The Siemens SIRIUS 3RH1911-1GA22-ZW96 is an auxiliary switch built for contactor relays and power contactors — the kind of part that lives on the front of a contactor and tells the PLC whether the main contacts are open or closed. It snaps onto the front of a 3RH2140 or 3RH2440 auxiliary switch block, so it's a stack-on module, not a standalone device. Rated for 6 A at 24 V and the same at 230 V, it handles the control-circuit loads you'd expect in a panel running at those voltages.
What the ratings mean for fit
The snap-on mounting means it clips onto the contactor without tools — a quick push and it's seated on the DIN-rail assembly. That 41.5 mm depth and 36.5 mm width keep it within the standard S00 contactor footprint, so it won't crowd adjacent wiring. The IP20 front protection is the usual panel-side rating — fine inside a closed cabinet, but not for washdown areas. The current ratings are given per voltage — 6 A at 24 V, 2 A at 48 V, 1 A at 110 V, 0.3 A at 220 V — so match the control voltage in your circuit. The AC-12 maximum is 10 A, which is the resistive-load ceiling; the AC-15 rating at 690 V is 1 A, covering inductive solenoid loads. The mirror contact function per IEC 60947-4-1 means this switch can be used in safety circuits where you need positive opening indication — a real plus for guarding applications.
Compliance and documentation
The substance prohibitance date of 07/01/2006 aligns with RoHS compliance — the switch meets the EU directive. The surge voltage resistance is rated at 6 kV, which covers the impulse withstand for most industrial panels. Contact reliability is spec'd at one faulty switching per 100 million operations at 17 V, 1 mA — that's the low-energy reliability figure, important for PLC input circuits that switch at milliamps.