Summer, holidays, family and friends visiting. Fifteen years ago, the first question after the greetings was: ‘What’s your Wi-Fi password here?’ These days, we sometimes have to add: ‘Where can I charge my electric car?’
For the simpler hybrid vehicles, the answer is usually quick: we’ll just plug an extension lead into the socket here. I see that quite often: an extension lead sticking through a slightly open window, recharging the battery all night long. Occasionally I ask – you have to be a bit careful, before you know it you’re seen as a prophet of doom – is that really sensible? The answer is invariably: no problem, it always works out fine.
But it could also turn out differently. First of all, those 16-amp sockets aren’t designed to handle a continuous heavy load. And furthermore, you don’t know – especially when dealing with an older electrical installation – how it’s all been wired up. Has 2.5 mm² cable been used rather than 1.5 mm²? Then there’s the excessive use of choco-blocks, once so popular with French electricians, even in junction boxes hidden from view? Daisy chaining of sockets (
répiquage) doesn't lower the total resistance...And unfortunately, even screws that were once tight have a tendency to become a little loose over time. And all those contact resistances then add up and form an additional source of heat. Until things go wrong and the wiring overheats. Another question: is that circuit actually protected by an RCD? It would be handy if it were to rain at night.
For many people, having a dedicated charging point installed will be a step too far if they only use it occasionally. And on top of that, you need to have the correct ‘
puissance souscrite’ for it. That is why it is recommended that you at least install a separate circuit for it from the fuse box, equipped with its own RCD (type A or better) and circuit breaker. Run a 2.5 mm² cable to the connection point, using a special rugged socket (
prise renforcée) that can withstand continuous use. In the latter case, you can also protect that circuit with a 20A circuit breaker instead of the usual 16A one.
Two possibiliies: use a rather expensive
Disjoncteur Différentiel or a standard Interrupteur Différentiel + disjoncteur.
As you might expect, Promotelec has also written something
on this subject.
