Although long retired :)

@sylm_2000wrote:

It seems the last discussion didn’t reach a conclusion. 

True. But I’ve continued to research this topic over the past 9 months leading up to the purchase of own EV.

• I’m pretty confident that I now understand the electrical safety regulations…
• and I’m pretty confident that I know how to fit the correct lightning/surge suppressors to quench their impact on houses with an EV charger.

The task now is to combine those two sets of knowledge into one diagram!

I’d like to wait a few hours and hear more of @Mateus77 ‘s situation to check that my solution could be applied there.

Then I’ll post the diagram and ask the Forum Members to see if they can spot any flaws. In particular my solution may not suit all possible ways in which our houses can be supplied from the Distribution Grid or all possible chargers.

HI again, 

How do I confirm if I have a PME feed?

Also no issues at all with Pete being an electrician - Hi Pete! 

Cheers

There should be more than one indicator if you’re on a PME feed to the house.

A: At your local substation there will be a notice/label which says “PME” in letters about 75mm high.

B: Your house will probably not have its own earth stake.

C: The earth connection to your Consumer Unit (box of trips/fuses) will emerge from the Service Fuse which belongs to the regional Distribution Network Operator (DNO). Ie They have provided the earth for you.

If still in doubt, check with a neighbour.

Either all houses fed from that substation will be PME or they will not. There can’t be a mix of different feeds.

Looks like a PME setup then...!

It sure does. Even without the photo of the earth wire, there’s a neat label to the right which seems to provide the answer!

And what about your EV charger, @Mateus77 ?

What is in your Consumer Unit which provides the electricity supply to it?

Does the charger have its own earthing (of any sort)?

I think this diagram provides the correct way to connect an EV charger to a house with a PME (TN-C-S) supply and has anti-surge protection for both the mains incomer and the ground wave induced by lightning.

Can you check if you think I’ve missed anything please @PeterR1947, @sylm_2000  and @D10hul ?

Once we’re agreed, I’ll copy it across to the topic How I installed an EV charging point and provide a full description there.

@Mateus77if you know a local electrician, this is the moment to ask them to have a look at what I’m suggesting!

For a full description of this wiring diagram see here.

Images to confirm my wiring of the charger, believe the missing parts are the surge protection!

The surge protection is optional, mine doesn’t have it

Thanks @Mateus77 - lots to consider here.

1: You have an earth stake. Let’s hope that it’s the only earth connection to your EV charger. You don’t want another one within the cable connecting it back to the Consumer Unit.

You should’ve been provided with a ‘Part-P’ test certificate for the mains part of the charger installation. With this should be a test-sheet showing the resistance readings and response-times for the relevant trips.

One of those readings will be the earth-loop resistance. That must be below 200Ω (ohms), and preferably a lot less.

2: I don’t like the choice of a Type-A RCBO in the metal enclosure marked “DB EV”. These don’t offer enough protection to all types of DC fault which the charger can impose onto the connection.

Rolec advertise it as “DC sensitive”, which it is if the DC component is pulsing at a frequency close to the 50Hz mains. I don’t think that’s adequate.

See the description I put on the topic about How I installed an EV Charging point and this diagram in particular:

3: I note that both the MCB feeding the EV circuit from the Consumer Unit, and the separate RCBO are rated 40A.

Your charger should take no more than 32A (7½kW). The 40A rating is to protect the wiring that leads to the charger. From the photo I can’t tell if that cable is thicker than the 2.5mm² which is used for power-rings. If it’s only 2.5mm² then the 40A is too high.

4: If your charger is within the garage and being fed from a standard Twin-and-earth cable, then we hope that the earth is not connected at the charger end. You probably can’t tell without having the cover removed.

@PeterR1947 wrote:

The surge protection is optional, mine doesn’t have it

The lightning/surge damage is also optional. You don’t need to have it

LOL

My new V2G charger is connected to a Crowd Charge controller in a metal case (as my CU is plastic) and this is fed from a Henley block directly from the meter.  This also has a Type-A RCBO so this seems to be a common issue.

I have also checked with Wallbox and my Quasar V2G charger does not have built in surge protection

@PeterR1947I can’t seem to find the Forum Topic where you introduced the Quasar V2G charger and the control system which drives it.

If there isn’t one yet, you’ll have both Moderators snapping at your heels!

@Jess_OVO- get him! 

Even so, we ought to be regarding the surge-suppression devices and the Type B RCD/RCBO in similar fashion to having house insurance to protect against fire.

Everything’s fine without paying the premium until it’s your house which gets reduced to a pile of ashes.

The level of protection devices which I’ve installed is expensive. But then so is your EV and its charger.

Any response from your insurers yet @Mateus77 ?

It would be great if they could be reading this discussion.

So for me at present I had to claim on both house and car insurance policies to repair damages to both car and household goods, the charger was actually done as goodwill gesture by Rolec. 

All the repairs were done after many weeks of dispute of liability and still fighting to get that acknowledged by Audi and possibly Rolec - via TMO at present, if that fails I think my only recourse is a small claims court action to claim that there is inadequate warnings on the car charging system to prevent damage e.g. a warning sticker on the charge interface - just like on public charging units funnily enough!

