Three-phase mains power system monitoring relay, has output change-over contact in connection with contactor reversal combination for automatic correction of phase sequence during incorrect phase sequence

摘要

The relay has two output change-over contacts (2, 3), where one of the contacts causes a disconnection of mains supply during an occurrence of a malfunction such as low voltage, high voltage, phase failure and phase asymmetry, of mains supply. Another contact is provided in connection with a contactor reversal combination (4) for automatic correction of a phase sequence, during an incorrect phase sequence.