Electric Vehicle (EV) charging and thunderstorms - Is it safe/recommended?

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.