Digital monitoring relay Voltage monitoring, 22.5 mm from 0.1-60 V AC/DC 0vershoot and undershoot 24 to 240 V AC/DC 50 to 60 Hz DC and AC Noise pulses delay 0.1 to 20 s Hysteresis 0.1 to 30 V 1 change-over contact with or without fault buffer spring-type connection system