Method for selective leakage protection of electric feeding switch protector

This invention relates to a selective leakage protection method for feed switch protection devices characterizing in utilizing CAN bus to communicate and endue the CAN bus ID of different priorities based on the level of the feed switch protection device places including setting the ID priority of the main feed switch protection device the lowest and the ID priorities of the branch devices higher in file, when leakage happens to the load side of any branch device, the branch and the main feed protection devices test it at the same time, the branch wins the bus arbitration in terms of its ID and transmits the information, the main and the branch feed switch protection devices without errors keep normal.