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Discuss EV Charger Installation - Cabling Query? in the Electric Vehicles Advice Forum area at ElectriciansForums.net

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Hi,

We had a EV charger installed recently over the past day ie 32amp 7.2kw. In the fuse cupboard I’ve attached before and after photos.
I have a 100amp fuse for the house.

For the new EV board setup, should the 2 grey cables entering the EV board (10mm) be the same 25mm thickness as the other cables?

Would this cause any issues for me? Or is this against certain electrical standards?
Someone mentioned to me if I was to change the meter or DNO were to action any new improvements, that I’d have to get these 10mm cables changed before any work would be carried out in the future?

I have yet to settle on the work, so if there’s non standard work complete here due to this, I would be in a position to highlight and query the relevant electrical company. I would appreciate any advise?

Please excuse, as my knowledge in electrical stuff is non existent. It maybe that all is looks fine, and I’ve been given wrong advise.

Regards,
HY

F5957AF5-7FE5-4D14-ACB2-378CC4193E39.jpeg

C7CC54DC-4E42-4463-A66E-C77983FB1518.jpeg
 
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  • Thread Starter Thread Starter
  • #3
The tails are ok.
Have you got an earth electrode outside connected to the charging point?
No I don’t believe there’s any earth electrode outside as the charge point is hosted internal inside our garage, where the garage is part of the house. I assume earth electrode is not applicable as my unit is installed internally?

I assume when you refer to the tails being ok, are referring to those 10mm cables going into the new EV board?

If all looks fine, and above board. I do wonder about the previous advise given in regards to having all cables set at 25mm to avoid future problems in meter changes or any dno type work?

Thanks,
HY

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bill01803

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Arms
There is no requirement for 25mm tails.
If the charging point could be used to charge a vehicle outside regulation 722.411.4.1 states that PME earthing facility must not be used, ie you must have an electrode
 
In this instance it would look like the garage door is very close to the charge point, so you would be able to plug in and move the car outside.
 
There is no requirement for 25mm tails.
If the charging point could be used to charge a vehicle outside regulation 722.411.4.1 states that PME earthing facility must not be used, ie you must have an electrode
You can use PME and the easiest way to do this is to use a charging unit that is made for use with PME.

The 2 other ways are either near enough impossible to satisfy or get very expensive.
 
  • Thread Starter Thread Starter
  • #7
There is no requirement for 25mm tails.
If the charging point could be used to charge a vehicle outside regulation 722.411.4.1 states that PME earthing facility must not be used, ie you must have an electrode
Thanks for your feedback.

Is there any truth in regards to if DNO were to action future works (upgrades) or change of meter (ie smart meter upgrade) that these 10mm tails would cause any probs? Ie DNO or provider refuse to carry out works due to these tails as a result of the recent EV charger install?

Thanks
 

JK-Electrical

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Judging from the photos you have posted, I can't see anything wrong with this install. Tails are fine, correct type of RCD.

Did the electrician give you an Electrical Installation Certificate in respect of the work? If so, what type of earthing system has the electrician listed on the certificate in respect of the charger? TN-C-S or TT? Could you post a close-up photo of the charger?

Was the install carried-out through the OLEV Homecharge Scheme?
 
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JK-Electrical

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Is there any truth in regards to if DNO were to action future works (upgrades) or change of meter (ie smart meter upgrade) that these 10mm tails would cause any probs?
None whatsoever.

Ie DNO or provider refuse to carry out works due to these tails as a result of the recent EV charger install?
The DNO should already know about this install as electrical contractors are obliged to inform the DNO whenever EV chargers have been added to an existing installation. Sometimes notification needs to be given in advance of the install.
 

Wilko

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Hi - 10mm is more than sufficient for the load, but I would not have used it. I would use 16mm minimum into a 100A fuse to ensure disconnection without heat damage in a fault, just saying.
 

davesparks

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Hi - 10mm is more than sufficient for the load, but I would not have used it. I would use 16mm minimum into a 100A fuse to ensure disconnection without heat damage in a fault, just saying.
Are you sure 10mm won't be adequately protected under fault conditions?
 

Wilko

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Are you sure 10mm won't be adequately protected under fault conditions?
Oops, foot in mouth time, I’ll have to check :) -

100A fuse needs 580A to clear in 5 sec and plugging that into adiabatic (from Reg 543.1.3) I get minimum size as 11mm. This would be unlikely to occur as it’d need Cmin and Ze max etc.

More likely could be 850A and 1 sec and that’s about 8mm, so all good.
 

Zdb

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I personally would have used 16mm L,N &E but as long as it's been calculated and it complies then it's all good.
 

pirate

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But for your suggestion, JK, I doubt he would have done so.
(Did you see what I did there? LOL!)


(Goes off to get a life...)
 
  • Thread Starter Thread Starter
  • #18
Judging from the photos you have posted, I can't see anything wrong with this install. Tails are fine, correct type of RCD.

Did the electrician give you an Electrical Installation Certificate in respect of the work? If so, what type of earthing system has the electrician listed on the certificate in respect of the charger? TN-C-S or TT? Could you post a close-up photo of the charger?

Was the install carried-out through the OLEV Homecharge Scheme?
Yes certificate details see attached.
Looks like its TN-C-S; Charger is EO Mini Pro.
Assuming from the certificate that the work conforms to Reg BS7671?
Apologies due to my lack of electrical knowledge, the last few posts regarding suitability of 10mm cabling didn't mean much? :)
But I assume the conclusion is that the 10mm cabling used (feeding the new ev board) is all good?

