The circuit breaker trips: what to check before a call-out
In August a flat in Sunny Beach runs the air conditioning, the water heater, the washing machine and three phones on chargers all at once. That is exactly when the consumer unit trips. In half of cases the reason is a simple one and can be found in ten minutes; in the other half it is something an electrician needs to look at. This article helps you work out which of the two you have.
Which switch has tripped
Look at the consumer unit. The different protective devices tell you different things:
- The circuit breaker. It protects the cable from overload and short circuits. It trips when more current flows along the line than the line can carry.
- The RCD. It reacts to current leaking away — through damp, say, or through a faulty appliance. If that is the one that has tripped, do not reset it before you know why.
- The main switch. It cuts everything. It usually means either a more serious fault or a genuinely heavy load.
If you cannot tell which is which, photograph the consumer unit — that photo is the first thing the tradesperson will ask for.
How to find the appliance at fault in ten minutes
- Unplug everything you switched on last.
- Reset the breaker. If it trips again straight away, do not try a third time — the problem is in the wiring.
- If it holds, switch the appliances back on one at a time, with a minute between them.
- The appliance that makes the unit trip again is your culprit.
If the culprit is one particular appliance, the problem is in that appliance rather than in the flat: take it to a repair shop. If it trips with nothing plugged in at all, call an electrician.
Overload or short circuit
An overload looks like this: everything is working, you switch on one more powerful appliance, and a minute or two later it goes. Typical of a holiday flat in August, where the air conditioning and the water heater hang off the same circuit. The answer is either not to use them at the same time or to have the circuit split — and that is a job for an electrician.
A short circuit looks different: it trips instantly, sometimes with a bang or a smell of burning. There is nothing to try yourself here. Switch off the main switch and stop using that socket.
What you should not do
- Fit a higher-rated breaker. That does not solve anything; it takes the protection away from the cable — the classic cause of fires in old wiring.
- Reset an RCD that tripped because of damp before the spot has dried out and been checked.
- Work on the consumer unit without switching the main switch off first.
- Leave a socket that is sparking or melting "until tomorrow".
Why it happens more often on the coast
Flats here stand shut from October to May. Damp collects in the sockets on the terraces and in the outdoor junction boxes, and the salt air oxidises the connections. That is why, when you open the flat up before the season, it is worth having a check done: terminals tightened, the consumer unit inspected, the RCD tested.
The second thing is the age of the wiring. In a large share of the older blocks the cable is aluminium and the consumer units date from a time when a flat had a fridge and a television. Today's load is several times greater, and the cable is the same size.
When the problem is outside the flat
If the power goes off on the whole floor or in the whole entrance, the fault is in the common parts or in the network. Check with the neighbours before calling anyone out to your own flat: the shared installation is the responsibility of the building's owners' association, and the network is the distribution company's.
What to write in the request
An accurate description saves a visit: which breaker trips, with what appliances running, since when, whether there is a smell or any sparking, what sort of building it is and which floor you are on. If you have already found the appliance at fault, say so straight away.
How to book an electrician
Describe what is happening — the first offers usually arrive within 5–15 minutes:
If the problem turns out to be the air conditioning, see air conditioning installation and repair. And if work is coming up in the flat, have a look at all services in Sunny Beach too.