Answer / jiten sharma

Hi, some times when you charge the transformer after some
duration, trafo will take high inrush current. Due to that
it will trip on overcurrent but some times it can be also
give the triping on differential protection with
overcurrent.

So keep the setting slight high and then charge the
transformer. N after charging keep the setting as it is.

It might solve your problem but before that do the all test
on your trafo and then if nothing will found follow this.

Regards,
Jiten

Answer / arun

Do all the tests in the transformer windings then you will
get the fault.

Differential protection is given mainly to isolate the
circuit when there is fault inside the transformer.

Answer / vaidegi

yes

Answer / engineer

Check all your system(Incuding Cables and trandformer and
control circuit) From 1st CT (at HV Side)to 2nd CT at(LV
side).

Answer / k.prakashchandra

I think it is REFR which picks up only if there is earth
fault whithin the transformer .i.e. between LT an HT
CTs.and an NCT is to be provided

Answer / k.prakashchandra

Dif relay acts even for faults anywhere between cts .check
cable glands and all others between cts on primary and
secondary

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