There are more and more large outdoor LED display screens, and they are becoming more and more popular in the past month. We can see large outdoor LED display screens in different cities and major streets and lanes. Compared with our LED display manufacturers, If the display area of the screen exceeds 10 square meters, it is called a large outdoor LED display. Then you need to pay attention to many things during the procurement, installation, and use of large outdoor LED displays, because there is still a certain degree of neglect in many places. And it is precisely some small details that are overlooked that often cause safety hazards, and in serious cases, they will cause safety accidents.
Large outdoor LED display screens are used in actual projects. In the large outdoor LED display system, the LED full-color display screen body, full-color display controller, control computer, optical fiber, audio equipment and control software are the most important in the entire system. And critical systems. In the implementation of large outdoor LED display screens, the owners pay more attention to the technical requirements of these main core parts. At the same time, these system countries also have related manufacturing standards and product quality inspection agencies, and the product quality is relatively reliable. Therefore, in order to obtain more benefits, many manufacturers often reduce the design standard of steel structure, lower the standard of wire rod, use inferior steel, hire cheap labor, etc., causing hidden dangers of accidents, and these points have also become the special attention of the majority of engineering companies. matter.
Outdoor led display
1. The large LED screen is installed outdoors often in the sun and rain, and the working environment is harsh. Electronic equipment getting wet or severely damp can cause short circuit or even fire, cause malfunction or even fire, and cause loss.
2. The large LED screen may be attacked by strong electricity and magnetism caused by lightning.
3. Outdoor LED large screens generally range from a few square meters to tens or even hundreds of square meters. The audience is wide, the viewing distance requires a wide range of vision, and the ambient light changes greatly, especially if it is exposed to direct sunlight, which affects the display effect.
4. The environment temperature changes greatly. When the LED screen is working, it will generate a certain amount of heat. If the ambient temperature is too high and the heat dissipation is poor, the integrated circuit may not work properly or even be burned, which will make the display system unable to work normally; and the ambient temperature in winter is too low, resulting in The display system cannot be started.
Through the above understanding, we need to make targeted understanding and attention to these 4 points. The specific precautions for the installation of large outdoor LED display are as follows:
Install the steel structure
As a steel frame structure for carrying large outdoor LED display screens, its firmness must be ensured during installation to achieve wind and earthquake resistance. Generally, outdoor LED display screens have a large installation area and are mostly installed in densely populated places. The design of its steel structure should consider foundation, wind load, waterproof, dustproof, moisture-proof, ambient temperature, lightning protection, surrounding population density, etc. factor. At the same time, the steel structure also needs to place auxiliary equipment such as power distribution cabinets, air conditioners, axial fans, lighting, etc., as well as maintenance facilities such as horse tracks and ladders. Therefore, during implementation, the entire outdoor screen steel structure should have design drawings that have passed the review of the competent government department to ensure the reliability and safety of the entire steel structure.
In addition, the erection of scaffolding is an important link in the construction process of steel structures. It is necessary to ensure that the plan before erecting the scaffold undergoes rigorous design calculations and plan demonstration, and to ensure that the on-site construction is carried out in accordance with the norms and timely inspections to eliminate the safety hazards caused by the erection of the scaffolding .
Regulate electricity usage
According to the provision of on-site temporary power usage specification (JGJ46-2005), the construction site must adopt a three-level power distribution system, a TN-S zero protection system must be adopted, and a two-level leakage protection system must be adopted. It should be avoided that the three-level power distribution is made into two-level power distribution during the construction process, the PE line is drawn out in the wrong position, and the repeated grounding position and the number of times are not equal to bury hidden dangers for safe construction.
Waterproof and moisture-proof
The large outdoor LED display is installed outdoors, often exposed to the sun, rain, wind and dust cover, and the working environment is harsh. If the electronic equipment is wet or severely damp, it will cause a short circuit or even a fire, cause a failure or even a fire, and cause losses; therefore, the screen body and The joint between the screen body and the building must be strictly waterproof and leak-proof; the screen body must have good drainage measures, once accumulated water occurs, it can be discharged smoothly; pay attention to waterproof and moisture-proof. It is worth noting that the outdoor LED display protection level (front/back) is at least IP65/IP54, and cannot be lower than this protection level.
