The Siemens 3RH2911-2HA10 is a front-mounted auxiliary switch block from the SIRIUS family, carrying a single normally-open (1 NO) contact. It snaps onto 3RT2 power contactors and 3RH2 contactor relays — the note "with 3RH2" confirms the intended mating frame. Spring-loaded terminals accept 2x (0.5 to 1.5 mm²) with ferrule or 2x (0.5 to 2.5 mm²) solid, or 2x (20 to 14 AWG).
The contact is rated 10 A maximum, but the real switching capacity depends on voltage and load type. At 24 V DC it handles 6 A; at 110 V DC it drops to 1 A; at 220 V DC it's 0.3 A. For AC-15 inductive control-circuit duty at 690 V, the rated current is 1 A — that's the figure to use when switching contactor coils or solenoid valves on a 690 V line. The AC-15 ratings at lower voltages are not listed here, but the DC inductive load table (at 24 V rated value: 10 A; 60 V: 4.7 A; 110 V: 3 A; 220 V: 1.2 A; 440 V: 0.5 A; 600 V: 0.26 A) gives a clear derating curve. If your load is a DC solenoid or brake coil, use the rated-value column, not the maximum.
Snap-on mounting — no tools, no screws. The block is 36 mm wide, 47.7 mm deep, 41.5 mm high. It mounts on the front of the contactor or relay, so it adds depth to the assembly but does not widen the DIN-rail footprint. Verify clearance in front of the contactor before laying out the panel.
Environmental and electrical endurance
Insulation voltage is 690 V at pollution degree 3, surge withstand 6 kV. Mechanical life is 10 million switching cycles typical. If you're switching PLC inputs or similar low-energy loads, this contact will stay clean.
Lifecycle stage is marked as current.