Answer / dinesh

CT has primary and secondary, Normally in industries most
of line cable is reffered as primary and your CT coil is
secondary. if you have a CT of 250/5 that means when there
will be a flow of 250A current in your primary side then
you will obtain 5A current on secondary side. Now if you
divide 250 by 5 you will get the CT ratio that is 50. now
if you obtain 3A in secondary that menas 3A mutiply by CT
ratio That is 50 you will get 150A flowing through primary.
your CT is used for protection as well as metering purpose.

Answer / velappan

it is not divided by 5
the primary current is 250A and secondary current is 5A in this case and 15VA is burden we connected on secondary

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