What is a potential transformer?
Potential transformer is a voltage step-down transformer which reduces the voltage of a high voltage circuit to a lower level for the purpose of measurement. These are connected across or parallel to the line which is to be monitored.
Open and dry type
Primary (normally high voltage) winding on inner side and thin wires with high resistance.
Secondary (normally low voltage) winding normally on inner side with very low resistance.
Power range: 11kVA-132KVA
Voltage range: Any input and output voltage
Frequency range: 50Hz, 60Hz, 50/60Hz & 400Hz
a. 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.
b. They are used for metering purpose, required for synchronization of feeders/generator with grid, for feedback of AVR, distance protection of feeders, impedance protection of generators and any protection which require voltage signal.
Open and enclosed transformers with different IP ratings and mounting are available.
Available values in market
Availability by voltage ratio: 11KV/110V, 22KV/110V,33KV/110V,100KV/110V,132KV/111V