what type of oil is used in electrical transformers?

Electrical transformers typically use mineral oil as an insulating and cooling medium. This oil is derived from refining crude oil and is chosen for its excellent dielectric properties, thermal conductivity, and ability to dissipate heat. In some cases, biodegradable ester oils are used as environmentally friendly alternatives. These oils help maintain the transformer’s efficiency and longevity by preventing overheating and providing electrical insulation between components.