What is constructional difference between CT and PT?

CT does not need any bushing only supporting arrangement are necessary to carry CT module. But in PT two bushings are need to connect it with the line voltage. CT is connected in series transformer under all conditions, but PT is a parallel transformer.

How can you tell the difference between a substation CT and PT?

Important is connection, as C.T is having thick bar primary connected in series, between transformer secondary and bus bar, can easily be judged, while P.T place is on side, looks having only low current, input wired connection, and connected in parallel.

Why do we use potential transformers?

The potential transformers are used in the protecting relaying scheme because the potential coils of the protective device are not directly connected to the system in case of the high voltage. Therefore, it is necessary to step down the voltage and also to insulate the protective equipment from the primary circuit.

How do you identify a current transformer?

1. Ratio Test. CT ratio is described as the ratio of primary current input to secondary current output at full load.
2. Polarity Test.
3. Excitation (Saturation) Test.
4. Insulation Resistance Test.
5. Winding Resistance Test.
6. Burden Test.

What do CTs and PTs do?

CTs stands for Current Transformers. They are the devices that measure the current in a circuit. PTs stands for Potential Transformers. They are devices that measure the voltage and frequency in a circuit.

How do you identify a current transformer and a potential transformer?

The primary winding of the current transformers has a small number of turns, whereas in potential transformer the primary winding has a large number of turns. The secondary of the current transformer has a large number of turns, and it cannot be open circuited when it is under the services.