System for eliminating arcing faults and power distribution system employing the same

• US 7,145,757 B2
• Filed: 01/13/2004
• Issued: 12/05/2006
• Est. Priority Date: 01/13/2004
• Status: Active Grant

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Shea, John J., Parry, Robert N.
• Primary Examiner(s): Sircus, Brian
• Assistant Examiner(s): Kitov, Zeev
• Application Number:
  US10/756,646
• Publication Number:
  US 20050152078A1
• Time in Patent Office: 1,057 Days
• Field of Search: 361/8, 361/2, 361/3, 361/9, 361/10
• US Class Current: 361/2
• CPC Class Codes: H02H 1/0023 sensing non electrical parameters, e.g. by optical, pneumatic, thermal or sonic sensors
• CPC Class Codes: H02H 3/023 by short-circuiting

Abstract

A shorting system, which eliminates persistent arcing faults in power distribution equipment, includes a first shorting switch having separable contacts, an actuation input and a fuse electrically connected in series with those contacts. A second shorting switch includes an actuation input and separable contacts, which are electrically connected in parallel with the series combination of the fuse and the first shorting switch contacts. A detection circuit includes one or more arcing light sensors and an actuation circuit. The light sensors detect arcing fault light and the actuation circuit responsively outputs a first trigger signal to the first shorting switch actuation input to close its contacts. For a persistent arcing fault, which is not eliminated by the first shorting switch, a predetermined time after the first trigger signal, the actuation circuit responsively outputs a second trigger signal to the second shorting switch actuation input to close its contacts.

Claims

1. A system for eliminating an arcing fault of power distribution equipment, said system comprising:

a first switch including a first input;

a circuit interrupter electrically connected in series with said first switch;

a second switch including a second input, said second switch being electrically connected in parallel with the series combination of said first switch and said circuit interrupter;

a circuit adapted to detect said arcing fault and responsively output a first signal to the first input of said first switch to close said first switch and, also, responsively output after a predetermined time a second signal to the second input of said second switch to close said second switch; and

wherein said circuit interrupter includes a closed state and an open state;

wherein said first switch is adapted to close in order to eliminate said arcing fault when said circuit interrupter is in the closed state;

wherein said arcing fault is a persistent arcing fault; and

wherein said second switch is adapted to close to eliminate said persistent arcing fault after said circuit interrupter is in the open state and after said predetermined time.

2. The system of claim 1 wherein said power distribution equipment includes two power lines;

and wherein said second switch is adapted for electrical connection to said power lines.

3. The system of claim 1 wherein said power distribution equipment includes a power line and a ground or neutral;

and wherein said second switch is adapted for electrical connection to said power line and said ground or neutral.

4. The system of claim 1 wherein said power distribution equipment includes a first power line and a second power line;

and wherein said second switch is adapted for electrical connection between said first power line and said second power line.

5. The system of claim 1 wherein said first switch and said second switch are shorting switches each of which comprises separable contacts and an operating mechanism including a closed state;

and wherein one of said first input and said second input actuates said operating mechanism and moves said operating mechanism to said closed state.

6. The system of claim 1 wherein said circuit interrupter is a fuse.

7. The system of claim 1 wherein said circuit comprises one sensor, which is adapted to detect arc light from said arcing fault.

8. The system of claim 1 wherein said circuit comprises a plurality of sensors each of which is adapted to detect arc light from said arcing fault.

9. The system of claim 1 wherein said arcing fault persists for greater than said predetermined time or is temporarily eliminated by said first switch before reoccurring before said predetermined time.

10. A shorting system for eliminating an arcing fault between a first conductor and a second conductor of a power distribution system, said shorting system comprising:

a first shorting switch comprising first separable contacts, a first operating mechanism and a first input to actuate said first operating mechanism to close said first separable contacts;

a fuse electrically connected in series with the first separable contacts of said first shorting switch;

a second shorting switch comprising second separable contacts, a second operating mechanism and a second input to actuate said second operating mechanism to close said second separable contacts, said second separable contacts being electrically connected in parallel with the series combination of said first separable contacts and said fuse, the parallel combination of said second separable contacts and the series combination of said first separable contacts and said fuse being adapted for electrical connection between the first and second conductors of said power distribution system; and

a circuit adapted to detect said arcing fault and responsively output a first signal to the first input of said first shorting switch to close said first shorting switch and, also, responsively output after a predetermined time a second signal to the second input of said second shorting switch to close said second shorting switch.

11. The shorting system of claim 10 wherein said power distribution system is a low voltage power distribution system;

and wherein said first and second shorting switches are adapted for operation between the first and second conductors of said low voltage power distribution system.

12. The shorting system of claim 10 wherein said power distribution system is a medium voltage power distribution system;

and wherein said first and second shorting switches are adapted for operation between the first and second conductors of said medium voltage power distribution system.

13. The shorting system of claim 10 wherein said power distribution system includes alternating current power having a line cycle period associated with at least one of said first and second conductors;

and wherein said predetermined time is about one-half to about two times said line cycle period.

14. The shorting system of claim 10 wherein said circuit includes an arcing light detector having an output and also includes an actuator having an input for the output of said arcing light detector and an output providing the first signal to the first input of said first shorting switch.

15. The shorting system of claim 10 wherein said circuit includes a display displaying that said first separable contacts of said first shorting switch are closed.

