Electrical Wiring Device

• US 20100053826A1
• Filed: 11/13/2009
• Published: 03/04/2010
• Est. Priority Date: 11/21/2000
• Status: Active Grant

• Current Assignee: Pass & Seymour Incorporated (Legrand SA)
• Original Assignee: Pass & Seymour Incorporated (Legrand SA)
• Inventors: Packard, Thomas N., Finlay, David A. SR.
• Granted Patent: US 8,295,017 B2
• Time in Patent Office: Days
• US Class Current: 361/42
• CPC Class Codes: H02H 3/338 also responsive to wiring error, e.g. loss of neutral, break

Abstract

The present invention is directed to an electrical wiring device that includes a plurality of line terminals including a line hot terminal and a line neutral terminal, and a plurality of load terminals including a load hot terminal and a load neutral terminal. An interrupting contact assembly includes four sets of interrupting contacts configured to provide electrical continuity at least between the line hot terminal and the load hot terminal and the line neutral terminal and the load neutral terminal in a reset state. The four sets of interrupting contacts are open in a tripped state. A miswire prevention arrangement is configured to prevent the interrupting contact assembly from maintaining the reset state when the load hot terminal and the load neutral terminal are connected to a source of AC power.

Claims

1. An electrical wiring device comprising:

a plurality of line terminals including a line hot terminal and a line neutral terminal, and a plurality of load terminals including a load hot terminal and a load neutral terminal;

an interrupting contact assembly including four sets of interrupting contacts configured to provide electrical continuity at least between the line hot terminal and the load hot terminal and the line neutral terminal and the load neutral terminal in a reset state, the four sets of interrupting contacts being open in a tripped state; and

a miswire prevention arrangement configured to prevent the interrupting contact assembly from maintaining the reset state when the load hot terminal and the load neutral terminal are connected to a source of AC power.

2. The device of claim 1, wherein the miswire prevention arrangement further comprises a switch element, the switch being configured to disable the miswire detection arrangement in an open state.

3. The device of claim 2, wherein the miswire prevention arrangement is enabled when the switch is in a closed state.

4. The device of claim 1, wherein the miswire prevention arrangement includes at least one fusible element configured to open-circuit a predetermined period of time after the AC power is coupled to the hot line terminal and neutral line terminal.

5. The device of claim 4, wherein the fusible element includes at least one resistor.

6. The device of claim 1, wherein a line terminal, a load terminal and an electrical path are shorted together by the interrupting contact assembly when in the reset state and electrically disconnected from each other when in the tripped state.

7. The device of claim 1, further comprising an indicator circuit configured to provide a user-perceivable indication signal in a tripped state or in the miswired state.

8. The device of claim 1, further comprising a low pass filter circuit having a capacitor coupled in series with a solenoid coil of the protective device, the low pass filter being coupled across the hot line terminal and the neutral line terminal and configured to filter transient over-voltage signals propagating in an AC electrical distribution system.

9. The device of claim 1, further comprising a fault detection assembly coupled to the plurality of line terminals and configured to generate a fault detection signal in response to detecting a fault condition, the four sets of interrupting contacts being driven into the tripped state in response to the fault detection signal.

10. An electrical wiring device comprising:

a plurality of line terminals including a line hot terminal and a line neutral terminal, and a plurality of load terminals including a load hot terminal and a load neutral terminal;

an interrupting contact assembly including four sets of interrupting contacts configured to provide electrical continuity at least between the line hot terminal and the load hot terminal and the line neutral terminal and the load neutral terminal in a reset state, the four sets of interrupting contacts being open in a tripped state;

a wiring state detection circuit including a non-user actuatable switch element, the non-user actuatable switch element being configured to propagate a predetermined signal when the plurality of line terminals are properly connected to a source of AC power such that the interrupting contact assembly may establish the reset state, the wiring state detection circuit being substantially disabled after the plurality of line terminals are properly connected to a source of AC power.

11. The device of claim 10, wherein the non-user actuatable switch element includes a fusible element that is open circuited a predetermined period of time after the line hot terminal and the line neutral terminal are properly coupled to a source of AC power.

12. The device of claim 11, wherein the fusible element includes at least one resistive element, the at least one resistive element being open circuited a predetermined period of time after the line hot terminal and the line neutral terminal are properly coupled to a source of AC power.

