Improvements in or relating to parallel-feeder directional...

Details Improvements in or relating to parallel-feeder directional... Improvements in or relating to parallel-feeder directional...

H - Electricity

02

H

H02H 7/26 (2006.01) H02H 3/08 (2006.01) H02H 7/30 (2006.01)

Patent

CA 2275065

When directional overcurrent protection relays (22, 32) are included at the load end of a set of parallel feeders (20, 30) fed from an AC power source (10), a minimum fault- current threshold is specified based on the potential of a phase-to-phase fault at the source to cause a relay to operate misleadingly. This threshold is, for plain (transformerless) feeders, approximately 50% and, for transformer feeders, approximately 85% (nominally 86.7%) of rated pre-fault load current. These thresholds can, however, be ignored if, according to a second aspect of the invention, the relay outputs are processed in a 2-out-of- 3 circuit (91), so that a relay on one phase will only operate its associated circuit breaker if a relay on another phase has also operated, a condition which has been found not to obtain in the case of a source fault.

Affiliated with

Also associated with

Rating

Improvements in or relating to parallel-feeder directional... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Improvements in or relating to parallel-feeder directional..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Improvements in or relating to parallel-feeder directional... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFCA-PAI-O-2000648