The Siemens SIRIUS 3UG4583-1CW30 is an insulation monitoring relay with an analog setting, designed to continuously check the insulation resistance of ungrounded AC/DC systems (IT systems) against earth. It monitors for a drop below a set threshold and triggers an alarm or trip. Supply voltage is universal AC/DC, rated 24 to 240 V at both 50 and 60 Hz, so it fits control voltages common across European and North American panels without a separate power supply module. The measurable voltage range on the monitored system goes from 0 to 400 V AC, covering standard low-voltage IT networks up to 400 V line-to-line. Operating frequency range of 15 to 400 Hz means it works on variable-frequency drives or genset supplies, not just the mains.
IP20 rating means the housing is finger-safe but not protected against moisture ingress — mount it inside a panel with at least an IP54 enclosure if the cabinet sees washdown or condensation. Screw-type terminals accept solid wire from 20 to 12 AWG and stranded (with ferrule) from 18 to 14 AWG, with a tightening torque of 0.6 to 0.8 N·m. Finely stranded with core-end processing goes up to 2.5 mm².
RoHS compliance date is May 1, 2012, so it meets the EU RoHS directive for lead and other restricted substances.