Answer / ranjan prasad

Normally NGR is being connected with the neutral of
transformers or Generators to limit the the fault current.
This NGR basically gives the out put in terms of voltage
during the fault condition (like Earth Fault). To sens the
voltage during fault condition, isolation transformer is
connected across NGR for voltage feed back. This v f/b goes
to the relay to operate in case of earth fault depending
upon the setting done at relay.

Answer / aamod tripathi

NEUTRAL GROUND RESISTANCE RELAY IS A RELAY WHICH WILL
OPERATE UNDER AN EARTH FAULT. AND WILL GET ACTIVATED IN
CASE OF AN EARTH FAULT ONLY TO ACTIVATE THE BREAKER IN
ORDER TO TRIP THE CIRCUIT.

Answer / aamod tripathi

IT IS FOR RESTRICTED EARTH FAULTS

Answer / biswajit sahoo

THIS IS BASICALLY REF TYPE RELAY. iT WORKS ON PRINCIPLE OF
DIFFERENCE IN NEUTRAL CURRENT IE TRANSFORMER END AND
CONSUMER FEEDER END

Answer / angela tong

NGR is neutral ground resistance which is inserted between
neutral and ground to operate during ground fault happens.
It could prevent generator or transformer from overvoltage
or arc flash grounding transient overvoltage and clear the
fault up.

in GEAFOL Cast-Resin trnaformer of 11/.72kv which has tapping of 11550v,11250,11000,10246v in primary side. To obtain 700v. which tapping should be used of HV side as we have 11000v/720v tapping now .

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