It's just that some "others" have specifically mentioned that tails need to be rated at 100AMP i.e. 25mm cabling; this was my initial concern?
So hence, I just wanted to clarify this?

Yes also, the charger unit has been installed next to the garage door, so yes I could still potentially charge the car outside with the cabling routed outside. But will mainly only charge inside tbh, which is why I have it installed inside the garage.

Regarding earth protection; the EO Mini Pro unit has a some DC Leakage Protection feature built-in; hence, am I right to assume its got earth protection in some ways?
i.e.
"Earth Leakage Protection
A dedicated 30mA Type A RCD must be used on the supply circuit Integral 6mA DC leakage detection – no Type B RCD required"

Cert1.jpg

Cert2.jpg

Cert3.jpg

EOMiniPro.jpg
 

happyhippydad

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Hi,

We had a EV charger installed recently over the past day ie 32amp 7.2kw. In the fuse cupboard I’ve attached before and after photos.
I have a 100amp fuse for the house.

For the new EV board setup, should the 2 grey cables entering the EV board (10mm) be the same 25mm thickness as the other cables?

Would this cause any issues for me? Or is this against certain electrical standards?
Someone mentioned to me if I was to change the meter or DNO were to action any new improvements, that I’d have to get these 10mm cables changed before any work would be carried out in the future?

I have yet to settle on the work, so if there’s non standard work complete here due to this, I would be in a position to highlight and query the relevant electrical company. I would appreciate any advise?

Please excuse, as my knowledge in electrical stuff is non existent. It maybe that all is looks fine, and I’ve been given wrong advise.

Regards,
HY

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View attachment 51232
As the others have said the 10mm tails are absolutely fine. They meet the existing regulations as the maximum demand they can ever be expected to need is 32A. They also meet the requirements for fault protection.

I realise you have mentioned a number of times that 'someone' has told you they need to be 25mm but they do not. They would need to be 25mm if they were supplying your main consumer unit (even then they may not need to be).

I would be more concerned with whether an earth rod has been installed for this install. The EO website makes no mention that their unit can be used with the earthing supply you have (i.e PME) and therefore you should have had an earth rod installed. In fact the following link by EO states clearly you should have an earth rod installed for use with their unit.

lastly, it's easy for us to make mistakes as we are not there. I would ask the electrician who installed it if he has installed an earth rod and if not then why? He would hopefully quote one of the 3 exceptions from BS7671 722.411.4.1 but I think this is unlikely.
 
  • Thread Starter Thread Starter
  • #22
As the others have said the 10mm tails are absolutely fine. They meet the existing regulations as the maximum demand they can ever be expected to need is 32A. They also meet the requirements for fault protection.

I realise you have mentioned a number of times that 'someone' has told you they need to be 25mm but they do not. They would need to be 25mm if they were supplying your main consumer unit (even then they may not need to be).

I would be more concerned with whether an earth rod has been installed for this install. The EO website makes no mention that their unit can be used with the earthing supply you have (i.e PME) and therefore you should have had an earth rod installed. In fact the following link by EO states clearly you should have an earth rod installed for use with their unit.

lastly, it's easy for us to make mistakes as we are not there. I would ask the electrician who installed it if he has installed an earth rod and if not then why? He would hopefully quote one of the 3 exceptions from BS7671 722.411.4.1 but I think this is unlikely.
I'm pretty certain there is no external earth rod installed for this.
As the unit has been installed for use internally; is this perhaps the reason why no earth rod was installed or required?
 

davesparks

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It's just that some "others" have specifically mentioned that tails need to be rated at 100AMP i.e. 25mm cabling; this was my initial concern?
So hence, I just wanted to clarify this?
Yes, lots of people get their regulations knowledge this way, by listening to 'others' who loudly proclaim their version or (mis) understanding of the rules as the truth.

There is a guide to the regulations which has a picture of a 'typical' domestic supply with 25mm tails feeding a single consumer unit which then supplies the whole installation. Many people fail to understand that this is just an example of a typical installation.
 
  • Thread Starter Thread Starter
  • #24
Yes, lots of people get their regulations knowledge this way, by listening to 'others' who loudly proclaim their version or (mis) understanding of the rules as the truth.

There is a guide to the regulations which has a picture of a 'typical' domestic supply with 25mm tails feeding a single consumer unit which then supplies the whole installation. Many people fail to understand that this is just an example of a typical installation.
This was one of the main reasons why I posted on here, as i'd be more confident in getting the truth than from others without an electrical background....and only knowing some knowledge which is rather dangerous. As I didn't know any better, thought this would be the best course of action.

However, it is interesting that a point was raised on the appropriate earthing? If my install was used outside, then I would no doubt want to ensure that a separate earthing rod was installed. As it is used internally, are we saying that we still need an earthing rod? or is that where the exception occurs which is why the installer did not quote or require this?
 

Paignton pete

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I'm pretty certain there is no external earth rod installed for this.
As the unit has been installed for use internally; is this perhaps the reason why no earth rod was installed or required?
Is it possible to charge the vehicle when it is parked outside? Will the charge lead reach? If so it must be TT

Or does the vehicle have to be parked fully in the garage for the lead to reach? If so pme is fine.
 
  • Thread Starter Thread Starter
  • #26
Is it possible to charge the vehicle when it is parked outside? Will the charge lead reach? If so it must be TT

Or does the vehicle have to be parked fully in the garage for the lead to reach? If so pme is fine.
Firstly, when I requested the install I obviously didnt know of these requirements on earthing etc.
I asked the installer that I wanted the charging unit internally within the garage and also stated on the given location of the unit. The unit sits next to the garage door from the inside.
When i use the charger i've always planned to use this internally - so car is fully parked inside.

