The Siemens SIRIUS 3RH1122-1BB40-0TK0-ZX95 is an auxiliary contactor, size S00, with a 24 VDC coil and a contact configuration of 2 normally-open and 2 normally-closed instantaneous contacts. It carries a 10 A rating at AC-12 duty, which means it's suited for switching resistive loads and control circuits in a panel — the AC-12 rating covers the load curve for resistive and solid-state loads, not motor inrush. The coil pulls 3.2 W on both pick-up and hold, so there's no power drop after engagement; the DC holding power matches the closing power, which simplifies thermal budgeting in a crowded DIN-rail enclosure.
Mounting and integration
Mounts via screw or snap-on onto a DIN rail — the 45 mm width and 57.5 mm height fit the standard S00 footprint, so it occupies the same slot as a S00 contactor. The mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward, which gives flexibility in tight panels. Clearance at the side is 0 mm, meaning it can sit flush against adjacent devices without derating for heat buildup at the sides. The front face carries an IP20 rating, so it's touch-safe in an enclosed panel but not for washdown environments. Wire capacity accepts 2x 0.5 to 1.5 mm², 2x 0.75 to 2.5 mm², or 2x 4 mm² solid, covering most control-circuit wiring gauges without needing ferrules.
Contact ratings and switching capability
The auxiliary contacts are rated for AC-12 at 10 A, but the switching capacity drops with voltage: 6 A at 230 V, 3 A at 400 V, 2 A at 500 V, and 1 A at 690 V. For DC switching, the contacts handle 10 A at 24 V, 1 A at 110 V, and 0.27 A at 220 V. The surge voltage resistance is 6 kV, which covers most industrial control circuits without external suppression. Mechanical life is typical 30 million operations, so it'll outlast most contactors it's paired with in cyclic service. No leading, lagging, delayed, or make-before-break contacts on this variant — it's a straight 2 NO + 2 NC block.