Are same transformer be employed for step up and step down services?

Are same transformer be employed for step up and step down
services?

Question Posted / iamdon

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Are same transformer be employed for step up and step down services?..

Answer / bajrang ahirwar

NO
same transformer can't be used for both operations.
exception is ICT like 220KV/400KV
ICT is inter connecting or interposing transformer, these type of transformers are specially designed.
there no load an on load losses ane calculated so that they can be operated from either side.

on the other hand if have a 2000 KVA 11kv/440V 0.85 pf step down transformer:
current in hv side will be = 123 A
and current in LV side will be =3087 A

the secondary has to bear heavy current so it is designed accordingly with Thick winding.
and HV Primary has to carry a comperatively low current so its windings are of thin windings.

NOW the reverse operation

the heavy winding will be connected to high Voltage 11 Kv side, fine no problem, because it has to carry a lower current of 123 A ans secondary is rated for 3500 A approx.

BUT
the thin wired high voltage winding will now have to supplly the larger gurrent 3080 A, this winding has also larger losses R=Rho L/A
result??
the winding will burn out.

so practically it is not possible.

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Are same transformer be employed for step up and step down services?..

Answer / iamdon

Strictly speaking No.

Most transformers rated above 3kVA can be used either as
step up or as step down depending upon the need.

But transformers rated below 2kVA can be used only for one
operation for which it is designed.It can not be employed
in revese(with respect to design) transformation,because
the winding used is compensated which will not work
satisfactorily in reverse.

Author:arbelectbit@yahoo.com

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Are same transformer be employed for step up and step down services?..

Answer / kushal

if we are using the same rating of transformer for same line
then only we can use it in both the ways otherwise if u say
that the distribution transformer can b used as a power
transformer just by changing its primary to secondry or vice
versa its not possible.
a transformer is the only device which can b used in step up
and step down both the ways.

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