What it is and what it does
The Siemens SIRIUS 3RH1140-2BB40-ZX95 is an auxiliary contactor — a switching device that extends the control-circuit capacity of a main contactor or provides isolated signal feedback. It carries 4 normally-open instantaneous contacts and no delayed, leading, or lagging contacts, so it's a straight four-pole make switch for control logic or status indication. The magnet coil is rated 24 V DC with a closing and holding power draw of 3.2 W. That's a continuous-duty coil — it stays energized as long as the control voltage is present, so factor the 3.2 W into your 24 VDC power-supply budget. The contacts are rated 10 A at AC-12, which covers resistive and solid-state loads in control circuits; for inductive switching at higher voltages, derate per the 110 V (1 A), 220 V (0.27 A), 230 V (6 A), 400 V (3 A), 500 V (2 A), and 690 V (1 A) values (–).
Mounting and integration
Mounts by screw or snap-on onto a DIN rail. The size S00 footprint — 45 mm wide, 60 mm high, 73 mm deep — fits standard control-panel layouts. Mounting position is flexible: +/-180° rotation on a vertical surface, and can be tilted forward/backward by +/-22.5°. No side clearance is required (: 0 mm at the side), so you can pack units tight on the rail. Front face is IP20, meaning finger-safe but not protected against moisture — keep it inside a closed panel. Terminals accept solid or stranded conductors from 0.25 to 2.5 mm². The shock resistance is 10g / 5 ms and 5g / 10 ms, which is typical for industrial panel gear — no special isolation needed for normal machine vibration.