Earth Leakage Relays

Earth leakage relays (also known as ELRs or by the alternative name of differential relays) are specialised latching relays that are used to monitor the leakage of current to earth on 3-phase electrical systems, interrupting the circuit in the event that a dangerous voltage leak is detected. Earth leakage relays can be found in domestic distribution boards and are used to sense insulation failu...