The Siemens 3UG4511-2AN20 is a SIRIUS-brand phase monitoring relay designed to supervise AC supply lines. It detects undervoltage, overvoltage, and phase loss on three-phase systems, with a rated voltage range of 160 to 260 V AC at 50 or 60 Hz. The output relay switches up to 3 A at 250 V AC, sufficient to signal a PLC input or drop out a contactor coil.
The 160-260 V AC operating range covers most European 230/400 V networks and North American 208/240 V systems. The relay's 3 A rated contact at 250 V AC is enough to energize a contactor coil or a small pilot lamp directly; for heavier loads, use it to gate a larger contactor or PLC input. The IP20 enclosure is fine for a clean control cabinet; keep it behind a sealed door in washdown areas.
The display LED confirms relay status at a glance.