The Siemens 3RH1131-2BB40-ZW95 is a SIRIUS auxiliary contactor with a 24 V DC coil, delivering three normally open instantaneous contacts rated at 10 A at 24 V. It's a size S00 device — 45 mm wide, 60 mm tall, 73 mm deep — designed for screw and snap-on mounting onto a DIN rail inside a control panel.
What the ratings mean for fit
The 3 NO contact set provides three independent signal paths. At 24 V DC the contacts are rated for 10 A. The coil draws 3.2 W closing and holding, so it's a continuous-duty magnet — no extra inrush to budget for beyond the steady-state power supply load. The 24 V DC coil holds at nominal and drops out reliably below the dropout threshold typical of this class. Surge voltage resistance is rated at 6 kV, which means the contactor withstands the switching transients common in industrial panels without external suppression on the coil. Wire termination accepts solid or stranded conductors from 0.25 mm² up to 2.5 mm² — standard for control wiring. The IP20 front protection means the terminals are finger-safe once the panel door is closed; no special tool access required.
Panel integration and mounting
Snap-on mounting onto a DIN rail, with an optional screw fix for vibration-prone locations. The mounting position is flexible: ±180° rotation on a vertical surface, plus ±22.5° tilt forward and backward. Size S00 means the 3RH1131 shares the same footprint as the smallest SIRIUS contactors — 45 mm wide per pole, so three auxiliary contactors fit in a 135 mm DIN rail section. The 73 mm depth leaves clearance behind a standard 80 mm deep enclosure.