A safe electrical installation starts with proper earthing. Whether you live in an apartment or a house, correct earthing can be the difference between a minor issue and a potentially dangerous situation.
Why is earthing so important?
In Belgium, electrical accidents still occur every year. Earthing primarily protects people, but it also plays a key role in the overall safety and reliability of the entire installation.
Protects against electric shock
A poorly insulated appliance or a damaged cable can put voltage on metal surfaces. If you touch such a surface, your body becomes a conductor. With proper earthing, fault current is immediately diverted into the ground instead of passing through you, preventing electrocution — even when insulation is worn or damaged.
Prevents fires
A defective installation without proper earthing can cause overheating or sparks, greatly increasing the risk of short circuits and electrical fires. Earthing safely discharges excess current before danger arises.
Protects electrical appliances
Modern household appliances are sensitive to power surges caused by lightning or fluctuations in the grid. By dissipating these surges, earthing helps protect equipment such as washing machines, refrigerators and computers, extending their lifespan.
How does earthing work?
The principle is simple. A complete earthing system consists of three elements::
- an earth conductor (green‑yellow cable) that connects metal parts of appliances to the ground
- the main earthing terminal, usually located near the electrical panel
- an earth electrode (rod or plate) driven into the soil or integrated into the building’s foundations
In the event of a fault, electricity always follows the path of least resistance. Earthing ensures that this path leads to the ground, not through a person.
The video below explains it clearly.
Is earthing mandatory?
Yes, it is mandatory under the Belgian General Regulations on Electrical Installations (AREI). Any element that may present a risk must be connected to earth, including:
- power outlets (earthed sockets)
- light points
- metal pipes (water, heating…)
- metal parts that could accidentally become live (stove, shower, bathtub…)
A main earthing switch (or disconnecting device) is also required. It allows measurement of the earthing resistance, which may not exceed 30 Ohms in Belgium. If the value is higher, the earthing cannot dissipate fault currents quickly enough.
Earthing + residual current device= an essential duo
Earthing and a residual current device (RCD), also called a differential switch, are often confused. However, they serve different purposes.
- Earthing diverts fault current safely into the ground.
- The RCD detects that current is leaking towards earth and immediately cuts the electrical circuit.
The RCD is therefore a complement to the earthing system and further increases safety. Together, they form an essential duo in every safe electrical installation.
Earthing in apartments and houses
Whether you rent an apartment or own a house, the principles of earthing remain the same. The practical implementation, however, can differ.
In apartments
You rely on the shared earthing system of the building, which is managed by the co‑owners’ association. What you can visually check:
- presence of earthed sockets or earth pins
- earthing symbols on sockets or junction boxes
- sensitive appliances (washing machines, computers, refrigerators…) plugged into earthed outlets
As a tenant, you are not allowed to modify the electrical installation. Contact your landlord if you have doubts.
If you are a co‑owner, any work on shared infrastructure — including earthing — must be decided via the co‑owners’ association.
In houses
As a homeowner, you carry more responsibility, but you also have greater insight into — and influence over — the condition of your earthing system. That’s why it’s important to regularly perform a visual check of the following:
- The main earthing terminal in the electrical cabinet (where the green‑yellow cables come together)
- The earthing connection of major appliances, such as the boiler, washing machine or dishwasher
- The earthing of all sockets, especially in damp or humid rooms
If you renovate, extend your electrical installation, or install new technologies (e.g. solar panels, a charging station, a heat pump), it’s best to have the entire earthing system inspected by a certified electrician, as required by the AREI.
FAQ
How can I know whether the earthing in an older home is still compliant?
If your home was built before 1981 and the electrical installation has not been thoroughly renovated since, there is a good chance that the earthing system no longer meets current standards.
When selling or renting out the property, an electrical inspection report is mandatory, and any identified defects must be corrected. Even if you’re not planning to move, it is recommended to have an older installation modernised to ensure your home is safe and reliable again.
Do solar panels need to be earthed?
Yes. The metal mounting structure must be earthed.
The panels themselves are double‑insulated, so they do not require separate earthing.
Grounding the structure prevents dangerous voltages if cables become damaged and reduces the impact of lightning without increasing the likelihood of a strike.
Important: Any modification to your electrical installation — including adding solar panels — requires a new inspection.