulation | Fluoropolymer or MgO; voltage and temperature. [2] [3] | Material; rating. |
| Braid or sheath | Earth path and mechanical protection. [1] [3] | Braid; sheath alloy. |
| Cold lead and terminations | Power connection and end seal. [3] | Length; kit. |
| Protection and control | Ground-fault device and thermostat. [1] | GFP trip; control. |
05
A heating cable quotation needs values for your pipes and vessels. The table explains each field, gives published values where a reviewed source states them, and says what to obtain from the supplier.
| Field | What it means and published values | Ask the supplier for |
|---|---|---|
| Rated Voltage (V AC) | 120, 208–277, 480 V; MI insulation to 600 V. [2] [3] | Voltage. |
| Power Output (W/m) | MI up to 50 W/ft (≈164 W/m) at lower temperatures. [3] | Output at pipe temperature. |
| Maximum Continuous Temperature (°C) | Exposure 85 (SRL), 200 (CWM), 648 (MI). [1] [2] [3] | Maintain and exposure. |
| Minimum Installation Temperature (°C) | Cold installation limit. | Value. |
| Insulation Resistance (MΩ) | Test value. | Value; test voltage. |
| Dielectric Strength (V AC) | Insulation test. | Value. |
| Conductor Resistance Tolerance (%) | Series MI resistance by design. [3] | Tolerance. |
| Outer Sheath Material | Fluoropolymer jacket; Alloy 825 or stainless sheath. [2] [3] | Material. |
| IP Rating | Terminations and enclosures. | Rating. |
| Bending Radius (×OD) | Field bending; annealed MI sheath. [3] | Minimum radius. |
| Cable Diameter (mm) | Fits under insulation. [2] | Diameter. |
| Weight (kg/m) | Per metre. | Weight. |
06
Paste it into your enquiry below or into an email to a maker, then replace every bracket.
Lines: [pipe sizes; lengths; materials] Insulation: [type; thickness] Ambient: [minimum; wind] Temperature: [maintain; maximum exposure] Power: [voltage; power points; breaker size] Area: [safe area; hazardous zone; T-class] Control: [thermostat; monitoring; GFP] Approvals: [required marks]
These companies list heating cables.
Lists custom electric heating cables and publishes guides on tank heat tracing, high-temperature cables and skin-effect tracing.
Product scope checked 2026-10-11
Lists self-regulating and other heat-tracing cables, floor heating cables and industrial heat-tracing solutions.
Product scope checked 2026-10-11
Lists heating cables among its electric heating products.
Product scope checked 2026-10-11
Lists heating cables alongside tubular and cartridge heaters.
Product scope checked 2026-10-11
Lists heating cables alongside cartridge, tubular and band heaters.
Product scope checked 2026-10-11
Lists heating cables among its heating elements.
Product scope checked 2026-10-11
Explore company information and manufacturing capabilities, then discuss the scope of your project with a relevant supplier.
Chromalox lists its SRL cable for maintaining up to 65 °C with 85 °C power-off exposure. [1]
Chromalox lists MI cable for maintaining up to 593 °C and withstanding 648 °C power off. [3]
Chromalox says its CWM constant-wattage cable can run up to 780 ft from a single power point. [2]
Chromalox cites the NEC requirement for ground-fault protection and recommends a 30 mA minimum trip level. [1]
Sources checked 2026-10-11. Chromalox is a heat-tracing maker publishing ratings for self-regulating, constant-wattage and mineral-insulated cables; Jiahong and Santo are linked suppliers.
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