Answer / mohit.k.k

for magnetic balance test apply the 415 v volt to R phase
then measure Y phase voltage it must be 60 to 80 % of i/p
voltage and B phase should measure around 40 to 20 % of i/p
volatge and when voltage applied to Y phase R & B phase
should read 40 to 60 % of i/p reading. For voltage applied
to B pahse reading should be reverse of first case.

and for measuring excitaation current just give 415 V to
either side H.V or L.V but H.V side prefer and measure
current with clamp meter of all phases.

and for vector group just short the R phase of H.V with r
Phase of L.V
measure voltage as
1R-1Y =
1Y-1B =
1B-1R =
1Y-2y =
1Y-2b =
1B-2b =
1B-2y =

then e.g Dyn11

these condition to fullfill
1Y-2y = 1Y-2b
1B-2y > 1B-2b

what is is the potential diffrence between two phase ?

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