The Siemens 3RH1911-1GA40-ZW96 is a SIRIUS auxiliary switch block with four normally open (NO) instantaneous contacts, designed for snap-on mounting onto contactor relays and power contactors of size S00. It carries AC-15 switching ratings that define its real-world control-circuit capability: 6 A at 24 V and 230 V, 2 A at 48 V and 60 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V and 250 V, and 3 A at 400 V. For DC-13 loads the ratings shift: 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 AC-12 maximum continuous current is 10 A.
Mounting and integration
Snaps onto the front of a 3RH2140/3RH2440 auxiliary switch block or directly onto an S00 contactor relay. Occupies a 36.5 mm wide slot, 41.5 mm deep, 37.5 mm tall — fits standard DIN-rail enclosures without overhang. Wiring accepts 2x (0.5... 1.5 mm²) solid or finely stranded with ferrule, or 2x (0.75... 2.5 mm²) — covers the common panel-building range. AWG equivalents: 2x (20... 16) and 2x (18... 14). Front protection class is IP20; the switch block is intended for inside-enclosure use where the front remains touch-safe.
Contact reliability and safety compliance
Rated contact reliability: one faulty switching per 100 million operations at 17 V, 1 mA — suitable for low-energy PLC and logic-level signals. The auxiliary contacts are mirror contacts per IEC 60947-4-1 when used with 3RT1 contactors, meaning the NO contacts reflect the main contact position for safety circuit integrity. Surge voltage resistance is 6 kV, covering industrial control-panel transients. Mechanical service life is 10,000,000 operating cycles typical.