Compressor bearing fault detected by a Vibration Analysis inspection of a refrigeration compressor.

Compressor bearing fault detected in refrigeration compressor

Inspection description:
Vibration analysis inspection of Refrigeration Compressor

Frequency of inspection:
Monthly

Equipment description:
Motor – Coupling – Compressor running 24/7

Vibration reading (acceleration power spectrum o/all value 1.787g) from the compressor input bearing recorded in may 2015:

This spectrum indicates the operating vibration baseline from the Compressor Input Bearing when first recorded. The o/all levels recorded from this compressor were moderately above recommended magnitudes at this time.

Vibration reading (acceleration power spectrum o/all value 3.679g) from the motor drive bearing recorded in aug 2015:

This spectrum indicates an increase of >100% in the overall high frequency vibration from the Compressor Input Bearing.
 
Vibration reading (demodulation power spectrum o/all value 2.314g in aug 2015) from the compressor input bearing recorded in may, june and aug 2015.

This spectrum indicates the increase in impacts occurring within Compressor Input Bearing at the associated bearing fault frequencies:

Fault detection and action

Fault detected:
Deterioration detected of the Compressor Input Bearing

Recommended Action:
Replacement of Compressor Input Bearing

Action Completed:
Compressor overhaul and replacement in Dec 2015 during shutdown period

Vibration reading comparison (demodulation power spectrum) from the compressor input bearing recorded in sept & oct 2015 pre-replacement (middle and bottom readings) and in feb 2016 (top reading) post-replacement.

TO BE COMPLETED

https://www.eastwaytech.com/case-studies/compressor-bearing-fault