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US 2003/0125885 A1Published application
Adaptive algorithm to prevent nuissance tripping
AssigneeGeneral Electric Company
InventorsJohn James Dougherty, Michael Sullivan Tignor
Life of this patent
Estimating the term…
Abstract
Abstract of Disclosure A trip unit and circuit breaker including the trip unit include phase protection circuits, a ground fault protection circuit, and, a phase current qualification circuit intermediate the phase protection circuits and the ground fault protection circuit, wherein the phase current qualification circuit includes circuitry for determining a minimum ground fault setting for detected phase currents.
Claims22
A trip unit comprising:
- phase protection circuits;
- a ground fault protection circuit;
- and,
- a phase current qualification circuit intermediate the phase protection circuits and the ground fault protection circuit, wherein the phase current qualification circuit includes circuitry for determining a minimum ground fault setting for detected phase currents.
1 more element
A trip unit comprising:
- means for determining a minimum ground fault setting for detected phase currents;
- means for comparing the minimum ground fault setting to a customer provided threshold;
- means for determining which of the minimum ground fault setting and the customer provided threshold has a larger value and setting the larger value as a maximum value;
- and,
- means for utilizing the maximum value as a ground fault threshold.
2 more elements
A circuit breaker comprising:
- a plurality of phases;
- a current transformer for each phase;
- phase protection circuits receiving signals from each current transformer;
- a ground fault protection circuit receiving signals from each current transformer;
- and,
- a phase current qualification circuit intermediate the phase protection circuits and the ground fault protection circuit, wherein the phase current qualification circuit includes circuitry for determining a minimum ground fault setting for detected phase currents.
3 more elements
Dependencies are inferred from the claim text.