CIRCUIT BREAKER SIGNALING SYSTEM FOR CONTROL OF AN ARC FAULT DETECTION SYSTEM

• US 20140055886A1
• Filed: 08/24/2012
• Published: 02/27/2014
• Est. Priority Date: 08/24/2012
• Status: Active Grant

• Current Assignee: Schneider Electric USA, Inc. (Schneider Electric SE)
• Original Assignee: Schneider Electric USA, Inc. (Schneider Electric SE)
• Inventors: Liptak, Julius Michael, Spangenberg, Richard Gerhard
• Granted Patent: US 8,964,344 B2
• Time in Patent Office: Days
• US Class Current: 361/2
• CPC Class Codes: H01H 33/26 Means for detecting the presence of an arc or other discharge
• CPC Class Codes: H02H 1/0023 sensing non electrical parameters, e.g. by optical, pneumatic, thermal or sonic sensors
• CPC Class Codes: H02H 7/222 for switches

Abstract

In an electrical distribution system an arc management system has a transducer mounted in proximity to the circuit breaker for detecting and signaling a secondary effect of an overcurrent event within the case of the circuit breaker. The transducer provides an additional input to an arc fault detection system using other detectors and thus helps to control nuisance activations of the arc extinguishing mechanism. The system is particularly suited for circuit breakers without electronics, or the like, allowing for retrofit of existing systems. The system may monitor and act upon the excessive duration of the secondary effects.

Claims

1. An arc fault signaling system for a circuit breaker, comprising

a circuit breaker,

a transducer mounted outside of the circuit breaker case in proximity to the circuit breaker for detecting and signaling a secondary effect of an overcurrent event within the case of the circuit breaker, and

an arc fault detection system for receiving and processing the transducer signal.

2. A method of operating an arc fault detection system in an electrical enclosure, comprising:

applying a transducer in proximity to the case of a circuit breaker within the enclosure,

detecting a secondary effect of an overcurrent event within the circuit breaker with said transducer,

transmitting a signal from the transducer when detecting said secondary effect of an overcurrent event to an arc fault detection system, and

receiving and processing said signal at the arc fault detection system as a filter for operation of an arc extinguishing mechanism of the arc fault detection system.

3. The method of claim 2 wherein said transducer is selected from the group including:

a magnetic sensor, a vibration sensor, a radio frequency sensor, and a thermal sensor.

4. The method of claim 3 wherein the transducer is a magnetic sensor located on the exterior of the circuit breaker case in proximity to a current path within the circuit breaker.

5. The method of claim 4 wherein the magnetic sensor is selected from the group including a reed switch, a hall effect transducer, and an inductor coil.

6. The method of claim 3 wherein the transducer is a vibration sensor located on the exterior of the circuit breaker case in proximity to a movable contact of the circuit breaker.

7. The method of claim 6 wherein the vibration sensor is selected from the group including piezoelectric sensors and accelerometers.

8. The method of claim 3 wherein the transducer is a radio frequency sensor located on the exterior of the circuit breaker case.

9. The method of claim 8 wherein the radio frequency sensor is selected from the group including stripline and microstrip antennas.

10. The method of claim 3 wherein the transducer is a thermal sensor located in proximity to an arc gas exhaust port of the circuit breaker.

11. The method of claim 10 wherein the thermal sensor is selected from the group including thermocouples and Resistance Temperature Detectors (RTD).

12. The method of claim 2 wherein the step of receiving and processing said signal at the arc fault detection system as evidence of a possible arc fault includes using the signal as a filter input to eliminate falsely positive indications of an arcing event.

13. The method of claim 2 wherein there are a plurality of transducers in proximity to the circuit breaker which are selected from the group including magnetic sensor, a vibration sensor, a radio frequency sensor, and a thermal sensor.

14. The method of claim 2 wherein the step of receiving and processing said signal at the arc fault detection system includes inverting and ANDing said signal with a current sensor signal or an optical sensor signal or both.

15. A method of operating an arc fault detection system in an electrical enclosure, comprising:

applying a transducer in proximity to the case of a circuit breaker within the enclosure,

detecting an excessive duration of a secondary effect of an overcurrent event within the circuit breaker with said transducer,

transmitting a signal from the transducer when detecting said excessive duration of a secondary effect of an overcurrent event to an arc fault detection system, and

operating an arc extinguishing mechanism in response to said signal.