Electrical equipment and wiring caused great harm

As network load increases and other reasons, resulting in insufficient voltage grid, it will motors, various types of electrical equipment and wiring caused great harm. Generally can be two kinds of solutions: one is to increase grid capacity; second is not  mcb circuit breaker  occasion using undervoltage release off the power. The second method will not only protect the electrical equipment under the level line, but also protect critical equipment in normal operation. Currently used undervoltage  air circuit breaker electromagnetic tripping device, which has a power self-reset function. But electromagnetic trip coil always energized, the control circuit is always output power.