In case there is a failure in the system, the circuit breakers of the electric panel will stop the current.
To restore the system's functionality, you will need to find and repair the failure.
If the power board has multiple split lines, we turn off all the switches. Now we're running the counter.
Let's reactivate the lines one at a time, when it will jump back to the current we will find what line the failure has occurred.
In the case of a single line, you will need to check all electrical appliances connected to that line and disconnect them. If the problem remains is the line that is somehow damaged, if the problem is resolved, one of the electrical appliances is definitely dead.
You will then need to check them one at a time.
It's not always easy to find an electrical failure but experience can help.
For these reasons it is important and practical to have a system with divided lines. The investment to divide the lines translates into practicality.