What are the faults of air circuit breakers(ACB)?

1. The air circuit breaker tripped and failed to reclose:
First, determine whether the air circuit breaker tripped non-accidentally. Non-accidental tripping means that it tripped without short circuit or overload fault. There are many reasons why the air circuit breaker cannot close. First, it is necessary to determine whether the trip is caused by short circuit and overload, or whether the circuit breaker itself or the control circuit is faulty. Follow the steps below to determine the cause of the fault. First, observe whether the primary circuit has blackened or burnt wires and contacts, smell whether there is any peculiar smell, and whether there is any fault in the relevant secondary control circuit in the low-voltage cabinet. If a fault point is found, it can operate normally after being eliminated; if no obvious fault point is found, the circuit breaker is closed under no-load conditions. If the circuit breaker is tripped and still cannot be put into operation, the air circuit breaker itself is faulty; If the circuit breaker is closed, there is no fault in the circuit breaker itself. Then branch line faults are detected in sequence.
2. Air circuit breaker’s intelligent controller failure:
After the intelligent controller of the air circuit breaker fails, the phenomenon of manual closing, electric closing, and failure of the three-stage protection function and other protection functions will generally occur. Intelligent controller failures are generally caused by burnout due to excessive voltage. Generally, manufacturers follow relevant national standards and design the rated working voltage to 400V. However, in actual operation, when the power consumption drops in the middle of the night, if the transformer is not voltage-regulated, the voltage will often reach 420V and above. A large capacity makes the smart The controller burned out due to high voltage. Another common problem of the controller is that if the fault memory is not cleared in time, even if the power grid fault has been eliminated, the circuit breaker will still think that the power grid is faulty and neither the manual nor the electric circuit breaker will be able to close the circuit breaker. At this time, you can only operate normally by following the operations in the instruction manual, clearing the fault memory and then resetting it. Ordinary people will not think that it is because the gate cannot close, and often cannot find the cause of the fault, or they know the cause, but because the clearing operation is too complicated, they can only find professional technicians, causing unnecessary power outages. The solution is that air circuit breaker manufacturers should develop controllers with better pressure resistance that are simpler and more intuitive to operate, and at the same time strengthen technical training for operators.