ELECTROMECHANICAL REALY:-

In electromechanical type of relays, when the actuating quantity exceeds a predetermined setting, a torque is developed which causes the moving element of the relay to travel and close a set of contacts in order to energise the trip coil of the circuit breaker. The different types of electromagnetic relays as per their construction are:

  1. Attracted armature type
  2. Induction disc type
  3. Induction cup type
  4. Printed disc type
  5. Moving coil type
  6. Polarised moving iron type

https://electricalenergyworld.blogspot.com/2019/05/what-is-electromechanical-relay.html
Electromechanical Relay


DISADVANTAGE OF ELECTROMECHANICAL RELAY:


Due to the fact that they have moving parts and contacts, the electromagnetic relay have some disadvantages -
  • The vibrations caused by external shocks affect the operation.
  • The inertia of the moving parts sometimes results in defects in the contact racing. The relay coordination gets disturbed by any defect  in the contact racing.
  • Contact racing result in a high burden on the CTs and PTs.
  • Contact pitting deteriorates the contacts and the relay starts mal-function.
  • The relays needs high operating time due to the inertia of the moving parts.