What it is and what it does
The Siemens SIRIUS 3RH1911-1HA22-ZW96 is a 4-pole auxiliary switch block (2 NO + 2 NC) with screw-type terminals, designed for use with contactor relays and power contactors in the SIRIUS family. It snaps onto the contactor or relay without tools, adding auxiliary contacts for status feedback, interlocking, or control logic. Rated for a maximum of 10 A, the switching capacity varies by voltage and duty: at 24 V it handles 6 A (AC-15/DC-13), at 230 V it handles 6 A, and at 400 V it handles 3 A. The contacts are rated for 6 kV surge voltage and 690 V insulation voltage (pollution degree 3), so it can be used in 400 V line-voltage control circuits without additional isolation. Mechanical service life is typical 10 million switching cycles, and contact reliability is rated at 1 faulty switching per 100 million operations at 17 V, 1 mA — suitable for PLC-level signal switching where low-level contact wetting is a concern.
Panel integration and wiring
Snap-on mounting onto the contactor relay or power contactor — no DIN rail required, no tools. The block adds 41.5 mm depth, 36.5 mm width, and 37.5 mm height to the assembly. Screw terminals accept 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. Front protection class is IP20 — suitable for enclosed panels.