What it is and where it fits
The Siemens 3RH1122-1AV00 is a SIRIUS auxiliary contactor in size S00 — a compact 45 mm wide block that adds two normally-open (NO) instantaneous contacts to a contactor or motor starter assembly. It mounts via screw or snaps onto a DIN rail, and the front face carries IP20 protection, so it's fine inside a closed panel but not for washdown areas. The operating temperature range of -25 to +60 °C covers most industrial enclosures without derating.
Rated switching — what the numbers mean
The contact ratings are given per voltage: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, and 1 A at 690 V. The 400 V rating matches the rated voltage of the coil (400 V AC at both 50 and 60 Hz). For a 24 V DC control circuit, the 10 A figure is the one to use — that's the maximum continuous current the contacts can make and break. The mechanical life is 30 million operations, and contact reliability is specified as one incorrect switching per 100 million at 17 V, 1 mA, which means it's dependable for low-level signal switching in PLC input circuits.
Mounting and wiring details
The unit accepts solid conductors: two wires of 0.5 to 1.5 mm², two of 0.75 to 2.5 mm², or a single 4 mm² per terminal. The mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward, so it fits in tight enclosures. Shock resistance is 10g for 5 ms and 5g for 10 ms — fine for normal industrial vibration but not rated for heavy impact near presses or hammers.