Why does your automatic circuit breaker consistently open?
Why does your automatic circuit breaker consistently open?

Why does your automatic circuit breaker consistently open?


If you think your automatic circuit breaker is new and your installation is proper, you can also access the source of your problem by looking at this issue through the tips provided by the protection features of automatic circuit breaker.


When dealing with this issue, you should especially consider the opening time of your automatic circuit breaker.


It can be said that if your automatic circuit breaker closes again after opening it and opens the circuit after an average period of time under the same conditions, over current flows over it and it provides thermal protection caused by heating. If available, you can measure the current passing through the automatic circuit breaker with the a clamp meter. If the current you are measuring is higher than the rated current of the automatic circuit breaker, it will be a solution to distribute some of the loads / devices in the lines fed by the circuit breaker to other circuit breakers. While making this change, it should be ensured that other circuit breakers will not be loaded with more current than their nominal currents. Ignoring the option to distribute loads / devices to other automatic circuit breakers and connecting a higher rated current circuit breaker to the circuit as the first solution may leave your conductor vulnerable to overcurrents. The cross-sections of the installation conductors and automatic circuit breakers are selected according to the highest current that will pass through the circuit they are in during the project design. If the devices in the circuit will continue to be used at the same time, replacing both the conductor and the circuit breaker is the best solution.


If your automatic circuit breaker suddenly opens the circuit when you try to close it, we can say that the magnetic protection is activated. The use of devices that causes sudden inrush currents or short circuit may cause this situation. If the breaker does not open suddenly when the devices activated individually, we can think that there is no short circuit in the circuit. In such a case, the automatic circuit breaker can be replaced by a type with higher instantaneous tripping current (type C if B, C type C if C), and the opening limit at the short-term inrush currents of first activating can be increased.


It is important that all these control and maintenance works are carried out by authorized, knowledgeable people.