What this part is and where it fits
The Siemens SIRIUS 3RH1911-1GA31-ZW96 is a 4-pole auxiliary switch block with 3 normally open and 1 normally closed contact, designed for use with contactor relays and power contactors in the SIRIUS family. It mounts via snap-on fastening onto a 35 mm DIN rail, occupying a 36.5 mm wide footprint with a depth of 41.5 mm and height of 37.5 mm, making it suitable for dense panel layouts where space is constrained.
Switching ratings and what they mean for your circuit
The block carries a maximum continuous current of 10 A, but the actual switching capacity depends on the circuit voltage. At 24 V AC/DC it handles 6 A; at 125 V it also handles 6 A; at 230 V it handles 6 A; at 250 V it handles 6 A. For higher voltages the rating drops: 3 A at 400 V, 0.3 A at 220 V, and 0.26 A at 600 V. These are the make-and-break limits for the auxiliary contacts — important for sizing control circuits, especially when switching inductive loads like contactor coils or solenoid valves at higher voltages.
Environmental and mechanical limits
Rated for operation from -25 °C to +60 °C and storage from -55 °C to +80 °C, this block suits most indoor industrial environments. The front face carries IP20 protection — finger-safe but not sealed against moisture or dust ingress. Mechanical service life is 10 million switching cycles typical, with contact reliability specified at one faulty switching per 100 million operations at 17 V, 1 mA, which is relevant for low-energy signal circuits where oxide films on contacts can cause intermittent failures.
Wiring and connection details
Connection is via screw-type terminals, accepting 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) with core end processing, or 2x (20 to 16 AWG) or 2x (18 to 14 AWG) for stranded wire. Insulation voltage is rated 690 V AC at pollution degree 3, with surge voltage resistance of 6 kV. These ratings confirm the block is qualified for installation in standard industrial control panels where overvoltage transients are expected.