Electrical safety device with conductive polymer sensor

An electrical apparatus for plugging into an electrical safety device, the safety device comprising a power interrupter responsive to an electrical quantity, the apparatus comprising:

• a sensor strip disposed in the apparatus, the sensor strip comprising a conductive polymer material having a positive temperature coefficient of resistivity, the positive coefficient of resistivity increasing with temperature;
• and
• an apparatus plug comprising a power connection to the apparatus, the apparatus plug insertable into a connector of the electrical safety device and comprising a sensor contact for electrically connecting the sensor strip to the electrical safety device when the apparatus plug is plugged into the connector of the electrical safety device.

An electrical cord for sensing overtemperature and mechanical damage comprising:

• a first conductor disposed in the cord, the first conductor extending from a first end to a second end of the cord;
• a first sensor strip disposed in an insulated portion of the cord and extending from the first end to the second end, the first sensor strip comprising a conductive polymer material having a positive temperature coefficient of resistivity, the positive temperature coefficient of resistivity increasing with temperature;
• a second sensor strip disposed in the insulated portion of the cord and extending from the first end to the second end, the second sensor strip further disposed between the first conductor and a first protected outside surface of the cord, wherein the second strip is open circuited by mechanical damage to the cord between the first protected outside surface and the first conductor.

An insulated electrical conductor with overtemperature and mechanical damage sensor, the apparatus comprising:

• an elongated electrical conductor surrounded by insulation, the insulation having an outside surface;
• at least two sensor strips extending the substantial length of the electrical conductor, each of said at least two sensor strips disposed in the insulation between the conductor and the outside surface so that each of said at least two sensor strips acts as a mechanical damage sensor by loss of continuity when the insulation is mechanically damaged, and at least one of said at least two sensor strips comprises a conductive polymer material comprising a positive temperature coefficient of resistivity which increases with temperature, resulting in an overtemperature sensor with a switching effect.

An insulated electrical conductor with overtemperature and mechanical damage sensor, the apparatus comprising:

• an elongated electrical conductor surrounded by insulation, the insulation having an outside surface;
• a sensor strip disposed in the insulation between the conductor and the outside surface, the sensor strip disposed in a helical configuration about the conductor and extending substantially the length of the conductor so that the sensor strip acts as a mechanical damage sensor by loss of continuity when the insulation is mechanically damaged, and the sensor strip comprises a conductive polymer material comprising a positive temperature coefficient of resistivity which increases with temperature, resulting in an overtemperature sensor with a switching effect.