Answer / gova

Hi

In our substations,tan delta tests were carried out on
transformer Bushing.This test is done
1)To ensure the dielectric strength of insulation or
2)to predict the life of bushing.

what they are doing is they are measuring the capacitance
values.If the capacitance values are good means insulation
is good.

regards
gova

Answer / sivaraman.s

the factor called 'dielectric dissipaton factor' s commonly
called as tan delta. this test s conducted not only to
predict the aging of bushing but also to predict the
contents of contaminants like soluable varnish, resins of
transformer oil.

Answer / natarajanramkumar

Tan-Delta also called loss angle OR Dissipation factor
testing is a diagnositic method of testing cables to
determine the quality of the cable insulation.This is done
to try to predict the remaining life expectancy and in
order to prioritize cable replacement and/or injection.It
is also useful for determining what other tests may be
worthwhile.

Answer / mrudang

hello friends

tan delta test is test about reveal the aging of about
Transformers , Bushings , Rotating machines , Reactors
Tan delta and capacitance both we are measured
capacitance reveals the aging of paper insulation and Tan
delta reveals the loss factor

we are applying 2,4,6,8,10 KV for more then 20kV Equipment

Answer / raj

before doing tan delta test, just we know that its for
determine the condition of insulation to the equipments.and
it has more benefits when compared to meggering(IR).megger
means to find insulation only behinds surface condition.but
for tan delta/dissipation factor/loss factor/power factor
is to determine internal void conditions, and their
capacitances.
permissible limits of tan delta for all bushings - 0.7%
then important one while testing of tan delta, we should
take the current test temperature, then correct that one to
20*c. . .
for that correction we should take the values from the
correction table that we do by using specific testing kit.
for megger make,doble,eltel we have different tables. just
refer and correct it.
impt: it will be compare with factory reports only after
correction of values to 20*c

Answer / jagan

This test is doing for bushings of high rating CVT
transformers .this is very essential test it should be in
determined value max in nanofarad.whwn u conduct this one
to three times clean the bushing.this have many provision
when u using special kit.max GST-g mode is using by
applying 10Kv.

Answer / nikhil

in our substance was that is a trospoment

Answer / kunal

ten delta is measurment of loss angle measured( during
testing for transformer oil) in terms of power factor

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