What the ratings mean for your panel
The 3RH2911-4HA02 is a SIRIUS auxiliary switch rated for 10 A maximum at AC-12 duty — that's the resistive load ceiling for the auxiliary contacts, so keep inductive or pilot-duty loads within the AC-15 derating curve (1 A at 690 V). It snaps onto the front of Siemens contactors in sizes S00, S0, S2, and S3 — the same mounting footprint covers the whole SIRIUS block contactor family, so one spare part number supports multiple panel builds. The mirror contact function per IEC 60947-4-1 is present when paired with a 3RT2 contactor — this matters for safety circuits where the NC mirror contact must positively indicate the main contact state, as required in fail-safe drive disconnects.
Current ratings across the voltage range
Rated operational current at 24 V is 6 A (with a separate 10 A rating at 24 V for the alternative duty class), stepping down to 2 A at 48 V and 60 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V and 250 V, and 3 A at 400 V. The alternative rated-value set shows 4.7 A at 60 V, 3 A at 110 V, 1.2 A at 220 V, 0.5 A at 440 V, and 0.26 A at 600 V — these are the figures to use when coordinating with the upstream protective device for the specific control voltage on site. Contact reliability is specified at 1 faulty switching per 100 million operations at 17 V, 1 mA — this is the low-level signal threshold; for dry-contact PLC inputs running at 24 V, the reliability margin is well into the safe zone.
Mechanical life and environmental limits
Typical mechanical service life is 10 million operating cycles — this is the unloaded mechanical endurance; actual electrical life depends on the switched current and voltage per the derating curves. Operating temperature range is -25 to +60 °C, with storage from -55 to +80 °C — the switch lives inside the contactor enclosure, so the panel ambient, not the machine-side temperature, governs the derating. IP00 on the front means no ingress protection at the operator face — the auxiliary switch relies on the contactor enclosure or panel door for splash and dust sealing.
Sourcing and lifecycle status
Termination is ring terminal lug connection — confirm the ring tongue size matches your panel wiring before committing the BOM line; the switch does not accept cage-clamp or screw-cage terminals. RoHS compliance date is 10/01/2009 — the switch meets the EU RoHS substance restrictions effective from that date.