The time from the occurrence of the fault to the final arc interruption in the circuit breaker Mathematically, Fault Clearing Time = [Relay Time] + [Breaker Time] Relay Time: Time from the fault occurrence to the closing of relay contactsThe time from the occurrence of the fault to the final arc interruption in the circuit breaker Mathematically, Fault Clearing Time = [Relay Time] + [Breaker Time] Relay Time: Time from the fault occurrence to the closing of relay contactsThe primary function of fault clearance relays is to minimize equipment damage and isolate the faulty component from the rest of the power system. Consequently, it is essential for fault clearance relays to operate at high speeds to promptly address faults, while also ensuring sensitivity and. Core idea: Protective relays monitor electrical quantities and command protective devices to isolate faults or abnormal operating conditions. Engineering use: Relays are used on feeders, transformers, buses, motors, generators, and transmission lines to protect equipment and improve system. Selectivity is a mandatory requirement for all protection, but the importance of it depends on the application. For example, unselective protection operation during a medium voltage network fault will cause an outage for an unnecessarily large number of consumers. It is a critical performance metric for power system protection. If a fault occurs but does not last for 1.
