Arc fault circuit interrupter

• US 9,577,420 B2
• Filed: 11/25/2013
• Issued: 02/21/2017
• Est. Priority Date: 07/29/2011
• Status: Active Grant

• Current Assignee: Leviton Manufacturing Company Incorporated
• Original Assignee: Leviton Manufacturing Company Incorporated
• Inventors: Ostrovsky, Michael, Libretto, John, Jansen, Ronald, Kamor, Michael, Kevelos, Adam
• Primary Examiner(s): Tran, Thienvu
• Assistant Examiner(s): Comber, Kevin J
• Application Number:
  US14/089,700
• Publication Number:
  US 20140218044A1
• Time in Patent Office: 1,184 Days
• Field of Search: 361/42
• US Class Current: 1/1
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• CPC Class Codes: G08B 21/185 Electrical failure alarms
• 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 3/16 responsive to fault current to earth, frame or mass with balanced or differential arrangement H02H3/26 ; monitoring earth connection H02H5/105

Abstract

An arc fault circuit interrupter is disclosed. This arc fault circuit interrupter can include any one or more of three different sensors such as a high frequency sensor, and any one of lower frequency sensors such as a current sensor or a differential sensor. The arc fault circuit interrupter can be configured as an in line arc fault circuit interrupter installed in a wall box. In addition, the arc fault circuit interrupter can include a processor configured to determine any one of a series arc fault, or a parallel arc fault.

Claims

1. An arc fault circuit interrupter, comprising:

a high-frequency sensor configured to detect high frequency components of a differential electrical current flow between a phase conductive path and a neutral conductive path, wherein the high frequency sensor is configured to provide a first signal representative of the high frequency components;

a current sensor configured to measure the electrical current flow and provide a second signal representative of the electrical current measurement;

a processor including;

an input structure configured to receive a third signal representative of a filtered version of the first signal and a fourth signal representative of a filtered version of the second signal;

logic configured to determine based on the third signal and the fourth signal that an arc fault has occurred; and

an output structure configured to generate a trigger signal; and

a reset lockout circuit configured to;

receive the trigger signal;

in response to the trigger signal, cause a circuit interrupt switch to open; and

prevent the circuit interrupt switch from closing until a reset signal is received from the processor.

2. The arc fault circuit interrupter of claim 1, wherein the high-frequency sensor is configured to sense signals in a range between 2 MHz and 440 MHz.

3. The arc fault circuit interrupter of claim 1, wherein the current sensor is further configured to sense signals in a range between 0 MHz and 2 MHz.

4. The arc fault circuit interrupter of claim 1, wherein the arc fault is a series fault along one of a phase conductive path and a neutral conductive path.

5. The arc fault circuit interrupter of claim 1, wherein the arc fault is a parallel fault, and is one of an arc fault between:

a phase conductive path and a neutral conductive path;

a phase conductive path and a ground conductive path; and

a neutral conductive path and a ground conductive path.

6. The arc fault circuit interrupter of claim 1, wherein the reset lockout circuit includes a silicon-controlled rectifier (SCR) in series with a plunger coil, and wherein the trigger signal causes the SCR to conduct such that current flows through the plunger coil, thereby controlling a plunger to forcibly open the circuit interrupt switch.

7. The arc fault circuit interrupter of claim 6, wherein the reset signal causes the SCR to stop conducting such that current stops flowing through the plunger coil and the circuit interrupt switch is allowed to close.

8. The arc fault circuit interrupter of claim 1, wherein the electrical current flow is a current flowing through one of a phase conductive path and a neutral conductive path.

9. The arc fault circuit interrupter of claim 1, wherein the electrical current flow is a summation of current flowing through a phase conductive path and a neutral conductive path.

10. The arc fault circuit interrupter of claim 1, wherein the electrical current flow is a difference of current flowing through a phase conductive path and a neutral conductive path.

11. The arc fault circuit interrupter of claim 1, wherein the high-frequency sensor detects high frequency components on a pair of line-side conductors.

12. The arc fault circuit interrupter of claim 1, wherein the high-frequency sensor detects high frequency components on one of a phase conductive path and a neutral conductive path.

13. The arc fault circuit interrupter of claim 1, further comprising an audible indicator, wherein the processor causes the audible indicator to emit a sound after the processor determines that an arc fault has occurred.

14. A circuit interrupter, comprising:

a detector circuit configured to detect an arc fault and provide an indication of the arc fault;

a processing circuit configured to receive the indication of the arc fault and generate a trigger signal in response to the indication;

an interruption circuit configured to receive the trigger signal and cause an interruption signal in response to the indication; and

a switch circuit configured to open two closed switches in response to the interruption signal, wherein the two switches when open electrically isolate a pair of load side conductors from a corresponding pair of line side conductors;

wherein the detector circuit includes a high-frequency detector and a low-frequency detector, wherein the low frequency detector is configured to detect a non-differential current, and wherein the high-frequency detector is a differential high frequency detector arranged to detect a differential electrical current flow between a phase conductive path and a neutral conductive path.

15. The circuit interrupter of claim 14, wherein the detector circuit includes an electrical current detector, and the electrical current detector is a differential current detector disposed to detect a differential current between a phase conductive path and a neutral conductive path.

16. The circuit interrupter of claim 14, wherein the detector circuit includes an electrical current detector, and the electrical current detector is a summing current detector disposed to detect a summation of current flowing in a phase conductive path and a neutral conductive path.

17. The circuit interrupter of claim 14, wherein the processing circuit includes an analog processing part and a digital microprocessor.

18. The circuit interrupter of claim 14, wherein the interruption circuit includes a silicon-controlled rectifier (SCR) and an inductor in series with the SCR, and the trigger signal is applied to a gate of the SCR such that the SCR conducts and current flows through the inductor to control an electromagnetic plunger to forcibly open at least one of the two closed switches.

19. The circuit interrupter of claim 14, wherein for each of the two switches, the switch includes:

a first contact to a load side conductor; and

a second contact to a line side conductor;

wherein the first contact is electrically and physically connected to the second contact, and opening the switch includes breaking the electrical and physical connection between the first contact and the second contact.