The Siemens SIRIUS auxiliary switch block 3RH1911-1GA13-ZW98 is a 4-pole block with 1 normally open and 3 normally closed contacts arranged per EN 50011, terminated with screw-type terminals. It snaps onto a contactor relay or power contactor in the SIRIUS family, adding auxiliary signaling or interlocking to the base device. Rated for a maximum of 10 A, the contact ratings vary by voltage: 6 A at 24 V, 6 A at 125 V, 6 A at 230 V, 6 A at 250 V, 3 A at 400 V, and 0.3 A at 220 V. Under AC-15 duty at 690 V it carries 1 A. The block is rated for a surge voltage resistance of 6 kV and an insulation voltage of 690 V at pollution degree 3. Mechanical service life is rated at 10 million switching cycles typical, with contact reliability of one faulty switching per 100 million operations at 17 V, 1 mA. Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C. Front-side protection class is IP20.
This order code is a phased-out product. The manufacturer lists the successor as the SIRIUS 3RH2 series. For BOM lines that require this exact 1 NO + 3 NC contact arrangement and screw-terminal termination, sourcing is through surplus or broker channels; the part is quoted to order against an RFQ.
Snap-on mounting onto a contactor relay or power contactor means no DIN-rail space is consumed — the block adds directly to the front of the base device. The 36.5 mm width, 37.5 mm height, and 41.5 mm depth keep the assembly compact. Wire termination accepts 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) with core-end processing, or 2x (20 to 16) and 2x (18 to 14) AWG for auxiliary contacts.