The Siemens SIRIUS 3RH2122-1BA40-0AA6 is a Size S00 auxiliary contactor with 2 normally-open instantaneous contacts. It mounts via screw or snap-on onto a 35 mm DIN rail — the standard panel integration for control cabinets. The 73 mm depth and 45 mm width fit the compact S00 footprint, leaving room for adjacent contactors or overload relays in a motor starter stack.
Switching capacity across the voltage range
Rated operational current varies by voltage and duty: 10 A at 24 V and 230 V, 4.7 A at 60 V, 3 A at 110 V and 400 V, 1.2 A at 220 V, 0.5 A at 440 V, 2 A at 500 V, 0.26 A at 600 V, and 1 A at 690 V. These are the AC switching limits for the auxiliary contacts — at 400 V it handles 3 A, enough for pilot-duty control circuits on a 400 V line. The DC coil draws 4 W closing and 4 W holding, so the coil suppression circuit must handle that steady-state power without overheating.
Environmental and mounting constraints
Operating temperature range -25 to +60 °C; storage -55 to +80 °C. Pollution degree 3 (conductive pollution, typical for industrial panels without climate control). Mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward — useful when the contactor sits on a swing panel or angled subplate. Clearances: 10 mm upward, 10 mm forward, 10 mm downward, 6 mm at the side. The 2x (0.5 to 2.5 mm²) solid/stranded terminal accepts ferruled wires; strip length 8 mm avoids whiskers under the spring cage.