Difference between Current Transformer and Potential Transformer

Current Transformer

1. If the CT is under service the secondary of a C.T cannot be open circuited on any condition.
2. The CT can be regarded as a series transformer.
3. The current in the primary side of a C.T is independent of the secondary also known as the burden.
4. The primary winding of the CT is connected in series with the line carrying the current to be measured. Hence it carries out the full line current.
5. With the help of CT, a 5A ammeter can be used to measure a high current like 200A.

Potential transformer

1. The secondary of a P.T can be open circuited without any damage being caused either by the operator or the transformer.
2. P.T may be considered as a parallel transformer.
3. The primary current of a P.T depends upon the secondary circuit conditions (burden).
4. The primary winding P.T is connected across the line of voltage to be measured. Hence the full line voltage is impressed across its terminal.
5. With the help of P.T, a 120V voltmeter can be used to measure very high voltages like 11KV.

Source : https://owlcation.com/stem/What-is-a-Current-transformer-How-does-it-work

Read More: Types of Current Transformer