抄録
This paper concerns the definition and evaluation of less-flammable of insulation fluids for transformers. In particular it focuses on the ISO5660 cone calorimeter method, which is widely used as an evaluation method for the less-flammable of solids, and proposes that such method is also valid for quantitative evaluation of the less-flammable of insulating fluids. Quantifying the combustion characteristics of insulation fluids and analyzing the causes of fires can be said to be the first step toward implementing appropriate safety measures that will render electric utility equipment more fire retardant or fireproof in the future.