The Siemens SIRIUS 3RH1911-1GA31 is a 4-pole auxiliary switch block designed for use with SIRIUS contactor relays and power contactors. It provides 3 normally open (NO) and 1 normally closed (NC) instantaneous contacts, wired via screw-type terminals. The AC-15 rating at 690 V is 1 A, which covers the inductive switching duty of contactor coils and solenoid valves in higher-voltage circuits.
The 10 A maximum at 24 V (and 6 A at 24 V for the auxiliary contact rating) means this block can switch multiple small loads in parallel without exceeding the contact current limit. Mechanical life is 10 million switching cycles typical, so in a machine cycling once every 10 seconds, the block outlasts about 3 years of continuous operation before mechanical wear becomes a concern.
Integration in the panel
Dimensions: 36.5 mm wide, 37.5 mm high, 41.5 mm deep — compact enough to fit alongside a contactor in a crowded gland plate. Wire termination accepts 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) with core-end processing, or 2x (20–16) and 2x (18–14) AWG. Screw terminals are standard; no special tooling needed.