In today's industrial production, as long as control is involved, PLC is inseparable. The layout and design of PLC cabinets are the foundation and key to making PLC control cabinets. What characteristics should a qualified PLC cabinet have?

Doublestar Automation has accumulated many years of PLC experience and summarized the following five major characteristics:

1. The selection of cabinet type is suitable for cabinets that install PLC. Fixed cabinets are usually selected, and cabinets with whole door panels are used, such as KB cabinets, 10-fold cabinets and 16-fold cabinets. GGD cabinets and fixed divided cabinets are not suitable. , chest of drawers. Because the components in the PLC cabinet are basically installed on the entire board, if a cabinet with divided cabinet doors is used, it will be inconvenient to install and debug. If you must choose a GGD cabinet, you need to make a non-standard design, merge the instrument door, front door and downdraft door into a whole door, and cancel the front and rear cross beams on the cabinet frame to facilitate installation and maintenance. .

2. Cabinet ventilation system design The cabinet ventilation scheme adopts the form of air inlet under the front door and air outlet above, and there is no air inlet or outlet on the back door. A ventilation filter is installed at the inlet and outlet respectively to prevent dust. The overall dimensions are 320mm × 320mm, and the air inlet and outlet area is about 0.08 square meters. Since the components in the PLC cabinet emit less heat, natural convection can be used. If you want to speed up the wind speed, you can install an axial flow fan on the outlet filter in the upper half of the door panel to exhaust the air outward. The top cover of the cabinet does not have ventilation holes, so install a holeless top cover.

3. Selection of row wire trough specifications. There are many specifications of row wire troughs. Commonly used row wire trough widths are 25mm, 40mm, 60mm, 80mm, and 100mm. The heights are 40mm, 60mm, 80mm, and 100mm. The preferred color is gray. The principle of selecting a row wire trough is usually based on the fact that the sum of the volume of the wires passing through the wire trough (including the insulation layer) is about 80% of the capacity of the wire trough. The remaining space is used to facilitate the heat dissipation of the wires. The cross-section relationship can be used when calculating, that is, the sum of the cross-sections of the wires (including the insulation layer) is about 80% of the cross-section of the trunking.

4. Principles of component arrangement The components in the cabinet are generally arranged from top to bottom and from left to right. It is convenient for operation and maintenance. Components that are frequently operated or maintained should be installed in a position that is easily accessible. In terms of height, try to install them within the height range of 400mm to 1800mm above the ground. If there are many components in the motor start control box, consider installing the components that are not frequently operated at a height of about 2000mm in the cabinet. The installation position of the bottom components should not be lower than 200mm from the ground, otherwise the wiring will not be possible on site. When laying out, avoid repeated winding of wires in the cable trough, and pay attention to saving costs.

5. Cabinet layout and structural design Based on the above layout principles, combined with the schematic diagram and cabinet list, draw the cabinet layout drawing. Whether it is cabinets, components or auxiliary materials such as wire ducts, they must be drawn in the maximum overall size and in a 1:1 ratio. After the layout drawing is completed, the structural design of the installation plate is carried out according to the location and installation method of the components. The material of the installation plate is usually aluminum-zinc plate, with a thickness of 2.0mm~3.0mm.

During the design process of PLC control cabinet, actual use needs must be combined. When designing PLC control cabinet manufacturers, technical operations must be strictly standardized. In order to achieve automatic electrical control, it is of great significance to improve the manufacturing and design of electrical control cabinets.