Basic Components Of A Protection System

There are several basic components of a protection system as listed below:

CT (current transformer) 

• Convert the primary current to secondary current and transmit the secondary current to protective relay.

VT (voltage transformer)

• Convert the primary voltage to secondary voltage and transmit the secondary voltage to protective relay.

Protective relay 

• Detect and locate the fault and send a trip signal to the circuit breaker.
• When a fault occurred, the relay will operate by closing the relay contact to complete the trip circuit.

Battery / DC system

• To supply the power for the relay and also to the trip circuit.

Trip coil

• As the trip coil of the circuit breaker energized, the CB operating mechanism actuated and will make the CB to open and isolate the fault.