How to Read a Heat Tracing Cable Datasheet: 8 Fields That Matter
Heat tracing datasheets look similar but hide the differences that matter. Two cables with the same "30 W/m" headline number can behave very differently at the same pipe temperature. This guide explains each field and the traps that buyers miss.
1. Power output is not a constant
For self-regulating cable, output is quoted at a specific pipe temperature (often 10 °C). At higher temperatures output drops; at lower temperatures it rises. Always compare output at your actual maintain temperature, not at the datasheet's reference point.
2. Voltage and output curve
Output depends on supply voltage. A cable rated at 220 V behaves differently at 230 V or 240 V. Check whether the datasheet gives an output curve or only a single point.
3. Maximum circuit length
This is limited by voltage drop and breaker size, not by cable reel length. A datasheet may say "max 100 m at 10 A" — exceeding it means the far end is under-powered even though the cable is fine.
4. Temperature class and maximum exposure
For hazardous areas, check the temperature class per model and the maximum continuous exposure temperature. The highest-power model in a family usually has the least favourable temperature class.
5. Minimum bend radius
This determines whether the cable can be installed on small valves and instrument bodies. A cable with a large minimum bend radius may simply not fit where the design needs it.
6. Jacket and outer insulation
Material determines resistance to chemicals, UV and mechanical damage. A "standard" jacket in a chemical plant is a maintenance problem waiting to happen.
7. Certificates
ATEX / IECEx certificates should list the model range and temperature class. A certificate number without the model list is not enough — verify the scope.
8. Ordering code
Decode the ordering code before ordering spares. Two codes that differ by one character may describe different power, voltage or jacket material. Wrong spare parts are a common cause of repeat failures.
Comparison checklist
| Field | What to check |
|---|---|
| Power | Output at your maintain temperature, not at the reference temperature |
| Voltage | Output curve and tolerance for the actual supply voltage |
| Max circuit length | Matches your breaker size and voltage drop |
| Temperature class | For the exact model and power level you are buying |
| Min bend radius | Compatible with the smallest pipe and instrument in the system |
| Jacket | Suitable for the chemical environment |
| Certificates | Scope includes the model range and the area classification |
| Ordering code | Decoded and verified against the design bill of materials |
Comparing datasheets?
Send the datasheets you are comparing and the pipe data. We will check the output at your maintain temperature and highlight the differences that matter.
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