what is resticted earth fault protection ? how did it protect & work in po

what is resticted earth fault protection ? how did it
protect & work in power transformer

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what is resticted earth fault protection ? how did it protect & work in power transformer..

Answer / siva

The restriction of current flow from the Earth Faults which
are Caused outside the Circuit of the Protected Equipment is
called Restricted Earth fault relay.

It is act as defense from nuisance!

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what is resticted earth fault protection ? how did it protect & work in power transformer..

Answer / jrk

EARTH FAULT CAUSED WITH IN ZONE IS CALLED RESTRICTED EARTH
FAULT.

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what is resticted earth fault protection ? how did it protect & work in power transformer..

Answer / sumit

REFP is mainly used for high speed tripping on star connected earthed secondary winding of power transformer

The relay does not operate for fault beyond the protected zone i.e neutral of the transformer.

Fault occurring near neutral is having small current becoz of small voltage which results in low fault current. To attend this fault the relay must be too sensitive to operate .To operate, the relay is set for the earth fault current of the order 15%of the rated winding current which protects restricted portion of the winding.

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