Old fuse box? When to upgrade your quadro elétrico
Fuses, no residual current device, no earth: the signs of an old quadro elétrico, what an upgrade involves, what it costs and what to ask.
Why it matters
The fuse box (quadro elétrico) is where your home's safety devices live. Many older Portuguese flats still have boards with fuses, a single circuit for half the home, or no residual current device. They worked for a few lights and a fridge, but not for today's ovens, heaters, air conditioning and chargers.
Signs it is time
- Fuses instead of circuit breakers, or a board made of wood or old porcelain parts.
- No residual current device (interruptor diferencial), usually marked 30 mA.
- Sockets with only two holes and no earth pin.
- Breakers that trip when two appliances run at once.
- Scorch marks, a warm board, a buzzing sound or a burning smell.
- No labels, so nobody knows which switch does what.
What an upgrade involves
- A new board with circuit breakers sized for each circuit.
- Separate circuits for lights, sockets and big appliances such as the oven or the water heater.
- A residual current device of 30 mA protecting the sockets, as modern installations expect.
- A check of the earth (terra) and, if needed, a new earth connection.
- Surge protection, if you want it.
- Clear labels, tests and the termo de responsabilidade for the new work.
What it costs
Published surveys put the labour for replacing a board from about €70, and a new board fitted at around €250. Extra circuits, an earth connection or surge protection add to it. If the cables behind the board are also old, rewiring may be the better answer; ask for both options in the quote.
Before you book
- In a rented home, ask the landlord first: the installation is theirs.
- In a flat, ask the condominium administrator if the work touches the common parts or the meter.
- Ask whether the power will be off and for how long.
- Ask for the declaration of the work and the fatura with your NIF.
Frequently asked questions
Do I need to rewire if I change the fuse box?
Not always. An electrician tests the existing cables. If they are in good condition and have an earth, a new board may be enough.
Does a new fuse box mean more contracted power?
No. Contracted power is set with your supplier. But a new board is often the first step before raising it.
Is a residual current device really needed?
It is the device that cuts the power when current leaks through a person or a faulty appliance. Every modern installation has one, and it is the single most useful safety upgrade in an old home.