Instantaneous Relay Operation

Instantaneous Relay Working Operation 

What Is Instantaneous Relay ?

An instantaneous relay is one in which there is no time delay provided intentionally. More specifically ideally there is no time required to operate the relay. Although there is some time delay which can not be avoided.

Instantaneous relay. An instantaneous relay is one in which no intentional time delay is provided. In this case, the relay contacts are closed immediately after current in the relay coil exceeds the minimum calibrated value. Figure shows an instantaneous solenoid type of relay. Although there Will be a short time interval between the instant of pickup and the closing of relay contacts, no intentional time delay has been added.

Instantaneous Relay Working Operation

The instantaneous relays have operating time less than 0-1 second. The instantaneous relay is effective only Where the impedance between the relay and source is small compared to the protected section impedance. The operating time of instantaneous relay is sometimes expressed in cycles based on the power-system frequency
e.g. one-cycle would be If 50 second in a 50-cycle system.


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