First of all, there are mainly two types of distribution boards in the market: metal shell and plastic shell, and there are two types of concealed type and exposed type in structure. Therefore, when selecting, select according to the actual needs. No matter which type of distribution board is selected, the boards must be intact. Secondly, the door panel of the distribution boards shall have a transparent window for inspection; Thirdly, the wiring busbar in the distribution boards shall be set with change, protective grounding wire and phase wire respectively, which shall be intact and have good insulation performance to ensure the safety of daily use.