What it is and what it does
The Siemens 3RH2911-2XA31-0MA0-ZW96 is a SIRIUS auxiliary switch designed for front-mounting on 3RT2 contactors and 3RH2 contactor relays. It provides 3 normally open (NO) and 1 normally closed (NC) auxiliary contacts, wired as current paths 53/54, 61/62, 73/74 (NO) and 83/84 (NC). The spring-loaded terminals accept 2x (0.5...1.5 mm²) with ferrule or 2x (0.5...2.5 mm²) solid, or 2x (20...14 AWG) stranded — no screwdriver needed for termination, which speeds up panel wiring. Rated for a maximum of 10 A, with specific AC-15 ratings: 10 A at 24 V, 6 A at 230 V, and 1 A at 690 V. The insulation voltage is 690 V AC at pollution degree 3, with a surge voltage resistance of 6 kV. Mechanical service life is 10 million switching cycles typical, and contact reliability is rated at 1 faulty switching per 100 million operations at 17 V, 1 mA — meaning it handles low-energy PLC signals without nuisance failures.
Where it fits
Snap-on mounting onto the contactor or relay front — no tools, no DIN rail footprint consumed beyond the base device. Dimensions: 36 mm wide, 47.7 mm deep, 41.5 mm high. The IP20 front protection means it's suitable for enclosed control panels only, not washdown environments. Operating temperature range is -25 to +60 °C; storage from -55 to +80 °C.