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Discussion Starter #1
I've been doing some reading and having watched John Ward's excellent video on this topic, I have come to notice that my EV charger has no earth rod.

Apparently this would be in violation of the OLEV grant regulations as the IEC code of practice for EV charging is supposed to be followed.

Is this a substantial issue - justifying contact with the supplier to get them to install it?

The installers were very quick to install the equipment, less than an hour and a half. I guess they make their money by not wasting time.

No faults with the charger at this time, just aware of the potential liability headache in the case of an electric shock due to open neutral. Very unlikely, but a possibility.
 

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No faults with the charger at this time, just aware of the potential liability headache in the case of an electric shock due to open neutral. Very unlikely, but a possibility.
Think you'll find that the vast majority of installs have not had them done and I would hesitate a guess that it is because the risk is so minimal, nobody cares in the slightest.

A possible approach I would take would be to wait until the first recorded case of a death from being electrocuted by a charge point.
  • In the unfortunate event that you are that first person, whilst it will be a bit of an inconvenience, very soon after the event you won't really care too much about it.
  • If you aren't that person, you can think about sorting out yours when the scandal hits the press.
 

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It's not up to the end user to judge the conformance of an installation carried out by an electrician with proper qualifications and certifications.

I would have thought any liability for incorrect installation lies solely with the installer.
 

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When was it installed? If this year it must have DC fault protection too (type B RCD).

Do you know what earthing arrangement you have? Chances are it should have a spike installed.

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Discussion Starter #6
It was installed November 2018.

I believe it's TN-C-S earthing, as the earth comes off the main input fuse.

My biggest concern isn't my person. I am an engineer and would be aware of the risks of an open neutral and take steps to isolate the supply should this occur. The concern is that my car is parked on my drive which is abutting a public footpath, and it would be very easy for someone to touch my car while it was charging.
 

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The earthing requirements for an EV charge point on TN-C-S changed when the 18th edition came into force - 1st Jan 2019. As your install was designed & installed prior to this, the installer was within their rights not to make it a TT island as they were working to the regulations in force at that time. As it was only 2 months ago, there's certainly no harm in raising this with the installer to see if they come back to alter the install, but I doubt they will do so willingly.

As long as something is installed in accordance to the regulations in force at the time, there is no reason for it to be condemmed purely on the basis it does not meet the current regulations.

*Edit* - Just looking back at my 17th Edition book - Whilst it said PME earthing for EV charging shall not be used, it does have a disclaimer that the regulation need not be applied for charging points at a dwelling if the 3 countermeasures are not resonably practicable.
This clause was taken out of the 18th Edition we are working to today.

If you want to get it "up to code", then any local electrician should be able to bang in an earth stake or two, test it to ensure it's under 200 ohms and make the install "up-to-date".
 

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Is some PME more susceptible to open neutral than others, are new housing estates fed on a ring system?

I guess having an earth spike eliminates all the risks that are associated with PME installations.
 

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I wouldn't know what the stats are regarding suseptability or likelyhood of such a fault. Im sure someone working for a DNO would have a better idea. From what I have seen of the concentric 3 core aly cable supplying my workshop with 3-phase (PME) the Neutral sheath looks robust and would take a lot of mechanical damage to compromise it.
 

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I wouldn't know what the stats are regarding suseptability or likelyhood of such a fault. Im sure someone working for a DNO would have a better idea. From what I have seen of the concentric 3 core aly cable supplying my workshop with 3-phase (PME) the Neutral sheath looks robust and would take a lot of mechanical damage to compromise it.
I've seen a JCB make short work of armoured cabling, went through the whole thing in one go and melted a bit of the bucket, think it was very HV though as it was in the middle of a field.:D
 

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The earthing requirements for an EV charge point on TN-C-S changed when the 18th edition came into force - 1st Jan 2019. As your install was designed & installed prior to this, the installer was within their rights not to make it a TT island as they were working to the regulations in force at that time. As it was only 2 months ago, there's certainly no harm in raising this with the installer to see if they come back to alter the install, but I doubt they will do so willingly.
If this was an OLEV-supported install, that's not true. As part of the OLEV paperwork, the installer has to sign a declaration that it meets the IET Code of Practice for EV Charging Equipment Installation, and that does not permit the use of PME earth without earth rods.

