The Siemens SIRIUS 3UG3081-1AW30 is an insulation monitor for AC systems, rated 110... 400 V AC/DC for the monitored circuit and 24... 240 V at 50/60 Hz for the control supply. It mounts on a 35 mm DIN rail via screw or snap-on, fits a 45 mm wide slot, and uses screw-type terminals accepting 0.75... 2.5 mm² solid or finely stranded wire. The IP20 housing suits enclosed panel installation.
The 110... 400 V range covers standard 230/400 V three-phase networks and 110 V control circuits — no separate voltage tap needed. The response threshold is adjustable: initial value 0.85 and full-scale value 1.1 (likely relative to the rated voltage, i.e. 85 % to 110 % of the set point). Fault storage is selectable, so the relay latches on a ground fault until manually reset, useful for unattended panels. Delayed switching (1 s) prevents nuisance trips from transient leakage. Clearance around the module is zero in all directions — upwards, forwards, backwards, downwards, and at the side — meaning it can be stacked tight against other devices without derating for heat dissipation.