Try to turn the compressor by hand. It should be possible to turn it around. It should turn around smoothly, without any ‘hiccups’ (be sure to completely shut down the air compressor!). Check the isolation of the motor winding.
[pdf] Loose screws, bolts, or other components can vibrate and create noise during operation. Tightening these components can often resolve the issue. 2. Worn Bearings Bearings wear out over time, causing friction and noise. Replacing worn bearings can restore quiet operation. 3. Intake Air Filter Clogged
[pdf] Compressor air screw VSDs usually have noise levels ranging from 60 dB to 85 dB, depending on the factors mentioned above. When selecting a compressor, it's important to consider the acceptable noise level for your specific application.
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