*Edit* - Just looking back at my 17th Edition book - Whilst it said PME earthing for EV charging shall not be used, it does have a disclaimer that the regulation need not be applied for charging points at a dwelling if the 3 countermeasures are not resonably practicable.
This clause was taken out of the 18th Edition we are working to today.
The CoP then expands on what "reasonably practicable" means, and concludes that you can always do something by way of 722.411.4.1 option (ii) even if you can't meet the 70V limit, so doing nothing at all is not reasonable.


There are cases where an installation without earth rods is legitimate - where the supply is guaranteed to be TN-S, or the chargepoint can only be used indoors. Plenty of installers are in fact following the rules.


Otherwise, this is a comparable situation to buying a car where the specification includes (say) airbags, the dealer gives you a certificate saying the car meets that specification, but when you find that there's no airbag installed they say "oh, airbags aren't legally required on all cars until next year, so we didn't bother to fit yours".
 

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First thing you need to ascertain is whether its actually TN-C-S/PME or TN-S.

The earth coming out of the service head is not an indicator. My supply is TN-S, and the split-concentric supply cable is terminated into the head, and the head has its own dedicated earth terminal, just as it would on TN-C-S....

On a TN-C-S install the only difference would be the presence of a link between the N and E terminals, something you cannot see without removing the cover.
 

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The only way to know for sure if it's PME is to test it at the supplier's cutout. I'm a bit concerned where you say it took the installers 'an hour and a half' to install the unit, whereby on average it takes me half a day!

Like has previously been said, the risk of a broken PEN conductor is minuscule but possible. The risks do increase though if you have say metal railings, gates etc near the car and the sort of ground it's on. This is a MUCH discussed topic and it doesn't just apply to EVSE. I won't start talking about hot tubs lol.

If it's easy enough to get an earth rod in the ground near to the garage then I would get your local electrician to do it. Otherwise I wouldn't lose sleep over it. The installation was carried out to the 17th edition and the connection to PME supplies was permitted if an earth rod was not 'reasonably practicable to install'. However since January this year the 18th edition wiring regs prohibit the use of PME earthing to charge points entirely in dwellings.
 

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It was installed November 2018.

I believe it's TN-C-S earthing, as the earth comes off the main input fuse.

My biggest concern isn't my person. I am an engineer and would be aware of the risks of an open neutral and take steps to isolate the supply should this occur. The concern is that my car is parked on my drive which is abutting a public footpath, and it would be very easy for someone to touch my car while it was charging.
I don’t know, but I would be surprised if the car bodywork was connected to neutral and/or earth, it would seem more logical and safer to me for the AC supply into the car and the associated rectifier and transformer to be isolated and built to double insulation standards (a larger version of the shaver socket in your bathroom). For the bodywork to become live, you would have to have several very low probability faults occurring simultaneously.

The most vulnerable component, which is protected by the Earth rod and/or other safety measures, I suspect is the charging cable itself.
 

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I don’t know, but I would be surprised if the car bodywork was connected to neutral and/or earth, it would seem more logical and safer to me for the AC supply into the car and the associated rectifier and transformer to be isolated and built to double insulation standards (a larger version of the shaver socket in your bathroom). For the bodywork to become live, you would have to have several very low probability faults occurring simultaneously.

The most vulnerable component, which is protected by the Earth rod and/or other safety measures, I suspect is the charging cable itself.
You're right, and to add to that car tyres have enough conductivity (from their carbon black content) to be fairy confident that the RCD would trip from the current imbalance anyway.

Cable faults in the charging lead are probably the most likely failure point, or a failure within one of the connectors. Charge cables have a pretty tough life, being used frequently, getting rolled up, twisted, maybe driven over and even left partially coiled up when charging (anyone remember the old public safety films that used to be shown warning not to ever run power through a coiled cable?).

Realistically, the chance of a fault developing such that the car bodywork became live, long enough to cause someone an electric shock before the RCD trips, has to be way down in the list of likely scenarios. Unlike pretty much any other outdoor item of equipment, a charge point has a fair degree of inherent protection against a charge cable of connector fault, in that the DP contactor can only operate to make the charge cable live if some very specific conditions are met.
 

