Comparison between Current Transformer and Voltage or Potential Transformer

 

Comparison between Current Transformer and Voltage or Potential Transformer

Current Transformer (CT)	Potential Transformer (PT or VT)
CT step-down the high current to the safe level of current.	PT step-down the high voltage levels to the safe level of voltage.
Symbol of CT	Symbol of PT or VT
Its primary winding is connected in series with the line to be measured.	Its primary is connected in parallel to the line to be measured.
It has a fewer number of turns in its primary winding.	It has a large number of turns in its primary winding.
It has a large number of turns in the secondary winding.	It has few numbers of turns in the secondary winding.
Its secondary cannot be open circuit.	Its secondary can be open circuit.
It has a very high turn ratio.	It has a very low turn ratio.
Its accuracy does not depend on the secondary burden (numerous ammeters can be connected to output).	Its accuracy depends on the secondary burden and causes an error when numerous voltmeters are connected.
The primary winding contains full line current.	The primary windings contain full line voltage.
Current transformer can be either wound type or core type.	The potential transformer can be either electromagnetic or capacitor voltage type.
The primary current does not depend on the secondary current.	The primary current depends on the secondary current.
It is a step-up transformer.	It is a step-down transformer.
It is used for measurement and monitoring of current in high power lines.	It is used for the measurement of high voltage in power lines.