The parties involved have all passed their liability. The electrical install meets the guidelines I'm told by NICEIC after several discussions. The car manufacturer claims as it states on page 200 odd, of a 400+ page owners manual they are covered and it's just bad luck, owners should unplug in case of storms

Thanks @Mateus77 - lots to consider here.

 

1: You have an earth stake. Let’s hope that it’s the only earth connection to your EV charger. You don’t want another one within the cable connecting it back to the Consumer Unit.

You should’ve been provided with a ‘Part-P’ test certificate for the mains part of the charger installation. With this should be a test-sheet showing the resistance readings and response-times for the relevant trips.

One of those readings will be the earth-loop resistance. That must be below 200Ω (ohms), and preferably a lot less.

 

2: I don’t like the choice of a Type-A RCBO in the metal enclosure marked “DB EV”. These don’t offer enough protection to all types of DC fault which the charger can impose onto the connection.

Rolec advertise it as “DC sensitive”, which it is if the DC component is pulsing at a frequency close to the 50Hz mains. I don’t think that’s adequate.

See the description I put on the topic about How I installed an EV Charging point and this diagram in particular:

 

3: I note that both the MCB feeding the EV circuit from the Consumer Unit, and the separate RCBO are rated 40A.

Your charger should take no more than 32A (7½kW). The 40A rating is to protect the wiring that leads to the charger. From the photo I can’t tell if that cable is thicker than the 2.5mm² which is used for power-rings. If it’s only 2.5mm² then the 40A is too high.

 

4: If your charger is within the garage and being fed from a standard Twin-and-earth cable, then we hope that the earth is not connected at the charger end. You probably can’t tell without having the cover removed.

The Rolec installer just sent me the carts again.. the earth loop resistance is shown as 0.33?…

The cable is the thicker cooker/shower type too.

I think the recourse to legal action (Small claims) is problematic. If an installation complies with the regulations (which yours did @Mateus77 ) then who is to decide liability for the absence of protection devices which are not mandatory?

There’s a big difference between the time taken for a trip to switch off and the faster response required to protect against surges/lightning. I wrote a separate tutorial about surge suppression last year when considering the issue roof-top solar panels.

Once insurers start receiving a lot more claims from EV owners, perhaps they should consider lower premiums for those who have anti-surge devices properly installed.

In the meantime the emphasis seems to be on the selection of which trip to use and how the earthing is to be wired.

The general lack of knowledge about either trips or surge-suppression isn’t helping.

The wiring diagram for a charger on a PME site, together with a full description is now posted on the topic How I installed an EV charging point.

Interesting - so was the surge caused by a lightning strike in your street? Surge protectors and careful earthing can protect against such events, but they are not always standard, especially in older houses.

A direct lightning strike on the other hand is very hard to mitigate, and it is typically cheaper just to write off sensitive electronics (like power supplies, land line phones and network cards) rather than protect against it. 

As for insurance, it would usually be included in your home insurance, but of course that excludes the car. 

The strike came to ground at a nearby house yes.

And yes aware that this is fully preventable, but fighting against a car manufacturer that does not make purchasers aware of this and home charge installers that don't offer as a precautionary safety measure on installs either! I would have been happy to pay £100 odd quid to add the SP when they fitted the charger and believe the car manufacturers should be making this very very clear on the car, in the manuals and on taking the vehicles!

We all need to be having these conversations in the pub - LOUDLY, so that everyone can hear!

Tell everyone, and that includes Matt Allright at BBC Watchdog.

The Type-2 surge suppressors which I use are made by Phoenix Contact. They have a test facility in the Black Forest, which has a reputation for the highest probability of lightning strikes in Europe. There’s no point buying such suppressors unless you trust them to do the job. Brand name and reliability really do matter in this instance.

There are over 100 versions of pluggable surge-protection devices in the Phoenix Contact range, with different voltage levels, reaction times etc. Prices vary enormously across suppliers. Official (non-ebay) outlets would typically sell you a pair of suppressors and their bases for £150+

If you’ve got a PME (TN-C-S) electric feed to the house, you’d need two pairs.

The Type-B RCD is also ‘optional’ but protects humans against faults/damage and costs around £250 for the Chint variety.

Add to that the DIN-rail enclosures, and earth-stake (PME sites) installation and testing. You won’t get much change out of £800.

Do not confuse what we’re discussing here (high-current surges from lightning) with the surge protection devices which are part of the CCS and CHAdeMO standards. Those offer fast-acting protection for voltage variations when plugging the charging lead into the car, and not a lot more.

But neither the car nor the charger are the right place to install surge protection. It should be in your consumer box, right next to your earthing point, where it is most effective. As I said, most installations will not include this for cost reasons, but that is a choice. 

For a TT-feed to the house, I agree @MrPuds.

And the Installer has to work in the Consumer Unit anyway to fit the required trip(s).

But if it’s a PME site, such as @Mateus77 has, then you also need a second pair of suppressors as close to the charger as possible, as I indicated in the diagram above.

I think the first issue is that so few customers even know that having surge-suppression is a possibility. Until they become aware of that, the options will never be considered.

Just as an update. 

Had a call from the Dept of Transport after emails to the EVA England (electrical vehicle association).

Seemed quite constructive and expecting some response in the coming weeks as to what can be changed in terms of regulations and standards for installs and car manufacturers... I'll update when I get more info.