The Siemens 3RH2911-1HA11-ZX95 is a SIRIUS auxiliary switch block that mounts on the front of 3RT2 contactors and 3RH2 contactor relays, adding one normally-open and one normally-closed auxiliary contact. It snaps onto the front without tools and connects via screw-type terminals, accepting 2x (0.5…1.5 mm²) or 2x (0.75…2.5 mm²) conductors.
Ratings and what they mean for fit
The auxiliary contacts are rated for a maximum of 10 A, but the actual switching capacity depends on the voltage and load type. At 24 V the contacts carry 6 A; at 230 V they also carry 6 A. At 400 V the rating drops to 3 A. For AC-15 inductive loads at 690 V the rated value is 1 A — that's the figure to use when switching contactor coils or solenoid valves on a 690 V line. The mechanical service life is 10 million switching cycles typical, and contact reliability is specified as 1 faulty switching per 100 million operations at 17 V, 1 mA, which covers dry-circuit PLC-level signals.