The Siemens 3RT1446-1BW40 is a SIRIUS power contactor in the S3 frame size, rated for motor loads up to 29.9 kW at 500 V and 38.2 kW at 690 V in AC-3 duty. That 690 V rating covers 575 V and 600 V line supplies common in North American and Canadian panels without derating the motor power.
Main circuit terminals are screw-type, accepting solid conductors 2x (0.5...1.5 mm²), 2x (0.75...2.5 mm²), max. 2x (0.75...4 mm²) on the control side, and stranded conductors 2x (10...50 mm²) on the power side. That's a 50 mm² maximum — enough for 1/0 AWG or 2 AWG depending on stranding — with a 35 mm² minimum at 60 °C ambient. IP20 on the front with the cover or box terminal installed; the terminal itself is IP00, so panel builders should plan for finger-safe shrouding or enclosure clearance if the contactor is mounted near an access door.
Coil and switching performance
Coil holds at 24 V DC nominal with a 10 A inrush at that voltage; at 60 V DC it draws 2 A, at 110 V DC 1 A, at 220 V DC 0.3 A. The arcing time is 10 to 20 ms, and the mechanical life is 10 million operations typical — that's a solid 10-year run at 2,700 ops/day. Maximum switching rate at AC-1 (resistive load) is 650 operations per hour.