Circuit Breaker ELCB works

Leakage circuit breaker works: If you have the power of human touch to the end of the line of fire, or electrical equipment internal leakage, when the current through the body from the line of fire or electrical equipment enclosure into the earth, rather than through the zero line,  circuit breakers  and zero line current will not equal, leakage protection detects differences in current immediately after this part of the trip and appliances protect the personal safety of the general flow of this poor Circuit breaker e in the tens of  electric meter .
However, phase three-wire and three-phase four-wire leakage circuit breakers are different, the former rely on the inside of the drain phase current imbalance, to trip (both leakage inside the device, the phase current imbalance), which is inside the device after the zero line leakage current flowing through it to trip. three-phase three-phase system leakage circuit breaker is mainly used for underground power supply.