Answer / dinesh lokhande

As such values mentioned above are not same for all
transformers. Because Insulation resistance consist of
summation of resistance value for composite dielectric. i.e
dielectric consist of paper, oil, metal part, wooden
barriers etc which can be considered as several
capacitances in series.
Point here is we have to find out polarisation index

PI = Megger value after 10 mins / Megger value after 1 min.

PI as a normal practice and also mentioned in some
technical papers should be more than 1.3

Considering PI we can judge measured Insulation resistance
values of insulation.

Answer / karan

the meggar value depend on insulation level,
but we can inicate in thumb rule,
& thumb rule is
minimum meggar(IR)value is per KV 5megaohmas

Answer / ravi

Which Value????

Answer / hasan mehdi

50 M Ohms

Answer / uday pratap singh

5 Mega ohm per kV.

Answer / venkatesh

minimum 200-250Mohms

Answer / naveen kumar mishra

mndnnv

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