Gas evolution from transformer oils under high-voltage stress

Some insulating oils when subjected to high-voltage stress undergo chemical changes that result in the formation of various gases. Since there are different insulating oils available to users that are made by various finishing techniques resulting in oils of significantly varied composition, a study of a range of these materials was made to show if they produced different amounts or types of gases. The evolution of gases from oils in atmospheres of hydrogen and nitrogen were studied when the stressing voltage and temperature were varied over reasonable ranges.