Try to turn the compressor by hand. It should be possible to turn it around. It should turn around smoothly, without any 'hickups' (be sure to completely shut down the air compressor!). Check the isolation of the motor windings.
[pdf] discover high-quality air compressor accessories including filters, valves, gauges, and spare parts to improve performance, extend lifespan, and ensure smooth operation of your screw compressor systems.
[pdf] The Atlas Copco’s TwinAir compressor is a package of two oil-injected rotary screw compressors, powered by two liquid-cooled, six cylinder turbocharged inter-cooler diesel engines. Both compressors can be used combined or separately from each other, increasing the versatility.
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