What is the oil transformer

Oil change refers to the oil-immersed transformer, the transformer tank shell that is, in the box is filled with transformer oil, which is an insulating medium, but also a heat sink circuit breakers . This  air circuit breaker is generally S7-S9 series. Dry-type transformers, there are two, one is the fan air cooling, one is epoxy resin casting, by naturally cooling. This transformer is generally saving transformer