What it is and what it fits
The Siemens SIRIUS 3RH1911-2HA22 is a 4-pole auxiliary switch block with 2 normally-open and 2 normally-closed contacts, terminated via spring-loaded terminals. It snaps onto 3RH1 contactor relays and power contactors — no tools needed for mounting. Rated for a maximum of 10 A, with DC-13 switching capability at 24 V rated at 10 A, 60 V at 4.7 A, 110 V at 3 A, and 220 V at 1.2 A. The AC-15 rating at 690 V is 1 A. Surge voltage resistance is 6 kV, insulation voltage 690 V at pollution degree 3. The compact footprint — 46 mm deep, 36.5 mm wide, 37.5 mm high — leaves room on the DIN rail for additional control gear. Snap-on mounting onto the contactor body means no extra panel space is consumed.
Wiring and integration notes
Spring-loaded terminals accept 2x (0.5 to 2.5 mm²) without core-end processing, or 2x (0.5 to 1.5 mm²) with ferrules. AWG equivalents are 2x (20 to 14). The IP20 front protection means the block is suited for enclosed panel installation only. Contact reliability is rated at 1 faulty switching per 100 million operations at 17 V, 1 mA — useful for PLC-level signal circuits where dry-contact switching is common. Mechanical service life is 10 million switching cycles typical. Storage temperature range is -55 to +80 °C; operating range is -25 to +60 °C. The block carries 2 instantaneous contacts and is designed for use with contactor relays and power contactors in the SIRIUS family.