Arc-flash hazard protection system for three-phase electrical distribution system
First Claim
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.
2 Assignments
0 Petitions
Accused Products
Abstract
An arc-flash hazard protection system for a three-phase electrical distribution system having a plurality of switchgear interconnected with a plurality of distribution buses is disclosed. The protection system includes 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. The bus differential relay includes 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.
4 Citations
13 Claims
-
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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. 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; a first bus differential relay connected to receive output signals from each of the first current transformers of each of the plurality of switchgear; a second bus differential relay connected to receive output signals from each of the second current transformers of each of the plurality of switchgear; wherein the plurality of switchgear is equal to or less than eighteen circuit breakers, that is, up to eighteen circuit breakers, and each bus differential relay is connected to receive up to eighteen current transformer output signals from the up to eighteen circuit breakers thereby establishing a bus differential protection scheme utilizing two bus differential relays, one relay for each of only two of the three available phases for each of the plurality of switchgear; wherein each 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.
-
Specification