Why might a circuit breaker not stay on?

Circuit breaker is to break the circuit in case of a fault. if the fault occurs and the sensing devices trigger the breaker, then breaker will not stay on.

There are two main reasons that a breaker might not reset. One is mechanical failure in the breaker itself. If this is the case the breaker has to be replaced. The other reason that the breaker might not reset is that the breaker is doing its job and still senses an overload when the breaker is switched back on after an overload trip.

To check the breaker as to which fault is occurring disconnect the load conductor from the breaker. Try resetting the breaker. If it will not reset then it is a mechanical fault. If the breaker resets with the load conductor off then shut the breaker off, reconnect the load conductor and turn the circuit back on.

If it trips this time then there is a fault in the circuit and it has to be located and repaired before the circuit is put back into service. You might need an electrician to troubleshoot the circuit depending on what equipment the circuit controls.