When an Oil-immersed transformer in operation, the heat of the coil and iron core firstly is transformed into the insulation oil and then to the cooling medium. And according to the capacity sizes, it can be divided into an immersed natural cooling transformer and an immersed forced air cooling transformer.

Why are transformers immersed in oil?

Most of transformers in service are oil-immersed. Their tank, containing the core, is filled with oil. The oil removes heat and ensures dielectric strength of insulation.

What does oil do in a transformer?

Transformer oil is used to insulate high-voltage electrical infrastructure such as transformers, capacitors, switches and circuit breakers. Transformer oils are designed to operate effectively at very high temperatures, cooling, insulating, and stopping corona discharges and arcing.