Fitting an outside socket for charging hybrid car

[shd1970]

I've recently taken delivery of a new car which is a PHEV hybrid
I've charged it a couple of times from empty from a 3 pin plug and it has taken 5 hours which is an acceptable time for us, albeit having to use an extension lead dangled through the letter box which is a pain
I don't want the expense or need the speed of a proper wall-charger like an Ohme or a Zappi as we are likely moving house next year so the 3 pin outside double socket will suffice

My thought is to :

• fit an IP65/6 with its supply feed coming via a new 2.5mm T&E
• route the supply cable into the wall cavity of the house, into the ceiling void, clip to the joists and then down some trunking inside the house and then...
• put a 3 pin plug on it and plug into an existing switched free socket
• the free socket will either be on "kitchen sockets (green - 2)" or "downstairs sockets (green - 3)" which you will see from the attached photo is on the RCD side of my CU

Rational is so i can safely switch-off/unplug the outside double socket when not being used for safety and to stop anyone nicking my electricity if we are away

Based on the above text and the photo :

1. Is this an acceptable solution ?
2. Any other checks or considerations to take onboard ?
3. Would the outside socket benefit from being an RCD type also for belt and braces, or not necessary ?
4. I assume that i would have to get this signed off by a suitable spark ?

My inspiration was taken from Ultimate Handyman here :

TIA guys/gals

 

[flameport]

Many problems:
Cable can't be directly installed in a wall cavity, as will very likely be damaged by hidden sharp edges of bricks, mortar, wall ties and all the other junk in there.
T&E is not suitable for connecting to a plug.
The existing RCD is a type AC, which is not suitable for loads that could create DC faults.
Normal sockets are not designed for continuous high loads for hours at a time, as they can overheat. The charger cable should have a sensor in the plug to detect this - but another plug/socket further back will not. That's also why extension leads should not be used for EV charging, plus many extension leads are only rated for 10A or less even when fully unwound.
There are no situations where a DIY electrical installation can be completed and then 'signed off' by an electrician afterwards.

That space in the front of the consumer unit at #4 needs to be filled with a suitable blank module, as there are live parts inside.

 

[shd1970]

Many problems:
Cable can't be directly installed in a wall cavity, as will very likely be damaged by hidden sharp edges of bricks, mortar, wall ties and all the other junk in there.
T&E is not suitable for connecting to a plug.
The existing RCD is a type AC, which is not suitable for loads that could create DC faults.
Normal sockets are not designed for continuous high loads for hours at a time, as they can overheat. The charger cable should have a sensor in the plug to detect this - but another plug/socket further back will not. That's also why extension leads should not be used for EV charging, plus many extension leads are only rated for 10A or less even when fully unwound.
There are no situations where a DIY electrical installation can be completed and then 'signed off' by an electrician afterwards.

That space in the front of the consumer unit at #4 needs to be filled with a suitable blank module, as there are live parts inside.

flameport - thanks for the advice and taking the time to reply, much appreciated !

So from what i have described above, would that type of solution only be suitable for an outside socket (except for the cable type mentioned), and to be used for a lawnmower, vacuum etc ? (ie. short usage)

Regarding your other valuable points :

1. The use of the cavity, is that a strict "no, not allowed" even if its only for 6 feet to get from floor to ceiling and could be guaranteed not to be damaged otherwise, its unsightly trunking outside, or fit somewhere where it can be drilled straight into house ?
2. Regarding the feed to the socket, should it have its own direct feed straight back to the CU then and if so, what rating of cable would be required please ?
3. Regarding the RCD being AC, that's past my knowledge levels now

So what would that mean in the scheme of what i'm trying to achieve, namely, can you confirm the most cost effective way of having an outdoor socket for use to charge my car sporadically please ?
I'll definitely be getting a spark in now but would like to know in advance to get my head around it

I've sorted the blank module btw....the cover had fell off !

thanks again

 

[oldbutnotdead]

