Three-phase failure relays for 3-phase systems amalgamate phase loss, unbalance (voltage deviation of more than 15%), and reverse phase detection into combined loss, unbalance, or incorrect sequence. As they maintain response times of fewer than 500 milliseconds, they help safeguard motors in manufacturing lines, and elevators, with modular designs that enable PLC integration and adherence to IEC 61508 SIL 2 standards.