Patent ID: 6512444
Filing Date: 2003-01-28
Classification: H02H

Abstract:
Apparatus for sensing overtemperature and mechanical damage in electrical wiring, the apparatus comprising:at least one fault sensing electrical wire, the fault sensing electrical wire comprising an electrical conductor surrounded by insulation, and at least one sensor strip disposed in the insulation along substantially the length of the wire, the sensor strip comprising a temperature responsive portion and a mechanical damage sensing portion, the temperature responsive portion made of a material having a positive temperature coefficient of resistivity which increases with temperature and the mechanical damage sensing portion disposed between the conductor and an outside surface of the fault sensing wire so that mechanical damage to the insulation opens the mechanical damage sensing element before the conductor is exposed; and a control unit responsive to the impedance of the sensor strip, the control unit providing a first control signal responsive to a first thermal condition of the temperature responsive portion and a second control signal responsive to an opening of the mechanical damage sensing portion.