Protective device with automated self-test

Patent metadata

Field	Value
Publication number	US-10012718-B2
Application number	US-201514684888-A
Country	US
Kind code	B2
Filing date	Apr 13, 2015
Priority date	Feb 17, 2000
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

The present invention is directed to an electrical wiring device that includes a test circuit that is configured to generate a recurring simulated fault signal. A detection circuit is configured to generate a test detection signal in response to the recurring simulated fault signal. An end-of-life monitor circuit is configured to generate an end-of-life detection signal if the test detection signal is not generated within a first predetermined period of time. At least one indicator is configured to emit an indication signal in response to the end-of-life detection signal. A response mechanism is configured to decouple the plurality of line terminals from the plurality of load terminals after a second predetermined period of time has elapsed following the end-of-life detection signal.

First claim

What is claimed is:

1. An electrical wiring device comprising:
a plurality of line terminals and a plurality of load terminals;
a test circuit coupled to the plurality of line terminals or the plurality of load terminals and configured to generate a recurring simulated fault signal, the recurring simulated fault signal being automatically provided in accordance with a predetermined test regimen;
a detection circuit coupled to the plurality of line terminals, the detection circuit being configured to generate a test detection signal in response to the recurring simulated fault signal;
a control system including,
an end-of-life monitor circuit coupled to the detection circuit, the end-of-life monitor circuit being configured to detect the test detection signal within a test detection monitoring interval and determine that an end-of-life condition has occurred if the test detection signal is not detected within the test detection monitoring interval;
a control circuit coupled to the end-of-life monitor circuit responsive to at least one failure condition in the end-of-life monitor circuit that prevents the end-of-life monitor circuit from being able to detect the end-of-life condition, the control circuit exhibiting a power denial state in response to the at least one failure condition or the end-of-life condition; and

a response mechanism coupled to the control circuit, the response mechanism being configured to decouple or prevent the coupling of the plurality of line terminals and the plurality of load terminals when the control circuit exhibits the power denial state.

2. The device of claim 1 , wherein the response mechanism permanently decouples the plurality of line terminals from the plurality of load terminals.

3. The device of claim 1 , further comprising a plurality of sensors coupled to the plurality of line terminals and the detection circuit, the plurality of line terminals being coupled to a hot line conductor and a neutral line conductor, the plurality of sensors including a first sensor coupled to the neutral line conductor, the plurality of sensors also including at least one second toroidal sensor configured so that the hot line conductor and the neutral line conductor pass through a central opening of the at least one second toroidal sensor.

4. The device of claim 3 , wherein the first sensor includes a toroidal sensor portion configured so that only one of the hot line conductor or the neutral line conductor pass through a center opening of the toroidal sensor portion.

5. The device of claim 1 , further comprising at least one indicator coupled to the control circuit arrangement, the at least one indicator being configured to emit an indication signal in response to the end-of-life condition.

6. The device of claim 5 , wherein the response mechanism decouples the plurality of line terminals from the plurality of load terminals a predetermined period of time after the at least one indicator has emitted the indication.

7. The device of claim 1 , wherein the response mechanism further includes a circuit interrupting assembly that is driven into the reset state by a user stimulus, the response mechanism being configured to prevent the user stimulus from maintaining or effecting the reset state.

8. The device of claim 1 , wherein the response mechanism further includes a power denial mechanism configured to permanently decouple the plurality of line terminals from the plurality of load when the end-of-life condition occurs.

9. The device of claim 8 , wherein the response mechanism is activated when at least one electronic component reaches a predetermined temperature.

10. The device of claim 1 , wherein the response mechanism is configured to decouple, or prevent the coupling, of the plurality of line terminals and the plurality of load terminals when the detection circuit is operating to detect at least one fault condition.

11. The device of claim 10 , wherein the at least one fault condition includes a ground fault, a grounded neutral fault, or an arc fault.

12. The device of claim 10 , wherein the response mechanism permanently prevents a latch member from being coupled to a reset button assembly.

13. The device of claim 1 , wherein the response mechanism is configured to prevent a latch member from being coupled to a reset button assembly when the reset button assembly is manually activated.

14. The device of claim 1 , wherein a portion of the detection circuit and a portion of the control circuit arrangement are combined in the same integrated circuit.

15. The device of claim 1 , wherein the control circuit arrangement is disposed in a single integrated circuit device.

16. An electrical wiring device comprising:
a plurality of line terminals including a hot line conductor and a neutral line conductor, and a plurality of load terminals;
a sensor assembly including a first sensor coupled to the neutral line conductor;
a test circuit coupled to the plurality of line terminals or the plurality of load terminals and configured to generate a recurring simulated fault signal, the recurring simulated fault signal being automatically provided in accordance with a predetermined test regimen;
a detection circuit coupled to the sensor assembly, the detection circuit being configured to generate a test detection signal in response to the recurring simulated fault signal;
a control system including,
an end-of-life monitor circuit coupled to the detection circuit, the end-of-life monitor circuit being configured to detect the test detection signal within a test detection monitoring interval and determine that an end-of-life condition has occurred if the test detection signal is not detected within the test detection monitoring interval;
a control circuit coupled to the end-of-life monitor circuit responsive to at least one failure condition in the end-of-life monitor circuit that prevents the end-of-life monitor circuit from being able to detect the end-of-life condition, the control circuit exhibiting a power denial state in response to the at least one failure condition or the end-of-life condition; and

a response mechanism coupled to the control circuit, the response mechanism being configured to decouple or prevent the coupling of the plurality of line terminals and the plurality of load terminals when the control circuit exhibits the power denial state.

17. The device of claim 16 , wherein the sensor assembly includes at least one second toroidal sensor configured so that the hot line conductor and the neutral line conductor pass through a central portion of the at least one second toroidal sensor.

18. The device of claim 17 , wherein the at least one second toroidal sensor includes a differential current sensor.

19. The device of claim 16 , wherein the first sensor includes a toroidal sensor portion configured so that only one of the hot line conductor or the neutral line conductor pass through a center opening of the toroidal sensor portion.

20. The device of claim 16 , wherein the response mechanism further includes a circuit interrupting assembly that is driven into the reset state by a user stimulus, the response mechanism being configured to prevent the user stimulus from maintaining the reset state.

21. The device of claim 16 , wherein the response mechanism further includes a power denial mechanism configured to permanently decouple the plurality of line terminals from the plurality of load when the end-of-life condition occurs.

22. The device of claim 21

Assignees

• Pass & Seymour Inc

Inventors

• Macbeth Bruce F
• Finlay Sr David A
• Richards Jeffrey C

Classifications

• H01H2071/044

  Monitoring, detection or measuring systems to establish the end of life of the switching device, can also contain other on-line monitoring systems, e.g. for detecting mechanical failures · CPC title

• G01R31/2829

  Testing of circuits in sensor or actuator systems (testing of apparatus for measuring electric or magnetic variables G01R35/00; testing of indicating or recording apparatus G01D; in airbag systems B60R21/0173; checking gas analysers G01N33/007; monitoring or fail-safe circuits for electromagnets H01F7/1844) · CPC title

• H01H73/045

  Bridging contacts · CPC title

• H02H3/335

  the main function being self testing of the device · CPC title

• G01R31/3277

  of low voltage devices, e.g. domestic or industrial devices, such as motor protections, relays, rotation switches · CPC title