Dry-type transformers are widely used in local lighting, high-rise buildings, airports, docks, CNC machinery, and other applications. Simply put, a dry-type transformer is one whose core and windings are not immersed in insulating oil.
Cooling methods are divided into natural air cooling (AN) and forced air cooling (AF). With natural air cooling, the transformer can operate continuously at its rated capacity for extended periods. With forced air cooling, the transformer's output capacity can be increased by 50%. It is suitable for intermittent overload operation or emergency overload operation; however, because load losses and impedance voltage increases significantly under overload conditions, resulting in uneconomical operation, it should not be subjected to prolonged continuous overload operation.
