What's in the box — three contactors, one assembly kit
The Siemens 3RA2444-8XH32-1NB3 is a factory-assembled star-delta (wye-delta) contactor assembly from the SIRIUS S3 family. It ships with three contactors: two 3RT2045-1NB30 units (one with the -0CC0 variant) and one 3RT2035-1NB30, plus the 3RA2943-2C RS assembly kit. The surge suppressor is a varistor type, wired in. All main, auxiliary, and control circuit connections use screw-type terminals — no spring-cage here, so factor in screwdriver torque time on the panel build.
Power ratings that drive the selection — 55 kW at 400 V, 90 kW at 690 V
Rated at 55 kW at 400 V AC-3 and 90 kW at 690 V AC-3, this assembly handles the common European motor voltages. The AC-3 duty class means it's rated for starting squirrel-cage motors and switching them off during running — the standard motor-switching load. The maximum switching frequency under AC-3 is 1 000 operations per hour, so it's sized for production cycles, not continuous jogging. Closing power of the magnet coil draws 154 W at DC, which matters for DC-supplied control circuits where the power supply headroom needs to cover the inrush.
Mounting and clearances — DIN rail with rotation freedom
Clearance requirements: 10 mm upwards, forwards, downwards, and to the side; 0 mm backwards. The 244 mm depth by 220 mm width by 180 mm height footprint fits a standard S3 contactor envelope.
Lifecycle and sourcing — current stage, quoted to order
No official replacement has been published, so this remains the direct BOM line item for star-delta applications in the SIRIUS S3 footprint.