Charging point: charge at home

Charging an electric vehicle from a standard household socket puts the home's circuit under load for several hours close to its rated limit, which is not its original purpose and carries a risk of overheating on older installations or undersized wiring. A wallbox is designed specifically for this sustained use and includes its own protective devices.

A wallbox also communicates with the vehicle to adjust the charging current and cut power in case of a fault, which a simple socket cannot do. This design difference, more than charging speed, is what justifies a dedicated charging point once regular use is expected.

A charging point is connected to a dedicated circuit, protected by its own circuit breaker and, depending on the configuration, a residual current device suited to the DC fault current that an onboard vehicle charger can generate. This circuit must not be shared with other household loads.

The power available at the grid connection is contractually limited. A load management system automatically adjusts the power delivered to the charging point based on simultaneous household consumption, which often allows a charging point to be installed without applying for a higher connection capacity from the grid operator. This is worth checking with the installer before ordering equipment.

A charging point can be supplied in single-phase or three-phase depending on the home's connection type and the desired charging power; three-phase allows higher power at equivalent current, but requires that the home's electrical installation support it. The installer determines the configuration suited to the existing distribution board.

The charging cable may be fixed to the unit or detachable depending on the model; a detachable cable reduces weather exposure and makes replacement easier. The mounting location must stay accessible from the parking space, protected from impact, and reachable with a cable length compatible with the vehicle.

In a single-family house, installation generally amounts to running a circuit from the distribution board to the parking space. In a co-owned building the situation differs: installing a charging point in a shared underground car park requires a decision by the general meeting of co-owners, individual metering so each user pays for their own consumption, and often a collective assessment of the infrastructure needed for several future charging points.

Planning this shared infrastructure ahead of time, even without immediately installing several points, avoids repeating structural work for every new request. A well-informed managing agent or co-owners' council typically commissions a technical study before putting the matter to a vote.

The grid operator must be informed of the installation of a charging point, in particular to check the capacity of the existing connection; the installer usually handles this as part of the project. The installation itself must be carried out by an electrical company holding a business permit, because of the specific protective devices required.

Where a photovoltaic installation is present, a charging point compatible with smart charging can adjust its power to prioritise electricity produced on site over electricity bought from the grid, particularly during the day. This function requires communication between the inverter, the charging point and, in some cases, a home energy management unit, which should be stated in the quote if sought.

The Klimabonus Wunnen, which replaced the former PRIMe House programme in 2022, includes a component dedicated to charging infrastructure and home energy management. The eligibility conditions, in both a house and a co-owned building, and the amounts applicable at the time of your application are published on guichet.lu; check the official sheet before starting the work.