Power-Limiting Technology

Tyco Thermal Controls provides heating cables that allow for higher exposure temperature and great power output. Raychem power-limiting cables are parallel heaters formed by a coiled resistor alloy heating element wrapped around two parallel bus wires. At a fixed distance, the insulation is removed from one of the bus wires. The process is then repeated removing the insulation from the other bus wire. This distance between contact points forms the heating zone length. The positive temperature coefficient effect (PTC) of the heating element reduces power output as ambient temperature increases. This effect allows the power-limiting cable to be overlapped once by reducing the temperature of the heating element at the overlap points.

Power-limiting cable can be used for freeze protection and process temperature maintenance requiring high power output and/or high temperature exposure. Power-limiting cables can provide process temperature maintenance up to 230°C and can withstand exposure temperatures up to 250°C with power off.

Heating Cable -- Parallel Power-Limiting VPL Parallel power-limiting – Field-terminated