Arc fault circuit breaker apparatus and related methods

• US 6,417,671 B1
• Filed: 11/07/2000
• Issued: 07/09/2002
• Est. Priority Date: 11/07/2000
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Tiemann, Jerome J.
• Primary Examiner(s): Le, N.
• Assistant Examiner(s): Nguyen, Vincent Q.
• Application Number:
  US09/707,405
• Time in Patent Office: 609 Days
• Field of Search: 324/536, 324/117.H, 324/509, 324/524, 361/42, 361/44
• US Class Current: 324/509
• CPC Class Codes: H02H 3/105 responsive to excess current and fault current to earth
• CPC Class Codes: H02H 3/33 using summation current transformers H02H3/347 takes precedence

Abstract

A circuit for detecting arc faults and over-currents includes two overcurrent detection circuits and a ground fault circuit referenced to a single ground and configured to receive power from a single power supply. Each over-current detection circuit includes a Hall effect current sensor configured to determine a current in a corresponding pole conductor. A method for detecting arc faults and over-currents includes determining a current in a pole conductor using a sensor not in contact with the pole conductor. This circuit and method allow a two-pole breaker circuit to be configured in a form similar to a one-pole circuit and eliminate tripping caused by spurious signals from bimetal sensors.

Claims

1. A method for detecting arc faults and over-currents in a circuit, said method comprising:

determining a current in a first pole conductor using a first over-current detection circuit not in contact with the first pole conductor;

determining a current in a second pole conductor using a second over-current detection circuit not in contact with the second pole conductor; and

determining a ground fault between at least one of the first pole conductor and a neutral conductor and the second pole conductor and the neutral conductor using a ground fault detection circuit including a transformer surrounding the first pole conductor, the second pole conductor, and the neutral conductor.

2. A method in accordance with claim 1 wherein said step of powering a ground fault circuit and two over-current detection circuits comprises the step of using a half-wave bridge power supply.

3. A method in accordance with claim 1 wherein said determining a current in a first pole conductor using a first over-current detection circuit not in contact with the first pole conductor comprises determining a current in a first pole conductor using a first Hall Effect Sensor, said determining a current in a second pole conductor using a second over-current detection circuit not in contact with the second pole conductor comprises determining a current in a second pole conductor using a second Hall Effect Sensor.

4. A method in accordance with claim 1 further comprising powering the ground fault circuit, the first over-current detection circuit, and the second over-current detection circuit using a single power supply.

5. A method in accordance with claim 1 further comprising actuating a trip device when an over-current is sensed by at least one of the first over-current detection circuit, the second over-current detection circuit, and the ground fault detection circuit.

6. A method in accordance with claim 1 wherein said step of powering a ground fault circuit and two over-current detection circuits comprises the step of using a full-wave power supply.

7. A method in accordance with claim 6 wherein said step of using a full-wave power supply comprises using a full-wave bridge power supply.

8. A method in accordance with claim 1 further comprising the step of referencing the ground fault circuit and over-current detection circuits to a single ground.

9. A method in accordance with claim 8 wherein the single ground is at a potential of a neutral line conductor.

10. A circuit for detecting arc faults and over-currents in a system, said circuit comprising:

a first over-current detection circuit not in contact with a first pole conductor configured to determine a current in a said first pole conductor;

a second over-current detection circuit not in contact with a second pole conductor configured to determine a current in a said second pole conductor; and

a ground fault detection circuit comprising a current transformer, wherein said current transformer is surrounding said first pole conductor, said second pole conductor, and a neutral conductor.

11. A circuit in accordance with claim 10 wherein said single power supply comprises a half-wave bridge power supply.

12. A circuit in accordance with claim 10 further comprising a single power supply electrically connected to said first over-current detection circuit, said second over-current detection circuit and said ground fault detection circuit.

13. A circuit in accordance with claim 10 wherein said single power supply comprises a full-wave power supply.

14. A circuit in accordance with claim 13 wherein said full-wave power supply comprises a full-wave bridge power supply.

15. A circuit in accordance with claim 10 wherein said first over-current detection circuit comprises a first Hall Effect Sensor electrically connected to a first operational amplifier, said second over-current detection circuit comprises a second Hall Effect Sensor electrically connected to a second operational amplifier, and said ground fault detection circuit comprises a sensor electrically connected to a third operational amplifier.

16. A circuit in accordance with claim 15 further comprising a trip device electrically connected to said first operational amplifier, said second operational amplifier, and said third operational amplifier.

17. A circuit in accordance with claim 10 further comprising a single ground to which said ground fault circuit and said over-current detection circuits are referenced.

18. A circuit in accordance with claim 17 wherein said single ground is at a potential of a neutral line conductor.

19. A circuit in accordance with claim 17 wherein said single power supply comprises a half-wave bridge power supply further comprising positive and negative rails, said positive rail configured at a neutral potential, said single ground configured at a potential of said negative rail.