The Siemens 3RH2122-1AH00 is a SIRIUS auxiliary contactor in size S00, carrying 2 normally-open instantaneous contacts rated 10 A at 24 V. Rated operational current drops with voltage: 4.7 A at 60 V, 3 A at 110 V, 1.2 A at 220 V, and 0.26 A at 600 V. The arcing time sits between 10 and 15 ms, with an AC switching frequency up to 15 ms and a DC mechanical endurance of 10,000 operations per hour. Mechanical life is typical 30 million operations.
Dimensions are 57.5 mm high, 45 mm wide, and 73 mm deep — the 45 mm width is a single 9 mm module equivalent, so it occupies one position on a DIN-rail terminal block assembly.