Short answer
An EV charger always gets its own circuit in the meter cupboard, with its own breaker and RCD protection suitable for DC faults. In addition a separate cable runs to the spot for the charger, with a cross-section that suits the length and the power. If there is no space or no three-phase in the meter cupboard, that is the first thing to sort out.
Who this article is for For anyone who has or is getting an electric car and wants to charge at home. The connection itself is work for an electrician, but it helps enormously if you know beforehand what is going to happen.
What needs to happen in the meter cupboard
An EV charger is not an appliance you just hang on an existing circuit. It draws its maximum current for hours, and that is exactly what a shared circuit cannot cope with. That is why:
The EV charger gets its own circuit, with protection that also sees DC faults.
- its own circuit with its own breaker
- RCD protection that also sees DC faults, usually type B or a type A with DC detection in the charger itself
- space on the rail, and that is often the problem
In a full consumer unit that means an extension or a new consumer unit. What that involves is in consumer unit replacement and in upgrading your connection.
The cable to the charger
The cable often decides the price, not the charger. Two things count: how much current has to go through it and how long it is. With a long cable voltage is lost, and you compensate for that by making it thicker.
| Situation | What to look out for |
|---|---|
| Charger on the outside wall next to the meter cupboard | Short cable, usually the cheapest |
| Charger on the other side of the house | Route through the crawl space or along the ceiling |
| Charger on the driveway or by the shed | Buried cable, digging, watertight entry |
| Garage separate from the house | Separate supply, sometimes its own distribution board |
Let the route be decided before the charger is chosen. A charger that can do 22 kW makes little sense if the cable or the connection will never deliver that.
Single-phase or three-phase
With single-phase you usually charge at home at 3.7 kW, at best 7.4 kW. With three-phase you get 11 kW, and with a heavy connection 22 kW. You mainly notice the difference if the car is almost empty every night.
If you have single-phase now and want three-phase, that means an application to the grid operator plus work in the meter cupboard. What that involves is in single-phase or three-phase charging.
Where it usually gets stuck
The meter cupboard is full. By far the most common. Expect that a consumer unit will first have to be added or replaced.
The four stumbling blocks, in order of how often I come across them.
The main fuse is too light. Charging while the hob and the tumble dryer are on easily goes over 25 amps. That is what load balancing is for, see load balancing.
The RCD is not suitable. An old type A without DC detection may not simply feed a charge point. More on that in which RCD for an EV charger.
The earthing is too old. In homes from before 1975 I still regularly come across an earth conductor that does not comply. That has to be put right first.
What it costs
The connection starts at € 1.815 including VAT for a short, straightforward situation, and goes up to € 3.025 with a long cable, digging or changes in the consumer unit. The charger itself comes on top. A complete example with charger is at the Zaptec Go 2.
What is needed in your case I can see in a quarter of an hour on site. That costs nothing and prevents a quote that turns out to be wrong afterwards.
From my own work
At a house in Beek the EV charger had already been ordered when I came to look. The meter cupboard was from 1998, full, and single-phase. The charger could go on the outside wall fine, but first a new consumer unit had to go in and three-phase had to be applied for from the grid operator. That application took longer than the whole installation. If you have it looked at first and only then order, you are usually done sooner.
When to call an electrician
- The meter cupboard is full or older than about twenty years
- You are not sure whether you have single-phase or three-phase
- The distance from the meter cupboard to the charging spot is more than fifteen metres
- There has to be digging or drilling through a cavity wall
I come and look and calculate the cable before anything is ordered. See also EV chargers and request a quote.
Frequently asked questions
How long does fitting an EV charger take?
If the meter cupboard has space and the distance is limited, I am there for half a day. If a consumer unit has to be added or there is digging, it becomes a whole day or two. The application for three-phase to the grid operator takes the longest, so you do that first.
May I fit an EV charger myself?
You may screw the charger to the wall yourself, but not connect it in the meter cupboard without the right knowledge. And most manufacturers require installation by a registered electrician, otherwise the warranty on the charger lapses.
Do I need a permit for an EV charger on my outside wall?
On your own outside wall or on your own property generally not. With a listed building, in a protected townscape or on municipal land you do. In an owners' association (VvE) you need permission from the meeting.
Further reading
EV charger at home: single-phase or three-phase, and which protection
The choice depends as much on your car as on your connection. With the costs, the RCD debate and why load balancing is not an optional extra.
Which cable to the EV charger, and what the distance does
The further the charger is from the meter cupboard, the thicker the cable has to be. That is usually the item that decides the price.
Load balancing: why your main fuse can cope after all
Without load balancing the car keeps charging at full power while the oven and the tumble dryer are on too. With load balancing the car automatically charges more slowly.
Questions and comments
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