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why ct is testing using dc.. y cant we use AC insted of dc
on POLARITY TEST.
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Answer Posted / raghavendran.r
I think for Polarity testing AC is being used in power transformers.Let me explain the circuit for the same .Keep the secondary side open.But short one of the terminals of the secondary side with the primary side, so that the primary current flows through the secondary.Now adjust the primary voltage using variac and note down the secondary voltage.If primary voltage is greater than secondary then the polarities are different.
If secondary voltage is more than primary then the polarities are same.
This is how polarity is tested in power transformers and Motors.
The same may apply to CT also.
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