Patent ID: 8212191

Claim:
A heating cable comprising: a spacer; a heating element comprising: an insulating core; and a plurality of resistance wires wrapped around the insulating core in a helical manner and coupled together at multiple points to provide redundant paths, the heating element positioned on an outer surface of the spacer and helically wrapped around the spacer; a plurality of bus wires, wherein a first bus wire is positioned on a first side of the spacer and a second bus wire is positioned on a second side of the spacer such that the heating element is helically wrapped in between the first bus wire and the spacer and in between the second bus wire and the spacer, wherein: the plurality of resistance wires are electrically coupled to the bus wires by coupling the plurality of resistance wires to the first or second bus wires at a plurality of node areas to create a plurality of resistance zones for generating heat, and the redundant paths via the plurality of resistance wires are provided in between two node areas to allow for current to flow in a resistance zone if one of the redundant paths is broken.