DIGITAL MONITORING RELAY FOR 3-PHASE LINE VOLT. W. N COND. REVERSIBLE PHASE SEQUENCE PHASE FAILURE 3X 160 TO 690V AC 50 TO 60 HZ UNDERVOLT. AND OVERVOLT. 160-690V HYSTERESIS 1-20V 0-20S EACH FOR UMIN AND UMAX 1 W FOR UMIN 1 W FOR UMAX SPRING-LOADED TERMINAL