However, to answer your question. It would be technically possible to charge the car outside provided that the car is reversed into the driveway and the garage door remains open.
I don't know if it would be possible to close the garage door and have the cabling routed outside to charge - as this might cause damage of the cabling?

Note that I don't actually have my car delivered yet, so I cant even charge it at this stage.
 

Paignton pete

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The whole instal looks to be to a very good standard. I think the installer has done well and despite my previous post I wouldn’t be too concerned.

I did the EV charge course and the one thing that seemed contradictory was the placement internally of a charge point. If it’s parked inside on a pme the charge point should be pme if it’s parked outside it should be TT.

What happens if it’s both as yours is?
In theory changing the whole of the installation to TT which is way over the top. I don’t like that solution at all.

For this reason and other points I won’t go into I don’t install these units until a better safety system has been designed and built into the units.
 
  • Thread Starter Thread Starter
  • #29
The whole instal looks to be to a very good standard. I think the installer has done well and despite my previous post I wouldn’t be too concerned.

I did the EV charge course and the one thing that seemed contradictory was the placement internally of a charge point. If it’s parked inside on a pme the charge point should be pme if it’s parked outside it should be TT.

What happens if it’s both as yours is?
In theory changing the whole of the installation to TT which is way over the top. I don’t like that solution at all.

For this reason and other points I won’t go into I don’t install these units until a better safety system has been designed and built into the units.
To be fair with the installer, it was me that stated that location. As the car charge port is located on the rear left side of the car. So naturally the best place was to have the charger where I've stated. As my car will be parked inside all of the time, this was the deciding factor of having the unit inside the garage.
But at the sametime, i thought the location I've picked gives me some flexibility if I wanted to use this to charge the car outside. However, at the time I was not aware of the earthing requirements until now. So unlikely to use it outside and remain to charge indoors.

Is there a large cost to install an earthing rod for this application?
Also, curiously what are the risks if the unit is using PME and one was to charge outside?

Thanks
 

davesparks

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Pete the whole install doesn't require TTing just the charging point in this instance.
But the charge point is inside, so it can't be connected to a different earthing system as the rest of the installation inside. You cannot mix two different earthing systems within one installation like this.
 

happyhippydad

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I'm pretty certain there is no external earth rod installed for this.
As the unit has been installed for use internally; is this perhaps the reason why no earth rod was installed or required?
This is a good point. Section 722 only says PME earthing shall not be used if the charge point is located externally OR if it is located internally and is used to charge a vehicle located outdoors.
If you only ever intend to charge the car in the garage then I guess this is ok.
I’d be interested in others thoughts on this?
 
I agree it's location is a bone of contention but then again wherever it's location like any other socket on a ground floor level it could be used out of doors.
 
  • Thread Starter Thread Starter
  • #33
This is a good point. Section 722 only says PME earthing shall not be used if the charge point is located externally OR if it is located internally and is used to charge a vehicle located outdoors.
If you only ever intend to charge the car in the garage then I guess this is ok.
I’d be interested in others thoughts on this?
Would like to know too now! Does it still mean charging the car outside from the inside unit is still a no-no?

Again, what are the risks in doing so?
 
  • Thread Starter Thread Starter
  • #34
I agree it's location is a bone of contention but then again wherever it's location like any other socket on a ground floor level it could be used out of doors.
I do this all the time, for the lawnmower....as I don't have an external socket - use an internal socket connected to an extension reel.
 

happyhippydad

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Would like to know too now! Does it still mean charging the car outside from the inside unit is still a no-no?

Again, what are the risks in doing so?
It does mean charging the vehicle outside is a 'no no'. I 'think' it also means the vehicle should not even be capable of being charged outside if PME is used.
Here is an article that you will find interesting and it explains the risks associated with using PME earthing.
 

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telectrix

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if the prohibition of PME for EV chargers is to eliminate risk if the supply N is lost (as with metalclad caravans) the I can't see any reason to differentiate between inside or outside. a fault occuring would have a similar result, in or out. then, i have not done any research on EV so my knowledge is limited.
 

davesparks

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This is a good point. Section 722 only says PME earthing shall not be used if the charge point is located externally OR if it is located internally and is used to charge a vehicle located outdoors.
If you only ever intend to charge the car in the garage then I guess this is ok.
I’d be interested in others thoughts on this?
I've never looked in any detail at the EV chargers regulations as ive never needed to yet. My thoughts are only based on my logic and what i've seen on the forum.

I assume the desire to connect the chargers to a TT earthing system relates to the car being connected to the installation earth whilst charging and thus becoming live during a PEN failure when connected to PME.
So if the car is inside then it becomes a big piece of exposed earthed metal whilst charging, so if it was connected to a TT system whilst the rest of the installation is connected to PME then the car would be an extraneous part to the installation introducing a dangerous earth potential.
 

Zdb

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As long as the installer made you aware that the car must only be charged inside then it's all good. Maybe a sticker stating this on the charger itself as a reminder would have been a good idea too.
 
But the charge point is inside, so it can't be connected to a different earthing system as the rest of the installation inside. You cannot mix two different earthing systems within one installation like this.
Ok so the whole installation would have to be TT for this particular set up to comply?
 
