What are constant Constant Wattage Heating Cables ?

The characteristics of Constant Wattage heating cables are designed to give out a constant output in comparison with
self regulating cables that adjust their power output in response
to changes in the ambient temperature.

How do they work ?

The cables are constructed from a single resistance wire element, connected between two insulated bus-bar conductors which run the length of the heating tape or cable. The resistance wire is designed to make electrical contact with the bus-bars at predetermined intervals, eg. 1m. These connections are made at the "NODE" points where the nickelchrome resistance heating wire is either welded or connected by rivets to the bus-bars forming the parallel resistance conductors. As a result, a sequence of electrically parallel heating circuits are formed along the length of the heating unit. Parallel resistance heaters may be cut to any convenient length within the limits imposed by the maximum heating circuit length.