Self-regulating Technology

What does self-regulating mean?

In 1970, Raychem first developed and launched self-regulating electric heating cables.

The cable delivers the right amount of heat exactly when and where it is needed. As the temperature drops more heat is produced. Conversely, as the temperature rises less heat is produced. This gives many benefits:

  • The smart cables can be overlapped without any risk of overheating.
  • The heating cables can be cut to length “in the field”. This means additional flexibility when plans do not correspond to the “real life” situation on site.
  • The length of pipe corresponds to the length of cable that is needed.

Self-regulating cable and how it works

The outer jacket, braid and inner jacket provide mechanical, chemical and electrical protection… but the magic happens in the conductive core. The conductive core is extruded over the two, parallel conductors.

As the ambient temperature drops, the core contracts microscopically and the number of electrical paths through the core increases, producing more heat. Conversely as the ambient temperature rises, the core expands and has fewer electrical paths, producing less heat.

A self-regulating heating cable adjusts its power output along its entire length. That’s what makes it a safe and reliable solution for many applications.

Self-regulating cable schematic with relative heat being shown

Cold Ambient = High Power Output

If the temperature in the immediate vicinity of the self-regulating heating cable is cold, the heat output from the heating cable is increased. The polymeric core of the cable contracts, creating many electrical paths across the integrated carbon particles.

Warm Ambient = Low Power Output

In response to a warmer environment, the heat output of the self-regulating cable is reduced. The polymeric core of the cable expands, reducing the electrical paths.

Hot Ambient = Virtually No Output

If the temperature in the environment of the self-regulating cable reaches a high temperature, the heat output is minimal. Due to the maximum expansion of the polymeric core of the cable, most of the electrical paths are broken.