The tripping of an earth leakage relay is a typical issue in electrical systems. An earth leakage relay is a safety device that detects current flow to the ground and activates the circuit breaker to protect the system from electrical problems.
Nuisance tripping happens when a relay trips unexpectedly disrupting the electrical supply to equipment (or) system.
Earth leakage relays are installed in the PCC’s outgoing MCC feeds. However the MCCs are simply protected by the fuses. If an earth leakage (or) earth fault occurs in MCC’s incoming motor load.
In this case, the main PCC outbound ELR will start immediately. As a result, the MCC outgoing motor 32 A fuse will require longer to run due to an earth fault. Any malfunction in outgoing motor feeder causes total power loss for all MCC parts.
To avoid a total shutdown, we advise deleting the ELR from PCC Outing Feeders and Incomer.
As a result, the defect would be isolated to only the faulty portion. In this case, the External defect has no effect on the remaining healthy components.
ELR is primarily intended for human safety. After dumping ELR, no live maintenance in plant shall be carried out. It is recommended to do maintenance using the LOTO procedure.
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