Each functional room is isolated from each other, such as functional unit room, bus room and cable room. The functions of each room are relatively independent and do not affect each other. The heat dissipation problem in the operation of the cabinet shall be fully considered in the design. There are different numbers of heat dissipation slot holes at the upper and lower ends of the cabinet. When the electrical components in the cabinet heat up, the heat rises and is discharged through the upper slot hole, and the cold air is continuously supplemented into the cabinet from the lower slot hole, so that the sealed cabinet becomes a natural ventilation channel from bottom to top, so as to achieve the purpose of heat dissipation.

(1) Fixed panel switchgear, often called switch board or distribution panel. It is an open switch cabinet with panel blocking. The front has protective effect, and the back and side can still touch the live parts. The protection level is low. It can only be used for centralized power supply in the substation in industrial and mining enterprises with low requirements for power supply continuity and reliability.

(2) Protective (i.e. closed) switchgear refers to a low-voltage switchgear whose sides are closed except the mounting surface. The switch, protection, monitoring and control and other electrical components of the cabinet are installed in a closed shell made of steel or insulating materials, which can be reliably installed on or off the wall. No isolation measures can be taken between each circuit in the cabinet, or grounded metal plate or insulating plate can be used for isolation. Generally, the door is mechanically interlocked with the main switch. In addition, there is a protective platform type switch cabinet (i.e. console), which is equipped with control, measurement, signal and other electrical appliances. The protective switch cabinet is mainly used as the power distribution device on the process site.

(3) Drawer type switch cabinet. This kind of switch cabinet is made of closed shell made of steel plate, and the electrical components of incoming and outgoing circuit are installed in withdrawable drawers to form a functional unit that can complete a certain type of power supply task. The functional unit is separated from the bus or cable by a grounded metal plate or a functional plate made of plastic to form three areas of bus, functional unit and cable. The cabinet door is connected with the frame with a rotating shaft movable hinge, which is convenient for installation and disassembly. A mountain shaped rubber and plastic strip is embedded outside the removed edge of the door. When closing the door, the strip between the door and the frame has a certain compression stroke, which can prevent the direct collision between the door and the cabinet and improve the protection grade of the door.

The main frame is designed to be fully assembled and partially welded (side cabinet and beam) to meet the different needs of users.