1. The dense bus duct provided by the high and low voltage bus duct has good dynamic and thermal stability and large transmission capacity. The conductive bar adopts 99.99% copper bar. The selection of copper bar meets the gb5585 standard. The insulating material is selected, with good insulation performance and fire resistance and aging life of more than 40 years. 2. The overlapping part of copper bar shall be silver plated and embossed. 3. The shell of dense bus duct is made of cold-rolled steel plate. The shell shall have sufficient strength, good surface treatment and anti-corrosion performance, flat outer surface and beautiful color. Cold galvanizing, ral7032 epoxy resin powder electrostatic spraying and matte orange peel are added, and the inner surface is cold galvanizing. 4. The low-voltage dense bus adopts single-chip copper bus conductor, its section and supporting span meet the requirements of short-circuit thermal stability and short-circuit dynamic stability, support span and avoid resonance zone, and the straight-line section and continuous section of bus copper conductor is 6m. 5. The bus conductor layout shall consider the balance of conductor current distribution, and the current imbalance shall not exceed 4% in phase and 5% between phases. 6. The specific size and transition connection device of the low-voltage dense bus connected to the transformer and switch cabinet shall be organized by the owner to participate in the liaison meeting attended by the Design Institute, the switch cabinet factory, the transformer factory and the supplier and demander. After determining the connection mode, the supplier of high-voltage and low-voltage bus duct shall conduct on-site measurement according to the minutes of the liaison meeting, and consider the convenience of maintenance and disassembly of joints.