SG, SBK series of three-coherent-type transformers for indoor air from the cooling, for the exchange of 50 ~ 60Hz, voltage of 1000V and 1000V the following circuit, As various types of machine tools, machinery and equipment, the control of the general electric power supply, local lighting and direct power supply, can also be used as a small power supply. Structural features: SG, SBK series of three-coherent-type transformers can be made into open-type or protective style, with a low loss, noise, fire safety performance is good and not pollute the environment and so on. One type is the use of protective steel plate processed into tank shell, the shell transformer boxes inside boxes outside the shell into the outlet hole, with more to install power lines.