Speak EV - Electric Car Forums banner
1 - 20 of 55 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter · #1 ·
Hello - I know there's a lot of 'my zoe won't charge' threads on here but as someone who knows absolutely zero about domestic electrics I've found some bits hard to follow and wanted to explain our situation to see if anyone has any advice.

We bought a 2013 Zoe about 5 months ago, got a rolec charger installed and it all worked fine for two weeks, then we started to get the occasional 'battery charging impossible' message for a couple of weeks and a flashing red and blue light on the nose, then it refused to charge at all. Still charges fine at public charge points but not at home. The charger installation company came back and tried about 6 different chargers, none of them would work so they concluded it was an earthing issue - We've got an old farmhouse with pretty old electrics which is apparently built on solid rock. They tried to replace our dodgy wobbly earth rod but couldn't drill down. They arranged for the power company (Western power) to make a PME connection but when they visited they said it wasn't possible for our property. We've today had an electrician fit two earth rods, he really struggled to get them in but got there in the end but the lowest he could get the earth impedance was 234 ohms - I understand that this is still too high for the Zoe and sure enough it still doesn't want to charge.

Is there anything else I can try? I'm holding out hope as it did work for the first couple of weeks we had it! We're looking at selling the car - which is a shame as we really like it - and buying an alternative, are we likely to have this issue with other non-Renault cars?

Sorry for my rubbish explanation, I wish I understood the house electrics better but I really do need everything explained like I'm 5... any advice gratefully received!
 

·
Registered
Joined
·
6,738 Posts
I'd suggest looking at a PodPoint which does not require an earth rod. This is on their website Why Pod Point homechargers do not require an earth rod | Pod Point (pod-point.com)

Don't think this will have any effect at all, as the Zoe measure the earth loop impedance during initialisation of the charge and if this is excessive then it fails to charge.

The solution is probably to look at installing a better earth electrode system, and my advice would be to see if you can fit a Condudisc, set into a shallow hole on the bedrock, perhaps with some conductive concrete around it to improve the local conductivity a bit further.

Rod electrodes are never a good idea on rock, anyway. A mat type electrode would have been my first choice before conductive concrete came out, and might still be an option. A mat will pretty much always get down well below 200 ohms, even in the most demanding conditions (it's what the telecoms companies and DNOs use much of the time).

Ra needs to be below 150 ohms for the Zoe to be happy, I was told.
 

·
Registered
Renault Zoe Intens Q210 22kw 2013
Joined
·
761 Posts
may sound silly but you know where the lowest you can get is 234 ohms have you tried or will you try getting your garden hose and absolutely drenching the area with water where your man placed the earth rod(s) - might be worth a go?
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #7 ·
may sound silly but you know where the lowest you can get is 234 ohms have you tried or will you try getting your garden hose and absolutely drenching the area with water where your man placed the earth rod(s) - might be worth a go?
I have tried this and unfortunately it didn't work, thank you for the suggestions though - I feel like I've tried every random trick I could find on the internet to get the car to charge, now I've resorted to just begging it.
 

·
Registered
Renault Zoe Intens Q210 22kw 2013
Joined
·
761 Posts
I have tried this and unfortunately it didn't work, thank you for the suggestions though - I feel like I've tried every random trick I could find on the internet to get the car to charge, now I've resorted to just begging it.
have you got a obdII Can adaptor at all? - i wondered what earth impedance CanZE reports on your car as it charges?
 

·
Registered
Joined
·
6,738 Posts
I have tried this and unfortunately it didn't work, thank you for the suggestions though - I feel like I've tried every random trick I could find on the internet to get the car to charge, now I've resorted to just begging it.

I can pretty much guarantee that installing a mat electrode, or, perhaps, a Condudisc electrode set in conductive concrete, will fix your charging problem, and, very much more importantly, improve the safety of your electrical installation.

Although the maximum Ra allowable in the regs is 1,667 ohms, the maximum recommended value in the On Site Guide to the regs is only 200 ohms. Getting below 200 ohms is a good thing, in terms of being confident that Ra will always be at a safe level through very dry conditions.
 

