Electrical device with miswire protection and automated testing

• US 8,299,799 B2
• Filed: 11/24/2010
• Issued: 10/30/2012
• Est. Priority Date: 02/17/2000
• Status: Expired due to Term

• Current Assignee: Pass And Seymour Incorporated (Legrand SA)
• Original Assignee: Pass And Seymour Incorporated (Legrand SA)
• Inventors: Finlay, David A. Sr., Macbeth, Bruce F., Morgan, Kent R., Murphy, Patrick J., Packard, Thomas N., Richards, Jeffrey C., Savicki, Gerald R. Jr., Weeks, Richard
• Primary Examiner(s): NATALINI, JEFF WILLIAM
• Application Number:
  US12/953,538
• Publication Number:
  US 20110115511A1
• Time in Patent Office: 706 Days
• Field of Search: 324/424
• US Class Current: 324/424
• CPC Class Codes: H01H 2071/044 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 Class Codes: H01H 83/04 with testing means for indicating the ability of the switch or relay to function properly

Abstract

The present invention is directed to an electrical wiring device that includes an actuator assembly that is responsive to the fault detection signal. The actuator assembly includes a breaker coil configured to generate an actuation force in response to being energized. A circuit interrupter includes four sets of movable contacts configured to be driven into a reset state in response to a reset stimulus, the four sets of movable contacts being configured to be driven into a tripped state in response to the actuation force. A self-test circuit is coupled to the plurality of line terminals or the at least one sensor. The self-test circuit is configured to automatically generate a test signal from time to time during a predetermined portion of an AC power line cycle. The self-test circuit is configured such that the test signal is sensed by the at least one sensor when the at least one sensor is operational, the sensor output signal being a function of the test signal. A monitor circuit is configured to monitor the fault detection circuit or the actuator assembly; the mechanical actuation force is substantially inhibited when the fault detection circuit or at least a portion of the actuator assembly properly respond to the test signal. The monitor circuit generates an end-of-life response if the fault detection circuit or the actuator assembly do not respond to the test signal within a predetermined period of time.

Claims

1. An electrical wiring device comprising:

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

at least one sensor coupled to the plurality of line terminals or the plurality of load terminals, the at least one sensor providing a sensor output signal corresponding to electrical perturbations propagating on the plurality of line terminals or the plurality of load terminals;

a fault detection circuit coupled to the at least one sensor, the fault detection circuit being configured to generate a fault detection signal if the sensor output signal substantially corresponds to at least one predetermined fault criterion;

an actuator assembly responsive to the fault detection signal, the actuator assembly including a breaker coil configured to generate an actuation force in response to being energized;

a circuit interrupter coupled to the actuator assembly, the circuit interrupter including four sets of movable contacts configured to be driven into a reset state in response to a reset stimulus, the four sets of movable contacts being configured to be driven into a tripped state in response to the actuation force;

a self-test circuit coupled to the plurality of line terminals or the at least one sensor, the self-test circuit being configured to automatically generate a test signal from time to time during a predetermined portion of an AC power line cycle, the self-test circuit being configured such that the test signal is sensed by the at least one sensor when the at least one sensor is operational, the sensor output signal being a function of the test signal; and

a monitor circuit configured to monitor the fault detection circuit or the actuator assembly, the mechanical actuation force being substantially inhibited when the fault detection circuit or at least a portion of the actuator assembly properly respond to the test signal, the monitor circuit generating an end-of-life response if the fault detection circuit or the actuator assembly do not respond to the test signal within a predetermined period of time.

2. The device of claim 1, wherein the test signal is generated during a negative half cycle of the AC line cycle.

3. The device of claim 1, further comprising at least one circuit coupled to the plurality of line terminals and configured to conduct a predetermined current flow if a proper wiring condition has been effected, a proper wiring condition being effected when the plurality of line terminals are connected to a source of AC power.

4. The device of claim 3, wherein the at least one circuit is configured to detect a miswiring condition, the miswiring condition being effected when the plurality of load terminals are connected to a source of AC power.

5. The device of claim 3, wherein at least a portion of the at least one circuit is disabled after the predetermined current conducts for a predetermined period of time.

6. The device of claim 3, wherein the four sets of movable contacts are inhibited from entering the reset state absent the predetermined current flow.

7. The device of claim 1, further comprising at least one circuit including at least one switch element, the at least one switch element opening independently of an opening of the four sets of interrupting contacts and closing independently of a closing of the four sets of interrupting contacts, the circuit interrupter assembly being substantially prevented from effecting the reset state until the at least one circuit conducts a predetermined signal derived from the source of AC power.