16. The shorting system of claim 10 wherein said circuit includes a display displaying that said second separable contacts of said second shorting switch are closed.

17. A power distribution system comprising:

a first conductor;

a second conductor;

a shorting system for eliminating an arcing fault between said first conductor and said second conductor, said shorting system comprising;

a first shorting switch including a first input,

a circuit interrupter electrically connected in series with said first shorting switch,

a second shorting switch including a second input, said second shorting switch being electrically connected in parallel with the series combination of said first shorting switch and said circuit interrupter, and

a circuit adapted to detect said arcing fault and responsively output a first signal to the first input of said first shorting switch to close said first shorting switch and, also, responsively output after a predetermined time a second signal to the second input of said second shorting switch to close said second shorting switch.

18. The power distribution system of claim 17 wherein said first conductor and said second conductor include alternating current power having a line cycle period associated with at least one of said first and second conductors;

and wherein said predetermined time is about one-half to about two times said line cycle period.

19. A system for eliminating an arcing fault of power distribution equipment, said system comprising:

a first switch including a first input;

a circuit interrupter electrically connected in series with said first switch;

a second switch including a second input, said second switch being electrically connected in parallel with the series combination of said first switch and said circuit interrupter;

a circuit adapted to detect said arcing fault and responsively output a first signal to the first input of said first switch to close said first switch and, also, responsively output after a predetermined time a second signal to the second input of said second switch to close said second switch; and

wherein said circuit comprises at least one sensor adapted to detect arc light from said arcing fault and responsively output at least one signal; and

an actuator including an input for at least one of said at least one signal and an output having said first signal responsive to said at least one of said at least one signal, said first switch being closed to eliminate said arcing fault when said circuit interrupter is also closed.

20. A system for eliminating an arcing fault of power distribution equipment, said system comprising:

a first switch including a first input;

a circuit interrupter electrically connected in series with said first switch;

a second switch including a second input, said second switch being electrically connected in parallel with the series combination of said first switch and said circuit interrupter;

a circuit adapted to detect said arcing fault and responsively output a first signal to the first input of said first switch to close said first switch and, also, responsively output after a predetermined time a second signal to the second input of said second switch to close said second switch; and

wherein said circuit comprises a sensor, which is adapted to detect arc light from said arcing fault and responsively output a third signal; and

wherein said circuit further comprises an activation time delay having an input for said third signal and an output responsive to said third signal after said predetermined time, an AND gate including a first input, which is electrically connected to the input of said time delay, a second input, which is electrically connected to the output of said time delay, and an output, and an actuator including an output having said second signal responsive to the output of said AND gate, said second switch being closed to eliminate said arcing fault when said circuit interrupter is open.

21. A shorting system for eliminating an arcing fault between a first conductor and a second conductor of a power distribution system, said shorting system comprising:

a first shorting switch comprising first separable contacts, a first operating mechanism and a first input to actuate said first operating mechanism to close said first separable contacts;

a fuse electrically connected in series with the first separable contacts of said first shorting switch;

a second shorting switch comprising second separable contacts, a second operating mechanism and a second input to actuate said second operating mechanism to close said second separable contacts, said second separable contacts being electrically connected in parallel with the series combination of said first separable contacts and said fuse, the parallel combination of said second separable contacts and the series combination of said first separable contacts and said fuse being adapted for electrical connection between the first and second conductors of said power distribution system;

a circuit adapted to detect said arcing fault and responsively output a first signal to the first input of said first shorting switch to close said first shorting switch and, also, responsively output after a predetermined time a second signal to the second input of said second shorting switch to close said second shorting switch; and

wherein said circuit includes an arcing light detector having an output with a third signal, an activation time delay having an input for the output of said arcing light detector and an output responsive to said third signal after said predetermined time, an AND gate including a first input, which is electrically connected to the input of said time delay, a second input, which is electrically connected to the output of said time delay, and an output, and an actuator having an input for the output of time delay and an output providing the second signal to the second input of said second shorting switch.

22. A shorting system for eliminating an arcing fault between a first conductor and a second conductor of a power distribution system, said shorting system comprising:

a first shorting switch comprising first separable contacts, a first operating mechanism and a first input to actuate said first operating mechanism to close said first separable contacts;

a fuse electrically connected in series with the first separable contacts of said first shorting switch;

a second shorting switch comprising second separable contacts, a second operating mechanism and a second input to actuate said second operating mechanism to close said second separable contacts, said second separable contacts being electrically connected in parallel with the series combination of said first separable contacts and said fuse, the parallel combination of said second separable contacts and the series combination of said first separable contacts and said fuse being adapted for electrical connection between the first and second conductors of said power distribution system;

a circuit adapted to detect said arcing fault and responsively output a first signal to the first input of said first shorting switch to close said first shorting switch and, also, responsively output after a predetermined time a second signal to the second input of said second shorting switch to close said second shorting switch; and

wherein said circuit includes a first arcing light detector having an output, a first actuator having an input for the output of said first arcing light detector and an output providing the first signal to the first input of said first shorting switch, a second arcing light detector having an output with a third signal, an activation time delay having an input for the output of said second arcing light detector and an output responsive to said third signal after said predetermined time, an AND gate including a first input, which is electrically connected to the input of said time delay, a second input, which is electrically connected to the output of said time delay, and an output, and a second actuator having an input for the output of time delay and an output providing the second signal to the second input of said second shorting switch.