There was a sudden power failure at home, but the main switch did not trip. Just pull down the brake and pull it up again. What's wrong with it?

When the power is suddenly cut off, but the circuit breaker does not trip, the circuit breaker is closed again, that is, it returns to normal, which is usually caused by the fault of the circuit breaker itself and needs to be repaired or replaced.

1. Opening and closing performance failure: Due to obvious mechanical defects, oil shortage or unqualified oil quality of the circuit breaker, it is possible that the current cannot pass through the circuit breaker, resulting in no power supply.

2. Faults with poor conductivity: Faults with poor conductivity are mainly caused by mechanical defects.

3. External insulation failure: the flashover explosion accident of circuit breaker is mainly caused by pollution flashover and lightning strike. The main reason for pollution flashover is that porcelain bottles are not suitable for use in polluted areas because of their small leakage distance; Secondly, the circuit breaker leaks oil, which is easy to accumulate scale on its porcelain skirt, causing flashover.