4 NC auxiliary switch block for SIRIUS contactor relays
The Siemens 3RH2911-2GA04-ZX95 is a front-mounted auxiliary switch block for SIRIUS contactor relays, delivering four normally-closed (NC) contacts in a single 36 mm wide package that snaps onto DIN rail. Rated 10 A maximum, with AC-15 switching capacity at 690 V rated at 1 A — this block handles control-circuit loads across a wide voltage range, from 10 A at 24 V down to 0.26 A at 600 V.
Contact configuration and terminal reality
Four NC contacts are wired as independent current paths (51/52, 61/62, 71/72, 81/82 per EN 50011), with zero leading or lagging switching — all four break simultaneously. Spring-loaded terminals accept 2x (0.5 to 2.5 mm²) without ferrule, or 2x (0.5 to 1.5 mm²) with ferrule; AWG 20 to 14 stranded fits the same cage.
Panel fit and environmental limits
Snap-on mounting to DIN rail, 36 mm wide × 47.7 mm deep × 41.5 mm tall — the depth is the critical dimension when fitting under a gland plate or enclosure door. Operates from -25 °C to +60 °C ambient, stores from -55 °C to +80 °C. IP20 on the front face means it's touch-safe but not washdown-rated — keep it behind a panel door.
Lifecycle and sourcing posture
Listed as current-production lifecycle stage — this is an active SIRIUS catalog item, not a legacy or phase-out part. Insulation rated 690 V AC at pollution degree 3, with 6 kV surge voltage resistance — meets the isolation requirements for industrial control panels per IEC 60947. Mechanical service life is 10 million operating cycles typical; contact reliability is 1 faulty switching per 100 million operations at 17 V, 1 mA — a solid figure for signal-level switching in PLC inputs.