question

Hi David,

I'm not an electrician but I am an electronics and electrical engineer and have also self-installed a similar EV charger (a Wallbox Pulsar Plus 7.4kW) and am very familiar with the regulations and PEN fault issue you mention. In fact I chose the Pulsar Plus because it was one of the few options at that time which included PEN fault detection along with the MyEnergi Zappi. I know there are others available today.

Firstly, you worried me a bit when describing the EV charger as replacing an existing 13A double socket. I'm hoping you only mean in terms of position and not the electrics, because the EV charge station needs at least a 6mm radial feed and will need a type A RCD and 40A MCB (or both combined in a 40A type A RCBO) to protect it. Depending on the age of your 13A socket wiring it might only have a type AC RCD which is not suitable to protect an EV charge socket because any DC components on the earth leakage might "block" the responsiveness of the RCD device. That could lead to it not performing correctly in the event of a fault which could be dangerous. This is all before we even talk about the PEN fault detection.

As for PEN faults, these are only an issue on TN-C-S (PME) earthing so presumably you already have determined that your earthing is of this type? If so then yes you do need PEN fault protection and this can either be integral to the EV charger (as it is with the Pulsar Plus and maybe(?) the Victron unit) or you can install a separate unit such as the Matt:e device. I had a read of the Victron data sheet for the EV charge and I can't tell for certain if it has PEN fault detection. It does talk about the following:

• Detection for Relay Contact welded
• Detection for missing protective conductor
• Detection for missing Ground
• Detection for shorted CP

So maybe the second one is PEN fault detection but it's not 100% clear. They might be describing this feature in generic terms rather than using more typical UK specific wording. With Wallbox, they describe it as "Integrated PEN fault protection" not just "detection". Wallbox also include a DC 6mA RCD integrated but also need a type A MCB+RCD/RCBO in addition.

I think you are right to press Victron to reveal the precise extent of protection provided and if in doubt consult an electrician who specialises in this area. Another option you can consider is to convert the EV charge station in to a TT earth but that is a whole other can of worms and you should probably get specialist advice to do that properly.

HTH, let me know if you have any other questions.

There literature doesn't expressly say pen fault detection although they mention some standards and stick detection of missing ground in there, But they do say that it needs an RCD https://www.victronenergy.com/upload/documents/Datasheet-EV-Charging-Station-EN.pdf kinda need victron or distort to confirm this really as this is a key safety mech that all chargers need either in built or external via like a Matte device Looks like i was late to this party. @craigc is correct if its a 13Amp socket that you have replaced 2.5m cable is not suitable to handle a 40Amp load you would at least 6mm twin and earth clipped to a wall but your best off with SWA cable new connection to the fusebox purely for safety compared to the twin and earth. I'm only assuming its twin and earth based on the 13amp plug socket and only assuming its not a ring circuit.

Hi David,

If you already have a battery system installed working with your Victron charger this is ace!

You should already have an earth rod for your batteries in place so your EV charger will be earthed Via the rod and your distributors earthing arrangements which is in the new regulations now, to do both.

Next is you have to use a DP or switched natural as well and line (Live) 30ma TYPE A RCBO to supply your EV charger.

FuseBox 32A 6kA Double Pole Mini Compact RCBO - Type A - Curve C | ElectricalDirect

Also notify DNO soon as you can within 28 days

Single-Electric-Vehicle-Charge-Point-and-Heat-Pump-Installation-Application-Form.doc (live.com)

That’s all you need todo to meet the regs.

Hope this helps

Thank you @Craig Chamberlain et al. I did purposefully miss out wiring details, hoping for advice as to additonal PEN fault detection, etc. Given that the responses above indicate that doubt still remains regarding this, could @Guy Stewart (Victron Community Manager) possibly contribute and help here. The Victron charging station is not in the UK approved government list but that may well reflect its relative newness on the market. It seems to be an expensive but excellent piece of kit.

The feed to the previous 'double socket' is a dedicated armoured cable protected by a Wylex 30mA B curve type A RCBO put in place some time ago with this conversion in mind. (Every circuit in the house is protected by an RCBO. I was a strong convert to Earth Leakage Current devices, as they were called, over 40 years ago when they were installed in my then work environment, adjusted to 10mA leakage.)

The feed is 4mm2 as opposed to 6mm2, an economy I now regret. That said, is not a 4mm2 feed protected by a 32A RCBO OK for an (up to) 7kW device?

I am delaying contacting the DNO before clarifying these points. (The EV supply was switched off after install and remains off.) The house fuse is the usual 100A rating although the DNO at the time of install said they were going to fit a 60A fuse (another long story). In reality the batteries are charged overnight and during the day the house runs absolutely fine off grid from the 10000VA Mulitplus 2. Any EV charging would occur overnight. The batteries are also charged overnight (if there has been insufficent PV) but limited to around 1kW, so even then the max current drawn from the grid would be circa 40A.

Whilst my off grid battery set up is earthed by a series of interconnected earth rods arranged around the perimeter of the hut, the house ESS system is simply connected to the house earth, ie the incoming neutral/earth connector. Have I missed something here? Is an additional local earth required for house ESS? If so I have no idea how I achieve that. (A friend also has a house ESS (different manufacturer) recently installed in a new build. That definitely has no additional earth. In fact his house is in a rural location and the incoming supply meter and the only earth connection is located in a box at the boundary of his property approx 40m away from the house. All has been installed and approved by qualified electricians, but seemingly at odds to me with what you read about PEN faults.)

I would love to hear from Guy and also anyone who has had this charger installed and DNO notification by a fully qualified installer. Whilst not a qualified electrician (but I do have relevant qualifications) I have either fully wired, or extended, house wiring several times over the past forty or so years. They have always been tested and signed off by a suitably qualified person, but that route does seem to be getting progressively harder over time.

