Patent ID: 7852605
Filing Date: 2010-12-14
Classification: H02H

Abstract:
1. An arc-flash hazard protection system for a three-phase electrical distribution system comprising a plurality of switchgear interconnected with a plurality of distribution buses, the protection system comprising: a plurality of first and second current transformers in signal communication with respective first and second phases of each of the plurality of switchgear; and a bus differential relay connected to receive output signals from each of the first and second current transformers of each of the plurality of switchgear to establish a bus differential protection scheme utilizing only two of the three available phases for each of the plurality of switchgear; wherein the bus differential relay comprises a processor responsive to computer executable code when executed thereon to provide a relay trip output signal to each of the plurality of switchgear in response to the bus differential protection scheme of the respective switchgear indicating an imbalanced three-phase current distribution thereat indicative of an arc-flash condition.