... -phase,three-phase,combination oil-immersed transformer of electrical power .2.The frequency of 50HZ,60HZ,rated voltage of 10KV,35KV,rated current of 30A~250A;the voltage ... ,neutral point,can be directly fixed on the box-cover of thetransformer3.under the non excitation condition regulating and changing.4.tao changer on load tap changer