Do transformers have oil in them?

Yes, transformers do have oil in them, specifically, oil-filled transformers utilize mineral oil or ester oil to provide insulation and cooling for their components. This oil helps to dissipate heat generated during operation and protects the internal parts from electrical and thermal stress, ensuring efficient and reliable performance. Additionally, the oil serves as a medium to enhance the transformer’s electrical insulating properties, preventing arcing and breakdown of the insulation system. Proper maintenance, including cleaning and regeneration of the oil, is crucial for the longevity and safe operation of transformers that contain oil.