EV charging questions

[Ace Rimmer]

Evening all

My missus is picking up a BMW X5 hybrid tomorrow and is supplied with the “granny” charging lead.

As it only takes 4 hours to charge using said lead a fast charger is not required.

Had an electrician come round the house today to fit an external plug socket but he said it needs loads of extra stuff such as a grounding point,its own isolated supply etc.

Im sure the standard charge lead is designed for a standard 3 pin plug.

Any thoughts?

[Ryder35]

I'm no electrician but ran an i3 for 3 years and charged every night using the standard socket in my garage without setting fire to anything!

[Smiljan]

Ace Rimmer said:

external plug socket

Sounds like your electrician knows what he's doing to me and ensuring it's done properly.

[anonymous-user]

Sounds like sensible advice for an external socket, whether it will be used for car charging or not

[Heres Johnny]

A 13a plug you don't need any extra protection just a decent waterproof socket. I wouldn't like to use it int he rain unless it has some shielding however.

Anything above that for EV charging, you need a dedicated feed from the consumer unit.

It kind of depends what you asked for. An EV charging supply and a sparky could easily be thinking 32A, a 13A plug is 10A continuous. But to be honest, I'd get a proper charge point installed while there are grants available.

[dhutch]

Does the house have RCD protection to the sockets?

If your on a shared pme earth system, for caravans and the like there are rules about exporting the earth, the same as rules against exporting it to metal frames garage/shed.

The risk is because the earth is shared, a fault elsewhere could cause it to go live or atleast reach a reasonable voltage. In a home the risk is low as all metal, plumbing etc, is bonded together and the rest is brick. With a caravan you could be in contact with the ground and the earthed body at the same time and get a shock.

The solution is to take just the live and neutral, bang and earth spike in, with an RCD, and issue goes away. This sounds like what the electrician is proposing. What's the damage?


Daniel

[Smiljan]

Heres Johnny said:

A 13a plug you don't need any extra protection just a decent waterproof socket. I wouldn't like to use it int he rain unless it has some shielding however.

I disagree, the electrician doing this job is correct. Dangerous to suggest you can just spur off with a waterproof socket without knowing what you're talking about I'm afraid.

[Heres Johnny]

Smiljan said:

Heres Johnny said:

A 13a plug you don't need any extra protection just a decent waterproof socket. I wouldn't like to use it int he rain unless it has some shielding however.

I disagree, the electrician doing this job is correct. Dangerous to suggest you can just spur off with a waterproof socket without knowing what you're talking about I'm afraid.

I disagree with your blanket disagreement , if you read what I said.

If we’re talking about a new installation to a outhouse or garage then you’re possibly right, if you’re talking about making a socket available in a garage where there’s already a sockets you don’t need a whole new dedicated spur which was what the OP was told.

Edited by Heres Johnny on Saturday 9th February 10:43

[Smiljan]

Outside socket to me means a socket on the outside. Regs are there for that circumstance.

If he meant an additional socket in a garage I'd expect him to say that in the OP.

[Ace Rimmer]

House is only 2 years old,waiting to get the quote from the sparky.

Can’t get government grant for charger as X5 not on list of compliant vehicles, Will cost £850 to get a 7kw charger fitted.

[Smiljan]

Hi Ace, is it just a waterproof 13A 3 pin socket your sparky is fitting on the outside of your house or is this just an additional socket in your garage?

I think one of the other poster and myself might have crossed wires misunderstanding your original post.

Regarding the sparky and what he's proposing, if you're concerned he may be doing too much and overcharging it's probably best you have a chat with him and go through the regs with him. There's a bit of gulf over someone in their own house bodging on a new socket vs a tradesman doing it to the book.

[Ace Rimmer]

Fitting an outside socket on the wall of the house next to the driveway.

Haven’t heard from the guy yet so will wait for the quote.

i’ve told him the outside plug was to be used to charge the car hence the extra work he suggests.

[Heres Johnny]

Ace Rimmer said:

Fitting an outside socket on the wall of the house next to the driveway.

Haven’t heard from the guy yet so will wait for the quote.

i’ve told him the outside plug was to be used to charge the car hence the extra work he suggests.

