Electric motors have permanently lubricated bearings, requiring no additional lubrication.
The compressors rely on their own oil supply, stored in the Carter of the same.
For oil addition in installations with long gas lines check the compressor manufacturer's recommendations. The compressors have an oil sight gauge for level checking. The oil level must be checked when the compressor is operating under stabilized conditions. In this case the oil level should be between 1/4 and 3/4 of the oil sight glass.