What it is and where it fits
The Siemens 3RH2911-1HA02-ZX95 is a front-mounted auxiliary switch block from the SIRIUS family, carrying two normally-closed (NC) contacts. It snaps onto 3RT2 power contactors and 3RH2 contactor relays, adding isolated signal feedback or interlock paths without extra panel wiring. The screw-type terminals accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) with core end processing, and the AWG equivalent is 2x (20 to 16) or 2x (18 to 14).
What the ratings mean for fit
The maximum thermal current is 10 A, but the real-world switching capability depends on voltage and load type. At 24 V it switches 6 A; at 230 V it handles 6 A; at 400 V it drops to 3 A. For DC loads the curve is steeper: 10 A at 24 V, 4.7 A at 60 V, 1.2 A at 220 V, and 0.26 A at 600 V. The AC-15 rating at 690 V is 1 A — that's the inductive load rating for solenoid valves or contactor coils at higher voltages. The insulation rating is 690 V AC with pollution degree 3, and surge withstand is 6 kV, so it's fine for standard 400 V panels with decent clearance.
Panel integration notes
Snap-on mounting means no tools needed — it clips directly onto the contactor or relay front. The block dimensions are 36 mm wide, 37.5 mm tall, and 43.7 mm deep, so it adds about 44 mm to the contactor depth. IP20 on the front means it's protected against finger contact but not washdown; keep it inside the enclosure. Operating temperature range is -25 to +60 °C, storage from -55 to +80 °C.