·
Registered
Joined
·
6,738 Posts
have you got a obdII Can adaptor at all? - i wondered what earth impedance CanZE reports on your car as it charges?

Very similar to the value of Ra quoted, I expect, as the Zoe uses exactly the same earth loop impedance measurement technique as most MFTs. I had a play around when my wife got hers, just out of curiosity, and the pulses where it's making the measurement are easy to see.
 

·
Registered
Joined
·
6,738 Posts
Does it charge at public chargers ? These earthing issues are ridiculous. Pod point do not require earth rods and is only £500 installed after grant......

It's nothing at all to do with the charge point, and anyway this is a TT installation, so it's obviously not connected to charge point protection in any way. The issue is solely because the earth loop impedance measured by the Zoe during initialisation is too high, and actually it's too high as far as the usual guidance on interpretation of BS7671:2018 is concerned, too.

To be clear, this is not a fault with the car, nor is it a fault with the charge point, it is an intrinsic problem relating to the high value of Ra in the electrical installation. To fix it just needs some attention paid to getting a decent earth electrode installed, given that conversion to TN-C-S is not an option (presumably because the DNO can't get Ze down below 0.35 ohms at the incomer).
 

·
Registered
Renault Zoe Intens Q210 22kw 2013
Joined
·
761 Posts
I wish there was a setting in DDT to change the threshold of OHMs setting for the ZOE (if there is I haven't found it - only found COSPHI whatever that does ) I know that its most probably could potentially jeopardise the earthing system of the zoe if you adjusted the acceptable figure and possibly cause a electrocution hazard but the Zoe does seem a bit ridiculous with its earthing requirements compared to other EV earthing requirements
 

·
Registered
40kW Leaf Tekna & 22kW Zoë Q210 dynamique intens
Joined
·
743 Posts
Does it charge at public chargers ? These earthing issues are ridiculous. Pod point do not require earth rods and is only £500 installed after grant......
It’s not the requirements of the pod point that’s the issue Zoe’s check the earth loop impedance and if it’s not low enough they refuse to charge.
 

·
Registered
Joined
·
6,738 Posts
Surely this should have been picked up when the charger was installed ?

Once again, it is nothing at all to do with the charge point, in any way shape or form. This is a TT electrical installation that happens to have a value of Ra that is a bit high, and in excess of the earth loop impedance safety check limit that the Zoe does during charge initialisation.
 

·
Registered
Hyundai Ioniq Electric Premium SE 2018 Black
Joined
·
130 Posts
I just got a Ohme chargepoint installed, no earth rod. Forgot what the earthing type is called for this property, but wondering if it will pose a problem for a Zoe later down the line when my wife gets a Zoe? Works fine for my Ioniq.
 

·
Registered
Renault Zoe Intens Q210 22kw 2013
Joined
·
761 Posts
I just got a Ohme chargepoint installed, no earth rod. Forgot what the earthing type is called for this property, but wondering if it will pose a problem for a Zoe later down the line when my wife gets a Zoe? Works fine for my Ioniq.
more than likely a earth system return to the sub station on the Neutral wire - PME system or TN-C-S i think it called in the UK especially in newer property
 

·
Registered
Joined
·
6,738 Posts
I just got a Ohme chargepoint installed, no earth rod. Forgot what the earthing type is called for this property, but wondering if it will pose a problem for a Zoe later down the line when my wife gets a Zoe? Works fine for my Ioniq.

Yet again, this has nothing at all to do with the charge point. It's a completely unrelated issue that is specific to the Renault Zoe when the electrical installation that it is connected to is TT and has a high value of Ra. For any non-TT installation the earth loop impedance will always be massively lower than the 150 ohm limit that Renault use. For example, for a TN-C-S installation the loop impedance will be less than 0.35 ohms, for a TN-S system it will always be under 0.8 ohms.
 

·
Registered
Joined
·
6,738 Posts
Hello - I know there's a lot of 'my zoe won't charge' threads on here but as someone who knows absolutely zero about domestic electrics I've found some bits hard to follow and wanted to explain our situation to see if anyone has any advice.

