In the field of industrial automation, PLC (Programmable Logic Controller) control cabinets play a vital role. Proper installation of PLC control cabinets can not only ensure the stable operation of the equipment, but also improve production efficiency and reduce maintenance costs. The following are some precautions for PLC control cabinet installation.
- Installation environment
Temperature and humidity: PLC control cabinets should be installed in an environment with suitable temperature and moderate humidity. Generally speaking, the temperature should be kept between 0℃ and 55℃, and the relative humidity should be controlled between 35% and 85% RH without condensation. Too high temperature may cause the performance of electronic components to deteriorate, while too low temperature may cause condensation in the equipment and damage the electronic components. High humidity environment is prone to electrical short circuits and other problems.
Good ventilation: Ensure that the installation site is well ventilated to dissipate the heat generated inside the control cabinet. Good ventilation can extend the service life of the equipment and improve the reliability of the equipment. You can consider installing ventilation equipment or using natural ventilation.
Stay away from interference sources: PLC control cabinets should be away from interference sources such as strong magnetic fields and strong electric fields, such as large motors and transformers. These interference sources may affect the normal operation of the PLC, causing problems such as signal distortion and malfunction. At the same time, the control cabinet should also be protected from mechanical vibration and impact.
- Installation requirements
Space layout: When installing the PLC control cabinet, the space layout should be planned reasonably. Ensure that there is enough space inside the control cabinet to facilitate the installation and maintenance of equipment. A certain distance should be maintained between each device to facilitate heat dissipation and operation. At the same time, the cable laying path should be taken into account to avoid cable crossing and excessive length.
Firm fixation: The control cabinet should be installed on a solid foundation to ensure its stability. The control cabinet can be fixed to the ground or bracket by bolts or welding. When fixing the control cabinet, pay attention to adjusting the horizontality and verticality to ensure the normal operation of the equipment.
Reliable grounding: Good grounding is an important condition to ensure the safe operation of the PLC control cabinet. The grounding resistance should meet the requirements of relevant standards and is generally not greater than 4 ohms. The grounding wire should select a suitable cross-sectional area to ensure reliable grounding. At the same time, pay attention to avoid the occurrence of circulating current in the grounding loop.
- Cable laying
Cable selection: Select a suitable cable according to the power and signal requirements of the PLC control cabinet. The cross-sectional area of the cable should meet the requirements of the current carrying capacity, and factors such as the length and voltage drop of the cable should be taken into account. For signal cables, shielded cables should be selected to reduce external interference.
Cable laying method: Cable laying should be neat and beautiful, avoiding crossing and entanglement. Cable troughs, bridges and other methods can be used for laying. When laying cables, pay attention to protecting the cables to avoid mechanical damage and corrosion. At the same time, a certain margin should be left for future maintenance and expansion.
Cable identification: In order to facilitate maintenance and management, cables should be identified. The identification should be clear and accurate, indicating the cable number, purpose, starting point and end point and other information. Labels, hanging signs and other methods can be used for identification.
4.Wiring requirements
Wiring specifications: Wiring should be carried out according to the wiring diagram of the PLC control cabinet to ensure that the wiring is correct and firm. Appropriate tools and materials should be used for wiring, such as screwdrivers, crimping pliers, terminals, etc. For different types of signals, cables of different colors should be used to distinguish them for easy identification and maintenance.
Shield grounding: For shielded cables, the shielding layer should be grounded. The grounding method can be single-point grounding or multi-point grounding, which should be selected according to the actual situation. Shield grounding can effectively reduce external interference and improve the quality of signals.
Check the wiring: After completing the wiring, carefully check whether the wiring is correct and firm. You can use tools such as a multimeter to check to ensure that each signal channel is unobstructed. At the same time, check whether the grounding is good to avoid grounding faults.
In short, the correct installation of the PLC control cabinet is the key to ensuring the stable operation of the industrial automation system. During the installation process, it is necessary to strictly follow the relevant standards and specifications, and pay attention to the installation environment, installation requirements, cable laying and wiring requirements. Only in this way can the safe and reliable operation of the PLC control cabinet be ensured, providing a strong guarantee for the production and operation of the enterprise.
