Simple analysis of LED display frequent trip

1, leakage protection device layout is not reasonable

Due to the particularity of LED display installation site has, such as wiring error, the wiring is shot, switch cabinet leakage protector damage, some electrical appliances without switch box, as well as the leakage protector itself inevitably misoperation and refused to move, plus no according to the actual amount of electricity leakage protector for decorate, caused the leakage protector the frequent trip. 

For this situation in addition to strengthen the management, but also from the perspective of technology, according to the actual situation of the leakage protection device for reasonable layout.

The leakage protector on the total power supply of the incoming line can be mainly used as the total protection to prevent electrical fire hazards and electrical short circuit, and also as the backup protection of each small leakage protection range. Its rated leakage current can be selected between 200 ~ 500mA, and the rated leakage action time can be selected between 0.2~0.3s. In this way, it can greatly reduce the impact of surge voltage, surge current and electromagnetic interference on the total leakage protection device, and improve the selectivity and reliability of the total leakage protection device. If can make each leakage protection range of two leakage protection in effective protection state, can greatly reduce the site total leakage protection of frequent trip probability.

2, in the scope of protection has not formed an effective two or three leakage protection

The final stage leakage protector in the switch box is the main protection of electrical equipment. If the final stage leakage protector is not installed, damaged or improperly selected, it may lead to frequent trip of the superior leakage protector. Because there are many metal conductors in the LED display, more wire joints, if the wire insulation is not very good, it will lead to the condition of leakage often; Some also add some sockets, in many cases do not install leakage protector, often cause leakage. Only by forming effective two or three leakage protection modes in each protection range can the frequent trip of leakage protector be effectively reduced.

3, leakage protector itself has certain limitations

(1) The current leakage protection device, whether electromagnetic or electronic, adopts magnetic induction voltage transformer to pick up the leakage current in the main circuit of electrical equipment. Three-phase or three-phase four-wire can not be arranged in the magnetic ring to be completely balanced. LED display three-phase power load can not be completely balanced, in large current or high overvoltage, there will be a high permeability magnetic ring induction of a certain electromotive force, the electromotive force is large to a certain extent, it will lead to leakage protection trip. Due to the larger rated current of the leakage protection device with a relatively large magnetic ring, the magnetic flux leakage is relatively large, and the leakage current to overcome the magnetic ring itself magnetization force, resulting in the actual use of the leakage protection device rated current is greater, the lower the sensitivity, the greater the rejection rate.

(2) the leakage protector in the rated leakage current and rated leakage current does not have an uncertain area of action, leakage current of the leakage protector in this region fluctuations, may cause the leakage protector irregular trip.

4, leakage protector selection is not reasonable

(1) rating of the switch used in the leakage current action more than 30 ma or is more than rated current electrical equipment more than twice the leakage protector, or with the delay type leakage protector, due to the increase of leakage current action rating or a reduction in the protection sensitivity, the leakage fault occurs, the end leakage protector no action, The superior leakage protector may act.

(2) to the LED display when the starting current is often relatively large, the large current may make the leakage protector trip. Therefore, the display box should be powered on in batches as much as possible. In addition, generally should choose to surge over voltage, over current is not too sensitive electromagnetic leakage protector; Or choose 1.5~2 times more than the rated current of the electronic leakage protection device, but as the final stage of leakage protection, the rated leakage action current should not be greater than 30mA.

In short, leakage protection frequent trip is the result of a variety of factors, the most important is to reasonable layout of leakage protection device, reduce the protection scope of two or three leakage protection device, the correct choice of leakage protection device and wiring, so that each range of two or three leakage protection device in effective protection state; On the other hand, it is to strengthen the management of electricity and improve the quality of electricity personnel through training, put an end to non-electrical wiring, so that we can not only improve the safety of electricity, but also reduce the frequent trip of leakage protector, to create better power supply conditions for the normal work of LED display.