Interesting combination of devices in your consumer unit....
Given your car charges at 13A, the usual deal would be to spur off from the nearest socket inside the house, drill through the wall (20mm hole sloping down to outside), put your external socket over the end of the hole, placcy conduit, cable (2.5mm t & e), done.
Your socket circuits all have 32A MCBs on them so probably ring final circuits, you need to ensure that the socket you spur from is not already a spur (2 bits of T & E is no guarantee). You don't have to have an FCU between the internal RFC and external socket but for many reasons it's a good idea to have a double pole isolator on a feed to outside, an FCU with DP isolation won't hurt.
The above job, by the way, is not notifiable (as in you would not be breaking any laws or regulations by doing it yourself).
RCD issue is more problematic. Others (or maybe even the car charger instruction book) will tell you what type you need, if you can find one of that type to fit your CU then again you are permitted to do that yourself BUT that new RCD needs testing to ensure it actually works properly- for that bit you need a lot of test gear, best bet is pay an electrician to supply fit and test that bit.

 

[shd1970]

Interesting combination of devices in your consumer unit....
Given your car charges at 13A, the usual deal would be to spur off from the nearest socket inside the house, drill through the wall (20mm hole sloping down to outside), put your external socket over the end of the hole, placcy conduit, cable (2.5mm t & e), done.
Your socket circuits all have 32A MCBs on them so probably ring final circuits, you need to ensure that the socket you spur from is not already a spur (2 bits of T & E is no guarantee). You don't have to have an FCU between the internal RFC and external socket but for many reasons it's a good idea to have a double pole isolator on a feed to outside, an FCU with DP isolation won't hurt.
The above job, by the way, is not notifiable (as in you would not be breaking any laws or regulations by doing it yourself).
RCD issue is more problematic. Others (or maybe even the car charger instruction book) will tell you what type you need, if you can find one of that type to fit your CU then again you are permitted to do that yourself BUT that new RCD needs testing to ensure it actually works properly- for that bit you need a lot of test gear, best bet is pay an electrician to supply fit and test that bit.

thanks obnd for the reply

So.....
one of these.... https://www.screwfix.com/p/british-...dp-weatherproof-outdoor-switched-socket/67928
to one of these.... https://www.screwfix.com/p/mk-logic-plus-13a-switched-fused-spur-flex-outlet-white/13479
joined with a bit of 2.5mm T&E and then spur off the closest socket that isn't already a spur and i'm good ?
Regarding the RCD, even if i install the above, is there still a possibility of DC faults then ?

I have no plans to tinker with the CU personally but i'll have a dig around in the car manual ('21 plate Skoda Octavia PHEV estate) and see if i can find anything mentioning the RCD
Time to get a spark in i reckon

Do you have a thought on how large a job this is please ?
Couple of hours max ?

thanks again for your input

 

[333rocky333]

I recall the socket needs to be for EV charging and should be marked as such, I believe this was an amendment in the 18th regs, the one in your link is a standard 13a socket.
Though unsure if this only applies to sockets built into a charging point and to be honest i have not seen any for sale.

"Regulation 722.55. 101.0. 201.1 of BS 7671:2018+A1:2020, requires each AC charging point to incorporate a socket-outlet complying with BS 1363-2, to be marked 'EV' on its rear. BS 1363-2 requires EV marked socket-outlets used for charging electric vehicles to be subjected to additional testing requirements."

 

[oldbutnotdead]

You don't need a flex outlet on the fcu, do make sure it's double pole switched.
Interesting comment from @333rocky333 , just had a look at dedicated EV sockets- price is a bit scarey. Check the car manual carefully, look for 'can be safely charged connected to a standard UK 13a socket' or something like, if it says that then you're good to go.
If you've got the tools ( SDS drill with a stop on it, 500mm x 20mm drill, chisel to recess the backbox internally) then yes, couple of hours.
Don't forget a bit of conduit through the hole in the wall to protect the cable and a tube of silicon to seal both ends of the hole round the conduit (don't want draughts in the wall cavity).
DC faults- not a clue.

 

[JohnD]

I didn't know you could charge a PHEV with a 13A plug.

That makes life much easier if you drive to visit someone who does not have a charging point.

