What is the difference between oil-filled and dry type transformers?

Oil-filled transformers use insulating oil for cooling and electrical insulation, which enhances heat dissipation and provides excellent dielectric strength. This oil also helps in preventing moisture ingress, leading to improved performance and longevity. In contrast, dry-type transformers rely on air for cooling and typically utilize solid insulation like epoxy resin. They are generally lighter, offer better safety in fire hazards, and are suited for indoor applications but may require larger installations for equivalent power ratings. The choice between these two types often depends on application, operating environment, and specific utility requirements. If you’re concerned about the performance of oil-filled transformers, conducting regular oil-filled transformer testing is essential to ensure their integrity and reliability over time.