(1) At present, the leakage protector, whether electromagnetic or electronic, uses a magnetic induction voltage transformer to pick up the leakage current in the main circuit of the electrical equipment, and the three-phase or three-phase four-wire cannot be completely balanced in the magnetic ring. The three-phase power load of Fixed LED Video Display is not completely balanced. Under high current or high overvoltage, a certain electromotive force is induced in a magnetic ring with high magnetic permeability. This electromotive force is large enough. The degree will cause the leakage protector to trip. Since the leakage current protector with larger rated current uses a relatively large magnetic ring, the leakage flux generated is relatively large, and the leakage current overcomes the magnetization force of the magnetic ring itself, resulting in the rated current of the actual leakage protector being used. The lower the sensitivity, the greater the rejection rate.
(2) The Fixed LED Video Display leakage protector has an action uncertainty zone between the rated leakage current and the rated leakage current. When the leakage current of the leakage protector fluctuates within this area, the leakage protector may be irregular. Tripped.
Leakage protector selection is not reasonable
(1) The rated leakage current used in the switch box exceeds 30 mA or the leakage protector that exceeds the rated current of the electrical equipment is more than twice, or the leakage protector with delay type is selected, due to the rated leakage current Increase or decrease the sensitivity of the protection. When the Fixed LED Video Display has a leakage fault, the final leakage protector does not operate, and the upper leakage protector may operate.
(2) When the Fixed LED Video Display is energized, the starting current is often large, and this large current may cause the leakage protector to trip. Therefore, the cabinet of the display should be powered up as much as possible in batches. In addition, the Fixed LED Video Display should generally use an electromagnetic leakage protector that is less sensitive to surge overvoltage and overcurrent; or an electronic leakage protector that is 1.5 to 2 times larger than the rated current, but as a final leakage protection. The rated leakage current should not exceed 30mA.