 

[ericmark]

I honestly don't know what is inside this however this I have found data sheets for, the "Built-In 16A 30mA Type B RCBO" is rather misleading, as it is curve B type A and the instructions say "For the installation to conform to IET requirements, the appropriate RCD should be selected by the electrician and fitted at the incoming source." which begs the question why bother fitting a RCBO if whole unit needs to be supplied from a type B RCD in the consumer unit?

But the major problem with EV charging is the earthing arrangement, and as said I don't know what is in this but with a TT or TN-S installation our only worry is the RCD, but with a TN-C-S (PME) we also have the earth problem, with a TN-C-S fault conditions can result in 230 volt being connected to earth connection, but in the home like the bird sitting on the power cables it is not too much of a problem as all bonded items are also at same voltage to true earth.

So as long as you put your car inside your house no problem, i.e. if charged in your integral garage. But charged outside when surrounded by true earth, this is very different. With garden equipment we use class II which means no earth connected, this option is not open to us for car charging.

So the 7 kW chargers use two methods, one is a small earth rod, and if the voltage at the earth rod does not match the supply earth voltage it disconnects including the earth, and two is voltage and if voltage not within range 207 - 253 again it disconnects, in both cases it fails safe (we hope).

But as far as I am aware this is not done with 2.3 kW supplies, unless in this unit. Loss of PEN as it is called which causes the problem is not too common,

According to HSE statistics (table 1), each year there are around 400 reported incidents of broken Protective Earth and Neutral (PEN) conductors on TN-C-S (PME) earthed electrical installations with around 10% of these causing an electric shock.

it also shows a diagram.

The problem is it is only with TN-C-S supplies that this is a problem, so there is nothing to stop charging points being sold for TT and TN-S supplies, and to charge once in a blue moon, one would need to be very unlucky to have a loss of PEN at same time as you are charging the car.

But on a regular basis the risks increase, and even then the chance of some one walking up your drive at back of house, and touching your car at the same time as PEN is lost is slim, but park at front of house and we have postman, milkman etc, and park on road any tom dick or harry can touch your car. But in all cases also you may touch it.

There is also the protecting of the car its self, surges can damage electrical equipment specially where semi-conductors are connected direct to mains supply, the socket shown has space for a surge protection device to protect your car, as to if required depends if one already fitted and where you live.

So for myself with both a rear and front drive to the house, to fit one of these at rear of house to charge a visitors car and also power the leaf blower, lawn mower, hedge cutter, and chain saw is reasonable, even with a TN-C-S supply. Most visitors would come to front of house, so even left on charge over night, risk is low. And if I build a garage and put a TN-C-S supply to garage and charge in the garage no problem. But since I have the room and the car can be charged well over the 2.7 meters required for fire protection I can make the socket TT so no problem at all.

Why we need 2.7 meters to a caravan but people can park a car right next to house, or even inside the house I have never worked out? Or why with a caravan, boat or petrol station a TN-C-S supply is banned, but we can have it to charge a car again not worked out?

I know at work our twin 22 kW charge point is TT, even when building is TN-C-S, but with three phase ensuring there is automatic disconnection with loss of PEN is much easier.

I suspect sooner or latter there will be a death due to loss of PEN with EV charging, and we will get a knee jerk reaction banning some charge points. Likely find we need planning permission in the future and the related costs.

Out of interest would like to know what is inside this at £170 clearly more than a simple lead.

 

[winston1]

Don’t put a FCU in line with your outdoor socket. The charging lead will have a fuse in its plug. If you want internal isolation use a double pole switch. The problem with a FCU is if will be operating at full load for a long time and get hot.

 

[shd1970]

Thanks for all the replies and input
The car manual is pretty light on useful information but i've attached a bunch of photos of the actual charger supplied with the car for use when charging via a 3 pin socket
There's plenty of numbers and other stuff mentioned that may be of interest and make more sense to you guys being more educated than myself in the land of electrics !

 

[shd1970]

I didn't know you could charge a PHEV with a 13A plug.

That makes life much easier if you drive to visit someone who does not have a charging point.

