General questions about electrical installations
Before you call, these answers might help you better understand your electrical installation. If your question is more specific, get in touch directly.
Why does the RCD trip, and how do I know if it's serious?
The RCD (residual current device) trips to protect people when it detects a current leak to earth — for example from a faulty appliance, damp in the wiring, or a damaged cable. If it trips once and doesn't happen again, it may be minor; if it trips repeatedly or when you plug in a specific appliance, it's worth having it checked before it becomes a bigger problem.
What's the difference between an RCD and a circuit breaker?
An RCD protects people from electric shock by cutting power when it detects a current leak. A circuit breaker (MCB) protects the wiring itself against overloads or short circuits, cutting the circuit before the cable overheats. A modern fuse box usually combines several circuit breakers with one or more general RCDs.
How often should a home's electrical installation be checked?
There's no legal requirement for periodic inspection of private homes, unlike commercial premises, but a general check every 10 years is recommended — or sooner if the installation is over 25-30 years old, if you notice frequent power cuts, or a burning smell from the fuse box.
How much power do I need for my home?
It depends on how many high-consumption appliances (induction hob, heat pump, air conditioning) you run at the same time. A standard home typically needs between 4.6 kW and 5.75 kW; a home running induction, an electric oven and air conditioning simultaneously may need up to 9.2 kW or more. An electrician can calculate the actual power you need before you over- or under-contract.
Is earthing mandatory?
Yes, current regulations require earthing in all new installations and any significant rewiring. Many older buildings in Barcelona, especially those built before the 2000s, still don't have it or have it incomplete — one of the most common reasons for a rewiring job.
What's the difference between a partial rewiring and a full installation?
A partial rewiring updates specific sections of the existing installation (for example, replacing the fuse box or adding a circuit) without touching the rest. A full installation replaces everything from the source: wiring, switches, fuse box and lighting points, usually as part of a full home renovation or new build.