Lightning Surge Protection

[sw25481]

Hi all

M3 LR is turning up soon. I am getting my charging point installed shortly. We have had some pretty exciting thunderstorms this year. Does anyone know how you should think about thunderstorms when you have an EV?

Will a strike locally cause damage to an EV?
I assume that would be only if you are plugged in, but then the advice is to always be plugged in.
Would the Type B RCD protect you?
Can you/should you buy anything else to protect the car?
Would you be covered by either warranty or Insurance if the car was damaged during a storm?

 

[Glan gluaisne]

Ask the electrician that's installing the charge point to fit an SPD at the same time. These are required on new installations anyway, and one will protect the whole installation. The only snag is that they take up space in the CU, as they also need their own MCB, but the newer single module SPDs, plus a single module MCB, will only take up two slots. If the electrician is going to install a small enclosure for the charge point connection, as is usually the case, then it may be possible to fit an SPD in that, subject to being able to meet the maximum cable length from the main switch.

 

[NewbieT]

The PodPoint includes surge protection (don’t know about other makes) but an external SPD isn’t a bad idea for the money. The cartridges need replacing every few ?years? depending on how much work it has done.

If there’s lightning I unplug my car just to be safe.

 

[Glan gluaisne]

TBH, the majority of appliances I've looked at in recent years have had MOVs across the input, and all that's in an SPD is a bigger MOV, so it's debatable as to how much real-world protection they provide. I'd be surprised if most charge points don't already have MOVs across the input terminals, given that they are dirt cheap, and probably reduce warranty claims. The MOVs I used to protect my home made charge points cost the princely sum of about 30p each IIRC.

 

[Vinny2102]

Surge protection is not mandatory on new domestic dwellings.

 

[Glan gluaisne]

Surge protection is not mandatory on new domestic dwellings.

Yes and no. You can take the time to work out whether or not the cost of the SPD (typically about £30, including the MCB) exceeds the value of likely damage from a surge event, but in pretty much every case I'd suggest that the result would come out that fitting an SPD to any new installation is required. The exact wording that applies in section 443 is this (my highlight):

443.4 Overvoltage control

Protection against transient overvoltages shall be provided where the consequence caused by overvoltage could:

(i) result in serious injury to, or loss of, human life, or

(ii) result in interruption of public services and/or damage to cultural heritage, or

(iii) result in interruption of commercial or industrial activity, or

(iv) affect a large number of co-located individuals.

For all other cases, a risk assessment according to Regulation 443.5 shall be performed in order to determine if protection against transient overvoltages is required. If the risk assessment is not performed, the electrical installation shall be provided with protection against transient overvoltages, except for single dwelling units where the total value of the installation and equipment therein does not justify such protection.

 

[Irata]

Since this is about lightning, does this not depend where the lightning strikes. I have always been advised that if it strikes the domestic side then no surge protector will stand any chance of protecting anything. So... Not to worry as nothing can be done.

As for other network surges or secondary to a lightning strike further away. Isn't that what surge protectors help with?

 

[Glan gluaisne]

Since this is about lightning, does this not depend where the lightning strikes. I have always been advised that if it strikes the domestic side then no surge protector will stand any chance of protecting anything. So... Not to worry as nothing can be done.

As for other network surges or secondary to a lightning strike further away. Isn't that what surge protectors help with?

Yes, as in the excerpt from BS7671:2018 above, they deal with external and atmospheric induced voltage surges. The emphasis used to be mainly on surges caused by nearby lightning strikes inducing voltages in the distribution network, but seems to now be more focussed on over-voltages caused by switching events. It also depends very much on where you live. The electricity distribution network in the east of England, for example, gets quite a lot of lightning events, significantly more than other areas, so that part of the country may well need better surge protection than some other areas.

In reality, almost all appliances that may be voltage-sensitive will almost certainly have surge protection anyway, even the cheap Chinese stuff often seems to have MOVs fitted on the incoming supply terminals, so it's debatable whether SPDs really add that much additional protection. I think the way we'll find out is by how often they wear out. Every time an MOV absorbs an over-voltage event it's life is shortened, until eventually it starts to conduct at normal operating voltages, so operating the over-current protection on the circuit. MOVs certainly do fail in this way in appliances, I've once had to replace one that failed like this, but it seems a relatively rare occurrence, which suggests that in reality we don't get that many surges on the supply network.

 

[Vinny2102]

Surge protection devices no doubt can have a positive effect and are definately better to have than not have but I wouldnt spend £30 or whatever they cost and expect to sleep soundly through an electrical storm smug in the knowledge that my £50k+ Tesla was happily plugged into the mains and 100% safe from any strikes to nearby power lines.
Rather put my money towards some AFDD's (arc fault detection device) which is likely to of more use when we are talking of charging circuits around 32amp considering the puny connections on some of these chargers and rcd units!

 

[Glan gluaisne]

Surge protection devices no doubt can have a positive effect and are definately better to have than not have but I wouldnt spend £30 or whatever they cost and expect to sleep soundly through an electrical storm smug in the knowledge that my £50k+ Tesla was happily plugged into the mains and 100% safe from any strikes to nearby power lines.
Rather put my money towards some AFDD's (arc fault detection device) which is likely to of more use when we are talking of charging circuits around 32amp considering the puny connections on some of these chargers and rcd units!

As I've mentioned twice now, I have doubts that SPDs offer any significant protection in real-world conditions. The debate about AFDDs is a separate topic, but suffice to say that my view is that they are yet another IET sticking plaster fix that fails to address the root cause of the problem, just like mandating fire-resistant CU enclosures, which is that the quality of terminations, both by design and the way some are poorly tightened, is the real problem. We even have CU manufacturers including tails clamps, to mitigate the poor design/installation of main switch terminals, by preventing the tails from moving and causing the cables to come loose. Complete and utter madness, when the older style of twin screw terminals were much more reliable than rising clamps, especially on large diameter cables.

