It should turn around smoothly, without any 'hickups' (be sure to completely shut down the air compressor!). Check the isolation of the motor windings. Should be in the mage-ohms (you need an isolation tester / high voltage ohm meter for this). Check the voltage when the compressor is running.
[pdf] Lishui Fucai Electromechanical Equipment Co., Ltd. has been deeply engaged in industrial products such as screw air compressors, air coolers, factory cooling and ventilation equipment for more than ten years.
[pdf] Replace screw air compressor lubricating oil by stopping the machine, draining old oil, cleaning pipelines, adding new oil, and replacing the oil filter. Check oil level after starting.
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