The Siemens 3RF3125-2AA42 is a SIRIUS 3RF31 series 1-pole solid-state relay in the 22.5 mm width, rated for 25 A continuous current. It switches loads on a 24-230 V AC supply, controlled by a 4-30 V DC signal from a PLC or sensor output. The spring-loaded terminal block accepts solid or ferruled stranded wire — no screwdriver needed for termination, which speeds up panel wiring and eliminates torque checks. This is a semiconductor relay, meaning there are no moving contacts to arc or wear. It's built for frequent switching of resistive or lightly inductive loads — heaters, lamps, solenoid valves — where a mechanical relay would fatigue. The 25 A rating covers the common control-panel load range; the 22.5 mm housing fits standard DIN-rail enclosures alongside contactors and breakers.
RoHS compliance is confirmed since 15-01-24.
No separate base required; the relay is self-contained. The 4-30 V DC control input is compatible with 24 V PLC outputs directly, no interposing relay needed.