 

[sw25481]

Super helpful on the tech, thank you all.

Does anyone know if you would be covered by any insurance or warrantee?

 

[Glan gluaisne]

My guess is that both the charge point and the chargers (which are built in to the car) will be designed to deal with the normal range of supply variations, including voltage surge, so should be covered by the warranty. Adding an SPD if you think you may have a particular problem (for example, if you've had more sensitive stuff in the house fail from surges in the past), seems a sensible precaution, although there is a requirement for the supply to the premises to remain within set limits.

 

[NewbieT]

Direct Line Fire & Theft:


doesn’t mention it has to be a direct strike but I can imagine any insurer arguing the intent of the clause and proximity of causation unless it was a direct strike to your house or your car. I would hope a direct strike is be easy to prove with photos, fire records, Meto satellite strike data. Google ‘lightning strike car’ & the pictures look . They say inside your car is a safe place to be!

For line fed damage I assume or hope if it ever happened it would be limited to the charging unit but how are you going to know or prove it was lightning that damaged your car?

Lightning is excluded from the Warranty https://www.tesla.com/sites/default/files/downloads/tesla-new-vehicle-limited-warranty-en-us.pdf but how are Tesla going to know/prove it was lightning that damaged the charging unit?

I’ve known people fall between two stools before. Charging units can’t be *that* expensive can they?!

Lightning is not an eventuality I worry about but I do unplug the car in a lightning storm as a precaution. It just wouldn’t be worth the grief if a neighbour two doors up was hit (as unlikely as that might be) and the car’s computer started playing up thereafter.

 

[Glan gluaisne]

Direct Line Fire & Theft:

View attachment 609194
doesn’t mention it has to be a direct strike but I can imagine any insurer arguing the intent of the clause and proximity of causation unless it was a direct strike to your house or your car. I would hope a direct strike is be easy to prove with photos, fire records, Meto satellite strike data. Google ‘lightning strike car’ & the pictures look . They say inside your car is a safe place to be!

For line fed damage I assume or hope if it ever happened it would be limited to the charging unit but how are you going to know or prove it was lightning that damaged your car?

Lightning is excluded from the Warranty https://www.tesla.com/sites/default/files/downloads/tesla-new-vehicle-limited-warranty-en-us.pdf but how are Tesla going to know/prove it was lightning that damaged the charging unit?

I’ve known people fall between two stools before. Charging units can’t be *that* expensive can they?!

Lightning is not an eventuality I worry about but I do unplug the car in a lightning storm as a precaution. It just wouldn’t be worth the grief if a neighbour two doors up was hit (as unlikely as that might be) and the car’s computer started playing up thereafter.

The charging unit is located under the rear seat of the Model 3 and is an integral part of the car. Not sure how much it costs to replace it, but it's definitely a Tesla SC job.

The charge point is just a contactor, that turns power on and off to the car. It has nothing within it that could offer any protection to the chargers in the car, as it just passes AC mains directly from the supply to the car. The electronics in the charge point are only there to switch power on and off, by closing the contactor when it's safe to do so and holding it open when it's not, or if the car signals that it has finished charging.

 

[NewbieT]

2018 TESLA MODEL X GEN 3 CHARGING SYSTEM CONTROL UNIT 1067677-00-C | eBay

Tesla SC price probably double that to £3k ...and the rest.

 

[sw25481]

Good find on the insurance and I feel reassured by that and the other comments. Like NewbieT says, I will probably leave it unplugged if I am sure there will be lighting just in case. Thanks all

 

[Wol747]

Interesting stuff, lightning! Many years ago my neighbour's TV aerial got struck: it melted and the masthead amp was blown off the chimney. The pulse travelled 100 yds upstream on the mains, 100 yds along the road and 100 yds up to my place where it destroyed my new CD player.
I would just unplug the car! If you get hit no-one can say which things will be destroyed and insurance should cover them, but the car would be a slightly bigger issue.....

 

[MrBadger]

The PodPoint includes surge protection (don’t know about other makes) but an external SPD isn’t a bad idea for the money. The cartridges need replacing every few ?years? depending on how much work it has done.

Are the cartridges user replaceable or do they need an electrician to replace something wired in to the CU? Presumably, when they need replacing, its obvious and they just stop being an effective protector rather than inhibiting the power supply?

 

[Glan gluaisne]

Are the cartridges user replaceable or do they need an electrician to replace something wired in to the CU? Presumably, when they need replacing, its obvious and they just stop being an effective protector rather than inhibiting the power supply?

They are the same size and fitment as an MCB, and are replaced as a unit, so require that the power be isolated, the cover of the CU be taken off and terminals unscrewed to remove one. This means access to live parts, so a proper dead check needs to be done after isolating the power (meter on the incoming to check the meter works, meter on the exposed parts to prove dead, meter back on the incoming supply to prove that the meter hasn't just died - never, ever do this with a voltstik). When fitting the replacement SPD (they cost around £25 or so) then the key thing is to ensure that the terminals are correctly torqued to the stipulated setting, which needs a torque screwdriver (many CU fires are caused by terminal problems).

SPDs have a window on the front that shows if they are still OK, plus they are connected via an MCB, so if they fail they may trip the MCB. Failure just means that they stop protecting the circuit, they don't shut off the power to the house.

 

[MrBadger]

Thanks. Shame that they are not modular units with a separate user replaceable cartridge - easy to replace, a bit like a fuse. If they only last a couple of years, I can see that many are not going to be replaced very often if at all.