Outdoor led display
The large outdoor LED display should be equipped with ventilation equipment to cool down, so that the internal temperature of the screen is -10 degree -40 degree . An axial fan is installed on the top of the back of the screen to dissipate heat; the outdoor LED display itself will generate a certain amount of heat when it is working. If the ambient temperature is too high and the heat dissipation is poor, the integrated circuit may not work properly or even be burned, causing the LED display The system is not working properly. Use industrial-grade integrated circuit chips with a working temperature between -40 degree and 80 degree to prevent the large-screen system from being unable to start due to the low temperature in winter.
Use high-quality wire
The larger the area of the large LED display, the greater the power consumption, and the higher the requirements for the stability of the wire. Only the use of wires that meet the requirements of the national standard can ensure its safety and stability. Among many wire products, there are three requirements that need to be emphasized: the core is a copper wire conductive carrier, the cross-sectional area tolerance of the core is within the standard range value, and the rubber covering the core The insulation and flame-retardant properties should meet national standards.
Lightning protection grounding
It is very necessary for large-scale outdoor LED display to do lightning protection. The LED body and shell should have good grounding measures, and the grounding resistance should be less than 3 ohms. The integration of electronic components in outdoor LED display screens is high, and the sensitivity requirements for anti-interference are getting higher and higher. Lightning can harm the display system in various ways. Under normal circumstances, it may directly hit the screen and then leak into the ground through a grounding device. Cause mechanical, electrical, and thermal damage where lightning current passes. The solution is equipotential bonding, that is, the ungrounded or ungrounded metal shell, the metal skin of the cable, the metal frame in the display screen and the grounding device are reliably welded and connected to prevent these objects from inducing high voltage or lightning on the grounding device. The transmission of ground high potential causes an overvoltage counterattack to the internal insulation of the equipment and the cable core. Large outdoor LED displays will also be attacked by strong electricity and magnetism caused by lightning, in order to discharge the large current caused by lightning in time, reduce the overvoltage appearing on the equipment, and limit the lightning intrusion wave. Generally, lightning protection devices should be installed on display screens and buildings.
The grounding of a large outdoor LED display should be considered according to the specific situation. When the display is set independently, a separate grounding system should be set up, and the grounding resistance should not be greater than 4 ohms; when the display is attached outside the building When on the wall, the main body and the shell of the display screen should be well grounded with the building, and should be connected to the building with a comprehensive grounding. The grounding resistance should not be greater than 1 ohm.
Choose the right power distribution cabinet
Large-scale LED display screens generally use AC220V current to supply power, require grid voltage fluctuations to be less than 10 percent , and provide good system grounding. For display screens with electric power exceeding 10kW, special power distribution cabinets should be provided. A power distribution cabinet with remote control function or PLC control function can be selected according to needs. The power distribution cabinet with PLC control function is more intelligent. The LCD controller can be used to remotely operate the outdoor LED display and the in-screen air conditioner, fan and other equipment. The switch can also monitor the ambient temperature inside the screen and the ambient brightness outside the screen in real time, with corresponding alarm information. In the LED outdoor screen, the general environmental conditions are poor, and it is recommended to use the power distribution cabinet with PLC control; in the indoor screen project, the environment is better and the space is limited, so PLC control is not required.
In order to prevent leakage fire, a fire leakage switch should also be installed at the main switch of the power supply line. The LCD controller monitoring interface in the power distribution cabinet can display real-time temperature in the display. In the automatic state, when the temperature inside the screen exceeds 65 degrees, the monitoring screen will prompt that the temperature is too high, and the LCD controller will sound an alarm at the same time, and the system will automatically power off to prevent a fire.
According to the actual situation, smoke detectors can be installed in the display screen. When a fire occurs in the screen, there will be corresponding prompt messages on the monitoring interface. At the same time, the power distribution system can be linked to automatically cut off the power.
safe education
Safety helmets, safety belts, and safety nets are the three magic weapons to reduce and mitigate safety construction accidents. At the construction site, the construction unit should require all personnel present to wear safety helmets correctly. According to relevant data, the higher the level of workers' safety education and the more complete the safety education physique, the risk of safety accidents is much lower than that of enterprises where safety education is a mere formality.
Summarize
According to most data and experience, in fact, as long as you do not pursue the best interests of the project one-sidedly, and reduce the related configuration of large outdoor LED display screens; do not blindly meet the project schedule, but ignore the quality and safety management of the project site; do not reduce the construction Cost, and reduce the wire configuration; large outdoor LED display installation can be carried out in an orderly manner. With the cooperation of the self-discipline of the LED display manufacturer, the professionalism of the engineer, and the supervision of the owner, many accidents will be avoided or at least the probability of accidents will be reduced.
