The open-close current transformer is mainly used for cables and copper bars. It has simple structure, reasonable design and flexible application. According to the specifications of the copper bars used in the main circuit, there are many kinds of through holes corresponding to each other. The primary current of the main circuit includes 50A ~8000A, and the rated secondary output current is 1A~5A (0~1V). This series of products can meet the technical requirements of grade 0.2, grade 0.5, grade 1 and other different precision .