Digital monitoring relay 3-phase supply voltage Autom. phase sequence correction Phase failure 3 x 160 to 690 V 50 to 60 Hz AC Undervoltage and overvoltage 160-690 V Hysteresis 1-20 V OFF delay 0-20 s Asymmetry 0-20% 1 CO for phase correction 1 CO for line supply faults spring-type connection system