I think the sentence I have heard most often in our trade is: “There's a problem with your box, it keeps tripping!”
Yes, for most clients, when “it trips”, it is the fault of the electrician or of their distribution box.
Back to basics
A distribution box is fitted with two main protective devices:
- a 30 mA RCD, which protects people against leakage current;
- one or more circuit breakers, which protect the circuits against a current higher than they can withstand.
So when an RCD has tripped, it means that one or more appliances plugged into the distribution box have a fault, often a current leakage problem. This fault, or these faults added together, exceed 30 mA, so the RCD cuts the power for safety.
The circuit breaker, for its part, trips as soon as the current flowing through it exceeds the current it is rated to let through (expressed in amperes). It also protects against short circuits (its breaking capacity is expressed in kiloamperes).
To sum up
Either you have one or more faulty appliances, or you have plugged too many appliances into the same circuit.
As for the box, it has either saved your life or saved your installation.