The Siemens SIRIUS 3RH1911-1FA20-ZW96 is an auxiliary switch block with 2 normally open (NO) instantaneous contacts, designed for snap-on mounting onto size S00 contactor relays and power contactors. It uses screw-type terminals for the auxiliary and control circuits, accepting 2x (0.5... 1.5 mm²) or 2x (0.75... 2.5 mm²) with core-end processing, or 2x (20... 16) and 2x (18... 14) AWG. Rated for a maximum of 10 A, the contact ratings vary by voltage and duty: at 24 V it handles 6 A (10 A rated value), at 60 V it handles 2 A (4.7 A rated value), at 110 V it handles 1 A (3 A rated value), at 220 V it handles 0.3 A (1.2 A rated value), at 400 V it handles 3 A (0.5 A rated value), and at 600 V it handles 0.26 A rated value. The AC-15 rating at 690 V is 1 A. These are the switching limits for the auxiliary contacts — match your load voltage and current to the appropriate row. Mechanical service life is typical 10,000,000 switching cycles, with contact reliability rated at 1 faulty switching per 100 million operations at 17 V, 1 mA — a solid figure for low-energy signal circuits where oxide films can cause intermittent opens. Surge voltage resistance is 6 kV, and insulation voltage is 690 V AC at pollution degree 3. Front protection class is IP20, so it's suitable for enclosed panel mounting where no washdown or dust ingress is expected. Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C.
Lifecycle and Sourcing
This part is a phased-out product. The official successor is the SIRIUS 3RH2 series. For new designs or BOM replacements, plan to qualify the 3RH2 equivalent for your specific contactor frame and wiring scheme. This unit is sourced to order through independent distribution against an RFQ — availability and current pricing are confirmed at quote time.
Panel Fit and Mounting
Snap-on mounting directly onto the front of a size S00 contactor — no DIN rail required for the block itself, though the contactor typically mounts on a 35 mm rail. Dimensions are 36.5 mm wide, 37.5 mm high, and 41.5 mm deep, so it adds minimal depth to the contactor assembly. The 2 NO contacts follow EN 50005 terminal numbering.