Common problems and precautions for outdoor LED display installation
With the rapid development of LED display technology and the continuous reduction of procurement costs, outdoor LED displays can be seen everywhere. In actual engineering applications, the LED full-color display screen, full-color display controller, control computer, optical fiber, audio equipment and control software in the outdoor LED full-color screen system are the most important and critical systems in the entire system.
In the process of installation and use, most of the LED display problems that do not work properly occur in the above-mentioned important LED display components. To this end, we have specially compiled some common problems and things that need to be avoided during the installation of outdoor LED display screens for you.
1. Common problems during the installation of outdoor LED screens
2. Outdoor LED screen installation precautions
1. Install the steel structure
As the steel frame structure carrying the large LED screen, its firmness should be ensured to achieve the effect of wind resistance and earthquake resistance. Usually outdoor LED displays have a large installation area and are mostly installed in densely populated places. The design of the steel structure should consider the foundation, wind load, waterproof, dustproof, moistureproof, ambient temperature, lightning protection, surrounding population density, etc. factor. At the same time, auxiliary equipment such as power distribution cabinets, air conditioners, axial fans, and lighting need to be placed in the steel structure, 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 part of the steel structure construction process. It must be ensured that the plan has undergone rigorous design calculations and program demonstrations before the erection of the scaffolding, and that the site is constructed in accordance with the specifications and tested in a timely manner to eliminate the safety legacy caused by the erection of the scaffolding.
2. Standardize electricity consumption
According to the provisions of the site temporary electricity specification (JGJ46-2005), the construction site must use a three-level power distribution system, a TN-S connection zero protection system, and a two-level leakage protection system. During the construction process, it should be avoided that the three-level power distribution is made into two-level power distribution, the PE line lead-out position is wrong, and the repeated grounding position and number of times are not equal to bury hidden dangers for safe construction.
3. Waterproof and moisture-proof
Outdoor LED display is installed outdoors, often exposed to the sun and rain, wind blowing dust cover, the working environment is harsh, and the electronic equipment is wet or seriously damp, which will cause short circuit or even fire, cause failure or even fire, and cause losses; therefore, the screen body and screen The junction between the body and the building must be strictly waterproof and leak-proof; the screen body must have good drainage measures, so that the water can be discharged smoothly in the event of water accumulation; pay attention to waterproof and moisture-proof. It is worth noting that the protection level (front/back) of the outdoor LED display is at least IP65/IP54, which cannot be lower than this protection level.
4. Ventilation and heat dissipation
Outdoor LED displays should be installed with ventilation equipment to cool down, so that the internal temperature of the screen is -10 ℃ ~ 40 ℃. An axial flow fan is installed on the back of the screen to discharge heat; the outdoor LED display 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, so that the LED display The system is not working properly. Select industrial-grade integrated circuit chips with a working temperature between -40°C and 80°C to prevent the large-screen system from being unable to start due to the low temperature in winter.
5. Use high-quality wire
The larger the area of the LED display screen, the greater the power consumption, and the higher the requirements for the power supply stability of the wire. Only the use of wire that meets the requirements of the national standard can ensure its safety and stability. Among many wire products, there are three requirements to be emphasized: the wire core is a copper wire conductive carrier, the cross-sectional area tolerance of the wire core is within the standard range, and the rubber wrapping the wire core The insulation and flame retardancy should meet the national standards.
6. Lightning protection grounding
Do a good job of lightning protection, and the LED body and shell should have good grounding measures, and the grounding resistance should be less than 3 ohms. The electronic components in the outdoor LED display are highly integrated, and the sensitivity requirements for anti-interference are also getting higher and higher. Lightning can harm the display system in various ways. In general, it may directly hit the screen and then leak into the ground through the grounding device.
Causes mechanical, electrical and thermal damage where the lightning current passes. The solution is equipotential bonding, that is, the ungrounded or ungrounded metal casing, the metal sheath of the cable, the metal frame in the display screen and the grounding device are reliably welded and connected to prevent the induction of high voltage on these objects or lightning on the grounding device. The transmission of high ground potential causes overvoltage counterattacks on the internal insulation of the equipment and the cable cores.
Outdoor LED displays will also be attacked by strong electricity and strong magnetism caused by lightning. In order to discharge the large current caused by lightning in time, reduce the overvoltage on the equipment and limit the intrusion wave of lightning. Generally, lightning protection devices should be installed on display screens and buildings.
The grounding of the outdoor LED display should be considered according to the specific situation; when the display is set up 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 to the outer wall of the building When connected, the main body and shell of the display screen should be well grounded with the building, and shared with the building for integrated grounding, and the grounding resistance should not be greater than 1 ohm.
7. Choose the right power distribution cabinet
LED outdoor displays are generally powered by AC220V current, requiring grid voltage fluctuation less than 10%, and providing good system grounding. For the display screen with electric power exceeding 10kW, a special power distribution cabinet should be equipped.
The power distribution cabinet with remote control function or with PLC control function can be selected according to the needs. The power distribution cabinet with PLC control function is more intelligent, and the LCD controller can be used to remotely operate the outdoor LED display and the indoor air conditioners, fans and other equipment. At the same time, it can also monitor the ambient temperature inside the screen and the ambient brightness outside the screen in real time, and have corresponding alarm information.
In the LED outdoor screen, the general environmental conditions are poor, and it is recommended to use a power distribution cabinet with PLC control; in the indoor screen project, the environment is better and the space is limited, so PLC control can be omitted.