8. The device of claim 1, further comprising a control circuit coupled to the self-test circuit and the monitor circuit, the control circuit being configured to operate in a self test mode and in a non-self test mode in accordance with a predetermined schedule, the control circuit being configured to direct the self-test circuit to generate the test signal during a predetermined half-cycle of selected AC line cycles while in the self test mode in accordance with the predetermined schedule.

9. The device of claim 8, wherein the test signal is generated during a negative half cycle of the AC line cycle.

10. The device of claim 1, wherein the end-of-life response includes tripping the four sets of movable contacts.

11. The device of claim 1, wherein the end-of-life response includes introducing a discontinuity between the plurality of line terminals and the plurality of load terminals.

12. The device of claim 1, wherein the plurality of load terminals includes a plurality of feed-through load terminals and a plurality of receptacle load terminals, the four sets of movable contacts being arranged such that the plurality of feed-through load terminals and the plurality of receptacle load terminals are discontinuous in the tripped state.

13. The device of claim 12, wherein the four sets of interrupting contacts are at least partially disposed on four cantilevered members.

14. The device of claim 13, wherein the four cantilevered members include a first set of two cantilevered members and a second set of two cantilevered members, the first set of cantilevered members being configured to rotate around a first axis in a first direction and the second set of cantilevered members being configured to rotate around a second axis in a second direction opposite to the first direction, the four sets of interrupting contacts being configured to provide electrical continuity between the plurality of line terminals, the plurality of load terminals, and the plurality of receptacle load terminals in a reset state, the four sets of interrupting contacts being decoupled in a tripped state to interrupt the electrical continuity between the plurality of line terminals, the plurality of load terminals and the plurality of receptacle load terminals.

15. The device of claim 1, wherein the four sets of movable contacts are disposed in a bus bar arrangement.

16. The device of claim 1, wherein the actuator assembly includes at least a first solenoid and a second solenoid.

17. The device of claim 16, wherein the first solenoid and the second solenoid include a trip solenoid and a reset solenoid.

18. An electrical wiring device comprising:

a housing assembly including a plurality of line terminals, a plurality of load terminals, and a plurality of receptacle load terminals;

a circuit assembly including at least one signal detection circuit, the at least one signal detection circuit being configured to detect at least one signal having predetermined signal characteristics propagating on at least one of the plurality of line terminals or at least one of the plurality of load terminals, the circuit assembly being configured to generate a detection stimulus in response to the at least one signal detection circuit detecting the at least one signal;

an interrupting contact assembly coupled to the circuit assembly, the plurality of line terminals, the plurality of load terminals and the plurality of receptacle load terminals, the interrupting contact assembly including four sets of interrupting contacts being at least partially disposed on four cantilevered members, the four cantilevered members including a first set of two cantilevered members and a second set of two cantilevered members, the first set of two cantilevered members being configured to rotate around a first axis in a first direction and the second set of two cantilevered members being configured to rotate around a second axis in a second direction opposite to the first direction, the four sets of interrupting contacts being configured to provide electrical continuity between the plurality of line terminals, the plurality of load terminals, and the plurality of receptacle load terminals in a reset state, the four sets of interrupting contacts being decoupled in a tripped state in response to the detection stimulus to interrupt the electrical continuity between the plurality of line terminals, the plurality of load terminals and the plurality of receptacle load terminals; and

an automated test assembly coupled to the plurality of line terminals and the circuit assembly, the automated test assembly being configured to generate an automated test signal during a predetermined half-cycle of AC power and monitor a circuit assembly response to the automated test signal, the detection stimulus being substantially inhibited if the circuit assembly properly responds to the automated test signal, the automated test assembly generating an end-of-life response if the circuit assembly fails to respond to the automated test signal within a predetermined period of time.

19. The device of claim 18, wherein the predetermined half-cycle of AC power is a negative half cycle of the AC power.

20. The device of claim 18, further comprising at least one circuit coupled to the plurality of line terminals and configured to conduct a predetermined current flow if a proper wiring condition has been effected, a proper wiring condition being effected when the plurality of line terminals are connected to a source of AC power.

21. The device of claim 20, wherein the at least one circuit is configured to detect a miswiring condition, the miswiring condition being effected when the plurality of load terminals are connected to a source of AC power.

22. The device of claim 20, wherein at least a portion of the at least one circuit is disabled after the predetermined current flow conducts for a predetermined period of time.

23. The device of claim 18, at least one circuit includes at least one switch element, the at least one switch element opening independently of an opening of the four sets of interrupting contacts and closing independently of a closing of the four sets of interrupting contacts, the circuit interrupter assembly being substantially prevented from effecting the reset state until the at least one circuit conducts a predetermined signal derived from the source of AC power.

24. The device of claim 18, wherein the end-of-life response includes tripping the four sets of movable contacts.

25. The device of claim 18, wherein the end-of-life response includes introducing a discontinuity between the plurality of line terminals and the plurality of load terminals.

