EV Charger Installation - Cabling Query?

[pirate]

I applaud your approach here hyeung, but more so the fact that from your first pic it seems you have an impossibly tidy garage...please tell me that you simply shifted a load of sh*t out of the way before taking the photo...

 

[hyeung]

I applaud your approach here hyeung, but more so the fact that from your first pic it seems you have an impossibly tidy garage...please tell me that you simply shifted a load of sh*t out of the way before taking the photo...

Hahah the garage is "sorta" tidy, but only becos I've managed to stack things up on one side of the garage. The other side I use to park the car. In that photo I had to move all the sh*t to the other side.....so they could install the cabling/trunking and the charge unit.

I don't think i'm getting anywhere with this.
I don't understand why others are able to have their unit in the garage and charge inside and out...with the earth rod setup. Am I missing something? Is my installer just trying to put me off and keep what I've got.
I've emailed the Manufacturer to also confirm use-cases for both inside and outside charging.

Wish I knew all this before the install, as i'd ended up not getting the EO unit; and probably got something that didn't have any earth rod requirements i.e. Zappi or more pricy Andersen.

 

[MJPD29]

It amazes me how messy the meter installs are in mainland, how could anyone be please with them

 

[HappyHippyDad]

Hahah the garage is "sorta" tidy, but only becos I've managed to stack things up on one side of the garage. The other side I use to park the car. In that photo I had to move all the sh*t to the other side.....so they could install the cabling/trunking and the charge unit.

I don't think i'm getting anywhere with this.
I don't understand why others are able to have their unit in the garage and charge inside and out...with the earth rod setup. Am I missing something? Is my installer just trying to put me off and keep what I've got.
I've emailed the Manufacturer to also confirm use-cases for both inside and outside charging.

Wish I knew all this before the install, as i'd ended up not getting the EO unit; and probably got something that didn't have any earth rod requirements i.e. Zappi or more pricy Andersen.

I will never suggest someone goes against what the regulations state, especially a customer. However, I will refer you to my post #63. The facts from the report show that absolute worse case scenario (so in reality nowhere near this) you have a 1 in a million additional chance of risk of death or serious injury from using a car charger with PME earthing.
As a professional I have to say don’t use it outside, but if you decide to you have the risk explained above.

 

[hyeung]

I will never suggest someone goes against what the regulations state, especially a customer. However, I will refer you to my post #63. The facts from the report show that absolute worse case scenario (so in reality nowhere near this) you have a 1 in a million additional chance of risk of death or serious injury from using a car charger with PME earthing.
As a professional I have to say don’t use it outside, but if you decide to you have the risk explained above.

Yeah I downloaded that pdf...intresting indeed.
Can I ask, if you had TT earthing which makes it fine for outside. Can you not use this inside? What is the issue with that?

The odds/risk are so low, but never the less I wouldn't personally risk it - PME outside charge? Would you? Its more the thought that you are putting others at risk. With young kids in the family enough said...

 

[JK-Electrical]

Regulation 722.411.4.1 unequivocally and unambiguously states that: "a PME earthing facility shall not be used as the means of earthing for the protective conductor contact of a charging point located outdoors OR that might reasonably be expected to be used to charge a vehicle located outdoors ..... ". Ergo it is self-evident that the EV charger which has been installed adjacent to the entrance of the OP's garage could be reasonably expected to be used to charge a vehicle located outdoors. All the OP need do to create this very scenario would be to park his/her car outwith the garage then connect the charging lead between his/her car and the charging point. Quod erat demonstrandum.

The OP stated in a previous post that he/she contacted the installer who advised him/her:

If you wish to use your charger to charge the car outside then regulations state the use of a TT earth is required, if the charge point is to be used inside then connection to your house earth is recommended

Whether or not the OP has any intention of charging his/her car outdoors is irrelevant. No provision has been made in regulation 722.411.4.1 for consideration of customers' wishes. What is of relevance, however, is that the regulation has not been complied with and has been breached by virtue of the fact that the installer has installed the charging point in a location where the point might reasonably be expected to be used to charge a vehicle parked outdoors. Quod erat demonstrandum.

The installer should have been aware of the inherent risks involved and acted accordingly by connecting an earth rod to the charging point therefore making this dedicated circuit a TT arrangement. The crucial point that I am making here is that locating an EV charging point indoors does not negate the need for an earth rod to be connected to the charger. That a charging point installed indoors can be used to charge a vehicle located outdoors necessitates a TT arrangement.

