Why do LED full-color screens often trip? Let us briefly analyze the causes of frequent trips of LED full-color screens.
1. The layout of the leakage protector is unreasonable
Due to the peculiarities of the LED full-color screen installation site, such as wiring errors, line damage, damage to the leakage protector in the switch box, some electrical appliances not passing through the switch box, etc., and the inevitable misoperation and rejection of the leakage protector itself In addition, the leakage protector was not arranged in accordance with the actual electricity consumption, resulting in frequent tripping of the total leakage protector.
In addition to strengthening management for this situation, it is also necessary to reasonably arrange the leakage protector according to the actual situation from a technical point of view. The leakage protector on the main power supply of the incoming line can be mainly used as a total protection to prevent electrical fire hazards and electrical short circuits. It also serves as a backup protection for each small leakage protection range. Its rated leakage action current can be 200-500mA Choose between, the rated leakage action time can be 0.2-0.3s. In this way, the influence of surge voltage, surge current, and electromagnetic interference on the total leakage protector can be greatly reduced, and the selectivity and reliability of the operation of the total leakage protector can be improved. If the secondary leakage protection in each leakage protection range can be in an effective protection state, the frequent tripping probability of the total leakage protector on the construction site can be greatly reduced.
2. There is no effective secondary or tertiary leakage protection in the protection range
The last-stage leakage protector in the switch box is the main protection of electrical equipment. If the last-stage leakage protector is not installed, damaged or selected improperly, it may cause the upper-level leakage protector to trip frequently. Since there are many metal conductors in the LED full-color screen and there are many wire connectors, if the wire insulation is not good, it will cause frequent leakage. Some sockets are added, and leakage protectors are not installed in many cases, which often causes leakage. . Only when an effective secondary or tertiary leakage protection mode is formed in each protection range, can the frequent tripping of the leakage protector be effectively reduced.
3. The leakage protector itself has certain limitations
(1) The current leakage protectors, whether electromagnetic or electronic, use magnetic induction voltage transformers to pick up the leakage current in the main circuit of electrical equipment. It is impossible to arrange three-phase or three-phase four-wire in the magnetic ring to be completely balanced. The three-phase power load of the LED full-color screen cannot be completely balanced. Under high current or high overvoltage, a certain electromotive force will be induced in the magnetic ring with high permeability, which is large to a certain extent. , It will cause the leakage protector to trip. Since a leakage protector with a larger rated current uses a relatively large magnetic ring, the leakage flux generated is relatively large, and the leakage current must overcome the magnetizing force of the magnetic ring itself, resulting in a larger rated current of the actual leakage protector , The lower the sensitivity, the greater the rejection rate.
(2) The leakage protector has a certain operation uncertainty area between the rated leakage operating current and the rated leakage non-operating current. When the leakage current of the leakage protector fluctuates in this area, it may cause the leakage protector to trip irregularly.
4. The selection of leakage protector is unreasonable
(1) The rated leakage current used in the switch box exceeds 30mA or the leakage protector that exceeds the rated current of the electrical equipment by more than twice, or the delay type leakage protector is selected, due to the rated leakage current Increase or decrease of protection sensitivity, when a leakage fault occurs, the last-stage leakage protector does not operate, and the upper-stage leakage protector may operate.
(2) The starting current when energizing the LED full-color screen is often relatively large, and this large current may trip the leakage protector. Therefore, the cabinets of the display should be electrified in batches as much as possible. In addition, electromagnetic leakage protectors that are not very sensitive to surge overvoltage and overcurrent should generally be selected; or electronic leakage protectors 1.5 to 2 times larger than the rated current should be selected, but as the final level of leakage protection, the rated leakage The operating current should not be greater than 30mA.
In short, the frequent tripping of leakage protectors is the result of the combined effects of various factors. The most important thing is to properly arrange the leakage protector, reduce the protection range of the secondary or tertiary leakage protector, and correctly select the leakage protector and wiring so that each leakage protector is within this range. Effective protection status; on the other hand, through training to strengthen power management, improve user quality, eliminate non-electrical wiring, improve power safety, reduce frequent tripping and leakage protectors, and create better power supply conditions for the normal operation of LED full-color screens .
