Protective Relays Articles: Protective Relay: A Protective Relay is a device that detects the fault and initiates the operation of the circuit breaker to isolate the defective element from the…
Buchholz Relay: Buchholz Relay is a gas-actuated relay installed in oil immersed transformers for protection against all kinds of faults. Named after its inventor, Buchholz, it is used to give an…
Differential Relay: Most of the relays discussed so far relied on excess of current for their operation. Such relays are less sensitive because they cannot make correct distinction between heavy…
Definite Distance Type Impedance Relay: Fig. 21.21 shows the schematic arrangement of a Definite Distance Type Impedance Relay. It consists of a pivoted beam F and two electromagnets energized respectively…
Distance Relays or Impedance Relays: The operation of the relays discussed so far depended upon the magnitude of current or power in the protected circuit. However, there is another group…
Induction Type Directional Overcurrent Relay: The directional power relay is unsuitable for use as a directional protective relay under short-circuit conditions. When a short-circuit occurs, the system voltage falls to…
Induction Type Directional Power Relay: This Induction Type Directional Power Relay operates when power in the circuit flows in a specific direction Unlike a non-directional overcurrent relay, a directional power…
Induction Type Overcurrent Relay(Non-Directional): This Induction Type Overcurrent Relay works on the induction principle and initiates corrective measures when current in the circuit exceeds the predetermined value. The actuating source…