What this part is and what it does
The Siemens SIRIUS 3RH1911-1GA04-ZW97 is a 4-pole auxiliary switch block with 4 normally open (NO) and 4 normally closed (NC) contacts (44 E per EN 50011), designed for use with contactor relays and power contactors in control panels. It mounts via snap-on onto a DIN rail, taking up 36.5 mm width and 41.5 mm depth, with a height of 37.5 mm — compact enough for dense panel layouts where every millimeter counts. The screw-type terminals accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) conductors with core-end processing, or 2x (20 to 16) / 2x (18 to 14) AWG for auxiliary circuits.
Contact ratings — what the numbers mean for your circuit
Rated at 10 A maximum, but the real switching capacity depends on voltage and duty. At 24 V it switches 6 A (AC-15? the spec doesn't label the duty, but these are typical auxiliary contact ratings for control circuits). At 230/250 V it handles 6 A, dropping to 3 A at 400 V and 1 A at 690 V — so for 400 V control circuits (common in European panels), derate to 3 A per contact. For DC switching: 10 A at 24 V, 4.7 A at 60 V, 3 A at 110 V, 1.2 A at 220 V, 0.5 A at 440 V, and 0.26 A at 600 V — the DC arc is harder to extinguish, so the current drops fast as voltage climbs. If you're switching a DC solenoid or valve at 110 V, plan for 3 A max per contact. Contact reliability is rated at 1 faulty switching per 100 million operations at 17 V, 1 mA — that's the dry-circuit spec, meaning it handles low-energy signals (PLC inputs, relay coils) without the contact film issue that plagues cheaper blocks. Mechanical service life is 10 million switching cycles typical, which is standard for SIRIUS auxiliary blocks — expect the contacts to outlast the contactor in most cyclic applications.
Mounting and integration notes
Snap-on mounting onto 35 mm DIN rail. The IP20 front protection means it's suitable for enclosed panels where the front face is behind a door — not for washdown or outdoor exposure. Insulation voltage is 690 V at pollution degree 3, with surge voltage resistance of 6 kV — adequate for 400/480 V panels with proper clearance. Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C.