When an HV motor is dismantled to make the stator winding accessible in a workshop setting, the UV camera greatly assists in identifying
problems. In particular, the camera helps locate superficial partial discharge issues from a safe distance. This is important since such tests are carried out in the presence of high voltages.
The above images are from a recent case where a clear increase in external partial discharge activity, compared with previous measurements, was detected. In this case, as in the others, the UV camera made it possible to pinpoint the source of the partial discharges on the terminal leads from a safe distance.
This improved the reliability of the diagnosis and gave more credibility to the repair recommendation.