The main function of transformer oil

(1) Insulation effect: transformer oil is much higher than the dielectric strength of air. Insulation material immersed in oil, not only can improve dielectric strength, but also from the tidal erosion
(2) Thermal effects: a large specific heat transformer oil, used as a coolant. The heat generated when the operation of the transformer air circuit breaker close to thermal expansion of the oil rise, the upper and lower convection through the oil, heat is dissipated through the radiator, to ensure the normal mcb circuit breaker of the transformer. 
(3) the role of the arc: In the oil circuit breaker and transformer load tap switch, the contact arcing when switching. Good thermal Circuit breaker of the transformer oil, and under high temperature of the arc of contact a large quantity of gas can produce a greater pressure, thereby improving the dielectric properties of the arc, the arc extinguished quickly.