What it is and what it does
The Siemens 3RH2353-1CF00-0KA0 is a SIRIUS auxiliary contactor — a compact switching block that extends the signal-routing capacity of a main contactor or provides standalone logic-level switching in a control panel. It carries 5 normally open instantaneous contacts, each rated 10 A at 24 V, with a full voltage ladder from 24 V through 690 V AC/DC.
Mounting and panel fit
Fastens with screws or snaps onto a 35 mm DIN rail. The S00 frame is 45 mm wide, 57.5 mm tall, 117 mm deep — a standard footprint that shares the same cutout as the 3RH2 contactor range. Mounting position is flexible: ±180° rotation on a vertical surface, and can be tilted forward/backward ±22.5°. Clearance distances: 10 mm upwards, 10 mm forwards, 10 mm downwards, 6 mm at the side. Pollution degree 3 rated, so it's suited for industrial environments with conductive dust or condensation.
Contact ratings and switching performance
The 5 NO contacts are rated for AC and DC loads across the voltage range: 10 A at 24 V, 6 A at 230 V AC, 3 A at 400 V AC, 1 A at 690 V AC. DC ratings drop with voltage: 4.7 A at 60 V, 1.2 A at 220 V, 0.5 A at 440 V, 0.26 A at 600 V. Arcing time is 10 to 15 ms; mechanical life is 10 million operations. Switching frequency for DC loads is 10,000 operations per hour. AC switching time is 4 to 15 ms. The coil operates at 50 Hz (0.8 to 1.1 x rated voltage) and 60 Hz (0.85 to 1.1 x rated voltage).
Environmental and compliance
Wire connection accepts 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or 2x 4 mm² solid or stranded. Fastening method is screw and snap-on mounting onto 35 mm standard mounting rail.