Integrator's spec recap
The Siemens SIRIUS 3RH1131-2VB40 is a coupling relay for switching auxiliary circuits — think of it as the signal-level interface between a PLC output or pushbutton and the coil of a larger contactor. It carries three normally-open instantaneous contacts, each rated 10 A at AC-12 and 10 A at 24 V. The coil is 24 VDC, pick-up at 85% of rated voltage, drop-out at 185%, with a constant 1.4 W power draw during both closing and holding. A built-in diode surge suppressor handles the back-EMF from the coil — no external snubber needed.
Mounting and integration
Mounts by screw or snap-on onto a DIN rail. The 45 mm width and 73 mm depth fit the S00 contactor footprint — it shares the same mechanical envelope as the 3RT1 series contactors, so it clips into the same rail space. Side clearance is zero; you can gang units side-by-side without extra spacing. The mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward, which covers most panel layouts. Wire termination accepts solid conductors from 0.25 to 2.5 mm² — standard for control wiring.
Environmental and compliance
Rated for operation from -25 to +60 °C, storage and transport from -55 to +80 °C. Pollution degree 3 — suitable for industrial environments with conductive dust or humidity. IP20 on the front means finger-safe terminals but no water ingress protection; install inside a cabinet. Shock resistance tested at 10g / 5 ms and 5g / 10 ms. Maximum operating altitude 2000 m.
Contact ratings across voltages
The three NO contacts are rated for switching at multiple voltage levels: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, 2 A at 500 V, and 1 A at 690 V. Also rated 1 A at 110 V and 0.27 A at 220 V. The 30,000,000 mechanical operating cycles reflect a long service life for auxiliary-duty cycling.