Subject to conditions (i), (ii) and (iii) of regulation 722.411.4.1 being satisfied, connection of an earth rod to a T-N-CS arrangement is permitted. However, we can immediately eliminate two of these conditions as plausible options. Since the OP's charging point is connected to a single-phase supply, condition (i) does not apply here. Given that it would be next to impossible to achieve the ultra-low Ra value that would be required to ensure that an open-circuit fault in the PEN conductor supplying the installation does not exceed 70 volts rms, condition (ii) is a non-starter. But condition (iii) can be satisfied by installing a charger that does not require connection to an earth rod. The Pod Point Solo is one such charger.

While regulation 722.413.1.2 permits the use of a fixed isolating transformer that complies to BS EN 61558-2-4 as a means of providing electrical separation for one electric vehicle supplied from one unearthed source, Mr. Smith and Mrs. Jones are not going to incurr an additional cost of several hundreds of pounds for an isolating transformer to be installed in their meter cupboard, assuming they had the physical space to accommodate the bulky transformer there in the first place.

So ultimately there were but two realistic choices open to whoever installed the OP's charging point: either install a charger that does not require connection to an earth rod, or install at least one earth rod to the charging point so forming a TT earthing arrangement for that dedicated circuit. Since the charging point that was installed in the OP's garage was not a model that would comply with the requirements of 722.411.4.1 condition (iii), the installer by default should have installed an earth rod and made the the earthing arrangement for that dedicated circuit TT. Quod erat demonstrandum.

​

John Ward has produced an excellent and most informative video regarding the earthing arrangements for electric vehicle charging equipment. The segment between 10:25 and 11:09 explains the TT arrangements for a dedicated EV charging circuit. What JW says here is what I have been saying throughout this thread. So if I am wrong, then so too is JW. Is there anyone here who would like to step up to the plate and call him out along with the author of two articles that were published in Connections in June 2018 and in Professional Electrician in November 2018?

The installer of the OP's charging point also advised him/her:

Looking back at the information you provided, you requested that the charge point be installed inside the garage and we have assumed that this would be for the purpose of charging inside, we will look to clarify this to all customers going forward.

The assumptions of the installer are inconsequential. The requirements of regulation 722.411.4.1 are unequivocal, unambiguous, and perfectly clear. Crystal is opaque by comparison. A PME earthing facility shall not be used as the means of earthing for the protective conductor contact of a charging point located outdoors OR that might reasonably be expected to be used to charge a vehicle located outdoors unless any one of the three conditions attached to that regulation can be satisfied.

The photographs below are of an install that I recently completed in the garage of a local car-hire company. The earthing system is T-N-CS. There was no need for any earth rods to be installed in this installation as all three charging points are located indoors and are located in such a manner that they could not ever be used to charge an electric vehicle located outdoors. If there had been even the slightest possibility of the client ever using any one of these chargers for outdoor charging, then rest assured that I would have connected each charger to an earth rod and undertaken a risk-assessment in accordance with section 6.8 of the Code of Practice for Electric Vehicle Charging Equipment Installation and attached a written risk-assessment document to the Electrical Installation Certificate.

​

The company who installed the OP's charger come across as being reasonable and approachable, The photos that the OP posted of the install indicate that it has generally been carried-out to a high standard. My advice to the OP, for what it;s worth, would be to ask the company to come back and carry-out a risk assessment with a view to converting the dedicated circuit for the charging point to a TT arrangement.

An alternative solution would be for the charging point to be replaced with a Pod Point Solo. However, given that the install was part-funded by grants from OLEV and the Energy Savings Trust, there would almost certainly be complications. But as things stand, the charging point in its present state cannot be left as it is because it does not comply.

I wish the OP well and trust that a satisfactory outcome will ensue. Please keep us posted of developments.

And on that note, I shall now exit stage left. I've stated my case and will make no further contribution to this thread.

 

[Wilko]

Very nice installation and nicely explained. Thanks JK. It does make me wonder if many of the chargers may have been unwittingly installed contrary to regs.

 

[hyeung]

Assuming one was to connect to a TT setup for that new EV circuit.
With regards to the risk-assessment in accordance with section 6.8 of the Code of Practice for Electric Vehicle Charging Equipment Installation....can I ask if there were any obvious issues shown in my recent photos of the garage area that would have highlighted a risk/problem?

