The Siemens SIRIUS 3RH1911-2NF11 is a solid-state compatible auxiliary switch block designed for use with SIRIUS contactor relays and power contactors. It provides one normally open and one normally closed contact, rated for switching at 24 V and 60 V at 0.3 A, in a compact size S00 housing that snaps onto the contactor. The spring-loaded terminals accept 2x (0.5... 1.5 mm²) with ferrule or 2x (0.5... 2.5 mm²) solid/stranded without, making for quick wiring in a panel build. Mechanical life is 5 million switching cycles typical, and contact reliability is rated at 1 faulty switching per 100 million operations at 17 V, 1 mA — solid for low-level signal switching in PLC or safety circuits.
This part is a phased-out product. The official Siemens successor is the SIRIUS 3RH2911-2NF11, which is the preferred drop-in replacement. For new designs, specify the 3RH2911-2NF11 to avoid a future last-time-buy scramble.
The 36.5 mm width and 46 mm depth fit the S00 footprint, so it does not steal extra rail space.