Atlas Copco 1083568651 / 1627326981 Air Compressor Fan Motor

Specifications: 1083568651 / 1627326981

The 1083568651 motor is a three-phase AC induction unit built for the cooler circuit of Atlas Copco air-cooled screw compressors. It mounts at the radiator outlet and turns the fan across the cooler fins to reject heat from the oil and the compressed air. Frame size and winding are matched to the cooling load of the specific compressor, which is why the exact number must be right. The table below lists the identifying and functional details that define the part.

Plan the swap during a service window. Isolate the compressor from supply and lock out the main disconnect before you open the cooler guard. Work only after the package has cooled and the pressure has been released. The fan can coast after shutdown, so confirm it has stopped.

Disconnect the motor leads and label them against the terminal block. Unbolt the motor from the cooler frame and lift it clear of the shroud. Seat the replacement square to the fan hub and tighten the mounting bolts to the original torque. Refit the guard and the terminal cover before restoring power.

Run the compressor and check the fan rotation matches the arrow on the shroud. Reverse rotation moves air the wrong way and the temperature rises within minutes. Let the unit reach operating temperature and confirm the cooler outlet stays within the normal band. A short test run at load confirms the new motor draws steady current and the cooler temperature holds.

Keep the cooler fins clean so the fan does not work against blocked airflow. A layer of dust on the fins forces the motor to pull more current and shortens its service life. Blow out the cooler with low-pressure air during each service interval, and check the fan blades for build-up. A blocked cooler also raises the discharge temperature and can trip the compressor, so fan motor health ties directly to uptime.

Listen for a growl that was not there last season and watch the amp draw at the same duty. A rising reading points to worn bearings before the motor fails. Note the reading in the service log so the trend is clear at the next interval. Catch it on a planned window and the change stays a simple swap rather than a hot shutdown.

Replace the motor when the noise, current, or vibration moves outside the normal band, not after a trip. The 1083568651 motor restores the rated cooling when fitted as the direct replacement. Fit it as a direct replacement and the cooler returns to its rated duty without further changes.