The Siemens SIRIUS 3RT1446-3XX40-0LA2 is a Size S3 power contactor built for motor switching in industrial control panels. It carries 29.9 kW at 500 V and 38.2 kW at 690 V in AC-3 duty, so it handles the common 400 V to 690 V motor loads you see on pump, fan, and conveyor circuits. The contactor mounts via screw or snap-on onto 35 mm and 75 mm standard mounting rail, which means it drops into a standard DIN-rail panel layout without special brackets. Main circuit connections are screw-type terminals sized for solid or stranded wire up to 50 mm² at the AC-1 maximum rating, with the control circuit accepting 2x (0.25... 2.5 mm²) solid.
DC switching and arc performance
For DC loads the contactor is rated at 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, and 0.3 A at 220 V — a useful curve for switching DC control circuits or small DC motors in the same panel. Arcing time is 10 to 15 ms, with a DC operating time of 14 to 20 ms, which gives you a predictable break sequence for coordinating with upstream protection.
Lifecycle and compliance
Storage temperature range is -55 to +80 °C, operating range -40 to +70 °C, so it's suitable for unheated enclosures in most plant environments.
Mounting and wiring clearances
Clearance requirements: 10 mm upwards, 20 mm forwards, 10 mm downwards, 10 mm at the side. Side-by-side mounting is permitted, which saves rail space when grouping multiple contactors. Main terminals accept 2x (10... 50 mm²) stranded or 2x (2.5... 16 mm²) solid/stranded, with AWG equivalents of 2x (10... 1/0). Control terminals take 2x (0.25... 2.5 mm²) solid.