What this part is and what it does
The Siemens 3RH1131-1BB40-0TK0-ZX95 is a SIRIUS auxiliary contactor in size S00, designed for switching control and signalling circuits in industrial panels. It carries three normally-open (3 NO) instantaneous contacts, with no leading, lagging, or delayed switching — a straightforward make-only set for extending the contact multiplication on a main contactor or building interlock logic. The coil is rated 24 V DC, drawing 3.2 W for both closing and holding — a constant-power solenoid that simplifies the DC supply sizing. At that coil voltage the contacts are rated 10 A, with a contact reliability specification of one incorrect switching operation per 100 million operations at 17 V, 1 mA, so it handles both power-level pilot duty and low-energy PLC inputs without stiction. Mechanically rated for 30 million switching cycles typical and shock-rated at 10 g / 5 ms and 5 g / 10 ms, it suits applications where vibration or frequent cycling is present — conveyor interlock chains, valve position feedback, or repeated machine-cycle signalling.
Panel fit and mounting
Mounts via screw and snap-on to DIN rail, occupying a 45 mm width, 57.5 mm height, and 72 mm depth — the compact S00 footprint that fits standard 45 mm-wide modular enclosure grids. The mounting position is flexible: ±180° rotation on a vertical surface and ±22.5° tilt forward/backward, so it fits in tight or angled sub-panel layouts without derating. Front protection is IP20, meaning finger-safe from the panel face but not sealed against moisture or dust ingress — fit it inside a cabinet or enclosure rated for the environment. Pollution degree 3 (conductive pollution or dry non-conductive pollution that becomes conductive due to condensation) is typical for industrial control panels not in clean-room service.
Wiring and termination
Auxiliary contact terminals accept solid or stranded conductors: 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or 2x 4 mm² — also specified in AWG as 2x (20 to 16), 2x (18 to 14), and 1x 12. This dual-wire capacity simplifies daisy-chaining common signals without extra terminal blocks. The auxiliary switch block is extendable (product extension auxiliary switch = Yes), so additional contact blocks can be stacked on the same footprint if the 3 NO set is insufficient.
Environmental and compliance
Operating temperature range is -25 to +60 °C; storage and transport range is -55 to +80 °C. The substance prohibition (RoHS) date is July 1, 2006, indicating compliance with the EU RoHS directive on restricted substances. Surge voltage resistance rated at 6 kV, which supports installation in circuits with overvoltage category III environments typical of industrial control panels.