13. The device of claim 10, further comprising a fault detection circuit coupled to the line hot terminal and the line neutral terminal, the fault detection circuit being configured to generate a fault detection signal in response to detecting a fault condition, the four sets of interrupting contacts being driven into the tripped state in response to the fault detection signal.

14. The device of claim 13, wherein the non-user actuatable switch element includes a rectifier element.

15. The device of claim 13, wherein the interrupting contact assembly further comprises:

a rectifier element coupled to the fault detection circuit, the rectifier element being turned ON in response to the fault detection signal;

a coil element coupled between the rectifier element and the hot load terminal, the coil element being configured to trip the interrupting contacts when the rectifier is in the ON state; and

an indicator element coupled between the neutral line terminal and the hot load terminal, the indicator element being configured to indicate a trip condition, a miswire condition, and an end-of-life condition.

16. The device of claim 15, wherein the indicator element is energized to provide a trip condition indicator.

17. The device of claim 10, wherein a line terminal, a load terminal and an electrical path are shorted together by the interrupting contact assembly when in the reset state and electrically disconnected from each other when in the tripped state.

18. The device of claim 10, wherein the non-user actuatable switch element is configured in an initially closed position when the device enters the stream of commerce.

19. An electrical wiring device comprising:

a plurality of line terminals including a line hot terminal and a line neutral terminal, and a plurality of load terminals including a load hot terminal, and a load neutral terminal;

an interrupting contact assembly including four sets of interrupting contacts configured to provide electrical continuity at least between the line hot terminal and the load hot terminal and the line neutral terminal and the load neutral terminal in a reset state, the four sets of interrupting contacts being open in a tripped state;

a miswire prevention circuit coupled between the line hot terminal and the line neutral terminal, the miswire prevention circuit being configured to generate a predetermined signal not simulating a predetermined fault condition in a properly wired state when the line hot terminal and the line neutral terminal are connected to a source of AC power, the miswire prevention circuit substantially preventing the interrupting contact assembly from effecting the reset state in a miswired state before generating the predetermined signal not simulating a predetermined fault condition.

20. The device of claim 19, wherein the miswire prevention circuit includes a non-user actuatable switch element configured to generate a predetermined signal not simulating a predetermined fault condition.

21. The device of claim 20, wherein the non-user actuatable switch element is open circuited a predetermined period of time after the line hot terminal and the line neutral terminal are properly coupled to a source of AC power.

22. The device of claim 19, further comprising a fault detection circuit coupled to the line hot terminal and the line neutral terminal, the fault detection circuit being configured to generate a fault detection signal in response to detecting a fault condition, the four sets of interrupting contacts being driven into the tripped state in response to the fault detection signal.

23. The device of claim 22, wherein the interrupting contact assembly further comprises:

a rectifier element coupled to the fault detection circuit, the rectifier element being turned ON in response to the fault detection signal;

a coil element coupled between the rectifier element and the hot load terminal, the coil element being configured to trip the interrupting contacts when the rectifier in the ON state; and

an indicator circuit configured to provide a user-perceivable indication signal in a tripped state or in the miswired state.

24. The device of claim 19, wherein a line terminal, a load terminal and an electrical path are shorted together by the interrupting contact assembly when in the reset state and electrically disconnected from each other when in the tripped state.

25. An electrical wiring device comprising:

a plurality of line terminals including a line hot terminal and a line neutral terminal, a plurality of load terminals including a load hot terminal and a load neutral terminal;

a fault detection circuit coupled to the plurality of line terminals and configured to generate a fault detection signal in response to detecting a fault condition;

a wiring state detection circuit configured to detect a wiring state associated with the plurality of line terminals and the plurality of load terminals, the wiring state detection circuit being configured to generate a predetermined wiring state detection signal to indicate whether the plurality of line terminals are coupled to a source of AC power;

a gated switch actuator coupled to the wiring state detection circuit, the gated switch actuator being turned ON in response to the predetermined wiring state detection signal; and

an interrupting contact assembly coupled to the gated switch actuator, the interrupting contact assembly including interrupting contacts that provide electrical continuity between the plurality of line terminals and the plurality of load terminals in a reset state subsequent to the predetermined wiring state detection signal, the interrupting contact assembly being substantially prevented from effecting the reset state in a miswired state.