Thanks to all for your time and expertise, very much appreciated.

Regards,

David

@Craig Chamberlain yes you are correct that it has become standard practice for local earth the DNO doesn't want the responsibility for this anymore, that's why the new regs are talking about foundation earthing, now i wish i had the hindsight to throw a couple of rods in my extension foundation. Now I'm having to do a long run into the garden to get away from everything.

@assyntdavid

Right this is a mine field of a topic, So i done a dive into TNC-S with PME as that what mine is. And the issue is the neutral tired to earth bond that goes when the house is in island mode. The issue here is yes you can put an earth rod in the ground and make a TT system but its very hard to keep it a TT system looking at some of the requirements it has to be about 5meters plus from the incoming as to not feed connect to the grids earth again, next is that in the UK all under ground pipes should be bonded which means we've just done all that work and still got a TNC-S system also all metal pipes feed to neighbouring properties are also earthed which feeds back to you which keeps it a TNC-S system. PS it is essential that all metal pipes entering the property be bonded to earth for everyone in or outside that house coming into contact with metal pipes are safe.

Glad i replaced my last metal pipe with plastic so not tired to earth meaning i just need to keep away form the coming mains and any metal work. I see a lot of people are looking at the earth bonding relay but really don't see the point in this, yes the resistance is a lot lower on the DNO due to the PME but if the relay contacts get stuck you have a problem. I would rather sink 4 to 5 rods deep get a good earth obviously tested to make sure its within the 200ohms or better still 100ohms or lower.

Thanks @Craig Chamberlain

I can easily change the RCBO to type B - I had missed that. The fuse is already 100A so fine there. I get that the PEN fault situation would be an issue in 'island mode'. Not at all sure how I install a local earth electrode given the house structure and the difficulties of caarying out the earth resistance tests. Something to sleep on!

David

According to Victron when I asked my dealer about this, it does have PEN fault detection. This is confirmed in the spec sheet https://www.victronenergy.com/upload/documents/Datasheet-EV-Charging-Station-EN.pdf which you can find on the product webpage.https://www.victronenergy.com/ev-charging/ev-charging-station

I didn't go for it yet as I'm awaiting the LAN connected version.

@l81ker I appreciate your response and would love to agree with you, but at the moment I am inclined to agree with the @Craig Chamberlain comment at the top that the documentation is ambiguous. The sceptic in me is also influenced by the fact that Victron has never added a simple comment to clarify this on the discussions on the forum even when invited directly by other and by me above to @Guy Stewart (Victron Community Manager). Neither did Victron reply when I emailed the question to them. Thus I feel I have to assume that it does not comply.

Forgive me asking, but do you have grounds for believing that your dealer has the technical expertise to reliably comment on this complex matter. There are several dealers/resellers out there who have minimal technical awareness of Victron equipment. For example, does your dealer also install and has thus registered these chargers with the local DNO? Did they, could they, forward a response from Victron to you?

I'd love to find out that the charger does comply with PEN fault detection, more because I want to continue to believe that Victron equipment is the best than the extra cost I need to fork out. And why is there not a type B RCD included in the device, then all the installer needs to do is fit the appropriate MCB in the consumer unit.

Hoping you can add clear ressurances re your dealer reply.

Regards,

David

Thanks @l81ker for the update. Are you saying that having explained the issues to the dealer, the Vicron Rep indicate that the charger does satisfy the PEN fault requirements. I am still waiting for a local electrician to come round and do the necessary. I strongly suspect that by the time I have provided a local earth for the house (a good idea because of 'islanding') and also installed the Matt:e thingie it is going to be a case of 'belt and braces +++' but given the deafening silence from Victron that seems the best way forward. As an aside I detected a potential difference of 250mV between my newly installed house earth rods and the grid earth. It can be difficult to make sense of some the scare senarios posted on the electrical websites.

Regards,

David

I'm coming into this conversation a little late as I've just raised pretty much the same question again on this group. I guess I should have searched further.

My understanding is that if the charger doesn't have an RDC-DD device internally to detect DC leakage then you definitely need a Type B RCD under the latest regulations.

I just made the mistake of buying a new consumer unit from my local electrical distributor which is specifically labelled as an EV consumer unit which he told me had a Type B RCD. Turns out it's a Type A. The guy didn't really seem to understand the regs for EVs even though they sell them which makes me think lots of these are getting installed with incorrect protection. The DC issue can affect upstream RCDs as well so if you feed the EV charger from a consumer unit in a garage which is then fed from an MCB in your main consumer unit in the house and that has a Type AC or A RCD then that can be blinded to AC faults if there is DC leakage at the garage end that isn't protected properly. This would result in it not tripping due to leakage faults within your house which isn't good. This won't happen if the garage feed is directly to the DNO supply though.

I have an earth rod installed for my ESS system for when I'm islanding during the day as has been mentioned in this group. I also use it for my solar panels.

I wish there was some clarity about this EV charger. I have bought one and now it looks like I need a £300 consumer unit unless Victron can clarify. I'd rather know and pay the money for safety than be in the dark.

@Semlohnhoj i wouldn’t assume this could easily be a load balancing facility allowing you to connect more than one to the same supply cable, the only people that can clear this up is Victron.

@Lucian Popescu (Victron Energy Staff) could you answer the question as to whether the EV Charger has internal DC RCD protection (RDC-DD) or do we need an external Type B RCD instead?

Hi @Lucian Popescu (Victron Energy Staff) ,

Yes, I read the data sheet and manual but the information is specifically for 3 phase, not single phase. Can you confirm that a Type B is required for single phase as well?

Thanks,

John