Thermography of High Voltage Motors


During the periodic routine measurements, it was instinctively determined that this high voltage motor was reasonably warm (especially near the lower clutch-side). To obtain insight in the temperature distribution, it was decided to take an IR photo.

  • Bearing temperature on the coupling side 115 8C (grease streams from the bearing) 
  • Temperature of the winding 1268C 
  • IR-measurement: casing up to max 80 8C
Thermography on high-voltage motorThermography on high-voltage motor

Suggested action:

This motor is air-cooled. The outside air is drawn in on the non-clutch-side, and cools the motor via axially placed hollow tubes in the mantle. We had the impression that the airflow rate through the tubes was relatively low. A small steal brush was fitted on a thin rod, after which the channels were cleaned. 


Result after cleaning: 

We see a dramatic fall in temperature.

  • Bearer temperature KK 668C (decreased by 508C)
  • Temperature winding 738C (decreased by 538C)
  • IR- measurement: casing up to max 60 8C (decreased by 208C)


As a result of a small change to this machine, we have been able to substantially increase the operation time. The components of the machine are safe guarded against high temperatures, without requiring downtime. On-site, we have developed a maintenance plan to clean all similar high-voltage motors annually and thus preventively.