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You're right, and to add to that car tyres have enough conductivity (from their carbon black content) to be fairy confident that the RCD would trip from the current imbalance anyway.

Cable faults in the charging lead are probably the most likely failure point, or a failure within one of the connectors. Charge cables have a pretty tough life, being used frequently, getting rolled up, twisted, maybe driven over and even left partially coiled up when charging (anyone remember the old public safety films that used to be shown warning not to ever run power through a coiled cable?).

Realistically, the chance of a fault developing such that the car bodywork became live, long enough to cause someone an electric shock before the RCD trips, has to be way down in the list of likely scenarios. Unlike pretty much any other outdoor item of equipment, a charge point has a fair degree of inherent protection against a charge cable of connector fault, in that the DP contactor can only operate to make the charge cable live if some very specific conditions are met.
You are missing the point here. In a TNCS system where there is a Neutral fault outside the property the RCD becomes useless - current is balanced because neutral is connected to earth on the suppliers side of the meter.

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That's not the point I was addressing, I was just generally addressing the specific point raised in the post I quoted regarding the probability of the vehicle metalwork becoming live and endangering life, nothing more.

How probable is it that there is an undetected PEN fault outside the property? Taking our incomer as an example, we have a pot joint to an underground cable about 2m below out meter box. That pot joint (like all of them I've seen in recent years) has a standard copper strip intermediate earth run out and along the trench for a short distance. Additionally, there's another intermediate earth plate at the base of a pole around 20m away. For our TN-C-S supply any PEN fault that might cause an RCD not to trip, if there was another fault downstream of it, could only occur on the 2m section of concentric that runs up to the box. Even if that PEN failed, there are also other paths to earth via bonding that would have a low enough impedance to ensure that the RCD tripped.
 

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Discussion Starter #18
I don’t know, but I would be surprised if the car bodywork was connected to neutral and/or earth, it would seem more logical and safer to me for the AC supply into the car and the associated rectifier and transformer to be isolated and built to double insulation standards (a larger version of the shaver socket in your bathroom). For the bodywork to become live, you would have to have several very low probability faults occurring simultaneously.
I was curious about this and assumed the car bodywork was not earthed. However, I have metered it out, and it is bonded directly to earth from the pin of the Type 2 connector, as is the -ve of the 12V battery (which is commonplace). I would imagine this is industry standard and makes the car a Class I earthed appliance.

Whether the paint provides a sufficient layer of insulation for someone brushing up against the car I don't know. However you still have wheels and parts like the exhaust, that will also be earthed.

The big issue with bonded earth-neutral is if the neutral fails somewhere - substation or on an overhead line - the car would effectively become live (neutral would rise to the same potential as live, as would earth.) An earthed person (on wet ground for instance) touching the car could then receive a fatal electric shock. It takes only 30mA to fibrillate the heart. Could be a hazard for pets as well.
 

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I've been doing some reading and having watched John Ward's excellent video on this topic, I have come to notice that my EV charger has no earth rod.
My installation is the same - no earth rod that I can see, and the charger is on the outside wall near the corner of the house on the driveway very close to ground where an earthing rod could be installed. I don't know what kind of earthing system I have in the house though and am not sure how to check either. Mine was installed around September 2017 with both OLEV and Scottish EST government grants.

I don’t know, but I would be surprised if the car bodywork was connected to neutral and/or earth, it would seem more logical and safer to me for the AC supply into the car and the associated rectifier and transformer to be isolated and built to double insulation standards (a larger version of the shaver socket in your bathroom).
It would seem logical but I don't think it's the case.

The DC high voltage system in an EV is fully isolated from the chassis and 12v system of the car for safety reasons, however I'm pretty sure that the Earth of the AC input on EV's does go to the chassis of the car - you've got me wondering now so I will be testing my Ion on the weekend to see if this is actually the case...
 

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I think asking the internet on these things is like... it's similar to when you have a cough or something and everything points to "OMG cancer"

Unless something is really obviously dangerous and they're blatant cowboys, I'd just trust the experts, that's what we pay them a not-insignificant amount of money for :)
 
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