If a circuit breaker keeps tripping, do not simply reset it: first reduce the load and isolate the circuit that may be at fault. One trip when several appliances are switched on can point to overload; an immediate trip, burning smell, damp or a hot socket means stopping, leaving the circuit off and calling a qualified professional. The aim is not to restore power quickly. It is to prevent electric shock, overheating or hidden damage to the installation.
Contents
- What has tripped: a circuit breaker or an RCD?
- What to do in the first few minutes
- How to isolate an appliance without creating a second fault
- When the fault may be in the fixed installation
- Warning signs that mean calling an electrician now
- How to prevent a repeat after the repair
What has tripped: a circuit breaker or an RCD?
Before unplugging anything, look at the consumer unit without removing covers or touching conductors. Many homes have breakers for specific circuits — lighting, sockets, kitchen or dedicated equipment — plus a residual-current device, often called an RCD, that protects against indirect contact. Portugal’s Low-Voltage Electrical Installation Technical Rules require differential protection and protective conductors in domestic circuits.
A circuit breaker can operate because of overload or a short circuit. An RCD can operate when it detects leakage current to earth. For a householder, the distinction helps organise observations; it is not a full electrical diagnosis.
- If only one circuit trips, begin with the appliances and sockets in that area.
- If the main RCD trips, switch off the circuit breakers before working out which circuit is involved.
- If the consumer unit is wet, marked by scorching, strongly smells of burning or makes unusual noises, do not operate it.
| What you see | Initial possibility | First safe action |
|---|---|---|
| One circuit breaker trips | Overload, short circuit or an appliance on that circuit | Switch off and unplug appliances on that circuit |
| The RCD trips | Leakage current in an appliance, cable or circuit | Switch off circuits and restore them one at a time |
| It trips again immediately after reset | Persistent fault or active risk | Leave it off and call an electrician unless a removed appliance clearly caused it |
What to do in the first few minutes
Set aside the urge to get everything working at once. Switch off appliances that were in use when the power went out: a portable heater, kettle, washing machine, oven, extension lead, chargers or outdoor equipment. Unplug by gripping the plug, never by pulling the cable. If there is water near a socket, appliance or consumer unit, do not touch the setup and do not approach barefoot.
- Make a quick note on your phone of what was running and which room was affected.
- Switch off accessible appliances on the affected circuit.
- Reset the protective device once only, with dry hands and on a dry floor.
- If it stays on, reconnect appliances one at a time, allowing a pause between attempts.
- If it trips again, leave that circuit switched off.
Do not replace a breaker with a larger rating, hold levers in place or use extension leads to bypass a faulty socket or circuit. Domestic electrical work must follow applicable technical and safety rules and be carried out by an installation business or responsible technician, as set out in the Portuguese rules on electrical-installation execution.
How to isolate an appliance without creating a second fault
If the consumer unit stays on with everything unplugged, a straightforward process can show whether the fault follows one appliance. Plug in and switch on one item at a time, starting with low-demand equipment and leaving appliances that heat water or use heating elements until last: kettles, toasters, washing machines, dishwashers, hot-water cylinders and portable heaters.
If the trip returns every time the same appliance is connected, unplug it, identify it clearly and do not carry out further tests. A cable bent near the plug, damaged insulation, heat marks or moisture are enough reason to stop using the appliance until it has been checked.
This test is unsuitable if the socket is loose, there are sparks, the cable is trapped under a door or the appliance has been in contact with water. Do not try to confirm the cause in those cases. Useful information for an electrician is simple: the affected circuit, the time, the connected appliance and whether the trip was instant or happened after several minutes.
When the fault may be in the fixed installation
If the breaker will not stay on even with plugs removed, the cause may be a socket, junction box, light point, concealed cable or the protective device itself. It also deserves attention when trips happen only during rain, after a water leak, when one particular light is switched on or when a machine runs and vibrates.
In Lisbon flats that have undergone several rounds of alteration, circuits are often changed without a clear record, extra sockets may have been added to already busy lines, or connections may be hidden behind kitchen furniture. Do not open sockets to look for a loose wire. Besides the direct hazard, a poor repair can conceal the fault and make the next intervention harder.
During a renovation, include circuits, accessible junctions and fixed equipment in a renovation interface map. Knowing where services run and who signed off each stage helps avoid reopening finished walls later.
Warning signs that mean calling an electrician now
In some situations, the right decision is to leave the circuit off and call an electrician without further attempts:
- a smell of burning plastic, smoke, crackling or dark marks at a socket;
- a socket, plug, extension lead or consumer unit that is hot to the touch;
- an electric shock when touching an appliance or tap;
- water near circuits, sockets, ceiling light fittings or the consumer unit;
- repeated tripping with no appliances connected;
- damaged visible cables, improvised connections or altered fuses.
If there is smoke or an incipient fire, move people away, call 112 where necessary and never use water on energised electrical equipment. Use an extinguisher only if it is suitable, you know how to use it and you have a safe exit. Leaving the area is more important than saving the appliance.
After a wider power outage, use torches rather than candles and avoid switching on demanding loads all at once when supply returns; ADENE’s guidance on power failures also advises careful steps to protect equipment.
How to prevent a repeat after the repair
Once the cause has been found and repaired, turn the incident into a short maintenance routine. Label the consumer unit with names that match the actual rooms, keep access clear and replace tired extension leads instead of hiding them behind furniture. Heating, laundry and kitchen equipment need suitable sockets and properly sized circuits; they should not depend on overloaded multiway adaptors.
If you are renovating a kitchen, laundry space or bathroom, decide on permanent electrical loads and planned appliances early. Allow for dedicated circuits where the technical design requires them, and confirm accessible junction locations before walls are closed. At the end of the works, include circuit identification and tests in the renovation handover record.
A breaker that trips is performing a protective function. The safe response is to find out why it operated, correct the cause and keep a record — never make the consumer unit ignore the warning.
Key takeaways
- Reset a tripped device only once after disconnecting appliances on the affected circuit.
- If the trip returns with everything unplugged, leave the circuit out of service and call an electrician.
- Burning smells, heat, water or electric shocks are signals to stop immediately.
- Clear consumer-unit labels and planned circuits shorten the response time when a fault occurs.
If the fault appeared during renovation work, or if the consumer unit no longer matches what is installed in the flat, ask Obra Lisboa to include circuit identification, access points and checks in the intervention plan before walls are closed or finishes are handed over.
Sources and further reading
- Low-Voltage Electrical Installation Technical Rules
- Portuguese rules on electrical-installation execution
- ADENE’s guidance on power failures
Editorial image; it does not depict an Obra Lisboa project.
Obra Lisboa
