Overcurrent Relay System

Overcurrent Relay

Overcurrent relay is a relay that works against overcurrent, it will work when the currents that flow exceeds the set value.

Basically the overcurrent relay is a device that detects the amount of current flowing through a network with the help of current transformer. Price or quantity that may be passed called the setting.

Various kinds of overcurrent relay characteristics:

a. Real-time relay (Instantaneous relay)

b. Overcurrent relay time (Definite time relay)

c. Inverse time overcurrent relay

Relay that works immediately (without time delay) when the value exceeds the current flowing settings, the relay will work within a few milliseconds (10-20 ms).

Relay is seldom stand alone but are generally combined with overcurrent relay with other characteristics. This relay will give orders to the PMT in the event of disturbances and the magnitude of short circuit fault current exceeds the setting (Is), and long working time relay start relay pick-up until work is extended by a certain time depending on the amount of current that does not work on relay.

Overcurrent Relay Statistic

phase neutral wire but the wire on the transformer secondary current. Thus the relay is energized by the current neutral, based on symmetrical component of neutral current is the sum of the three phase currents. Zero sequence currents can flow dirangkaian new primary if there is a way back through the ground (through the neutral wire)