HappyHippyDad

~
Esteemed
Arms
Supporter
Dec 18, 2011
5,378
6,731
405,788
Gloucestershire
If you're a qualified, trainee, or retired electrician - Which country is it that your work will be / is / was aimed at?
United Kingdom
What type of forum member are you?
Practising Electrician (Qualified - Domestic or Commercial etc)
At some point I'm going to get asked to fit one of the above and I'd like to know a bit more about it from some people that have already fitted them.

I've had a look through section 722, am I right in thinking the following:

1. Has to be on a dedicated circuit?
2. Has to have Type A RCD protection.
3. PME cannot be used if the charging point is located outdoors, therefore has to be TT'd?

Are the charging points that you can buy universal for every electric car or do you have to fit one that is suited to the customers specific car?

Any recommendations for charging points?

Cheers :)
 
At some point I'm going to get asked to fit one of the above and I'd like to know a bit more about it from some people that have already fitted them.

I've had a look through section 722, am I right in thinking the following:

1. Has to be on a dedicated circuit?
2. Has to have Type A RCD protection.
3. PME cannot be used if the charging point is located outdoors, therefore has to be TT'd?

Are the charging points that you can buy universal for every electric car or do you have to fit one that is suited to the customers specific car?

Any recommendations for charging points?

Cheers :)
My advice is to either invest in GN7 or the IET guide to electrical vehicle charging units for further guidance other than section 722
 
Dedicated circuit yes when looking at single chargers in domestic or workplace settings(however you can have more than 1 charger on them when there is software to balance load etc across the chargers and no overload circuit).
Some chargers have integrated type a rcd protection so dont need to put it at the cu but others such as the ev:box elvi units need upfront type a rcd protection as the dc monitoring stuff inside isnt compliant in the uk. I use rolec type a rcbos as they are only £20 a pop.
Cant use pme for a charger outdoors. cant really use tns either as the dno wont commit to saying they wont upgrade in the near future. so always assume it will be pme.

all new uk evs should now be on a type 2 plug rather than the older type 1. with tethered chargers you can usually replace just the lead if the car changes. teslas are a bit different.

Worth knowing that the renault zoe electric car does a loop check and if the Zs/Ra is too high it wont charge. not sure of the figure but its quite low so when on a rod it often stops charging if say ground dries out... customers go a bit mad when they find out. it isnt always posible to get a sufficiently low enough reading from even 2 rods so Renault pulled a cracker on this one.
 
Dedicated circuit yes when looking at single chargers in domestic or workplace settings(however you can have more than 1 charger on them when there is software to balance load etc across the chargers and no overload circuit).
Some chargers have integrated type a rcd protection so dont need to put it at the cu but others such as the ev:box elvi units need upfront type a rcd protection as the dc monitoring stuff inside isnt compliant in the uk. I use rolec type a rcbos as they are only £20 a pop.
Cant use pme for a charger outdoors. cant really use tns either as the dno wont commit to saying they wont upgrade in the near future. so always assume it will be pme.

all new uk evs should now be on a type 2 plug rather than the older type 1. with tethered chargers you can usually replace just the lead if the car changes. teslas are a bit different.

Worth knowing that the renault zoe electric car does a loop check and if the Zs/Ra is too high it wont charge. not sure of the figure but its quite low so when on a rod it often stops charging if say ground dries out... customers go a bit mad when they find out. it isnt always posible to get a sufficiently low enough reading from even 2 rods so Renault pulled a cracker on this one.
Does the Renault Zoe onboard Efli testing equipment need calibration every year? Just a thought!
 
Another thing to bear in mind is that for a new install; if the customer is looking to claim the charger grant; you need to be a registered installer with OLEV.
 
  • Like
Reactions: Baddegg
I have been looking into this myself.

Im doing the C&G 2919-01 2day course next week which is required to register with OLEV.

Ill let you know how it goes.
Please do let me know how it goes Brendon, I'd be very interested.
How much does it cost?
 
I can’t seem to find a recent thread on car charging/PME supply, which had all the discussion about PME supply, so resurfaced this one (bet someone will find it now).

What makes of charges use a system that completely isolates the car from the supply?

Neighbours just got an electric car. So wanna be a smart arse before he has the charger installed.
[automerge]1582652298[/automerge]
I’ve just googled the vehicle. £72,000. Doesn’t include the charger, nor a sunroof. Perhaps it’s got PV on the roof?
 
Last edited:
At some point I'm going to get asked to fit one of the above and I'd like to know a bit more about it from some people that have already fitted them.

I've had a look through section 722, am I right in thinking the following:

1. Has to be on a dedicated circuit?
2. Has to have Type A RCD protection.
3. PME cannot be used if the charging point is located outdoors, therefore has to be TT'd?

