LED display analysis of frequent tripping
LED display analysis of frequent tripping? The following is a simple analysis of the frequent tripping of the LED display. Hope to solve the problem of your LED display tripping.
1. The layout of the leakage protector is unreasonable
Due to the particularity of the installation site of the LED display, such as wrong wiring, broken lines, 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 is not arranged according to the actual power consumption, resulting in frequent tripping of the total leakage protector.
In addition to strengthening management in 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 the total protection to prevent electrical fire hazards and electrical short circuits, and also serve as backup protection for each small leakage protection range. Its rated leakage current can be between 200 ~ 500mA. The rated leakage action time can be selected from 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 within 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 within the protection scope
The final leakage protector in the switch box is the main protection of the electrical equipment. If the final leakage protector is not installed, damaged or improperly selected, it may cause frequent tripping of the superior leakage protector. Because there are many metal conductors in the LED display screen and many wire connectors, if the insulation of the wires is not very good, it will lead to frequent leakage; some sockets are also added, and leakage protectors are not installed in many cases, which often causes leakage. . Only by forming an effective secondary or tertiary leakage protection mode 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 they are electromagnetic or electronic, use magnetic induction voltage transformers to pick up the leakage current in the main circuit of the electrical equipment, and it is impossible for three-phase or three-phase four-wire to be completely balanced in the magnetic ring. The three-phase electrical load of the LED display screen cannot be completely balanced. Under high current or high overvoltage, a certain electromotive force will be induced in the magnetic ring with high magnetic permeability. This electromotive force is large to a certain extent. , it will cause the leakage protector to trip. Since the leakage protector with a larger rated current adopts 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 leakage protector actually used. , the lower the sensitivity, the greater the rejection rate.
(2) The leakage protector has an uncertain action 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. Unreasonable selection of leakage protectors
(1) The rated leakage current used in the switch box exceeds 30mA or more than twice the rated current of the electrical equipment, or the leakage protector with time delay is selected. When the protection sensitivity is improved or the protection sensitivity is decreased, when a leakage fault occurs, the last-level leakage protector does not act, and the upper-level leakage protector may act.
(2) When the LED display is energized, the starting current is often relatively large, and this large current may trip the leakage protector. Therefore, the cabinets of the display screen should be powered on in batches as much as possible. In addition, an electromagnetic leakage protector that is less sensitive to surge overvoltage and overcurrent should generally be used; or an electronic leakage protector that is 1.5 to 2 times larger than the rated current, but as the final leakage protection, the rated leakage action The current should not be greater than 30mA.
In short, the frequent tripping of the leakage protector is the result of the combined effect of various factors. The most important thing is to arrange the leakage protector reasonably, reduce the protection scope of the two or three-level leakage protector, and correctly select the leakage protector and wiring so that each The two or three-level leakage protectors within the range are in an effective protection state; on the other hand, it is to strengthen the management of electricity consumption and improve the quality of electricity users through training, and eliminate non-electrician wiring, so as to improve the safety of electricity consumption, It can also reduce the frequent tripping of the leakage protector and create better power supply conditions for the normal work of the LED display.
