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] Smaller compressors with basic features range from $2,000 to $5,000. Medium-sized compressors (10-50 HP) cost around $5,000 to $20,000 or. .
Rotary air compressor machines are not suitable for hand tools and where continuous air is not required. Rotary compressors are needed for larger facilities where air is used continuously for various applications. Instead of rotary compressor, it is.
[pdf] When pressing “Enter” the following interface will pop up and the password will be required (9999). NOTE: Customer Password can be modified in the CUSTOMER PARAMETER menu. Page 23 KRSD series ENTER PASSWORD ****. Page 24 UNLOAD P. *.**Mpa Unload pressure setting.
[pdf] 