  • Thread Starter Thread Starter
  • #40
As long as the installer made you aware that the car must only be charged inside then it's all good. Maybe a sticker stating this on the charger itself as a reminder would have been a good idea too.
Actually, when the installation team of 2 were out here. I did query about the cabling size to see if there was any possibility in charging the car outside, with the garaged closed (concerned that the cabling would not accommodate?). Installer didn't say or point out this concern; instead is was actually suggesting that my cabling could potentially fit through the side gap in the garage to allow outside charging! So makes you wonder eh?
 

telectrix

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i fail to see any detriment in a PME system having a rod added as well. it's done as standard in some other countries, and round here a lot of older
TN-S systems also have a rod.
 
  • Thread Starter Thread Starter
  • #42
i fail to see any detriment in a PME system having a rod added as well. it's done as standard in some other countries, and round here a lot of older
TN-S systems also have a rod.
So I assume the rod is installed outside, under the ground? I assume simply a connection from this rod is routed and connected to the charging unit inside (replacing the earth of this unit from the PME). Is that right?
 

pirate

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My neighbour has an electric car. he parks it in the runway in front of his garage, and he brings the charging cable under the door from the garage and plugs it in to his car. There is no way he can ever get his car into the garage. Should I assume that he has an earth rod externally, because there is no evidence of such a thing. The outside parking court is a communal area, so if he has an earth rod, he needs consent from the other owners...not that anyone is likely to object, but you know how it is with awkward neighbours. Does the very fact that he parks outside, within 10' of the socket, make a difference?
 

JK-Electrical

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I've recently quoted for two jobs and in both instances none of the other people who quoted mentioned anything to the client about the possibility of an earth rod(s) having to be installed. I asked each client for details of the EV charging unit that was to be installed. All of the units listed would most certainly have required a rod(s). The earthing system for each of the two installations was T-N-CS.

So, either the clients weren't, for whatever reason(s), informed of the need for an earth rod(s), or the installers weren't planning on fitting any. I would be most alarmed indeed if it was the latter and hope that this isn't an ominous warning of corners being cut in order to produce competitive quotes that will win jobs. Alas, I fear it is, and that yet another race to the bottom has begun within the domestic market.

Those of us who are OLEV approved installers can obtain grants on behalf of clients under the Homecharge Scheme. The grant will cover up to 75% of the installation costs of an EV charger up to a maximum of £500. As this places non-approved installers at a huge disadvantage when competing for jobs, such installers must either reduce their profit margins in order to compete. One way to do so is to cut corners. The other would be to do the City & Guilds course at a cost £400+ and then join either SELECT or NICEIC as OLEV will not approve Scottish contractors who are not a member of either of these two trade bodies.

If an EV charger is to be installed on a T-N-CS system, not only is a rod(s) to be installed, but additional measures also need to be taken. For instance, any class I luminaires that are connected to the T-N-CS system and are located within simultaneous touching distance of the charger, the connection point and the vehicle under charge; would need to be replaced with class II fittings. Any extraneous conductive metalwork such a water or gas pipe would either need to be shielded in a non-conductive enclosure or converted to plastic piping. These arrangements are absolutely vital so to prevent simultaneous contact being made by a person between two different types of earthing systems. A risk-assessment needs to be undertaken. The written risk assessment document should be appended to the Electrical Installation Certificate. For clarity and reference, I have uploaded section 6.8 of the Code of Practice for Electric Vehicle Charging Equipment.

On the basis of what I have seen in the photographs that were uploaded by the OP, I conclude that an earth rod(s) should have been installed. Furthermore, there is no mention in the manufacturer's installation instructions for the EO Mini Pro that their product incorporates any in-built protection that would negate the need for an earth rod(s).

Although the OP has conceded in a previous post that it was him/her who advised the contractor to install the charger in the position that it now occupies, the contractor should nevertheless have been aware of the risks that would ensue from positioning the charging point in a place where it could be used to charge a vehicle located outdoors and should have advised the OP accordingly IMHO.
 

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happyhippydad

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So I assume the rod is installed outside, under the ground? I assume simply a connection from this rod is routed and connected to the charging unit inside (replacing the earth of this unit from the PME). Is that right?
Its probably best to put all these points to the electrician who installed it, they can then hopefully answer some of the questions.
If a rod does need to be installed it then needs to be connected at the right point in the installation (I.e. the small consumer unit housing the RCD and circuit breaker). The earth cable going into the small consumer unit would need to be removed otherwise you have 2 separate earthing systems together.
The earth cable needs to be the correct size and the earth rod needs obtain a suitable resistance value.
But... rather than getting bogged down with lots of differing views on this forum I would chat to the installing electrician. They seem to have done a neat job and have ticked all other required boxes (apart from one or 2 errors in the certificate), so put the questions to them now that you have a little more knowledge.
 

JK-Electrical

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I've never looked in any detail at the EV chargers regulations as ive never needed to yet. My thoughts are only based on my logic and what i've seen on the forum.

I assume the desire to connect the chargers to a TT earthing system relates to the car being connected to the installation earth whilst charging and thus becoming live during a PEN failure when connected to PME.
So if the car is inside then it becomes a big piece of exposed earthed metal whilst charging, so if it was connected to a TT system whilst the rest of the installation is connected to PME then the car would be an extraneous part to the installation introducing a dangerous earth potential.
Spot on Dave.
 