Are the charging points that you can buy universal for every electric car or do you have to fit one that is suited to the customers specific car?

Any recommendations for charging points?

Cheers :)
As I am a tutor of EV charge points the correct answers are:
1.
[automerge]1585488167[/automerge]
As I am a tutor of EV charge points the correct answers are:
1. It is best to be a dedicated circuit so as not to make it a more difficult installation.
2. Yes you are right it must have a type "A" rcd.
3. If the charge point is in a garage that is attached to the building it does not need to be "tt'D" if it is not attached it then needs to be made into a "TT" system. The earthing is more detailed but I would need to know the installation in more detail.

Regards

[email protected]
 
Last edited by a moderator:
As I am a tutor of EV charge points the correct answers are:
1.
[automerge]1585488167[/automerge]
Did you mean to write more rather than just '1'?
I think possibly a tutor would have written an explanation for each of the 3 questions, not just written '1'. :D
 
Did you mean to write more rather than just '1'?
I think possibly a tutor would have written an explanation for each of the 3 questions, not just written '1'. :D

Think his reply is within the 'quote box', and I'm no expert but I don't agree with his answer for 3.
 
Did you mean to write more rather than just '1'?
I think possibly a tutor would have written an explanation for each of the 3 questions, not just written '1'. :D
read the next bit
[automerge]1585490793[/automerge]
Think his reply is within the 'quote box', and I'm no expert but I don't agree with his answer for 3.
yes your are right you are not an expert or even picking up that more information is required to give accurate and correct information.
 
read the next bit
[automerge]1585490793[/automerge]

yes your are right you are not an expert or even picking up that more information is required to give accurate and correct information.

Thats a bit harsh?

You said;

'If the charge point is in a garage that is attached to the building it does not need to be "tt'D" if it is not attached it then needs to be made into a "TT" system''.

Thats, if I recall, is not what is exactly said in Section 722.
 
read the next bit
[automerge]1585490793[/automerge]

yes your are right you are not an expert or even picking up that more information is required to give accurate and correct information.
When I was teaching Maths many moons ago I don't think I would have ever responded to a pupil like that. It would not have aided in their learning, it would just embarrass them and stop them from asking questions again.
Ps. Thankyou for taking the time to offer suggestions to my questions though.
 
  • Funny
Reactions: Midwest
My take on the answers are
1. Has to be on a dedicated circuit?

Not mandatory, but makes sense much more than any general circuit

2. Has to have Type A RCD protection.

Sort of! The output must be protected by type A - PLUS 6mA DC protection, (or type B as an alternative), often this is included within the charge point, so swa and mcb protection can be used on the supply to the charge point.


3. PME cannot be used if the charging point is located outdoors, therefore has to be TT'd?

In my opinion - yes, but the standards do allow the use of the pme earth if you utilise special devices to identify a lost pen/CNE; if these are within the charge point, then ok, although I don't believe they actually provide the protection needed for safety - but as the manufacturers have pressurised the committee to accept them, and it's in the spec (amd 1) then you could use them.
 
Last edited:
  • Informative
Reactions: HappyHippyDad
My neighbour had his car charger fitted this week (PME supply). As far as my nosey neighbour goggles tell me, there's no obvious signs of a rod. Can't quite make out the make of the box of tricks, but the stress is getting to me. Might just ask him outright. :)
 
  • Funny
Reactions: DPG
Thats a bit harsh?

You said;

'If the charge point is in a garage that is attached to the building it does not need to be "tt'D" if it is not attached it then needs to be made into a "TT" system''.

Thats, if I recall, is not what is exactly said in Section 722.
The 18th Edition amendment does say this. When i delivered the course 2 weeks ago this was discussed at length because when it is made into a "TT" system the swa if it is used, will have the armouring earthed at the domestic consumer unit but not attached as an earth at the EV charge unit. You then use the earth rod, if you are using one for an earth, for the EV charge point system in the garage. Also it must not be possible to simultaneously touch the house extraneous conductive parts and those of the garage as if they are at a different potential we all know what could happen.
[automerge]1585500698[/automerge]
I can’t seem to find a recent thread on car charging/PME supply, which had all the discussion about PME supply, so resurfaced this one (bet someone will find it now).

What makes of charges use a system that completely isolates the car from the supply?

