An HV Insulation Fault Relay is a protective relay designed to monitor and detect faults in the insulation of high-voltage electrical systems. Its primary function is to continuously monitor the insulation resistance of equipment such as transformers, cables, and circuit breakers, and detect any degradation or failure in insulation integrity. Insulation faults can be caused by various factors, such as aging, contamination, mechanical stress, or electrical overloading. Once a fault is detected, the relay triggers a protective action, such as an alarm, shutdown, or isolation of the faulty section, to prevent further damage to the equipment or the electrical network.