Its 24 VDC coil pulls in at 0.8 of rated voltage and holds across the full operating range of -25 to +60 °C. The screw-type main terminals accept stranded conductors from 10 to 50 mm², sized for the 37 kW rating at 500 V and 18.6 kW at 690 V. Snap it onto 35 mm or 75 mm DIN rail — the 70 mm width and 146 mm height fit standard panel layouts, and side-by-side mounting is supported for multi-contactor assemblies.
The 3RT1044-1BB44 carries AC-1 through AC-4 duty ratings that define its real switching capability. At AC-3 (standard motor start) it handles 37 kW at 500 V and at AC-2 (slip-ring motor start) 30 kW at 400 V. For heavy inching or plugging duty at AC-4, the maximum operational current is 55 A at 400 V. These are not continuous ratings — the contactor is designed for switching cycles, with a maximum of 1000 cycles per hour at AC-1 and AC-3, and 300 cycles per hour at AC-4. The auxiliary contacts on the front are rated for 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V, covering typical control circuit needs. Pollution degree 3 means it tolerates conductive dust in industrial environments, and the IP20 front with IP00 terminal area is standard for enclosed panel mounting.
The main circuit terminals are screw-type, accepting 2x (10... 50 mm²) stranded or 2x (2.5... 16 mm²) solid/stranded. Solid auxiliary wire range: 2x (0.5... 1.5 mm²), 2x (0.75... 2.5 mm²), max. 2x (0.75... 4 mm²). Depth of 201 mm leaves clearance for wiring ducts and terminal blocks on the rail.