SOLUTION

Flash Point of Transformer Oil is defined as the temperature at which light hydrocarbon present in the transformer oil starts evaporating causing a flash on the introduction of the source under specified conditions.

• Transformer oil or insulating oil is an oil that is stable at high temperatures and has excellent electrical insulating properties.
• In any case, this temperature should not be allowed to be less than 130 degrees Celsius for transformer oil in service.
• We know that the maximum continuous operating temperature of transformer oil is around 105 degrees Celsius.
• However, during fault conditions, transformer oil temperature may go as high as 130 degrees Celsius.
• Therefore, it is very much required that the flashpoint of oil should be maintained above 130 degrees Celsius to prevent fire during fault conditions.
• As per standard rules, the flashpoint of transformer oil should be greater than or equal to 140 degrees.
• Due to the relatively high flash point and boiling point of transformer oil, transformer fires can be extinguished quickly by properly designed water spray systems.