Electrical safety device with conductive polymer sensor

A sheath for providing overtemperature and mechanical damage sensing for a plurality of electrical conductors, the sheath comprising:

• a layer of insulative material positionable to substantially surround said plurality of electrical conductors;
• and
• at least two sensor strips in communication with the layer of insulative material, each of said at least two sensor strips extending a length of said plurality of electrical conductors, a first of said at least two sensor strips made of a conductive polymer material comprising a positive temperature coefficient of resistivity which increases with temperature, and a second of said at least two sensor strips disposed between an outside surface of the sheath and said plurality of electrical conductors so that mechanical damage originating on an outside surface will result in mechanical damage to said second of said at least two sensor strips before mechanical damage is sustained to said plurality of electrical conductors.

A preformed harness for providing overtemperature and mechanical damage sensing for a plurality of electrical conductors, the harness comprising:

• a molded body comprising a feed end, a main distributor end and an auxiliary distributor end;
• a plurality of conductors disposed in the molded body, at least one conductor exiting each of said feed end, main distributor end, and auxiliary end;
• at least one sensor strip disposed in the molded body in a mechanical damage sensing pattern between said feed end, said main distributor end, and said auxiliary end whereby mechanical damage occurring from the outside surface of the molded body will open the sensor strip before at least one of said plurality of conductors is damaged, and wherein at least a portion of the sensor strip comprises a material having a temperature coefficient of resistivity which increases with temperature.

A method for forming a mechanical damage and overtemperature sensing sheath over a plurality of electrical conductors, the method comprising the steps of:

• assembling said plurality of electrical conductors in a bundle;
• positioning at least one sensor strip in a mechanical damage sensing pattern over the bundle, said at least one sensor strip extending over a first substantial length of the bundle and comprising a positive temperature coefficient of resistivity which increases with temperature, the magnitude of increase in positive coefficient of resistivity sufficient to provide a switching temperature and wherein the mechanical damage sensing pattern over the bundle provides a mechanical damage sensing function by opening said at least one sensor strip upon mechanical damage occurring outside the bundle before said plurality of conductors in the bundle are damaged.