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. If the voltage drop significantly when the compressor starts/runs, you have a bad connection somewhere.
[pdf] There is dirt stuck in the wind flap or other rotating parts 1. Send the minor repair station in time to remove or replace the necessary parts. 3. If you use the air duct to refuel, do not add too much fuel at a time, but you must work hard.
[pdf] We specialize in high-efficiency rotary screw air compressors engineered to deliver unmatched reliability, energy savings, and durability for demanding industrial operations.Our oil-free rotary screw technology eliminates contamination risks while reducing maintenance costs, making it the ideal choice for manufacturing, automotive, and heavy machinery applications.
[pdf] 
