Why and when is insulating oil dielectric breakdown voltage test performed?
The dielectric breakdown voltage test is a relatively quick and easy way of determining the amount of contamination in insulating oil. Usually the contaminant is water, but it can also be conductive particles, dirt, debris, insulating particles and the by-products of oxidation and aging of the oil.
For in-service equipment, the dielectric breakdown voltage test offers a useful and convenient way to detect moisture and other contamination in the oil before it leads to a catastrophic failure. The information gained from the test can also be used as an aid to:
(1) Predicting the remaining life of a transformer
(2) Enhancing operational safety
(3) Preventing equipment fires
(4) Maintaining reliability
Dielectric breakdown voltage testing is also carried out on new oil before it is used to fill equipment, and as part of the acceptance testing for deliveries of new and reprocessed oil.
