Enhancing the flame, thermal and partial discharge performance of mineral oil

The results of an experimental investigation into the heat transfer, flame retardency and partial discharge extinction properties of an optimum mixture of pure transformer oil with perchlorethylene are presented. When transformer oil is mixed with perchlorethylene the heat transfer, partial discharge properties as well as the flame retardency of the mixture are enhanced. Two different mixtures were used in temperature rise tests on distribution transformers. The partial discharge performance was assessed by refurbishing a HV current transformer with excessive partial discharge levels, simply by flushing and filling with an optimum mixture. The partial discharge level was then measured and found to have decreased significantly. Some simple observations are presented which show that the mixture possess enhanced flame retardency. The purpose of this work is to present much needed practical data on the application of mixtures in typical engineering situations