SIRIUS S3 power contactor — 3RT1044-3AH20
It handles motor loads up to 37 kW at 500 V 50 Hz and 18.6 kW at 690 V, with a 24 V DC coil rated at 10 A.
The 37 kW rating at 500 V 50 Hz and 18.6 kW at 690 V define the motor switching capacity under AC-3 duty — this contactor is sized for medium-horsepower induction motors typical on pumps, fans, and conveyors. Screw-type terminals accept solid conductors 2x 0.25–2.5 mm² and stranded 2x 10–50 mm², so power wiring up to 50 mm² terminates directly without lugs. The S3 frame is a standard footprint across the SIRIUS contactor family, meaning auxiliary contact blocks and overload relays from the same series snap on without adapters.
Side-by-side mounting is permitted, so multiple contactors can pack tightly on the rail for multi-motor groups. IP20 on the front with cover/box terminal means the front face is touch-safe in a typical enclosed panel; the terminal area itself is IP00, so the panel door or additional shrouding must be closed before energizing.