SIRIUS power contactor, size S2 — 18.5 kW at 500 V AC-3
The Siemens SIRIUS 3RT1034-3KK84-0LA0 is a size S2 power contactor rated for motor switching at 18.5 kW at 500 V AC-3 and 10 kW at 690 V, with an AC-4 rating of 29 A at 400 V for reversing or inching duty. Snap-on mounting onto 35 mm DIN rail per EN 50022, with screw terminals for the main circuit accepting 2x (0.75...25 mm²) stranded or 2x (0.25...2.5 mm²) solid — sized for motor branch circuits up to 16 mm² at 40 °C. Dimensions 80 mm wide × 110 mm high × 167 mm deep, with side-by-side mounting permitted for dense panel layouts.
Duty-cycle ratings and thermal limits
Maximum operating frequency at AC-3 is 1,000 switching cycles per hour; AC-4 duty is limited to 250 cycles per hour — the lower figure governs for plugging or jogging applications. Ambient operating range -40 to +70 °C, storage -55 to +80 °C. Pollution degree 3 suits industrial environments with conductive dust or condensation. Arcing time 10...15 ms, DC coil dropout 20...30 ms — relevant for timing coordination in safety circuits or sequential start schemes.
Lifecycle and compliance
RoHS compliance date 05/01/2012; substance prohibitions per EU directive apply from that date. Typical mechanical life 10 million operations.
Panel integration
Screw-and-snap-on fastening onto 35 mm DIN rail per EN 50022. Side-by-side mounting allowed — no mandatory spacing between contactors in a row, which saves rail length in multi-contactor motor control centers. Screw terminals on the main circuit accept up to 16 mm² at 40 °C minimum permissible cross-section. Solid wire range 2x (0.25...2.5 mm²) for control wiring; stranded 2x (0.75...25 mm²) for power connections.