Hence making this option of moving to a TT setup for the EV circuit not an applicable solution?

Apologies for my lack of understanding. But if there was the possibility of crossing PME earth with TT earth (ie TT setup indoor charger) Are my risk of hazard shocks still the same in the event of a supply fault (pen fault)?

 

[DPG]

You've got to feel sorry for customers in these cases when even we can't always agree what the right approach is with chargers.

 

[Midwest]

From @JK-Electrical quotes;

"a PME earthing facility shall not be used as the means of earthing for the protective conductor contact of a charging point located outdoors OR that might reasonably be expected to be used to charge a vehicle located outdoors ..... "

Would I be correct in thinking that most domestic garages fall into the remit of the latter?

 

[Wilko]

Apologies for my lack of understanding. But if there was the possibility of crossing PME earth with TT earth (ie TT setup indoor charger) Are my risk of hazard shocks still the same in the event of a supply fault (pen fault)?

Because your charger is located indoors (by the sounds) it needs to be the same earthing system as the house, which I understand is TNCS. But this is prohibited by regulation if the charger can be used outdoors.

Just thinking out loud - if the charger in the garage was TT but the nearby beer fridge was on a house circuit and the supplier lost neutral fault occurred, you’d have the fridge door handle at a high V and the car at zero V. This would present a significant shock hazard that your house RCD could not disconnect and the car / charger would nicely keep itself connected to E via the rod.

If your whole house, garage and charger were all TT and the same supplier lost N fault occurred then you would have no power, but you would be safe as N and E remain separated. Safe to get beer and touch the car .

 

[hyeung]

Thanks for confirming the hazards on the other way ie indoor charger TT earth setup, and where such supply fault occurs. Touch the car would cause shock hazard.

With that in mind I understand the risk assessment that was mention (section 6.8 code of practice of EV equip installs) would identify these possible hazards if they exist? Ie items in reach...
So with than in mind, my previous question asked was there anything obvious that one could see In the photos of the garage that posted previously that would highlight these types of issue? I appreciate this is not an assessment but just to help me understand if there was anything there that sprung to mind as an issue?

 

[HappyHippyDad]

Thanks for confirming the hazards on the other way ie indoor charger TT earth setup, and where such supply fault occurs. Touch the car would cause shock hazard.

With that in mind I understand the risk assessment that was mention (section 6.8 code of practice of EV equip installs) would identify these possible hazards if they exist? Ie items in reach...
So with than in mind, my previous question asked was there anything obvious that one could see In the photos of the garage that posted previously that would highlight these types of issue? I appreciate this is not an assessment but just to help me understand if there was anything there that sprung to mind as an issue?

Hyeung, some of the posts above have mentioned TT. There are 2 different forms of this involved in the case of an electric vehicle charging point (EVCP). The case which is mainly being discussed is connecting an earth rod to the actual EVCP. This would be acceptable and meets the regulations. However, the regulations do not always take in to account practicality. There is absolutely no way this method will work for you as you would not need just one little earth rod, you would need multiple deep earth rods littered all around your garden, perhaps dozens, it would cost a fortune and is not practical.

The other option is to TT the entire garage, this is what I shall be doing for a customer soon (although now I am actually tempted to leave it as PME and suggest an EVCP that is suitable). However, their garage is 20m from the house so there is no chance of coming into contact with anything connected to the PME earth (e.g water pipes, gas pipes). With this form of TT only one earth rod will probably be needed.

With both options I think it unlikely you would get indoor charging as you have stated you have gas pipes in the garage. These will be simultaneously touchable with the car, thus introducing a potentially dangerous voltage (in the event of PEN break, ie a break in the neutral coming into your house).

The last option is to TT your whole house, you could then charge the car in or out of the garage without worry. However, this is really a step backwards with the earthing safety of your whole house as a PME earthing system is far better than a TT.

Realistically your options are as follows, if you want to meet the regulations and avoid the one in a million additional risk.

1. Change EVCP for one that can be used with PME.
2. Ask company to move EVCP further into garage so it cannot be used outside.

 

[pirate]

I have a diesel car for sale...very economical, and can be "recharged" at thousands of points all over the world, in a matter of minutes, and each charge will take you about 500 miles.
Just saying...

 

[DPG]

I have a diesel car for sale...very economical, and can be "recharged" at thousands of points all over the world, in a matter of minutes, and each charge will take you about 500 miles.
Just saying...

It's the future.

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