What are the fundamental elements of relay?

Basic fundamental elements of the relay are:

  • Sensing element: It is the measuring element measures the actuating quantity. Actuating quantity is change in current in case of over current relay
  • Comparing element: It compares the actuating quantity with the relay pre-setting of the relay
  • Control element: On pick up of the relay control element carryout the final switching operations such as closing the circuit to operate the circuit breaker