JK-Electrical

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If a rod does need to be installed it then needs to be connected at the right point in the installation (I.e. the small consumer unit housing the RCD and circuit breaker). The earth cable going into the small consumer unit would need to be removed otherwise you have 2 separate earthing systems
No! The rod is connected to the EV charger!! The CPC of the T&E would be insulated and parked at the charger end of the circuit, but connected to the MET at the supply side of the circuit. It's no different from the arrangement that would be used if you were installing a consumer unit in a garage via a TT system.
 

JK-Electrical

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Ok so the whole installation would have to be TT for this particular set up to comply?
No. The whole installation remains T-N-CS apart from the EV charging circuit. As the rod is connected to the EV charger only that one dedicated circuit becomes TT.
 

davesparks

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No. The whole installation remains T-N-CS apart from the EV charging circuit. As the rod is connected to the EV charger only that one dedicated circuit becomes TT.
No, the circuit does not become TT, the circuit is connected to the PME. It is only the charger which would be connected to the earth electrode, this creates some interesting issues to my mind.

But the problem with this as I stated earlier is that you cannot have the charger which is inside connected to its own earth rod because that makes it and the car an extraneous part to the PME connected installation.
The charging point and car in the garage is within the equipotential zone of the installation.
 

davesparks

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No! The rod is connected to the EV charger!! The CPC of the T&E would be insulated and parked at the charger end of the circuit, but connected to the MET at the supply side of the circuit. It's no different from the arrangement that would be used if you were installing a consumer unit in a garage via a TT system.
It is very different to installing a supply to an outbuilding, this unit is within the equipotential zone of the installation, not seperate from it.
 

davesparks

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If an EV charger is to be installed on a T-N-CS system, not only is a rod(s) to be installed, but additional measures also need to be taken. For instance, any class I luminaires that are connected to the T-N-CS system and are located within simultaneous touching distance of the charger, the connection point and the vehicle under charge; would need to be replaced with class II fittings. Any extraneous conductive metalwork such a water or gas pipe would either need to be shielded in a non-conductive enclosure or converted to plastic piping. These arrangements are absolutely vital so to prevent simultaneous contact being made by a person between two different types of earthing systems. A risk-assessment needs to be undertaken. The written risk assessment document should be appended to the Electrical Installation Certificate. For clarity and reference, I have uploaded section 6.8 of the Code of Practice for Electric Vehicle Charging Equipment.
These arrangements you suggest are laughable, changing lights to class 2? What happens when the light is replaced?
Shielding pipes in non-conductive material? How do you test this site applied insulation? Who will maintain it and ensure it remains in good order?

Let me guess, the solution to the problems is going to be some sort of label telling people what to do or not do? Again, pointless, nobody reads these labels.
 

davesparks

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As long as the installer made you aware that the car must only be charged inside then it's all good. Maybe a sticker stating this on the charger itself as a reminder would have been a good idea too.
Stickers are a pointless waste of time, they will not be read or taken notice of.
 

happyhippydad

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Stickers are a pointless waste of time, they will not be read or taken notice of.
Completely agree. I feel they are a way of making the installer feel more comfortable with themselves even though they have potentially left a dangerous situation.
I have just seen a garage CU fed by 1.5mm SWA. It has as 32A MCB in it to feed 3 double sockets on a radial. It has a sticker on each socket saying '6A only'!
 

JK-Electrical

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No, the circuit does not become TT, the circuit is connected to the PME. It is only the charger which would be connected to the earth electrode, this creates some interesting issues to my mind.

But the problem with this as I stated earlier is that you cannot have the charger which is inside connected to its own earth rod because that makes it and the car an extraneous part to the PME connected installation.
The charging point and car in the garage is within the equipotential zone of the installation.
Source:

https://professional-electrician.com/18th-edition/18th-edition-ev-charging

What do the Wiring Regulations say?

When opened to public comment, the draft revisions for section 722 came under intense scrutiny from the industry. In the final published document, the option to use a protective multiple earthing (PME) facility was reduced. PME is the most common form of earthing provided in new electrical installations.

There are ways that PME can be used, but these are often difficult to achieve. Therefore, most installations will rely on separation of the earthing system and making the EV a TT system (using an electrode in the ground).
 
I see your point davesparks.

The fact on this particular job then is

1 - Either make the whole system TT
2 - Install a charging unit suitable for PME
3 - Remove the garage

I do not agree with the sticker idea as this is a step backwards, if we cannot label a socket in the loft 'TV booster only' then a EV charger is out of the question.
 

JK-Electrical

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The attached scan is from section 5.3.3.3.1, page 32 of the Code of Practice for Electric Vehicle Charging Equipment Installation. The section heading is: Providing a TT earthing system for the charging equipment.
 

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JK-Electrical

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These arrangements you suggest are laughable, changing lights to class 2? What happens when the light is replaced?
These are not my suggestions, they are what I was taught on the City & Guilds course in EV charging that I did. I dare say that anyone else who has completed the course would have been taught the same.

If these 'suggestions' amuse you, why not e-mail Bill Allan of NAPIT and laugh loudly at him while you tell him that you know more about EV charging than he does. Meanwhile, kindly desist from trying to me appear foolish. Fair enough?

https://professional-electrician.com/18th-edition/changes-introduce-shock-risk
 

Paignton pete

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These are not my suggestions, they are what I was taught on the City & Guilds course in EV charging that I did. I dare say that anyone else who has completed the course would have been taught the same.

If these 'suggestions' amuse you, why not e-mail Bill Allan of NAPIT and laugh loudly at him while you tell him that you know more about EV charging than he does. Meanwhile, kindly desist from trying to me appear foolish. Fair enough?

https://professional-electrician.com/18th-edition/changes-introduce-shock-risk
I was also taught as you describe, and that is what we have to do in installing ev systems, but I think Dave sparks is also right ( maybe I wouldn’t go as far as to say laughable).

