What are two different types of power distribution box installation?
Power distribution box is a kind of distribution box. The distribution box is divided into power distribution box and lighting distribution box, which is the last level equipment of the distribution system. The distribution box is to assemble the switchgear, measuring instruments, protective appliances and auxiliary equipment in the enclosed or semi enclosed metal cabinet or on the screen according to the electrical wiring requirements to form a low-voltage distribution device.
According to the requirements of power supply system:
1) The primary distribution equipment is collectively referred to as power distribution center. They are installed in the substation of the enterprise and distribute the electric energy to the subordinate distribution equipment in different places. This equipment is close to the step-down transformer, so the requirements of electrical parameters are high, and the output circuit capacity is also large.
2) Secondary distribution equipment is a general designation of power distribution cabinet and motor control center. The power distribution cabinet is used in the situation where the load is relatively scattered and the circuit is less; the motor control center is used in the situation where the load is centralized and the circuit is more. They distribute the electric energy of a circuit of the upper level distribution equipment to the nearby load. This level of equipment shall provide protection, monitoring and control for the load.
3) The final power distribution equipment is called lighting power distribution box. They are far away from the power supply center and are distributed small capacity distribution equipment.
Classification by structural characteristics and use:
1) Fixed panel type switch cabinet, often called switch board or distribution panel. It is a kind of open type switch cabinet with panel barrier, with protective function on the front, and it can still touch the electrified part on the back and side, with low protection level. It can only be used for centralized power supply in the substation for industrial and mining enterprises with low requirements for power supply continuity and reliability.
2) Protective (i.e. closed) switch cabinet refers to a low-voltage switch cabinet with all sides closed except the installation surface. The switch, protection, monitoring and control and other electrical components of the cabinet are all installed in a closed enclosure made of steel or insulating material, which can be reliably installed on or off the wall. Each circuit in the cabinet can be isolated without isolation measures, or with grounded metal plate or insulating plate. Generally, the door is mechanically interlocked with the main switch operation. In addition, there is a protective platform type switch cabinet (i.e. console), on which control, measurement, signal and other electrical appliances are installed. The protective switch cabinet is mainly used as the power distribution device at the process site.
3) Drawer type switch cabinet. This kind of switch cabinet is made of steel plate with closed shell. The electrical components of the incoming and outgoing circuit are installed in the withdrawable drawer to form a functional unit that can complete a certain kind of power supply task. The functional unit is separated from the bus or cable by the grounded metal plate or plastic functional plate, forming three areas of bus, functional unit and cable. There are also isolation measures between each functional unit. Drawer type switch cabinet has high reliability, safety and interchangeability. It is a relatively advanced switch cabinet. Most of the switch cabinets produced are drawer type. They are suitable for industrial and mining enterprises and high-rise buildings that require high reliability of power supply, as the distribution center of centralized control.
4) Power and lighting distribution control box. Most of them are closed vertical installation. Due to different use occasions, the protection level of the shell is also different. They are mainly used as power distribution devices in the production site of industrial and mining enterprises.
