NGR means Neutral grounding resistor. This is connected to
neutral wire to ground the extra leekage current.
Since in UT,UAT & ST star connection is used, that means
there are 4 wires (R,Y,B & N).Thus neutral is grounded with
any short circuits occur in stator or rotor then that short
circuit current will limitig and any erath fault occur in
rotor or stator then thats current will also limited value
by depending on resisance value
Neutral Earthing Resistors (NERs) – sometimes called Neutral Grounding Resistors – are employed in medium-voltage AC distribution networks to limit the current that would flow through the neutral point of a transformer or generator in the event of an earth fault. NERs limit fault currents to a value that does not cause any further damage to switchgear, generators or transformers beyond what has already been caused by the fault itself.
While connecting the flood light plug on to the 415 V
distribution panel,there was spark and the cable got burnt.
Three ignitors of the flood light also burnt of. The lamps
are of 400 W (total 6 lamps) connected through 1.5 mm2
cable. The plug was immediately removed from the circuit.
There was a 30 mA RCD connected and a 250 A MCCB; however
both did not trip. What could be the possible reasons for
the circuit devices not to trip?Can someone assist please.
Additional info if needed can be provided.
hi frienda We have 750kva cater pillet dg set we are fasing
one diffrent proublam in dg we are start dg set after one
mint applying load around 450a load but dg was run 3 Or 4
mints after 3 mints dg was shuding down automatic how to
face this proublam pls tel any budy