For these reasons I won’t fit EV charging points until the code of practice is sorted and an appropriate voltage potential device is invented and fitted in all ev chargers.
 

marconi

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Dear JK-Electrical, you have made a major contribution (#44) to this thread and are clearly installing EV professionally and strictly in accordance with the regulations - thank you and 10/10 Sir.

I did not read Davesparks' comments as directed at you and intended to make you look foolish; rather I interpreted his remarks as directed at the regulations and how they will perform in practical settings - a professional debate on the regulations then, some of the content of which he regards as 'foolish'. Not a great choice of word though IMHO - perhaps ill-thought out would be better said.

:)
M
 

happyhippydad

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I obtained a copy of the report mentioned in the wiring matters magazine article (linked in post #35) sometime ago.

It was an in depth study on the use of PME with regards electric vehicle charging points, authorised by the IET standards Ltd and carried out by the Health and safety Laboratory (HSL).

I have the full report in my emails if anyone wants a copy (I seem to be unable to save/copy it) or the 'results' part of the report is below. It does seem that the 'additional' risk of using PME for the EVCP is very, very low.
From the report below you can see that the 'additional' risk of death or serious injury (p/year) is 0.0000011 (this is 1 in a million). This is also the worst case scenario AND they state that the risk value calculated is likely to be significantly higher than reality, so this means the risk is likely to be far lower than 1 in a million (for example 1 in 10 million), meaning its highly, highly unlikely to pose an additional risk of death or serious injury.
 

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happyhippydad

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Thanks alot for putting this video clip up JK, it was very interesting and answered a few questions for me.
I see where you are coming from with regards connecting the earth rod to the charge point, you are referring to method (ii) of 722.411.4.1. You are basically adding a supplementary earth electrode rather than making the whole system TT.
 
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Hi,

Hmm i'm not sure where to start with all this. There appears to have been a lot of debate on the subject, and some of the discussions i'm not even entirely sure if I fully followed or not?

Please correct me if I'm wrong in my understanding.

1) The primarily use of the EVCharger will to charge the car whilst it is parked inside the garage. I wanted to confirm that, for this primary purpose am I correct to say that the current installation/setup is OK? So while the car is charging in the garage and in the event of a certain major fault conditions (PEN faults?), we would not be at ANY risk whilst inside, despite touching the car or anything metal in the surroundings (see uploaded photos).
And in this setup, we would not required an earthing rod for this primary use stated here?

2) The main issue that arises is when one decides to charge the car parked outside i.e. car is on the monoblock drive outside of the garage door, whilst connected to the internal EVCharger unit. Under this scenario, if a major fault condition (PEN fault) occurred, there would be a risk if one was touching the car and standing outside on the driveway? In this use-case scenario, one would require an earth rod installation to mitigate the above risk. Is that correct?

However, in situation where I do have an earth rod installed to accommodate use-case scenario (2). Does that mean I can no longer charge the car whilst inside the garage as per use-case (1) without risk?
If I get an earth rod installation, can it accommodate both scenarios of (1) and (2)?

I am not sure I fully understood the previous debates, but seemed to get the impression that if we had an earth rod setup it'll be fine to charge the car outside (scenario 2); but this then has a knock-on-effect as could cause similar risks if one is to charge the car inside the garage and a fault condition arises (PEN fault).
Is this correct?

It sounds like for the given EVCharger that we have, I can only either use this inside only or outside only; and not a mix. Again, correct me if i'm wrong as this is what I've picked up.
At the moment due to the installation setup, i'm only safe to use this when the car is charged inside.
If that is the case, that's fine I would opt to charge the car inside. Prior to the install I was never aware of this issue, no mention was made on the earth rod etc.

I assumed that one could use it charger both ways (inside and outside - provided you could get the cable out). If I have to choose, I'm happy to stick with using the charging inside the garage as this will be my primary use.

Btw, just to be clear i have posted some further pictures of the garage surrounds as it shows other items in there i.e. boiler, any gas pipework, garage opener, smoke alarms etc. In case its of any relevance to all this...

Just to add, the installation was only carried out on Friday. The company is approved for the OLEV scheme; and I also got an application for EST funding for this install.
I wish I knew about this issue, as I may have ended up picking a different charging unit that didn't require earth rod requirements.

I really appreciate everyone's input; and your patience.

Cheers,
HY

garage1.jpg

garage2.jpg

garage3.jpg
 

Paignton pete

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I think you’ve pretty much got it.

As for choosing a unit that wouldn’t need an earth rod. They don’t exist yet.

It states in ev code of practice you can install a voltage trip monitoring device, but they don’t exist and haven’t been invented yet.

This is one of the reasons I don’t fit EV yet even though I can as I’ve done the C&G course.
It’s not been thought through.
 

Paignton pete

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Photo didn’t work
Ev code of practice.
6.9 (iii) if a risk assesment shows that the risk of simultaneous contact between any accessible conductive parts connected to PME earth , and any extraneous or exposed conductive parts associated with outdoor vehicle charging equipment( including the connection point and the vehicle on charge) cannot be prevented, the adoption of a TT system for the whole installation can be considered.
 

happyhippydad

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Hi,

Hmm i'm not sure where to start with all this. There appears to have been a lot of debate on the subject, and some of the discussions i'm not even entirely sure if I fully followed or not?

Please correct me if I'm wrong in my understanding.

