
US Patent No: 5,940,256
Number of patents in Portfolio can not be more than 2000
Circuit breaker responsive to repeated in-rush currents produced by a sputtering arc fault
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Aug 17, 1999
Issued date -
Nov 9, 1994
filing date -
08/336,721
serial no -
In Force
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Importance
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Abstract
A circuit breaker responds to sputtering arc faults by counting the times that a bandwidth limited di/dt signal exceeds a threshold magnitude within a selected time interval. In the exemplary circuit breaker, if the threshold is exceeded twice within a one second interval, a trip solenoid is energized. The di/dt sensor can share a sensing coil with a ground fault detector. Alternatively, the resistance of the neutral lead within the circuit breaker is utilized to sense current which is converted to a bandwidth limited di/dt signal for level detection and counting of sputtering arc events.
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First Claim
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International Classification(s)
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Cited Art
| Patent Info | (Count) | # Cites | Year |
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| 4,402,030 Electrostatic voltage control circuit | 28 | 1982 | |
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| 5,280,404 Arc detection system | 66 | 1992 | |
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| RE30678 Dormant oscillator ground to neutral protection for ground fault interrupters | 40 | 1976 | |
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| 4,376,243 Arc detector for electric rod furnace | 38 | 1981 | |
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| 4,949,214 Trip delay override for electrical circuit breakers | 74 | 1989 | |
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| 4,897,756 Add-on ground fault module | 12 | 1989 | |
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| 4,466,071 High impedance fault detection apparatus and method | 124 | 1981 | |
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| 5,224,006 Electronic circuit breaker with protection against sputtering arc faults and ground faults | 217 | 1991 | |