Check out my photos recently attached John
I've added some photos of the 3 pin lead that comes with the car
There is also a fatter lead for when charging off a proper wall box

 

[shd1970]

I honestly don't know what is inside this View attachment 252034 however this View attachment 252035 I have found data sheets for, the "Built-In 16A 30mA Type B RCBO" is rather misleading, as it is curve B type A and the instructions say "For the installation to conform to IET requirements, the appropriate RCD should be selected by the electrician and fitted at the incoming source." which begs the question why bother fitting a RCBO if whole unit needs to be supplied from a type B RCD in the consumer unit?

But the major problem with EV charging is the earthing arrangement, and as said I don't know what is in this View attachment 252034 but with a TT or TN-S installation our only worry is the RCD, but with a TN-C-S (PME) we also have the earth problem, with a TN-C-S fault conditions can result in 230 volt being connected to earth connection, but in the home like the bird sitting on the power cables it is not too much of a problem as all bonded items are also at same voltage to true earth.

So as long as you put your car inside your house no problem, i.e. if charged in your integral garage. But charged outside when surrounded by true earth, this is very different. With garden equipment we use class II which means no earth connected, this option is not open to us for car charging.

So the 7 kW chargers use two methods, one is a small earth rod, and if the voltage at the earth rod does not match the supply earth voltage it disconnects including the earth, and two is voltage and if voltage not within range 207 - 253 again it disconnects, in both cases it fails safe (we hope).

But as far as I am aware this is not done with 2.3 kW supplies, unless in this View attachment 252034 unit. Loss of PEN as it is called which causes the problem is not too common, it also shows a diagram.

The problem is it is only with TN-C-S supplies that this is a problem, so there is nothing to stop charging points being sold for TT and TN-S supplies, and to charge once in a blue moon, one would need to be very unlucky to have a loss of PEN at same time as you are charging the car.

But on a regular basis the risks increase, and even then the chance of some one walking up your drive at back of house, and touching your car at the same time as PEN is lost is slim, but park at front of house and we have postman, milkman etc, and park on road any tom dick or harry can touch your car. But in all cases also you may touch it.

There is also the protecting of the car its self, surges can damage electrical equipment specially where semi-conductors are connected direct to mains supply, the socket shown View attachment 252035 has space for a surge protection device View attachment 252041 to protect your car, as to if required depends if one already fitted and where you live.

So for myself with both a rear and front drive to the house, to fit one of these View attachment 252035 at rear of house to charge a visitors car and also power the leaf blower, lawn mower, hedge cutter, and chain saw is reasonable, even with a TN-C-S supply. Most visitors would come to front of house, so even left on charge over night, risk is low. And if I build a garage and put a TN-C-S supply to garage and charge in the garage no problem. But since I have the room and the car can be charged well over the 2.7 meters required for fire protection I can make the socket TT so no problem at all.

Why we need 2.7 meters to a caravan but people can park a car right next to house, or even inside the house I have never worked out? Or why with a caravan, boat or petrol station a TN-C-S supply is banned, but we can have it to charge a car again not worked out?

I know at work our twin 22 kW charge point is TT, even when building is TN-C-S, but with three phase ensuring there is automatic disconnection with loss of PEN is much easier.

I suspect sooner or latter there will be a death due to loss of PEN with EV charging, and we will get a knee jerk reaction banning some charge points. Likely find we need planning permission in the future and the related costs.

Out of interest would like to know what is inside this View attachment 252034 at £170 clearly more than a simple lead.

ericmark...wow, thanks for the mega reply but i have to say, you lost me VERY early on !

i've added some photos of the supplied charging cable so not sure if anything there clarifies anything more for you

 

[ericmark]

This video tries to explain

but the we get reports in trade mags

Clause 722.411.4.1 does allow for protection to be built into the EV charge point, but this protection has often been referred to as the “Unicorn device” – some people claim to have seen one but it’s generally thought to be a myth!

and as an electrical engineer I am not sure if the box built into your lead protects you (or any one else who touches your car) or not.

But I have not been trained to fit EV charging points, so as long as the EV charging point is fitted by some one trained I would assume they will insure it is safe, but it is not a DIY job.

 

[RandomGrinch]

As @flameport suggested in post #2,
The 3 core + 2 mains cable suggests monitoring is going on in the plug itself.

Also interesting to me... Is the plug only rated at 10A?