In a house in Essonne, Seine-et-Marne, Val-de-Marne, or elsewhere in Île-de-France, the project rarely depends on the charging station alone. The consumer unit, the earthing, the distance to the parking space, the cable routing, and the power already drawn by the home can modify the solution to be planned and the content of the quote.
Why check the installation before the quote?
A charging station operates for several hours and adds a regular electrical use to the home. The quote must therefore be based on the actual situation: location of the consumer unit, apparent condition of the protections, length of the run, installation conditions, and appliances running in parallel.A preliminary check also makes it possible to distinguish between what relates to the charging station and what relates to the existing installation. An old consumer unit, earthing that needs checking, or an outdoor run do not automatically mean that the project is impossible. They simply indicate that certain checks or adaptations must be integrated from the start, rather than discovered after the quote has been accepted.
The field checklist: from the consumer unit to the parking space
The first step consists of observing the entire route, without opening the equipment or touching the conductors. Photographs taken from a distance of the closed consumer unit, the meter, and the parking space can help prepare the first exchange.Here are the useful points to note:
- The consumer unit: location, accessibility, apparent condition, available space, and the possible presence of rows or protections already identified for major uses.
- The house power supply: single-phase or three-phase indication if known, type of meter, subscribed power, and any circuit breaker that already trips when several appliances run together.
- The earthing: presence of a protective conductor and an identifiable earthing installation. Its quality cannot be deduced from a simple glance: it must be measured by the professional.
- Protections: identification of visible circuit breakers and residual current devices (RCDs), without concluding on their compliance yourself. A charging station must be supplied by a dedicated circuit and protected according to the chosen charging configuration.
- The distance between the consumer unit and the station: route through the garage, cellar, outdoor areas, or an outbuilding, with any changes in direction, drilling, and crossings.
- The car's location: usual position, necessary clearance, exposure to moisture or impacts, useful cable length, and the risk of leaving a cable across a walkway.
What the professional must check during the pre-diagnosis
The pre-diagnosis transforms observations into electrical checks. The professional can notably examine the continuity and quality of the earth, the condition of the conductors, insulation, the tripping of differential protections, and the presence of the conditions necessary for safe charging. The exact measurements depend on the installation, the charging station, and the charging mode; there is no single value to be deduced from a photo of the consumer unit.The consumer unit must be able to accommodate the charging circuit and the appropriate protections. The French regulatory framework provides for a dedicated circuit for each charging point and a dedicated differential protection with a sensitivity at most equal to 30 mA. The type of protection and additional devices depend on the equipment and the charging mode. They should therefore not be chosen from a universal list copied from the Internet.
The professional also checks the cable route. A short, protected link in a garage is not treated the same as a long link to an outbuilding, an exterior wall, or a separate parking space. The routing may require trunking, a crossing, protection against impacts, or a buried solution compliant with the context. This work must appear clearly in the quote, just like the supply and installation of the charging station.
Finally, the available power must be compared with the home's usage. Electric heating, hot water tanks, cooking, heat pumps, or another vehicle may operate at the same time as the charging. The professional can then study an adaptation of the subscription, a power setting, or a management device that modulates the charging when the house consumes more. Load management does not fix a dangerous installation: it helps manage an available power that has been correctly assessed.
Preparing a useful pre-diagnosis before the visit
A few simple pieces of information save time without replacing the technical visit. They primarily allow for the identification of questions that will need to be decided on-site and avoid a quote based on overly general assumptions.You can gather:
- a clear photo of the closed consumer unit and, if possible, the meter or the space located nearby;
- the subscribed power indicated on your contract or your supplier portal, as well as single-phase/three-phase information if known;
- the vehicle model and its AC charging power, solely to establish the need;
- a description of the route between the consumer unit and the space: attached garage, exterior wall, courtyard, outbuilding, or distance between buildings;
- major electrical equipment likely to operate during charging hours.
What self-checking cannot conclude
Looking at a consumer unit does not allow for declaring an installation compliant, validating a cable section, or confirming that a charging station will be able to operate at its nominal power. Even a recent consumer unit can hide insufficient earthing, unsuitable protection, an imbalance between phases, or a constraint on the cable route. Conversely, an old installation may be improvable without it being necessary to rewire the whole house.The owner can therefore prepare information, measure the distance of the route, and describe their usage, but the electrical measurements and work remain the responsibility of a professional authorised and qualified for EVSE (IRVE) when regulations require it. You must not remove covers, handle conductors, perform a live measurement, or modify the consumer unit to obtain a quote.
The formalities at the end of the installation are not identical in all cases. The type of building, the connection, the power at the delivery point, and the nature of any modification can change the documents to be planned. For a detached house, the right reflex is to ask the professional to confirm the procedure applicable to the specific project, rather than considering a certificate or an exemption as automatic.
A reliable quote starts with a precise site assessment
Before comparing several offers, check that they are based on the same information: location of the charging station, length and routing method, planned protections, earthing check, available power, potential adaptations of the consumer unit, and commissioning conditions. A quote that does not specify these assumptions is difficult to compare, even if its amount seems attractive.If you are preparing a charging station installation in a detached house in Île-de-France, you can send these elements to MGTEC to frame your request. The MGTEC contact page allows for discussion of the project; the article Choosing a qualified EVSE installer completes this pre-diagnosis with points to look for in an offer and in the scope of intervention.
The goal of this preparation is simple: arrive at the quote with a verifiable description of the house, then let the electrical study confirm the truly adapted solution. A well-integrated charging station starts with a correctly examined consumer unit, earthing, route, and available power.
To frame this pre-diagnosis, consult Enedis recommendations on home charging station installation: diagnosis of the electrical installation, earthing, necessary power, and use of a qualified EVSE professional. This source completes the checklist without replacing the visit or the measurements carried out on-site.
