Fail safe fault interrupter

• US 6,262,871 B1
• Filed: 05/27/1999
• Issued: 07/17/2001
• Est. Priority Date: 05/28/1998
• Status: Expired due to Term

• Current Assignee: X-L Synergy, LLC
• Original Assignee: X-L Synergy, LLC
• Inventors: Rubio, Edward, Hirsh, Stanley S., Nemir, David C.
• Primary Examiner(s): Leja, Ronald W.
• Application Number:
  US09/320,951
• Time in Patent Office: 782 Days
• Field of Search: 361/42-50, 324/423, 324/424, 324/418, 324/522, 324/523, 324/527-529
• US Class Current: 361/42
• CPC Class Codes: G01R 31/327 Testing of circuit interrupters, switches or circuit-breakers
• CPC Class Codes: H01H 2083/148 with primary windings formed of rigid copper conductors
• CPC Class Codes: H01H 2083/201 the other abnormal electrical condition being an arc fault
• CPC Class Codes: H01H 47/004 using plural redundant serial connected relay operated contacts in controlled circuit
• CPC Class Codes: H01H 83/144 with differential transformer
• CPC Class Codes: H02H 1/0015 Using arc detectors
• CPC Class Codes: H02H 3/044 Checking correct functioning of protective arrangements, e.g. by simulating a fault for differential current circuit breakers H02H3/335
• CPC Class Codes: H02H 3/335 the main function being self testing of the device

Abstract

An electronic test circuit for the self-testing of fault detection devices such as GFCI'"'"'s, AFCI'"'"'s and RCD'"'"'s enhances the safety of such devices by automatically testing the function of all components of these detection components without the need for manual intervention. This self-test device tests the functioning of the primary circuit breaker and detects failure modes such as welded contacts in the circuit breaker. By using a secondary, “one-shot” circuit breaker, power may be safely and automatically removed from a malfunctioning fault detection device.

Claims

1. A self-testing fault interrupt apparatus comprising:

a fault sensing component that detects an electrically unsafe operating condition;

a primary electrical current interrupting component for preventing power delivery upon the detection of an electrically unsafe operating condition;

a fault sense testing component that periodically and automatically disables the primary electrical current interrupting component, applies a simulated fault, verifies that the fault sensing component correctly detects this simulated fault, removes the simulated fault, and reenables the primary electrical current interrupting component if the fault sensing component correctly detected the simulated fault;

a circuit breaker testing component that, when the fault sensing component detects an electrically unsafe operating condition, automatically checks that the primary electrical current interrupting component has satisfactorily interrupted power delivery; and

a secondary electrical current interrupting component that permanently removes power from the self-testing fault interrupt apparatus if the fault sense testing component does not correctly detect a simulated fault or if the circuit breaker testing component determines that the primary electrical current interrupting component has not satisfactorily interrupted power delivery.

2. The apparatus of claim 1 wherein said fault sensing component detects a ground fault.

3. The apparatus of claim 2 wherein said fault sense testing component simulates a ground fault by imposing an electrical leakage path around a current sense transformer.

4. The apparatus of claim 1 wherein said fault sensing component detects an arcing fault.

5. The apparatus of claim 1 wherein said primary electrical current interrupting component comprises a solenoidal relay.

6. The apparatus of claim 5 wherein said fault sense testing component disables the primary electrical current interrupting component by disabling an actuating solenoid on said solenoidal relay.

7. The apparatus of claim 1 wherein said primary electrical current interrupting component comprises a member selected from the group consisting of solenoidal relays, bimetallic thermal circuit breakers, thermal magnetic circuit breakers, piezoelectric acutuated circuit breakers, shape memory alloy circuit breakers, or circuit breakers employing a fusible link.

8. The apparatus of claim 1 wherein said secondary current interrupting component comprises a one shot circuit breaker.

9. The apparatus of claim 1 wherein said secondary current interrupting component interrupts only one of two current carrying conductors.

