1. In the process of line design, the capacity of the site shall be accurately verified, and the possibility of new capacity in the future shall be fully considered, and the appropriate type of conductor shall be selected. The larger capacity, the thicker conductor should be selected. Line design and reasonable selection are the key steps to prevent overload. If the design and selection are improper, it will leave a congenital hidden danger that is difficult to rectify. Some small projects and places are not carefully designed and selected. It is very dangerous to choose and lay lines at will. The bearing capacity of the original circuit shall be fully considered for new electrical appliances and electric equipment. If the original line does not meet the requirements, it shall be redesigned and reconstructed.