Heat Tracing Installation FAQ: Wrapping, Cold Lead, Bending

Frequently Asked Questions

1. Should the cable be run straight or wrapped around the pipe?

Straight runs are preferred where a single cable provides enough watts. Wrapping increases the watts per metre of pipe, and is used when one straight cable is insufficient. Self-regulating cable may be overlapped without overheating.

2. How is the cold lead connected?

The cold lead is terminated in an approved junction box. The termination must be sealed against moisture - a badly sealed cold lead is the most common cause of earth leakage trips.

3. What is the minimum bending radius?

For self-regulating cable the minimum bending radius is generally 5 times the cable diameter; for MI cable it is larger and given in the datasheet. Do not bend at the cold lead joint.

4. Can the cable be cut to length on site?

Self-regulating cable can be cut to any length on site. Constant wattage and MI cable are manufactured to the calculated circuit length and must not be shortened arbitrarily.

5. How is the cable fixed to the pipe?

Use fibreglass or polyester tape at intervals of about 300 mm on straight runs and more frequently on bends and valves. Do not use metal ties directly on the cable jacket.