Technology | Why does your LED display screen trips frequently ？
The leakage protector layout is not reasonable
Due to the particularity of LED display screen installation place ，If the wiring is wrong, the circuit is damaged, the switch box of the leakage protector is damaged, some of the power supplies do not pass through the switch box, etc , and the erroneous operation and refusal of the leakage protector itself, together with the actual use of electricity Leakage protectors are arranged to cause frequent tripping of the total leakage protector.
In addition to strengthening management in this case, it is also necessary to rationally arrange the leakage protector according to the actual situation from the technical side . The leakage protection device on the main power supply of the incoming line can be mainly used as a total protection against electrical fire hazards and electrical short-circuits. It also serves as backup protection for each small leakage protection range. Its rated leakage action current can be between 200 and 500 mA. Interval selection, rated leakage action time can choose 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 total leakage protector action can be improved.If the secondary leakage protection within each leakage protection range can be effectively protected, the frequent tripping probability of the total leakage protector on the construction site can be greatly reduced.
There is no effective secondary or tertiary leakage protection within the scope of protection.
The last-stage leakage protector in the switch box is the main protection of the power equipment. If the last-stage leakage protector is not installed, damaged or improperly selected, it may cause frequent tripping of the upper leakage protector.Due to the large number of metal conductors in the LED display screen , there are many wire connections. If the wire insulation is not very good, it will lead to frequent leakage; some people also add some sockets, and they do not install leakage protection devices, the make leakage happens very often .Only by forming an effective secondary or tertiary leakage protection mode within each protection range can the frequent tripping of the leakage protector be effectively reduced.
leakage protection itself has some limitations
Current leakage protectors, whether of electromagnetic type or electronic type, use magnetic induction voltage transformers to pick up leakage currents in the main circuit of the electrical equipment. Three-phase or three-phase four-wires cannot be completely balanced in the magnetic ring.The three-phase power load of the LED display screen cannot be completely balanced. Under high current or high over voltage, a certain electromotive force is 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.Because the larger rated current leakage protector uses a relatively large magnetic ring, the generated leakage magnetic flux is also relatively large, and the leakage current must overcome the magnetizing force of the magnetic ring itself, resulting in a larger rated current of the actually used leakage protector. The lower the sensitivity, the greater the rejection rate.
Leakage current protector has a zone of motion uncertainty between the rated leakage action current and the rated leakage action current. When the leakage current of the leakage protector fluctuates in this area, it may cause the leakage protector to trip irregularly.
Leakage protection device selection is unreasonable
The rated leakage current used in the switch box exceeds 30mA or is more than twice the rated current of the power equipment, or a time-delay type leakage protector is used because of the rated leakage current. When the leakage current fails, the last-stage leakage protector does not operate and the upper leakage protector may operate.
The starting current when the LED display screen is powered on is often relatively large. This large current may trip the leakage protector. Therefore, the display box should be powered up in batches as much as possible. In addition, electromagnetic leakage protectors that are less sensitive to surge over voltages and over currents should generally be selected; or electronic leakage protectors that are 1.5 to 2 times larger than the rated current should be used, but as the last stage leakage protection, rated leakage action The current should not exceed 30mA.
In short, the frequent tripping of the leakage protector is the result of a combination of various factors. The most important thing is to rationally arrange the leakage protector, reduce the protection range of the second or third class leakage protector, and correctly select the leakage protector and the wiring so that each The second or third-order leakage protectors in the scope are in effective protection status; on the other hand, they strengthen the management of electricity use and improve the quality of the electricity users through training, and eliminate non-electrical wiring, so that the safety of electricity can be improved. It can also reduce frequent tripping of the leakage protector and create better power supply conditions for the normal operation of the LED display screen.