The 3RH2122-2AF00 in the panel: tight integration, two NO contacts
The Siemens SIRIUS 3RH2122-2AF00 is a size S00 auxiliary contactor rated with 2 NO instantaneous contacts. It mounts via screw and snap-on onto 35 mm DIN rail, occupying a 45 mm wide footprint and a 73 mm depth, with 70 mm height. That depth keeps it within a 100 mm shallow enclosure backplane clearance — no need to reach for a deeper gland plate. The two NO contacts handle 10 A at 24 V rated value and 10 A at 230 V rated value, so they can switch PLC-level loads (pilot lights, small relays) without an intermediate interposer. The contacts are rated for 30,000,000 typical mechanical operations — not a wear item in normal service. Mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward, so you can lay the contactor on its side in a crowded panel and still meet the derating curve. Clearances: 10 mm upwards, 10 mm forwards, 6 mm at the side — standard for the S00 frame.
The product complies with substance prohibitance per the 10/01/2009 date, covering RoHS-like restricted materials. A full declaration pack (RoHS, REACH, UL, IEC) is available from the manufacturer — nameplate trace to the order code is straightforward.