Siemens 3UG4815-1AA40 (3UG48151AA40), Digital Monitoring Relay For Three-Phase Mains Voltage For Io Link Ac 50 To 60 Hz 3X 160 To 690V Line Phase Sequence, Phase Failure, Phase Asymmetry Under- Andovervoltage Hysteresis 1-20V Network Stability Time Trigger Delay Time 1 Changeover, Screw Connection