SG (B) 10 series of non-encapsulated dry-type transformer is a new product with environmental protection, energy saving and security concepts. NOMEX insulation material which is made by U.S. Du Pont is used. Anaerobic, high-conductivity copper electromagnetic isused in high-voltage winding and low- voltage winding. Well-designed continuous, foil-type structure and vacuum pressure treatment process Impregnation (VPI) make partial discharge to small. And without any cracking or reduction in the level of insulation phenomenon in the entire period. Overall vacuum impregnation, high temperature curing treatment, supported by using high-strength ceramics, and have a good capacity of sudden short-circuit current. The maximum allowable operating temperature of H-class heat-resistant coil insulation levels is 180℃, and the main insulating material is C-level (heat-resistant up to 220℃) of NOMEX paper. And there have more design margin. Products can be installed in the dirty environment and fire safety requirements, larger load area. They are widely used in high-rise buildings, airports, subway, terminal, petrochemical, densely populated areas, nuclear power plants and so on.