SG series three-phase dry-type transformer 1. The wires are made of PEW, UEW, EIW, SEIW, FEAI enameled wire and glass fiber covered wire, and the temperature resistance grades are F class (155°C), H class (180°C), HC class (200°C), C class (220°C) . (The conventional temperature resistance grade is H grade 180°C). 2. The insulating material adopts improved A type of Aroma company of Japan and Nomex insulating paper of Dopont company of the United States as the insulating material, which has multiple properties of high temperature insulation, flame retardancy and moisture resistance. 3. Terminal block The small power adopts Taiwan mark terminal block, which has beautiful appearance, excellent pressure resistance, temperature resistance and flame retardant performance. High-power uses high-quality copper bars.