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