1) The primarily use of the EVCharger will to charge the car whilst it is parked inside the garage. I wanted to confirm that, for this primary purpose am I correct to say that the current installation/setup is OK? So while the car is charging in the garage and in the event of a certain major fault conditions (PEN faults?), we would not be at ANY risk whilst inside, despite touching the car or anything metal in the surroundings (see uploaded photos).
And in this setup, we would not required an earthing rod for this primary use stated here?

2) The main issue that arises is when one decides to charge the car parked outside i.e. car is on the monoblock drive outside of the garage door, whilst connected to the internal EVCharger unit. Under this scenario, if a major fault condition (PEN fault) occurred, there would be a risk if one was touching the car and standing outside on the driveway? In this use-case scenario, one would require an earth rod installation to mitigate the above risk. Is that correct?

However, in situation where I do have an earth rod installed to accommodate use-case scenario (2). Does that mean I can no longer charge the car whilst inside the garage as per use-case (1) without risk?
If I get an earth rod installation, can it accommodate both scenarios of (1) and (2)?

I am not sure I fully understood the previous debates, but seemed to get the impression that if we had an earth rod setup it'll be fine to charge the car outside (scenario 2); but this then has a knock-on-effect as could cause similar risks if one is to charge the car inside the garage and a fault condition arises (PEN fault).
Is this correct?

It sounds like for the given EVCharger that we have, I can only either use this inside only or outside only; and not a mix. Again, correct me if i'm wrong as this is what I've picked up.
At the moment due to the installation setup, i'm only safe to use this when the car is charged inside.
If that is the case, that's fine I would opt to charge the car inside. Prior to the install I was never aware of this issue, no mention was made on the earth rod etc.

I assumed that one could use it charger both ways (inside and outside - provided you could get the cable out). If I have to choose, I'm happy to stick with using the charging inside the garage as this will be my primary use.

Btw, just to be clear i have posted some further pictures of the garage surrounds as it shows other items in there i.e. boiler, any gas pipework, garage opener, smoke alarms etc. In case its of any relevance to all this...

Just to add, the installation was only carried out on Friday. The company is approved for the OLEV scheme; and I also got an application for EST funding for this install.
I wish I knew about this issue, as I may have ended up picking a different charging unit that didn't require earth rod requirements.

I really appreciate everyone's input; and your patience.

Cheers,
HY

View attachment 51253

View attachment 51254

View attachment 51255
I'll try and answer some of your points hyeung but I think the main answer is that electric vehicle charging points (EVCP) are fairly new and as such all the implications have not been thought through, so you may not get the simple 'yes/no' answers that you would like (as I would).

Point 1
The way I read it you should not even be able to charge the vehicle outside if it is PME, just having good intentions of always doing it inside is not good enough as at some point someone will do it outside, be it your self or the next owners.
However, if you do charge it inside then the risk will be far less (its kind of impossible to say negated as there is always some risk with electrics). This is assuming that your existing electrics are up to standard, in particular you have all the required Main bonding in your house or indeed bonding in the garage if required.

Point 2
Having an earth rod for the whole garage or perhaps just for the EVCP would seem to negate the effect of electric shock whilst outside as long as you cannot come into contact with any metal parts (whilst simultaneously touching the car) which are part of the PME system, exposed or extraneous.

As with point 2 it would still be ok to charge the vehicle indoors if you have an earth rod as long as you cannot come into simultaneous contact with any metal parts which are part of the PME system. (e.g. touching car and other metal part at the same time)

I would have thought a bit of investigation when installing these units would be undertaken to establish if any extraneous conductive parts are simultaneously touchable with the vehicle or charging point.
 
  • Thread Starter Thread Starter
  • #70
I'll try and answer some of your points hyeung but I think the main answer is that electric vehicle charging points (EVCP) are fairly new and as such all the implications have not been thought through, so you may not get the simple 'yes/no' answers that you would like (as I would).

Point 1
The way I read it you should not even be able to charge the vehicle outside if it is PME, just having good intentions of always doing it inside is not good enough as at some point someone will do it outside, be it your self or the next owners.
However, if you do charge it inside then the risk will be far less (its kind of impossible to say negated as there is always some risk with electrics). This is assuming that your existing electrics are up to standard, in particular you have all the required Main bonding in your house or indeed bonding in the garage if required.

Point 2
Having an earth rod for the whole garage or perhaps just for the EVCP would seem to negate the effect of electric shock whilst outside as long as you cannot come into contact with any metal parts (whilst simultaneously touching the car) which are part of the PME system, exposed or extraneous.

As with point 2 it would still be ok to charge the vehicle indoors if you have an earth rod as long as you cannot come into simultaneous contact with any metal parts which are part of the PME system. (e.g. touching car and other metal part at the same time)

I would have thought a bit of investigation when installing these units would be undertaken to establish if any extraneous conductive parts are simultaneously touchable with the vehicle or charging point.
I'll try and answer some of your points hyeung but I think the main answer is that electric vehicle charging points (EVCP) are fairly new and as such all the implications have not been thought through, so you may not get the simple 'yes/no' answers that you would like (as I would).

Point 1
The way I read it you should not even be able to charge the vehicle outside if it is PME, just having good intentions of always doing it inside is not good enough as at some point someone will do it outside, be it your self or the next owners.
However, if you do charge it inside then the risk will be far less (its kind of impossible to say negated as there is always some risk with electrics). This is assuming that your existing electrics are up to standard, in particular you have all the required Main bonding in your house or indeed bonding in the garage if required.

