CIRCUIT INTERRUPTER INCLUDING TEST CIRCUIT

• US 20090040666A1
• Filed: 08/07/2007
• Published: 02/12/2009
• Est. Priority Date: 08/07/2007
• Status: Abandoned Application

• Current Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: ELMS, ROBERT T., Parker, Kevin L., Miller, Theodore J.
• Application Number:
  US11/834,935
• Publication Number:
  US 20090040666A1
• Time in Patent Office: Days
• US Class Current: 361/42
• CPC Class Codes: H02H 1/0015 Using arc detectors
• CPC Class Codes: H02H 3/334 with means to produce an artificial unbalance for other protection or monitoring reasons or remote control H02H3/338 takes precedence

Abstract

A circuit interrupter includes separable contacts, a neutral conductor, an operating mechanism structured to open and close the separable contacts, and a plurality of current sensors structured to sense at least current flowing through the separable contacts. Each of the current sensors includes a primary winding and a secondary winding, the primary winding being electrically connected in series with the separable contacts. A trip mechanism is structured to cooperate with the secondary winding of the current sensors and the operating mechanism to trip open the separable contacts. A test circuit tests the current sensors and the trip mechanism. The test circuit is structured to apply a test signal directly to the secondary winding of each of the current sensors.

Claims

1. A circuit interrupter comprising:

separable contacts;

a neutral conductor;

an operating mechanism structured to open and close said separable contacts;

at least one current sensor structured to sense at least current flowing through said separable contacts, each of said at least one current sensor comprising a primary winding and a secondary winding, said primary winding being electrically connected in series with said separable contacts;

a trip mechanism structured to cooperate with the secondary winding of said at least one current sensor and said operating mechanism to trip open said separable contacts; and

a test circuit for testing said at least one current sensor and said trip mechanism, said test circuit being structured to apply a test signal directly to the secondary winding of each of said at least one current sensor.

2. The circuit interrupter of claim 1 wherein said circuit interrupter is a ground fault circuit interrupter;

and wherein said at least one current sensor is a current transformer structured to sense a difference between said current flowing through said separable contacts and a current flowing through said neutral conductor.

3. The circuit interrupter of claim 1 wherein said circuit interrupter is an arc fault circuit interrupter;

wherein said current flowing through said separable contacts includes frequencies greater than about 100 kHz; and

wherein said at least one current sensor is a current transformer structured to sense said current flowing through said separable contacts including said frequencies.

4. A circuit interrupter comprising:

separable contacts;

a neutral conductor;

an operating mechanism structured to open and close said separable contacts;

at least one current sensor structured to sense at least current flowing through said separable contacts;

a trip mechanism comprising at least one of a ground fault analog sensing circuit and an arc fault analog sensing circuit cooperating with said at least one current sensor, said trip mechanism being structured to cooperate with said at least one current sensor and said operating mechanism to trip open said separable contacts;

a reset mechanism structured to cooperate with said operating mechanism to close said separable contacts after said operating mechanism trips open said separable contacts;

at least one annunciator; and

a test circuit structured to periodically test said at least one current sensor and said at least one of the ground fault analog sensing circuit and the arc fault analog sensing circuit, to activate said at least one annunciator responsive to a failure of a periodic test and to cause said trip mechanism to cooperate with said operating mechanism to trip open said separable contacts responsive to said failure of said periodic test, and, otherwise, to maintain said at least one annunciator inactive and maintain said separable contacts being closed responsive to passage of said periodic test.

5. The circuit interrupter of claim 4 wherein said test circuit is further structured to permanently activate said at least one annunciator responsive to failure of said periodic test.

6. The circuit interrupter of claim 4 wherein said test circuit is further structured to periodically test said at least one current sensor and said at least one of the ground fault analog sensing circuit and the arc fault analog sensing circuit about once per day.

7. The circuit interrupter of claim 4 wherein said at least one annunciator is an audible indicator.

8. The circuit interrupter of claim 4 wherein said at least one annunciator is a visible indicator.

9. The circuit interrupter of claim 4 wherein said circuit interrupter is a ground fault circuit interrupter;

and wherein said at least one current sensor is a current transformer structured to sense a difference between said current flowing through said separable contacts and a current flowing through said neutral conductor.

10. The circuit interrupter of claim 4 wherein said circuit interrupter is an arc fault circuit interrupter;

and wherein said at least one current sensor is a current transformer structured to sense said current flowing through said separable contacts.

11. The circuit interrupter of claim 4 wherein said circuit interrupter is a ground fault/arc fault circuit interrupter;

wherein said at least one current sensor comprises a first current transformer structured to sense a difference between said current flowing through said separable contacts and a current flowing through said neutral conductor, and a second current transformer structured to sense said current flowing through said separable contacts.

