Power cut or a breaker that keeps tripping: what to do
Is it the street or your home? How to read the fuse box, reset a breaker safely, find the appliance that trips it, and when to call E-REDES or an electrician.
Safety first
If there is smoke, fire, or someone has had an electric shock, call 112. If you smell burning, see sparks, or water is near sockets or the fuse box, do not touch anything wet. Switch off the main switch only if you can reach it with dry hands and without standing in water, then call an electrician.
Is it the street or just your home?
Look outside and ask a neighbour. If the street lights and the houses around you are also dark, it is a fault in the public network.
That is the job of E-REDES, the network operator, not of an electrician: call their fault line on 800 506 506 (24 hours) or check their website or app for planned and known outages. Your electricity supplier cannot repair the network either.
Your fuse box, in plain words
- Main switch (interruptor geral or disjuntor geral): cuts the whole home.
- Residual current device (interruptor diferencial, often 30 mA): cuts the power when current leaks to earth, for example through a faulty appliance, damp in a socket or a damaged cable. It protects people.
- Circuit breakers (disjuntores): one per circuit, such as lights, sockets, kitchen or water heater. They cut a circuit that draws too much current or has a short circuit.
- In older homes you may find fuses instead of breakers. A blown fuse must be replaced with one of the same rating, which is a job for an electrician.
Resetting safely
- Switch off or unplug the appliances on the circuit that went off.
- Push the switch that dropped back up to on.
- If it holds, plug things back one at a time. The one that trips it again is your suspect.
- If the residual current device trips even with everything unplugged, there is probably a leak in the wiring. Leave it off and call an electrician.
- Never hold a switch up, tape it, or swap a breaker or fuse for a bigger one.
When the whole home goes off at busy times
If the power goes when the oven, the washing machine and the heater run together, you may be using more than your contracted power (potência contratada).
Switch something off and reset the main switch or the meter, following your supplier's instructions. If it happens often, ask your supplier about raising the contracted power, and ask an electrician whether your installation can take it.
When to call an electrician
- A breaker or the residual current device trips again and again.
- A socket, plug or switch is warm, discoloured or smells of burning.
- Lights flicker or dim when something else switches on.
- There is no earth in the sockets, or the fuse box still has old fuses.
- Water got into a socket, a light or the fuse box.
Frequently asked questions
Who do I call for a power cut in my street?
E-REDES, on 800 506 506, available 24 hours. An electrician cannot work on the public network.
Can I reset the residual current device myself?
Yes, once. If it trips again straight away, or every few days, have an electrician find the leak. It is there to protect people.
Will my landlord pay for the repair?
Faults in the installation of a rented home are usually for the landlord to repair, while damage caused by your own appliance is usually yours. Tell the landlord in writing and keep the electrician's invoice.