10. The apparatus of claim 1 wherein said secondary current interrupting component comprises a member selected from the group consisting of solenoidal relays, bimetallic thermal circuit breakers, thermal magnetic circuit breakers, piezoelectric actuated circuit breakers, shape memory alloy actuated circuit breakers or circuit breakers employing a fusible link.

11. The apparatus of claim 1 wherein said secondary current interrupting component comprises conducting blades that are forced apart by an insulating wedge to interrupt power flow.

12. The apparatus of claim 11 wherein said insulating wedge is connected to a spring held in compression by a low wattage resistor.

13. The apparatus of claim 12 wherein said spring is released when a high electrical current is passed through said low wattage resistor.

14. The apparatus of claim 1 wherein said apparatus is connected to an outlet comprising manual test and reset means.

15. The apparatus of claim 1 wherein said apparatus is connected to an outlet not having manual test and reset means.

16. A self-testing fault interrupt method comprising the steps of:

a) detecting an electrically unsafe operating condition via a fault sensing component;

b) preventing power delivery upon the detection of an electrically unsafe operating condition via a primary electrical current interrupting component;

c) employing a fault sense testing component that periodically and automatically disables the primary electrical current interrupting component, applies a simulated fault, verifies that the fault sensing component correctly detects this simulated fault, removes the simulated fault, and reenables the primary electrical current interrupting component if the fault sensing component correctly detected the simulated fault;

d) employing a circuit breaker testing component that, when the fault sensing component detects an electrically unsafe operating condition, automatically checks that the primary electrical current interrupting component has satisfactorily interrupted power delivery; and

e) employing a secondary electrical current interrupting component that permanently removes power if the fault sense testing component does not correctly detect a simulated fault or if the circuit breaker testing component determines that the primary electrical current interrupting component has not satisfactorily interrupted power delivery.

17. The method of claim 16 wherein the detecting step detects a ground fault.

18. The method of claim 17 wherein the detecting step simulates a ground fault by imposing an electrical leakage path around a current sense transformer.

19. The method of claim 16 wherein the detecting step detects an arcing fault.

20. The method of claim 16 wherein the preventing step comprises preventing power delivery upon the detection of an electrically unsafe operating condition via a primary electrical current interrupting component comprising a solenoidal relay.

21. The method of claim 20 wherein the step of employing a fault sense testing component comprises disabling the primary electrical current interrupting component by disabling an actuating solenoid on the solenoidal relay.

22. The method of claim 16 wherein the step of employing a secondary electrical current interrupting component comprises employing a member selected from the group consisting of solenoidal relays, bimetallic thermal circuit breakers, thermal magnetic circuit breakers, piezoelectric acutuated circuit breakers, shape memory alloy circuit breakers, or circuit breakers employing a fusible link.

23. The method of claim 16 wherein the step of employing a secondary current interrupting component comprises employing a one shot circuit breaker.

24. The method of claim 16 wherein the step of employing a secondary current interrupting component comprises interrupting only one of two current carrying conductors.

25. The method of claim 16 wherein the step of employing a secondary current interrupting component comprises employing a member selected from the group consisting of solenoidal relays, bimetallic thermal circuit breakers, thermal magnetic circuit breakers, piezoelectric actuated circuit breakers, shape memory alloy actuated circuit breakers or circuit breakers employing a fusible link.

26. The method of claim 16 wherein the step of employing a secondary current interrupting component comprises employing conducting blades that are forced apart by an insulating wedge to interrupt power flow.

27. The method of claim 26 wherein employing conducting blades comprises connecting the insulating wedge to a spring held in compression by a low wattage resistor.

28. The method of claim 27 wherein the connecting step comprises releasing the spring when a high electrical current is passed through the low wattage resistor.

29. The method of claim 16 additionally comprising providing an outlet comprising manual test and reset means.

30. The method of claim 16 additionally comprising providing an outlet not having manual test and reset means.