Phase monitoring relay with LCD and IO-Link
The Siemens SIRIUS 3UG4815-1AA40 is a network monitoring relay that tracks phase sequence, phase failure, and asymmetry on three-phase AC supplies. It combines five monitoring functions in one 22.5 mm housing, with an LCD for local readout and IO-Link COM2 (38.4 kBaud) for parameterization and diagnostics into a PLC or higher-level system. Rated operational current is 3 A at 250 V and 400 V at 50/60 Hz, which covers the typical control-circuit contactor coil or alarm load. The relay detects asymmetry and can be set for auto-reset or external reset, with a configurable start-up delay up to 999.9 s to ride through motor inrush or generator ramp-up.
Terminal capacity accepts 2x (20–14) AWG solid or stranded, with zero clearance required on all sides — no derating for side-by-side installation. IP20 protection class means it is suited for dry indoor panels only; no washdown or dust ingress protection. Pollution degree 2 is the standard for normal industrial environments with non-conductive contamination.