We bought a 2013 Zoe about 5 months ago, got a rolec charger installed and it all worked fine for two weeks, then we started to get the occasional 'battery charging impossible' message for a couple of weeks and a flashing red and blue light on the nose, then it refused to charge at all. Still charges fine at public charge points but not at home. The charger installation company came back and tried about 6 different chargers, none of them would work so they concluded it was an earthing issue - We've got an old farmhouse with pretty old electrics which is apparently built on solid rock. They tried to replace our dodgy wobbly earth rod but couldn't drill down. They arranged for the power company (Western power) to make a PME connection but when they visited they said it wasn't possible for our property. We've today had an electrician fit two earth rods, he really struggled to get them in but got there in the end but the lowest he could get the earth impedance was 234 ohms - I understand that this is still too high for the Zoe and sure enough it still doesn't want to charge.

Is there anything else I can try? I'm holding out hope as it did work for the first couple of weeks we had it! We're looking at selling the car - which is a shame as we really like it - and buying an alternative, are we likely to have this issue with other non-Renault cars?

Sorry for my rubbish explanation, I wish I understood the house electrics better but I really do need everything explained like I'm 5... any advice gratefully received!

I'm starting again with a proper reply, as there's a bit of deflection above into wholly unrelated stuff about charge points.

First off, I'm pretty sure that your problem can be resolved, hopefully without too much expense.

The problem you have is a pretty simple one on the face of it, you have a TT electrical installation, where the earth is provided locally on your side of the installation, rather than imported from the Distribution Network Operator's (DNO's) side. The Renault Zoe has a very useful safety feature, in that it checks this earth every time it tries to start a charge. In your case, your local earth is not good enough to pass the test the Zoe does, nor is it good enough to comply with the guidance to applying the wiring regulations.

The minimum acceptable value of Ra, the resistance of the earth electrode, is generally taken to be 200 ohms (from the On Site Guide to BS7671:2018). However, the Zoe is made for a wider market than just the UK, and so it uses a lower safe limit of 150 ohms. Your installation seems to have a value of Ra of 234 ohms, which is what is causing the Zoe to refuse to charge.

You've already asked the DNO/supplier to see if you're installation can be reconfigured as Protective Multiple Earth (PME), also known as TN-C-S, but they can't do this. My guess is that this is because to do this they need to ensure that the earth loop impedance, Ze, measured at your incoming supply, does not exceed 0.35 ohms. If you are on a long supply cable there is a good chance that Ze will be higher than this, and by law (specifically the ESQCR, Electricity Safety, Quality and Continuity Regulations) the DNO cannot convert your supply to TN-C-S if this is the case.

That leaves you with the problem of trying to get the value of Ra down below the Zoe threshold of 150 ohms. It sounds as if you have shallow soil over hard rock, which does create problems when trying to use a rod type earth electrode. They rarely ever work well in these conditions, but there are a couple of earth electrode solutions that do work OK in these circumstances. Which you choose depends very much on the space you have available, the amount of disruption you can tolerate, as well as the overall cost.

First choice would be to see if you can bury an earth mat, ideally right on top of the underlying rock. They are a bit more expensive than a rod, but are a DIY proposition when it comes to the main work involved in installing one. Expect to pay around £70 or so for one, like this: Earth Mat – lattice copper – Churchill Specialist Contracting Ideally it wants to be as deep as you can get it, within reason, but a couple of feet down and in close contact with underlying rock will probably be OK.

Second choice is more costly, but may be better suited if the underlying rock is very shallow, and that is to use either a buried Condudisc electrode (like this: ConduDisc - Earthing Services ) or to use their conductive concrete, perhaps both if the conditions are really poor. You can also combine the use of conductive concrete with a copper lattice grid, perhaps a better solution if the underlying rock is irregular, as it allows the copper lattice to be in more intimate contact with the rock, via the conductive concrete.

Is there any chance of some photos of where the earth rods are, please? I might be able to refine the suggestions above knowing what the ground is like and how much space you have. The good news bit is that improving the earth is generally a good thing to do anyway, especially given that it really needs to be under 200 ohms.
 
1 - 20 of 55 Posts
Top