Distribution boxes shall be made of non-combustible materials; open distribution boards may be installed in production places and offices with low electric shock risk; enclosed cabinets shall be installed in processing workshops, foundries, forging, heat treatment, boiler rooms, woodworking houses and other places with high electric shock risk or poor working environment; and enclosed cabinets shall be installed in hazardous working places where conductive dust or flammable and explosive gases are produced. Installation of closed or explosion-proof electrical facilities; distribution box electrical components, meters, switches and lines should be arranged neatly, firmly installed, easy to operate. The bottom of the board (box) installed on the ground should be 5-10 mm higher than the ground; the center height of the operating handle is generally 1.2-1.5 m; there are no obstacles in the range of 0.8-1.2 m in front of the box; the protective wires are reliable; bare charged bodies are not exposed outside the box; the electrical components installed on the outside surface of the box or on the distribution board must have reliable screen protection.