How can we calculate ngr resistance for a generator and
Transformer ?
What type of transformer requires ngr ?

Answer Posted / a s bhandari

Ohmic value of neutral grounding resister for a transformer is calculated as follows:

R = Vph/ I where I - value of fault current to be limited to flow through the neutral path, normally it is 50A for 5 sec.

Based on above, for 6.6 kv star side of a transformer
resister value shall be 76.21ohm.

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