26. The device of claim 18, wherein the automated test assembly further includes:

a control circuit configured to operate in a self test mode and in a non-self test mode in accordance with a predetermined schedule, the control circuit being configured to cause the automated test signal to be generated during a predetermined half-cycle of selected AC line cycles while in the self test mode in accordance with the predetermined schedule,

an automated self test circuit responsive to the control circuit, the automated self test circuit being configured to generate the automated test signal, and

a monitor circuit configured to monitor a circuit assembly response to the automated test signal during the selected AC line cycles and make an end-of-life determination.

27. The device of claim 26, wherein the monitor circuit generates an end-of-life detection signal when the end-of-life determination indicates that the circuit assembly has failed to respond to the automated test signal.

28. The device of claim 27, wherein the end-of-life detection signal trips the four sets of movable contacts or introduces a discontinuity between the plurality of line terminals and the plurality of load terminals.

29. The device of claim 26, wherein the monitor circuit monitors the circuit assembly response in accordance with predetermined noise immunized decision criteria, the monitor circuit being further configured to generate the end-of-life detection signal based on the predetermined noise immunized decision criteria.

30. An electrical wiring device configured to be installed in an electrical distribution system having an AC power source, the AC power source providing an AC power line signal characterized by a first half cycle having a first AC polarity and a second half cycle having a second AC polarity, the device comprising:

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

at least one circuit coupled to the plurality of line terminals and configured to conduct a predetermined current flow if a proper wiring condition has been effected, a proper wiring condition being effected when the plurality of line terminals are connected to the AC power source;

at least one sensor coupled to the plurality of line terminals or the plurality of load terminals, the at least one sensor providing a sensor output signal corresponding to electrical perturbations propagating on the plurality of line terminals or the plurality of load terminals;

a fault detection circuit coupled to the at least one sensor, the fault detection circuit being configured to generate a fault detection signal if the sensor output signal substantially corresponds to at least one predetermined fault criterion;

an actuator assembly responsive to the fault detection circuit, the actuator assembly including a switch element and a solenoid, the switch element being turned ON in response to the fault detection signal to thereby conduct an energization signal through the solenoid, the solenoid exerting an actuation stimulus in response to the energization signal;

a circuit interrupter coupled to the actuator assembly, the circuit interrupter including a latching mechanism, the circuit interrupter being in a reset state when the latching mechanism is latched, the circuit interrupter being in a tripped state when the latching mechanism is unlatched, the latching mechanism being unlatched by the actuation stimulus, the circuit interrupter being inhibited from entering the reset state absent the predetermined current flow; and

an end of life detection circuit being configured to provide a test signal to the at least one sensor during the second half cycle, the end of life detection circuit being further configured to monitor the fault detection circuit or the actuator assembly, the fault detection circuit or the actuator assembly generating a test response to the test signal when operational and not generating the test response otherwise, the actuation stimulus being substantially inhibited when the fault detection circuit or the actuator assembly generate the test response.

31. The device of claim 30, wherein the circuit interrupter includes four sets of movable contacts.

32. The device of claim 31, wherein the plurality of load terminals includes a plurality of feed-through load terminals and a plurality of receptacle load terminals, the four sets of movable contacts being arranged such that the plurality of feed-through load terminals and the plurality of receptacle load terminals are discontinuous in the tripped state.

33. The device of claim 32, wherein the four sets of interrupting contacts are at least partially disposed on four cantilevered members.

34. The device of claim 33, wherein the four cantilevered members include a first set of two cantilevered members and a second set of two cantilevered members, the first set of two cantilevered members being configured to rotate around a first axis in a first direction and the second set of two cantilevered members being configured to rotate around a second axis in a second direction opposite to the first direction, the four sets of interrupting contacts being configured to provide electrical continuity between the plurality of line terminals, the plurality of load terminals, and the plurality of receptacle load terminals in a reset state, the four sets of interrupting contacts being decoupled in a tripped state to interrupt the electrical continuity between the plurality of line terminals, the plurality of load terminals and the plurality of receptacle load terminals.

35. The device of claim 31, wherein the four sets of movable contacts are disposed in a bus bar arrangement.

36. The device of claim 31, wherein the at least one circuit includes at least one switch element, the at least one switch element opening independently of an opening of the four sets of interrupting contacts and closing independently of a closing of the four sets of interrupting contacts, the circuit interrupter assembly being substantially prevented from effecting the reset state until the at least one circuit conducts a predetermined signal derived from the source of AC power.

37. The device of claim 30, wherein the actuator assembly includes at least a first solenoid and a second solenoid.

38. The device of claim 37, wherein the first solenoid and the second solenoid include a trip solenoid and a reset solenoid.

39. The device of claim 30, wherein the second half cycle is a negative half cycle of the AC line cycle.