The Siemens SIRIUS 3RH1911-1GA22 is a 4-pole auxiliary switch block with 2 normally-open and 2 normally-closed contacts, arranged per EN 50011 (identification 22 E). It snaps onto a contactor relay or power contactor in the SIRIUS family, adding feedback or interlock contacts without extra wiring space. The screw-type terminals accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) with core-end processing, or the AWG equivalents. Contact ratings are given per voltage: 10 A at 24 V, 6 A at 230/250 V, 3 A at 400 V, and derated further at higher voltages. The mechanical service life is 10 million switching cycles typical, with contact reliability of 1 faulty switching per 100 million operations at 17 V, 1 mA — a solid figure for PLC-level signal circuits.
Snap-on mounting onto the contactor relay or power contactor — no DIN rail required for the block itself; it clips directly onto the base device. Dimensions are compact: 36.5 mm wide, 37.5 mm high, 41.5 mm deep.