Electrical wiring device

• US 7,133,266 B1
• Filed: 07/02/2004
• Issued: 11/07/2006
• Est. Priority Date: 11/21/2000
• Status: Expired due to Term

• Current Assignee: Pass & Seymour Incorporated (Legrand SA)
• Original Assignee: Pass & Seymour Incorporated (Legrand SA)
• Inventors: Finlay, David A.
• Primary Examiner(s): Sircus, Brian
• Assistant Examiner(s): Benenson, Boris
• Application Number:
  US10/884,304
• Time in Patent Office: 858 Days
• Field of Search: 361/42
• 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 protection device that includes a housing assembly having a hot line terminal, a neutral line terminal, a hot load terminal, and a neutral load terminal partially disposed therein. A miswire detection circuit is coupled to the hot line terminal, the neutral line terminal, the hot load terminal, and the neutral load terminal. The miswire detection circuit is configured to generate a miswire fault condition when AC power is coupled to the hot load terminal and the neutral load terminal and open circuit when AC power is coupled to the hot line terminal and neutral line terminal. A fault detection circuit is coupled to the miswire detection circuit. The fault detection circuit is configured to generate a fault detection signal in response to detecting at least one fault condition. The at least one fault condition including the miswire fault condition. An interrupting contact assembly is connected to the fault detection circuit. The interrupting contact assembly includes interrupting contacts that provide electrical continuity between the hot line terminal and the hot load terminal, and the neutral line terminal and the neutral load terminal in a reset condition. The interrupting contact assembly is also configured to open the interrupting contacts in response to receiving the fault detection signal.

Claims

1. An electrical wiring protection device comprising:

a hot line terminal, a neutral line terminal, a hot load terminal, and a neutral load terminal;

a miswire detection circuit coupled to the hot line terminal, the neutral line terminal, the hot load terminal, and the neutral load terminal, the miswire detection circuit being configured to generate a miswire fault condition when AC power is coupled to the hot load terminal and the neutral load terminal and open circuit when AC power is coupled to the hot line terminal and neutral line terminal;

a fault detection circuit coupled to the miswire detection circuit, the fault detection circuit being configured to generate a fault detection signal in response to detecting at least one fault condition, the at least one fault condition including the miswire fault condition; and

an interrupting contact assembly connected to the fault detection circuit, the interrupting contact assembly including interrupting contacts that provide electrical continuity between the hot line terminal and the hot load terminal, and the neutral line terminal and the neutral load terminal in a reset condition, the interrupting contact assembly being configured to open the interrupting contacts in response to receiving the fault detection signal.

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

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

4. The device of claim 1, wherein the miswire detection circuit includes at least one fusible element configured to open-circuit when 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 the miswire fault condition generates a differential current.

7. The device of claim 1, 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; and

a coil element coupled between the rectifier element and the interrupting contacts, the coil element being configured to trip the interrupting contacts when the rectifier in the ON state.

8. The device of claim 7, further comprising an indicator circuit coupled to the rectifier element, the indicator circuit being energized when the rectifier is short circuited to thereby indicate an end-of-life condition.

9. The device of claim 1, 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 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.

10. The device of claim 9, wherein the indicator element is energized to provide an trip condition indicator.

11. A method for detecting a miswire condition in an electric circuit, the electric circuit being configured to propagate power, the method comprising:

coupling a protection device to the electric circuit, the protection device including line terminals and load terminals partially disposed therein, and interrupting contacts configured to provide electrical continuity between the line terminals and the load terminals in a reset state and configured to trip in response to receiving a fault detection signal, whereby the electrical continuity between the line terminals and the load terminals is interrupted;

detecting a miswire condition when the power is connected to the load terminals;

generating a fault detection signal in response to the step of detecting a miswire condition;

tripping the interrupting contacts in response to the fault detection signal, whereby the electrical continuity between the line terminals and the load terminals is interrupted;

resetting the interrupting contacts to restore electrical continuity between the line terminals and the load terminals; and

repeating the steps of detecting, generating, and tripping if the power is connected to the load terminals.

12. The method of claim 11, wherein the miswire condition is generated by directing current into a conductive path coupled to the line terminals and the load terminals, the conductive path including at least one fusible element.

13. The method of claim 12, further comprising the step of opening the at least one fusible element when the AC power is coupled to the line terminals.

14. The method of claim 12, further comprising:

coupling the power to the line terminals, whereby current is directed into the conductive path;

tripping the interrupting contacts in response to the current within a first predetermined time period is elapsed;

opening the at least one fusible element after a second predetermined time period is elapsed, the second predetermined time period being greater than the first predetermined time period; and

resetting the interrupting contacts to restore electrical continuity between the line terminals and the load terminals.

