The Siemens SIRIUS 3RH1911-1FA22 is an auxiliary switch block with 2 normally open and 2 normally closed contacts, wired via screw-type terminals. It snaps onto size S00 contactor relays and power contactors in the SIRIUS family, adding auxiliary signal feedback or interlocking without extra panel wiring. The block is rated for a maximum of 10 A, with contact ratings that vary by voltage — 6 A at 24 V, 6 A at 230 V, and 3 A at 400 V, for example — so the actual switching capacity depends on the control voltage in your circuit.
Contact ratings and reliability
The auxiliary contacts are rated for AC-15 and DC-13 duty. At 24 V DC the continuous rating is 10 A; at 110 V DC it drops to 3 A; at 220 V DC it is 1.2 A. For AC loads at 230 V the rating is 6 A, and at 400 V it is 3 A. The block carries a mechanical service life of 10 million switching cycles typical, and contact reliability is specified at 1 faulty switching per 100 million operations at 17 V, 1 mA — a figure that matters for low-energy signal circuits where oxide film on dry contacts can cause intermittent failures. The insulation voltage is rated 690 V AC at pollution degree 3, with surge voltage resistance of 6 kV.
Mounting and wiring
Snap-on mounting directly onto the contactor — no tools needed. The block fits size S00 contactors (36.5 mm wide, 41.5 mm deep, 37.5 mm high). Screw terminals accept 2x (0.5... 1.5 mm²) or 2x (0.75... 2.5 mm²) with core end processing, or 2x (20... 16) and 2x (18... 14) AWG. Front-side protection class is IP20, so it is suitable for enclosed panel environments but not washdown or outdoor exposure.