SIRIUS S2 Power Contactor — 3RT1034-1BP44
The Siemens 3RT1034-1BP44 is a SIRIUS S2 power contactor with a 230 V AC coil, designed for motor switching and general load management in industrial control panels. It mounts via screw and snap-on onto 35 mm DIN rail per EN 50022, fitting into a 55 mm wide footprint. Rated for AC-3 duty at 400 V delivering 18.5 kW, this contactor handles typical three-phase induction motor loads up to that power level. The AC-1 resistive rating supports 1,200 operating cycles per hour, while AC-3 motor duty allows 1,000 cycles per hour — figures that govern thermal endurance in high-cycle applications like conveyors or compressors. Coil pick-up is guaranteed at 0.8 × rated voltage (184 V for the 230 V coil), drop-out at 1.1 × (253 V). Operating times are 20–30 ms DC closing, with arcing time 10–15 ms. Pollution degree 3 means it's rated for conductive environments typical of industrial enclosures.
Termination and Wiring
Main current circuit uses screw-type terminals. Solid wire acceptance: 2× (0.5–1.5 mm²), 2× (0.75–2.5 mm²), max 2× (0.75–4 mm²). Stranded: 2× (0.75–25 mm²). Solid or stranded: 2× (0.75–16 mm²). At 40 °C, minimum permissible conductor is 16 mm² — relevant for derating when ganging multiple contactors side-by-side. Front face carries IP20 finger-safe protection; terminal area is IP00 — wire entry zone is open during installation. Side-by-side mounting is permitted, which reduces panel width but requires attention to thermal derating per the manufacturer's arrangement guidelines.
DC Switching Capability
For DC load switching, the contactor is rated: 24 V at 10 A, 60 V at 2 A, 110 V at 1 A, 220 V at 0.3 A. These values define the resistive DC breaking capacity — useful for switching solenoids, DC brake coils, or control transformers in mixed-voltage panels.
Motor Ratings by Voltage
Motor power ratings: 18.5 kW at 500 V (AC-3), 10 kW at 690 V. AC-2 duty at 400 V delivers 15 kW. AC-4 at 400 V is rated 29 A — relevant for reversing or inching applications where the contactor makes and breaks stalled rotor current. AC auxiliary ratings: 230 V at 6 A, 400 V at 3 A. These cover control-circuit switching for pilot devices or small auxiliary loads.