CHW Pump Bearing Outer Race Fault

Vibration Analysis:
Severe bearing wear on the motor DE bearing with additional wear present on the motor NDE bearing. Both of the motor bearings are 6317-C3’s
The motor DE bearing spectra displayed non-synchronous harmonics of BPFO (Outer Race Defect) at 45.26 hz, and each fundamental BPFO harmonics had sub-synchronous sidebands equating to the FTF bearing defect frequency at 5.65 hz. The time waveform analysis displayed modulation and impacting with a delta frequency of 45.26 hz equating to BPFO (Outer Race Defect)
The highest pk-pk value is 22g's increasing from 13g's. Additionally, suspect bearing fluting is occurring due to the number of sidebands and electrical noise surrounding the BPFO fundamental frequencies.
Following the motor bearing replacement conducted on the 26th of August, all of the vibration readings have decreased to healthy levels.
A new baseline has been created for this asset and its data set.

Bearing Analysis:
Bearing received in poor condition, the initial inspection found the lubricating grease was discoloured, however, the bearing did rotate freely. Inspection of the housing interface of the outer race showed evidence of localised fretting corrosion. The inner race mounting interface was in good condition.
The motor bearing (location unknown) was found to have evidence of electrical fluting damage on both inner and outer raceways, probably caused by the variable frequency drive (VFD) supplying the motor.
The lubricant analysis compliments the inspection with elevation in the raceway elements (iron, chromium).

Recommendation:
Our recommendation would be to ensure a correctly specified VFD-rated motor is installed, examine the motor earth and ensure it is sufficient and correctly earthed or install ceramic/insulated bearings.

ESTIMATED AVOIDED COSTS: £ 12,814.50