What this auxiliary switch does in the panel
The 3RH2911-1HA01-ZW96 is a front-mounted auxiliary switch block for Siemens SIRIUS 3RT2 contactors and 3RH2 contactor relays, adding one normally-closed (NC) contact path to the base device. It snaps onto the front of the contactor or relay without extra tools — the 36 mm width and 43.7 mm depth keep it within the same DIN-rail footprint as the base unit. Rated for 10 A maximum, with the NC contact carrying 6 A at 24 V, 6 A at 230 V, and 3 A at 400 V — the current path is the single NC, no other contact configurations on this variant.
Contact ratings and switching duty
The NC contact is rated for AC-15 duty at 690 V, 1 A — this covers solenoid and relay loads typical in control circuits, not motor switching. Rated insulation voltage is 690 V at pollution degree 3, with a 6 kV surge voltage resistance, so it holds up in industrial panels without additional creepage clearance. Contact reliability is specified at 1 faulty switching per 100 million operations at 17 V, 1 mA — this matters for low-energy signal circuits where oxide films can cause intermittent opens. Mechanical service life is 10 million switching cycles typical, which for a control-circuit auxiliary block means it outlasts most contactor main-contact replacements.
Wiring and environmental limits
Screw-type terminals accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) conductors per clamp, or 2x (20 to 16 AWG) or 2x (18 to 14 AWG) — two conductors per terminal is standard for daisy-chaining control wiring. Operating temperature range is -25 to +60 °C, storage from -55 to +80 °C — fine for unheated enclosures in most climates. Front-side protection is IP20 — the terminals are touch-safe but the unit is not sealed against dust ingress; it belongs inside a panel, not in a washdown zone.
Sourcing and lifecycle reality
This is a multi-unit packaged variant (240 units per pack), so single-unit pricing may differ from the standard 3RH2911-1HA01-ZW96 single-pack version — confirm the pack quantity against your BOM line.