15. The method of claim 13, wherein the step of repeating is not performed if power is coupled to the line terminals.

16. An electrical wiring protection device comprising:

a hot line terminal, a neutral line terminal, a hot load terminal, and a neutral load terminal;

a fault detection circuit coupled to the hot line terminal, the neutral line terminal, the hot load terminal, and the neutral load terminal, the fault detection circuit being configured to generate a fault detection signal in response to detecting at least one fault condition;

an interrupting contact assembly connected to the fault detection circuit, the interrupting contact assembly including interrupting contacts that provide electrical continuity between the hot line terminal and the hot load terminal, and the neutral line terminal and the neutral load terminal in a reset condition, the interrupting contact assembly being configured to open the interrupting contacts in response to receiving the fault detection signal; and

an indicator circuit coupled to the interrupting contact assembly and the fault detection circuit, the indicator circuit being configured to indicate a trip condition, a miswire condition, and an end-of-life condition.

17. The device of claim 16, further comprising a miswire detection circuit coupled to the hot line terminal, the neutral line terminal, the hot load terminal, and the neutral load terminal, the miswire detection circuit being configured to generate a miswire fault condition when AC power is coupled to the hot load terminal and the neutral load terminal and open circuit when AC power is coupled to the hot line terminal and neutral line terminal, the at least one fault condition including the miswire fault condition.

18. The device of claim 17, wherein the miswire detection circuit further comprises a switch element, the switch being configured to disable the miswire detection circuit in an open state.

19. The device of claim 18, wherein the miswire detection circuit is enabled when the switch is in a closed state.

20. The device of claim 17, wherein the fusible element includes at least one resistor.

21. The device of claim 16, wherein the interrupting contact assembly further comprises:

a rectifier element coupled to the fault detection circuit and the indicator circuit, the rectifier element being energized in response to the fault detection signal, the indicator circuit being energized by the rectifier to signal the tripped condition; and

a coil element coupled between the rectifier element and the interrupting contacts, the coil element being configured to trip the interrupting contacts when the rectifier is energized.

22. The device of claim 21, wherein the indicator circuit is energized in response to the rectifier element being short circuited to thereby indicate an end-of-life condition.

23. An electrical wiring protection device comprising:

a hot line terminal, a neutral line terminal, a hot load terminal, and a neutral load terminal;

a miswire detection circuit coupled to the hot line terminal, the neutral line terminal, the hot load terminal, and the neutral load terminal, the miswire detection circuit being configured to generate a miswire fault condition when AC power is coupled to the hot load terminal and the neutral load terminal and open circuit when AC power is coupled to the hot line terminal and neutral line terminal;

a fault detection circuit coupled to the miswire detection circuit, the fault detection circuit being configured to generate a fault detection signal in response to detecting at least one fault condition, the at least one fault condition including the miswire fault condition;

an interrupting contact assembly connected to the fault detection circuit, the interrupting contact assembly including interrupting contacts that provide electrical continuity between the hot line terminal and the hot load terminal, and the neutral line terminal and the neutral load terminal in a reset condition, the interrupting contact assembly being configured to open the interrupting contacts in response to receiving the fault detection signal; and

an indicator circuit coupled to the interrupting contact assembly and the fault detection circuit, the indicator circuit being configured to indicate a trip condition, a miswire condition, and an end-of-life condition.

24. A method for manufacturing an electrical wiring device, the method comprising:

assembling the electrical wiring device, the electrical wiring device including

a hot line terminal, a neutral line terminal, a hot load terminal, and a neutral load terminal,

a miswire detection circuit coupled to the hot line terminal, the neutral line terminal, the hot load terminal, and the neutral load terminal, the miswire detection circuit including a switch configured to disable the miswire detection circuit in an open state, the miswire detection circuit being configured to generate a miswire fault condition when the switch is in a closed state, the miswire fault condition being generated when AC power is coupled to the hot load terminal and the neutral load terminal and open circuit when AC power is coupled to the hot line terminal and neutral line terminal,

a fault detection circuit coupled to the miswire detection circuit, the fault detection circuit being configured to generate a fault detection signal in response to detecting at least one fault condition, the at least one fault condition including the miswire fault condition, and

interrupting contacts configured to provide electrical continuity between the hot line terminal and the hot load terminal, and the neutral line terminal and the neutral load terminal in a reset condition and trip in response to receiving a fault detection signal, whereby the electrical continuity between the hot line terminal and the hot load terminal, and the neutral line terminal and the neutral load terminal is interrupted;

opening the switch to thereby disable the miswire detection circuit;

performing at least one test on the electrical wiring device; and

closing the switch to thereby enable the miswire detection circuit.

25. An electrical wiring device comprising:

line terminals and load terminals;

a fault detection circuit coupled to the line terminals and/or the load terminals, the fault detection circuit being configured to generate a fault detection signal in response to detecting at least one fault condition;

a wiring detection circuit coupled to the line terminals and/or the load terminals, the wiring detection circuit including at least one electrical component in series with a switch, the at least one electrical component being coupled to a control input of a silicon controlled rectifier, the wiring detection circuit being configured to propagate a current signal through the at least one electrical component when the switch is closed and power is applied to the line terminals; and

an interrupting contact assembly connected to the fault detection circuit and the wiring detection circuit, the interrupting contact assembly including interrupting contacts configured to provide electrical continuity between the line terminals and the load terminals in a closed state and configured to open the interrupting contacts in response to receiving the fault detection signal, the interrupting contact assembly being in the open state absent the current signal flowing through the at least one electrical component.