The work shouldn't be because of its use, but because of what it is. There are slightly variable regulations for the commando socket depending on its use (I find it odd that a generic, universal socket should have different requirements depending on its intended use as that kind of implies its not a generic universal socket). but a standard 3 pin waterproof outdoor socket is a standard 3 pin waterproof outdoor socket. Be interesting if he quoted you the same if you said it was there for plugging in your car power wash but I guess that horse has bolted.

[Smiljan]

Totally agree Johnny. Only differences are the car charger is likely to draw a high current for a long period whereas most other electrical devices you would plug in don't do this, some chargers are a bit fussy about the earth on the supply also. Maybe the sparky has come across this before.

Do you know how many amps the granny charger provided draws Ace? Has your sparky done a lot of installs for EV use?

Edited by Smiljan on Saturday 9th February 11:51

[Heres Johnny]

Smiljan said:

Totally agree Johnny. Only difference is the car charger is likely to draw a high current for a long period whereas most other electrical devices you would plug in don't do this.

Do you know how many amps the granny charger provided draws Ace?

I know the question is directed at Ace but none of them will be above 10As as the regs limit a continual long term load, you'd certainly want it to support a continual 10A for the future.

You're also very right about the earth, in Europe where the Neutral is within a few volts of a Earth some of these chargers won't work if the live and neutrai are swapped, a not uncommon problem. Any earth/neutral issues will prevent it working.

Edited by Heres Johnny on Saturday 9th February 11:54

[Ace Rimmer]

[dhutch]

Heres Johnny said:

The work shouldn't be because of its use, but because of what it is. There are slightly variable regulations for the commando socket depending on its use but a standard 3 pin waterproof outdoor socket is a standard 3 pin waterproof outdoor socket.

I don't know the details, at it may be that 13amp sockets are exempt, but there are certainly different rules if the intended use is to feed a caravan or boat than other applications, typically these are 16amp or larger ceeform/commando socket.

Again, I don't know if these rules apply to all/any car charging sockets, and they may for instance be different rules for a 13amp outdoor socket for a car than a 16/32amp socket, and it may be even the electrician doesn't know the exact letter of the law.

Obviously if the chargers outlet is isolated from the inlet and or double insulated rather than replying on the provided earth, which I can well believe, then that negates the need to worry about exporting a pme earth to the car.

We have just had our house re-wired, including multiple outdoor sockets, and these are all fed from various ring mains. RCD protected, but on the pme earth. So that's obviously allowed, atleast by our electricans interpretation of the rules.

Best bet would be to continue asked/reading about the subject. Either here, second electricans input, or the IET website/forums etc.


Daniel

[gangzoom]

I've charged a Leaf using a normal plug point in an open barn, i3 using a x2 20m extension cables again via normal plug, normal 3 pin plugs with a 20m extension in holiday cottage/cabins all over the UK, in France we charged the Tesla off a normal plug via a 20m extension cable, and when visiting parents in London same - normal plug, 20m extension run out of the letter box to the car.

Its slow but gets the job done, never tripped any RCDs or blown a fuse.

For home charging you want something more permanent and quicker, but pretty much any plug point will charge up any EV with little issues.

You do need to keep an eye on heat/warm plugs, as not all extension cables can handle 10amps sustained. And I wouldn't charge with a 3pin on an extension cable overnight, not worth the fire risk.

[Nick928]

As an electrician and an OLEV approved Chargepoint installer this my advice.
If it’s just an outside socket then install as an outdoor socket without consideration to it being used for charging the car. There are issues if it’s on a garage that’s outside the equipotential zone with regard to exporting PME so this may be what your electrician is referring to and the need for installation of an earth electrode and all that entails.

If it is a dedicated charge point then that will almost certainly need at least an earth electrode and specialist RCD protection (not the same type of RCD that you fine in you normal fuseboard).

The best bet is to have a chat to your electrician (ply them with tea and biscuits and they’ll talk for hours). As others have said, there is a big difference between banging a DIY outside socket in and a tradesman installing a socket complying with the many requirements of BS7671:2018 (the big blue book).

[Ace Rimmer]

have tried to contact the sparky several times but no luck
(i presume he doesn’t want to do the job)
Have ordered one of these for now:

https://www.toughleads.co.uk/collections/ev-electr...

May just get a proper fast charger instead.