26. The device of claim 25, wherein the wiring state detection circuit further includes a switch element, the switch element being open circuited by the predetermined signal after a predetermined period of time to disable the wiring state detection circuit.

27. The device of claim 25, wherein the wiring state detection circuit further includes a switch element, the wiring state detection circuit being enabled when the switch element is in a closed state.

28. The device of claim 25, wherein the wiring state detection circuit includes at least one fusible element configured to open-circuit a predetermined period of time after the AC power is coupled to the hot line terminal and neutral line terminal.

29. The device of claim 25, wherein a line terminal, a load terminal and an electrical path are shorted together by the interrupting contact assembly when in the reset state and electrically disconnected from each other when in the tripped state.

30. An electrical wiring device comprising:

a plurality of line terminals including a line hot terminal and a line neutral terminal, a plurality of load terminals including a load hot terminal and a load neutral terminal;

a wiring state detection arrangement coupled between the plurality of line terminals, the wiring state detection arrangement including a circuit component configured to open circuit in response to detection of a proper wiring state;

a fault detection assembly coupled to the plurality of line terminals and configured to generate a fault detection signal in response to detecting a fault condition; and

an interrupting contact assembly coupled to the wiring state detection arrangement and the fault detection assembly, the interrupting contact assembly including four sets of interrupting contacts that are configured to provide electrical continuity between the plurality of line terminals and the plurality of load terminals in a reset state and configured to interrupt the electrical continuity in tripped state, the interrupting contact assembly being configured to trip the four sets of interrupting contacts in response to the fault detection signal, the interrupting contact assembly being substantially prevented from effecting the reset state until the circuit component open circuits in response to detection of the proper wiring state.

31. The device of claim 30, wherein a line terminal, a load terminal and an electrical path are shorted together by the interrupting contact assembly when in the reset state and electrically disconnected from each other when in the tripped state.

32. The device of claim 30, wherein the circuit component is a switch element.

33. The device of claim 30, wherein the circuit component is a fusible device.

34. The device of claim 30, wherein the circuit component is a rectifier device.

35. A protection device comprising:

a plurality of line terminals and a plurality of load terminals;

a fault detection circuit responsive to at least one fault condition in an electrical distribution system, the fault detection circuit comprising a fault sensor configured to generate a sensor signal in response to sensing perturbations in the electrical distribution system, the fault detection circuit also comprising a fault detector coupled to the sensor, the fault detector generating a fault detection signal based on predetermined signal characteristics of the sensor signal;

an interrupting contact assembly coupled to the fault detection circuit and configured to provide electrical continuity at least between the line hot terminal and the load hot terminal and the line neutral terminal and the load neutral terminal in a reset state, the interrupting contact assembly being configured to interrupt the electrical continuity in a tripped state in response to the fault detection signal; and

a miswire circuit coupled between the plurality of line terminals, the miswire circuit comprising a non-user accessible component characterized by a variable impedance, the non-user accessible component being configured to propagate signal perturbations greater than a predetermined amount for a predetermined period of time when power is applied to the miswire circuit, the signal perturbations being configured to enable the reset state to be effected thereafter, the signal perturbations propagated by the non-user accessible component being eliminated or substantially less than the predetermined amount after the predetermined period of time has elapsed.

36. The device of claim 35, wherein the miswire circuit is configured to prevent the reset state from being effected when AC power is connected to the plurality of load terminals,

37. The device of claim 35, wherein the non-user accessible component includes a switching element.

38. The device of claim 37, wherein the signal perturbations are greater than the predetermined threshold only when the switching element is closed.

39. The device of claim 37, wherein the switching element includes a fuse.

40. The device of claim 35, wherein the miswire circuit is configured such that perturbations propagated by the miswire circuit are not sensed by the fault sensor.

41. The device of claim 35, wherein the interrupting contact assembly comprises an actuator operably coupled to the fault detector.

42. The device of claim 41, wherein the miswire circuit is operably coupled to the actuator and not to either the fault sensor, the fault detector, or both.

43. The device of claim 35, wherein the interrupting contact assembly comprises four sets of interrupting contacts.

44. The device of claim 35, wherein the plurality of load terminals include user accessible face terminals for accommodating a user attachable plug.

45. The device of claim 35, wherein a line terminal, a load terminal and an electrical path are shorted together by the interrupting contact assembly when in the reset state and electrically disconnected from each other when in the tripped state.