In lowest temperature fault conditions the hydrogen generation is possible, of course it is with other hydrocarbon radicals; because the hydrocarbon molecule breakdown without new produced material containing carbon atom in related temperature is impossible. The identification and significance of gases in electrical equipment was first used to distinguish between combustible and non-combustible gases produced in transformers as long ago as the 1920s. This was carried out by applying a light to the gas collected from the sample or vent tap of the Buchholz relay. Transformer Oils consisting of high molecular weight hydrocarbon molecules can suffer degradation due to decomposition of these molecules into lighter more volatile fractions. This process is also accelerated by temperature. It is desirable that it should not occur at all within the normal operating temperatures reached by the plant, but it cannot be prevented at the higher temperatures generated by fault conditions. Initially the procedure aimed to detect the presence of hydrogen, which meant that there was a