New turbines above 3MW are being developed at a rapid rate in order to maximise energy yields. Therefore turbine components also have to be upgraded. A transformer is required to step up the voltage from the generator (400 to 3000V) to a medium voltage level. Safety and fire behaviour of transformers is an important issue for our industry. Fire damage accounts for between 9 and 20% of wind power insurance claims. In this article, the authors compare the safety and fire behaviour of dry-type transformers with high temperature liquid-filled transformers.