What it is and what it does
The Siemens SIRIUS 3RH1131-1BB40-ZW97 is a size S00 auxiliary contactor — a 45 mm wide block that adds signal-feedback or pilot-duty contacts to a motor starter or contactor assembly. It carries 4 normally-open instantaneous contacts, rated 10 A in AC-12 duty (resistive/control loads). The 24 VDC coil draws a constant 3.2 W for both pick-up and hold, so there is no inrush spike to size your DC supply around. IP20 on the front means it is protected against finger contact but lives inside an enclosure.
Contact ratings — what the numbers mean
The 10 A AC-12 rating at 400 V is the resistive / control-circuit maximum. For inductive DC switching the numbers drop fast: 1 A at 110 V, 0.27 A at 220 V. If you are switching a DC solenoid or brake coil, that 220 V figure is the one that governs — the 10 A headline applies only to resistive AC loads. The contact reliability spec (one incorrect switching per 100 million operations at 17 V, 1 mA) tells you this contactor is fine for dry-circuit PLC inputs; you do not need a gold-plated reed for low-level signals.
Mounting and integration
Screw and snap-on mounting onto DIN rail — the same 45 mm width as a S00 contactor, so it lines up mechanically. Mounting position is flexible: +/-180° rotation on a vertical surface, plus +/-22.5° tilt forward/backward. That matters when you are squeezing it into a crowded panel and the rail is not perfectly horizontal. The screw terminals accept 2x 4 mm² solid or 2x 2.5 mm² stranded — sized for control-circuit wiring, not power feed.
Environmental and compliance
Operates from -25 to +60 °C; stores and ships from -55 to +80 °C. Pollution degree 3 (conductive pollution, typical for industrial control panels). Shock rated at 10g / 5 ms and 5g / 10 ms. Surge voltage resistance is 6 kV. RoHS compliance date is July 1, 2006 — the part meets the original RoHS directive.