12. The circuit interrupter of claim 11 wherein said at least one annunciator is a first annunciator corresponding to said ground fault analog sensing circuit and said first current transformer, and a second annunciator corresponding to said arc fault analog sensing circuit and said second current transformer.

13. The circuit interrupter of claim 12 wherein said test circuit is further structured to periodically test both of said ground fault analog sensing circuit and said first current transformer, and said arc fault analog sensing circuit and said second current transformer;

and wherein said test circuit is further structured to activate said first annunciator responsive to failure of a test of said ground fault analog sensing circuit and said first current transformer and to activate said second annunciator responsive to failure of a test of said arc fault analog sensing circuit and said second current transformer.

14. A circuit interrupter comprising:

separable contacts;

a neutral conductor;

an operating mechanism structured to open and close said separable contacts;

a first current sensor structured to sense a difference between a current flowing through said separable contacts and a current flowing through said neutral conductor;

a first analog sensing circuit cooperating with said first current sensor;

a second current sensor structured to sense current flowing through said separable contacts;

a second analog sensing circuit cooperating with said second current sensor;

a trip mechanism comprising a ground fault detector cooperating with said first analog sensing circuit and an arc fault detector cooperating with said second analog sensing circuit, said trip mechanism being structured to cooperate with said first analog sensing circuit, said second analog sensing circuit and said operating mechanism to trip open said separable contacts; and

a test circuit structured to provide both of a first test of said first current sensor and said first analog sensing circuit and a second test of said second current sensor and said second analog sensing circuit, and to cause said trip mechanism to cooperate with said operating mechanism to trip open said separable contacts responsive to failure of at least one of said first test and said second test, and, otherwise, to maintain said separable contacts being closed responsive to passage of both of said first test and said second test,

wherein said first current sensor and said first analog sensing circuit have a first transfer function,

wherein said second current sensor and said second analog sensing circuit have a second transfer function, and

wherein said test circuit is further structured to provide a first test signal to said first current sensor and said first analog sensing circuit to test said first transfer function without causing a ground fault to be detected by said ground fault detector, and a second test signal to said second current sensor and said second analog sensing circuit to test said second transfer function without causing an arc fault to be detected by said arc fault detector, in order to provide both of said first test and said second test before causing said trip mechanism to cooperate with said operating mechanism to trip open said separable contacts.

15. The circuit interrupter of claim 14 wherein said current flowing through said separable contacts has a first frequency;

wherein said first test signal has a second frequency, which is one-half of said first frequency; and

wherein said test circuit is further structured to input a first signal from said first analog sensing circuit and determine if said first signal is less than a negative predetermined value in order to pass said first test.

16. The circuit interrupter of claim 15 wherein said first current sensor is a current transformer including a coil;

and wherein said test circuit is further structured to input a second signal from said first analog sensing circuit and determine if said second signal is greater than a positive predetermined value in order to confirm that said coil is continuous and to pass said first test.

17. The circuit interrupter of claim 14 wherein said current flowing through said separable contacts has a first line frequency;

wherein said second test signal has a second frequency, which is substantially greater than said first line frequency and which is greater than about 100 kHz; and

wherein said test circuit is further structured to input a third signal from said second analog sensing circuit and determine if said third signal is greater than a positive predetermined value in order to pass said second test.

18. The circuit interrupter of claim 17 wherein said second current sensor is a current transformer structured to sense said current flowing through said separable contacts including said second frequency.

19. The circuit interrupter of claim 18 wherein said current transformer is further structured to resonate in response to said second frequency.

20. A circuit interrupter comprising:

separable contacts;

a neutral conductor;

an operating mechanism structured to open and close said separable contacts;

a first current sensor structured to sense a difference between a current flowing through said separable contacts and a current flowing through said neutral conductor;

a first analog sensing circuit cooperating with said first current sensor;

a second current sensor structured to sense current flowing through said separable contacts;

a second analog sensing circuit cooperating with said second current sensor;

a third current sensor structured to sense current flowing through said separable contacts;

a third analog sensing circuit cooperating with said third current sensor;

a trip mechanism comprising a ground fault detector, a parallel arc fault detector and a series arc fault detector;

a test pushbutton; and

a test circuit structured to provide all of (i) a first test of said first current sensor and said first analog sensing circuit, (ii) a second test of said second current sensor and said second analog sensing circuit, and (iii) a third test of said third current sensor and said third analog sensing circuit, to cause said trip mechanism to cooperate with said operating mechanism to trip open said separable contacts responsive to passage of all of said first test, said second test and said third test, and, otherwise, to maintain said separable contacts being closed responsive to failure of at least one of said first test, said second test and said third test.