How does mineral oil in transformers support arc suppression and cooling?

Mineral oil acts as an insulating medium that reduces the likelihood of unintended arcing by increasing dielectric strength between energized parts. In some transformer components, oil helps quench minor discharge events by limiting oxygen and cooling hot spots rapidly. Its cooling role is primary: it transports heat away from windings to radiators and cooling surfaces. By keeping temperatures lower, oil reduces insulation aging and helps prevent conditions that can lead to arcing, gas generation, and thermal runaway.