Distribution box is a common distribution box product, mainly composed of wires, components, boxes, etc., which is widely used in industry, electronics, power, construction, mining and other fields. Switch cabinet is an electrical equipment. The external line of the switch cabinet enters the main control switch in the cabinet first, and then enters the sub control switch. Each branch circuit is set according to its needs. For example, instruments, automatic control, motor, magnetic switch, various AC contactors, etc., some of them are equipped with high-voltage room and low-voltage room switch cabinet, with high-voltage bus, such as power plant, and some are also equipped with low cycle load shedding to ensure the main equipment. The power distribution cabinet distributes the electric energy of a circuit of the upper power distribution equipment to the nearest load. This equipment shall provide protection, monitoring and control of the load. According to the electrical wiring, the switchgear, measuring instruments, protective electrical appliances and auxiliary equipment are required to be assembled in closed or semi enclosed metal cabinet or on the screen to form a low-voltage distribution box. In normal operation, the circuit can be connected or disconnected by manual or automatic switch. Users need to understand the installation points of power box to avoid errors during installation. How to install the distribution box? The following is a detailed introduction to the installation of small series of distribution boxes. The application of the distribution box, the rated current of the distribution box is 40-125a, the rated working voltage is 220 V and 380 V, the height is not more than 2000 m, the temperature is not more than 40 ℃ and - 40 ℃, and the pollution level is 3. The frame of the equipment can be connected by screw welding or assembly, which can bear large mechanical stress and thermal stress, prevent the formation of magnetic circuit and cause large eddy current loss. It is widely used in various buildings, squares, stations, industrial and mining enterprises and other places as the terminal electrical equipment of power distribution system. The structure and simple circuit of the distribution box make the application of the distribution box more and more widely, also promote a variety of additional products, the market is more and more mature. Installation specification of distribution box. The power distribution system on the construction site shall be equipped with indoor main distribution panel and distribution box or outdoor main distribution box and distribution box by grade, and the capacity of distribution devices at all levels shall match the actual load. Power and power should be set up separately. The rated value and action setting value of electrical appliances in the main distribution box shall be consistent with the rated value and action setting value of shunting switch apparatus. General automatic switch, leakage protector and shunt automatic switch are installed. All kinds of electrical components and leakage protectors used in distribution boxes at all levels shall meet the quality requirements of national standards. The leakage protector of distribution boxes at all levels should be reasonably arranged to play the role of staged and sectional protection. Only by doing these works well can the safety of box type substation be ensured and the normal operation of power engineering be ensured.