The Siemens SIRIUS 3RH1911-1FA40-ZX95 is an auxiliary switch block with 4 normally open (NO) contacts, terminated via screw-type terminals. It snap-mounts onto contactors in the SIRIUS family and is rated for a maximum of 10 A across its switching capacity. This is a phased-out product. The official successor is the SIRIUS 3RH2 series. If you are sourcing for a BOM that lists this exact order code, the replacement path is clear, but the footprint and ratings differ — verify panel fit before committing the line.
Contact Ratings — What They Mean for Your Circuit
The 10 A maximum applies across the board, but the voltage-specific ratings tell you what the block can actually switch under load. At 24 V DC it handles 6 A; at 125 V DC, 6 A; at 230 V DC, 6 A; at 400 V AC, 3 A. The AC-15 rating at 690 V is 1 A. These are the numbers that govern real-world contact life — the 10 A ceiling is only valid for resistive loads at low voltage. Contact reliability is specified at one faulty switching operation per 100 million cycles at 17 V and 5 mA (or 1 mA for the auxiliary contacts). That is the low-energy switching floor — below those levels, you risk intermittent contact. Do not use this block for dry-circuit logic signals below that threshold.
Lifecycle Status — Phased Out, Successor Identified
The 3RH1911-1FA40-ZX95 is explicitly marked as a phased-out product. The manufacturer's designated successor is the SIRIUS 3RH2 series. No last-time-buy date is listed here, so procurement must treat this as a non-stocked item available only through independent distribution or remaining surplus.
Mounting and Integration
Snap-on mounting onto the contactor or contactor relay. The block carries 4 NO instantaneous contacts and uses screw-type terminals accepting 2x (0.5 to 1.5 mm²) and 2x (0.75 to 2.5 mm²) with core-end processing, or 2x (20 to 16) and 2x (18 to 14) AWG. Front protection is IP20 — suitable for enclosed panels, not open washdown environments. Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C. Surge voltage resistance is rated at 6 kV, with insulation voltage at 690 V for pollution degree 3.