Factors affecting the breakdown strength of transformer oil

The a. c. breakdown strength of technical grade transformer oil is dependent on many factors. Some of the factors which have been studied in this paper are the effect of electrode area for brass and steel electrodes, the effect of gap spacing and the effect of oil velocity in the uniform field region (up to a few cm.sec−1). The phenomenon of spark conditioning has also been examined especially the effect of test cell capacitance. A few experiments have also been carried out to measure the effect of added contamination.