Siemens 3UG4633-2AL30, Digital Monitoring Relay Voltage Monitoring, 22.5Mm From 17 To 275V Ac/Dc Overshoot And Undershoot Internal Power Supply Dc And Ac 50 To 60 Hz Spike Delay 0.1 To 20S Hysteresis 0.1 To 150V 1 Changeover Contact Spring-Loaded Type