26. The device of claim 25, wherein the at least one fault condition includes a ground fault, an arc fault, and/or a simulated fault generated by a test circuit.

27. The device of claim 25, wherein the current signal is propagated for a predetermined period of time.

28. The device of claim 27, wherein the at least one electrical component includes a fuse element that opens at the conclusion of the predetermined period of time.

29. The device of claim 28, wherein the fuse element includes a resistor.

30. An electrical wiring device comprising:

line terminals and load terminals;

at least one detection circuit coupled to the line terminals and/or the load terminals, the at least one detection circuit being configured to generate a signal in response to detecting a wiring condition wherein power is applied to the line terminals; and

an interrupting contact assembly coupled to the at least one detection circuit, the interrupting contact assembly including interrupting contacts that are configured to provide electrical continuity between the line terminals and the load terminals in a closed state and configured to interrupt the electrical continuity in an open state, the interrupting contact assembly being in the open state absent the signal being provided by the at least one detection circuit.

31. The device of claim 30, wherein the at least one detection circuit includes at least one electrical component in series with a switch an electrical component.

32. The device of claim 31, wherein the signal is a current that flows through the at least one electrical component for a predetermined period of time.

33. The device of claim 32, wherein the at least one electrical component includes a fuse element that opens at the conclusion of the predetermined period of time.

34. The device of claim 33, wherein the fuse element includes a resistor.

35. The device of claim 34, wherein the at least one detection circuit includes a fault detection circuit coupled to the line terminals and/or the load terminals, the fault detection circuit being configured to generate a fault detection signal in response to detecting at least one fault condition.

36. The device of claim 35, wherein the interrupting contacts are configured to interrupt the electrical continuity in response to the fault detection signal.

37. The device of claim 30, wherein the at least one detection circuit includes a wiring detection circuit coupled to the line terminals and/or the load terminals, the wiring detection circuit including at least one electrical component in series with a switch, the at least one electrical component being coupled to a control input of a silicon controlled rectifier, the wiring detection circuit being configured to propagate the signal through the at least one electrical component when the switch is closed and power is applied to the line terminals.

38. The device of claim 37, wherein the signal is a current that flows through the at least one electrical component for a predetermined period of time.

39. The device of claim 38, wherein the at least one electrical component includes a fuse element that opens at the conclusion of the predetermined period of time.

40. The device of claim 39, wherein the fuse element includes a resistor.

41. The device of claim 30, wherein the at least one detection circuit includes a miswire detection circuit configured to generate a miswire fault condition when power is coupled to load terminals.

42. The device of claim 41, wherein the at least one detection circuit includes a fault detection circuit coupled to the miswire detection circuit, the fault detection circuit being configured to generate a fault detection signal in response to detecting at least one fault condition, the at least one fault condition including the miswire fault condition.

43. The device of claim 42, wherein the interrupting contacts are configured to interrupt the electrical continuity in response to the fault detection signal.

44. An electrical wiring device comprising:

line terminals and load terminals;

an interrupting contact assembly coupled to the line terminals and the load terminals, the interrupting contact assembly including a trip solenoid coupled to interrupting contacts, the interrupting contacts being configured to provide electrical continuity between the line terminals and the load terminals in a reset state and interrupt the electrical continuity in an open state; and

at least one detection circuit configured to detect power coupled to the line terminals, the detection circuit permitting the interrupting contacts to be driven into the reset state without an enabling signal being received from the trip solenoid.

45. The device of claim 44, wherein the at least one detection circuit is configured to generate a signal in response to detecting power coupled to the line terminals.

46. The device of claim 45, wherein the at least one detection circuit includes a fault detection circuit coupled to the line terminals and/or the load terminals, the fault detection circuit being configured to generate a fault detection signal in response to detecting at least one fault condition.

47. The device of claim 45, wherein the interrupting contacts are configured to interrupt the electrical continuity in response to the fault detection signal.

48. The device of claim 45, wherein the at least one detection circuit includes a wiring detection circuit coupled to the line terminals and/or the load terminals, the wiring detection circuit including at least one electrical component in series with a switch, the at least one electrical component being coupled to a control input of a silicon controlled rectifier, the wiring detection circuit being configured to propagate the signal through the at least one electrical component when the switch is closed and power is applied to the line terminals.

49. The device of claim 44, wherein the at least one detection circuit includes a miswire detection circuit configured to generate a miswire fault condition when power is coupled to load terminals.

50. The device of claim 49, wherein the at least one detection circuit includes a fault detection circuit coupled to the miswire detection circuit, the fault detection circuit being configured to generate a fault detection signal in response to detecting at least one fault condition, the at least one fault condition including the miswire fault condition.

51. The device of claim 50, wherein the interrupting contacts are configured to interrupt the electrical continuity in response to the fault detection signal.