Neighbours just got an electric car. So wanna be a smart arse before he has the charger installed.
[automerge]1582652298[/automerge]
I’ve just googled the vehicle. £72,000. Doesn’t include the charger, nor a sunroof. Perhaps it’s got PV on the roof?
Isolation from the supply can be achieved by using an isolation transformer. But it is still fed from the house originally. Or a PV array but the charging will take a lot longer.
[automerge]1585500827[/automerge]
When I was teaching Maths many moons ago I don't think I would have ever responded to a pupil like that. It would not have aided in their learning, it would just embarrass them and stop them from asking questions again.
Ps. Thankyou for taking the time to offer suggestions to my questions though.
no problem
 
Last edited by a moderator:
The 18th Edition amendment does say this. When i delivered the course 2 weeks ago this was discussed at length because when it is made into a "TT" system the swa if it is used, will have the armouring earthed at the domestic consumer unit but not attached as an earth at the EV charge unit. You then use the earth rod, if you are using one for an earth, for the EV charge point system in the garage. Also it must not be possible to simultaneously touch the house extraneous conductive parts and those of the garage as if they are at a different potential we all know what could happen.
[automerge]1585500698[/automerge]

Isolation from the supply can be achieved by using an isolation transformer. But it is still fed from the house originally. Or a PV array but the charging will take a lot longer.
[automerge]1585500827[/automerge]

no problem
But it does not mention ‘an attached garage’ or ‘not attached’.

It says (paraphrasing slightly),

‘PME earthing facility shall not be used as the means of earthing for the protective conductor contact of a car charging point located outdoors or that might be reasonably expected to be used to charge a vehicle located outdoors, unless one of the following methods is used;’ (722.411.4.1)

A subtle difference, do you not agree?

I‘ve not seen an isolating transformer for a car charger just yet.
 
Last edited:
  • Like
Reactions: DPG
But it does not mention ‘an attached garage’ or ‘not attached’.

It says (paraphrasing slightly),

‘PME earthing facility shall not be used as the means of earthing for the protective conductor contact of a car charging point located outdoors or that might be reasonably expected to be used to charge a vehicle located outdoors, unless one of the following methods is used;’ (722.411.4.1)

A subtle difference, do you not agree?

I‘ve not seen an isolating transformer for a car charger just yet.

I looked into the isolation transformer option some time ago, but the cost was ridiculous, a 230/230v 8kVA is around £853, it weighs around 75kg, and this is without an enclosure (or delivery)

This is from a standard manufacturer, I would expect you will be able to get a Chinese version on-line for around 1/2 of this, but with import duty etc, not sure how big a saving you could make.

the isolation transformer idea, sort of ok as an idea, but I think impractical in the real world for normal charge points.
 
  • Like
  • Agree
Reactions: Risteard and DPG
I’m far from being an expert, and have yet to fit an EV charger but from watching the discussions, regs and evolution of the technology... surely they have to be fitted according to manufacturer instructions?
 
I looked into the isolation transformer option some time ago, but the cost was ridiculous, a 230/230v 8kVA is around £853, it weighs around 75kg, and this is without an enclosure (or delivery)

This is from a standard manufacturer, I would expect you will be able to get a Chinese version on-line for around 1/2 of this, but with import duty etc, not sure how big a saving you could make.

the isolation transformer idea, sort of ok as an idea, but I think impractical in the real world for normal charge points.

Yes thats what I've read here before, may have been yourself.

There does seem to be a lack of clarity on this subject. I wonder if some of these training courses are fit for purpose, no aimed at you @Ed Evans.
 
i come on looking for help in installing one of these and now im even more confused!!!
 
  • Funny
Reactions: DPG
Watching that video just confirms what I thought, the earthing requirements in the Car charging Regs are An absolute crock and totally poorly thought out and impractical and until they come up with a solution for all chargers to be able to safely connect to PME then it’s just not safe to do it
 
Or a PV array but the charging will take a lot longer.
Especially at night, which for many people (current situation excepted) is when the car is at home rather than the office car park,
 
Especially at night, which for many people (current situation excepted) is when the car is at home rather than the office car park,
,

I have heard so many people say ‘why haven’t they thought of putting solar panels on top of the cars to power them, its so simple’

just got to laugh!
 
,

I have heard so many people say ‘why haven’t they thought of putting solar panels on top of the cars to power them, its so simple’

just got to laugh!

But the perfect solution for keeping batteries charged up during daylight hours. Car manufacturers really need to get this in place. Also it would reduce demand on the power supply infrastructure.
 
  • Like
Reactions: dodger421

Similar threads

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electric Underfloor Heating Electrician Courses Heating 2 Go Electrician Workwear Supplier
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

Advert

Daily, weekly or monthly email

Thread starter

HappyHippyDad

Esteemed
Arms
Supporter
~
Joined
Location
Gloucestershire
If you're a qualified, trainee, or retired electrician - Which country is it that your work will be / is / was aimed at?
United Kingdom
What type of forum member are you?
Practising Electrician (Qualified - Domestic or Commercial etc)

Thread Information

Title
Electrical car charging point installation
Prefix
N/A
Forum
Electric Vehicles Advice Forum
Start date
Last reply date
Replies
28

Advert

Thread statistics

Created
HappyHippyDad,
Last reply from
DPG,
Replies
28
Views
8,882

Advert