How does an oil cooled transformer manage thermal stress?

It manages thermal stress through efficient heat transfer from windings to oil, and from oil to cooling surfaces such as radiators or heat exchangers. Cooling modes may be natural oil natural air, forced air, or forced oil with pumps. Temperature indicators and control systems manage fan and pump activation to control top oil and winding hot spot temperatures. Keeping temperatures within limits reduces cellulose aging rate and prevents oil oxidation acceleration. Thermal management is crucial during peak loads and overload events.