What it is and where it fits
The Siemens 3RH2911-2GA22-ZW96 is a front-mounted auxiliary switch block for the SIRIUS contactor relay line, specifically designed to mate with the 3RH2140 and 3RH2440 contactor relays per EN 50011. It provides 2 normally-open and 2 normally-closed instantaneous contacts, wired to terminals 53/54, 61/62, 71/72, and 83/84, giving you four discrete signal paths off the relay's armature position. Snap it onto a DIN rail — the fastening method is snap-on mounting, so it clips into the same rail the contactor relay sits on, no tools needed for the mechanical install. The spring-loaded terminals accept 2x (0.5 to 2.5 mm²) solid wire or 2x (0.5 to 1.5 mm²) with ferrules, and the equivalent AWG range is 2x (20 to 14).
What the ratings mean for the panel
The headline maximum is 10 A, but that's a thermal current rating — the real switching capacity depends on the voltage and load type. At 24 V it handles 6 A; at 230 V it still carries 6 A; at 400 V it drops to 3 A. For DC switching, the numbers tighten: 24 V at 10 A, 60 V at 4.7 A, 110 V at 3 A, 220 V at 1.2 A, and 600 V at just 0.26 A. The AC-15 rating at 690 V is 1 A — that's the inductive load curve for solenoid valves and contactor coils at higher voltages. Contact reliability is spec'd at 1 faulty switching per 100 million operations at 17 V and 1 mA — that's the dry-circuit confidence for low-energy signal switching. Mechanical service life is 10 million switching cycles typical, so this block outlasts most contactor relays it rides on. Surge voltage resistance is 6 kV, and insulation voltage at pollution degree 3 is 690 V AC. IP20 on the front means finger-safe but not washdown-rated — keep it inside the enclosure, not on the panel door. Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C.
Wiring and integration notes
The spring-loaded terminals are physically coded — the housing has a keying feature that prevents inserting the wrong terminal type. Wire preparation is standard: strip to 8 mm, insert solid or ferruled stranded, and the cage clamps automatically. No screwdriver needed for the connection, which speeds up panel wiring on repetitive builds. Dimensions are compact: 36 mm wide, 41.5 mm tall, 47.7 mm deep. It sits flush on the front of the contactor relay, so it doesn't increase the panel depth beyond the relay's own envelope. The 2 NO + 2 NC contact arrangement follows EN 50011 for auxiliary contact blocks, meaning the terminal numbering is standardized across the SIRIUS family.