Point 2
Having an earth rod for the whole garage or perhaps just for the EVCP would seem to negate the effect of electric shock whilst outside as long as you cannot come into contact with any metal parts (whilst simultaneously touching the car) which are part of the PME system, exposed or extraneous.

As with point 2 it would still be ok to charge the vehicle indoors if you have an earth rod as long as you cannot come into simultaneous contact with any metal parts which are part of the PME system. (e.g. touching car and other metal part at the same time)

I would have thought a bit of investigation when installing these units would be undertaken to establish if any extraneous conductive parts are simultaneously touchable with the vehicle or charging point.
Hi,

So for point 1; sounds like I'm perfectly fine with indoor charging as it stands. I wasn't sure what you meant by bonding.

For point 2; assuming i had the earth rod setup, as per my recent uploaded photos. The only obvious metal areas that come to mind would probably be the gas pipe entering the wall towards to garage door and where that pipe comes down toward the boiler. The garage opener situated at the top; i imagine is using the house earth (PME), and not sure if that conducts with the garage door as such.

Looking at the gas pipe connection from outside coming in, it appears to be earthed.

It just sounds impratical if one has to shield all these areas? assuming I am correct on what i've highlighted?

You can give me your thoughts, but it sounds like alot hassle to accommodate this indoor charger for outdoor use; and as my primarily use is indoors, then i might as well just stick with that. I appreciate it doesn't negate things from a safety point of view as it does not stop some else using it in another way.
Not sure what to do!?
If i knew this, i would have consider a different unit that supports PME i.e. Zappi or the more expensive Andersen A2 units.

Is it still worth while querying the installer, on the use of this outdoors to see what they say? or just act unaware and mention I noticed that for the unit, there appears to be mention of a mandatory earth rod required for this given unit i.e. does this mean i can't use this outside etc?

Can I ask what the cost would be involve to get an earth rod installed? I assume the part is cheap but more of the labour? Sounds like i'm gonna get stung for additional labour costs to install? But as mentioned, if makes charging inside problematic then i'd be inclined not to do it?
Thoughts?

garage4.jpg
 

Midwest

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I've been reading these posts & links back and forth, and I 'm confused. Easily done.

After watching the vid, I think it suggest using a supplementary earth, connected to the MET of a TN-C-S supply. Why would TT'ing just the charger be an option, with the problems outlined?
 

happyhippydad

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It is all getting a bit confusing isn't it!
I know what i'd do in my own home but i'm afraid that would be irresponsible to say on a open forum!
Have a chat with the installer @hyeung and put a few of these points to them.
 

Midwest

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I've been reading these posts & links back and forth, and I 'm confused. Easily done.

After watching the vid, I think it suggest using a supplementary earth ROD, connected to the MET of a TN-C-S supply. Why would TT'ing just the charger be an option, with the problems outlined?
Missed that bit in my post :rolleyes:
 

Midwest

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When put into maths it requires a stupid low Ra value which cannot in reality be sustained.

That's my understanding?
But isn't that the case for all earth rods with ev chargers (don't they do an efli test), whether TT or supplementary earth rod?
 
I dont think the maths is the same.

When PME and using a supplementary earth rod it takes into account the max current of the installation and this is put into the equation which brings up a low Ra value.[/QUOTE]
 

Paignton pete

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When put into maths it requires a stupid low Ra value which cannot in reality be sustained.

That's my understanding?
Yes we did some calcs at college when we did the course. It was nigh on impossible. I think 3 earth rods 1 meter apart 2.4 meters deep might do it. Depending on resistivity of the earth.
So they have given us a solution to the problem that is pretty pointless.
 

Paignton pete

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I dont think the maths is the same.

When PME and using a supplementary earth rod it takes into account the max current of the installation and this is put into the equation which brings up a low Ra value.
[/QUOTE]
You don’t take the pme into account when doing the maths as the rods are there in case you loose the neutral, thus loose the pme.
 

Paignton pete

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The major point of TT for ev is in case of dropped neutral on supplier side.

That in itself is pretty rubbish that we have to prepare for faults that are nothing to do with our regs and are in the control of the DNO’s.

So we need to know that the earth rods being put in at the origin are adequate without the pme if the neutral is lost by DNO
 

davesparks

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These are not my suggestions, they are what I was taught on the City & Guilds course in EV charging that I did. I dare say that anyone else who has completed the course would have been taught the same.

If these 'suggestions' amuse you, why not e-mail Bill Allan of NAPIT and laugh loudly at him while you tell him that you know more about EV charging than he does. Meanwhile, kindly desist from trying to me appear foolish. Fair enough?

https://professional-electrician.com/18th-edition/changes-introduce-shock-risk
I don't claim to know more about EV charging than anyone. However is is obvious (hopefully) that introducing an extraneous earth potential into an installation then connecting it to a big piece of exposed metal (car) goes against the basic principles of protection against electric shock.

I am not trying to make you appear foolish, I have no need to do this. By suggesting that one can laugh loudly in an email you have achieved this appearance without my input.
 

davesparks

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if the prohibition of PME for EV chargers is to eliminate risk if the supply N is lost (as with metalclad caravans) the I can't see any reason to differentiate between inside or outside. a fault occuring would have a similar result, in or out. then, i have not done any research on EV so my knowledge is limited.
If the vehicle is inside then it is, technically, within the equipotential zone and becomes no different to any other exposed, earthed, metal in the building. The car being charged in the garage presents the same hazard as the class 1 freezer in the garage.
 
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