Electric vehicle charger fault
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- Опубліковано 10 вер 2024
- Sound on for this one.
Join us on a little fault find! This is one for the sparks, as this was attended by another electrician, who changed parts inside the EV point, which didn’t resolve the issue.
I’ve come a cross this fault before, and for electricians, it’s handy to know the maximum Earth fault loop impedance allowable on an older Renault Zoe was 150ohms, rumour has it that it’s been raised to 200ohms, but finding this information online is practically impossible. Other vehicles have different maximums, so getting as low of a reading as possible is vital. So if you’re putting in an Earth Rod, make sure you have good contact. I would say call the car manufacturer for guidance, but that’s often not the most helpful either. Ev point manufacturers have been the best and providing EFLI information in terms of specific vehicle.
Back to everyone who’s not an electrician, this was a dangerous fault, I passed over to the electrical supplier, they struggled to re-create the fault so I spoke to them on the phone and explained what I had found. Eventually they agreed that there was a fault and the supply head was changed. Any works by the supplier due to faulty supply equipment is completely free to the home owner, and is usually addressed within 2 - 3 hours.
#ElectricVehicleChargerFault #EVChargerFault #EVChargerInstaller #electricalfault #ElectricalContractor
411.4.2 regs! ( ammedment 2) TN TNCS systems
It is recommended that an additional connection to Earth, by means of an earth electrode in accordance with Chapter 54, is made to the main earthing terminal. This recommendation does not apply to outbuildings of dwellings served by the installation.
So to comply with current best practice and assuming you don't have PEN fault detection already, is it simply a matter of wiring an earth spike to the earth connection on the EV feed in place of the house earth ?
Basically yes. That's what the official regulations call for when installing an EV charger, and especially if there is no Earth Spike you absolutely must have PEN Fault protection, which is easier done with 3-phase than 1, and 1 phase I think then requires an Earth spike anyway so why not just install one to begin with.
Adding in an Earth Rod to a property with a PEN system opens the door to some additional risks of potential fault voltage conditions. So without a PEN monitor, you would need to Earth Rod it, but the guidance would need to be followed.
As you know you shouldn't be removing the DNO fuse and covers on the cut out , for obvious reasons.
Not exactly, the DNO request that we remove the cutout and take a reading at the head, to ensure they have the most accurate reading. But absolutely generally, it shouldn’t be touched or removed.
@@core7557 the reason for mot removing the fuse is if the cut out breaks up whilst you are pulling the fuse it can short out and explode in your face showering you in molten brass . Not a good day
@@dennisphoenix1 there's also the issue with some older cutouts leaking voltage through the plastic. Efixx did a video on that hazard for normal electricians, but that is still up to the DNO to rectify.
If an electrician finds an issue with a customer's installation, why wouldn't the DNO request further information ahead of sending out an engineer to change the cutout if the electrician is still there?
@@CoolSteve08yes I saw that e fixx video. As I said if you pull the main fuse it can go wrong. When I worked on street lighting I went on a course so I could pull DNO fuses in columns and feeder pillars. The photos they showed us of when it had gone wrong brings it home. Just be safe and wear the correct ppe
The DNO should not be requesting you do this.
Further to info already provided John ward says there no reason why you can’t add a Stake to a TNCS to keep touch voltages lower but you should aim for less than 10 ohms! What he doesn’t make clear is whether he’s referring to allowing the fusing device to trip or simply allowing touch voltages to remain within safe limits. As I’ve already stated this is to mitigate a PME break supply side. Touch voltages would be lower but unless you get low enough impedance the fusing wouldn’t operate. 4 ohms should be sufficient in most cases.
Risk assessment : 400-500 PME faults a year in the uk
Touch voltage keep within safe limits
Separate or joined earthing systems
Distance away 10m etc if separate
4 ohms and below For ADS
Just some of the considerations 😁
(Qualified Electrician) Advise I got when to mitigate pen fault on a TNCS and keep touch voltage lower is to add an earth stake to the MET this in effect lowers potential touch voltages in the event of damage to a TNCS neutral incomer ( always isolate supply before any work including solar and battery)
Absolutely would work, however it’s a dangerous setup to mix earth types in the same property, the risk being that if there is a lost PEN on the estate, the entire estate would be earthed via your Earth Rod, and it’s not designed for that, or rated for that level of earth / neutral path, and could create a dangerous potential in your property, or melt the cable and MET. It’s best to keep earthing arrangements separate.
Bs7671 and new 18th edition regs state the an earth rod can be beneficial to supplement earthing and keep touch voltages lower particularly when gas and water bondings can rise in plastic. This is not a mix of earthing types but merely a safety recommendation !@@core7557
Main MET connected to a ground stake at less than 10O ohms on a TNCS earthing system is actually accepted by new 18th edition regs as not being detrimental. Phone NICEIC they will confirm. The more parallel earth paths you have the safer the touch voltages will be.( although obviously a proper good TNCS would be the priority)
Also the likelihood of your ground stake being the only parallel path to ground for the whole road is ridiculous! The road would be full of house with gas and water bonds providing a path where gas and water services join 😀
Amazing video ! New subscriber gained 👍🏻
Welcome aboard!
Surely this fault is a PEN fault?
Absolutely was a PEN fault, however the customer didn’t know that when they called us. We found it was a PEN fault, got the DNO out to fix the fault and hey presto, car started charging again. 🤙🏻
@@core7557 So who pays your bill when it's a DNO fault? The poor customer, or do the DNO have to cover it?
@@TheEulerIDunfortunately this is a grey area, potentially you could put a case forward to the DNO to reimburse you, but it’s unlikely they will pay it. So on this occasion it is the home owner paying the bill. However we found that fault quite quickly, and highlighted a number of other faults at the property, unrelated to supply, that should be addressed as soon as possible, so there was value for the customer in our visit.
I always thought that you need a separate earth for an EV charger ?
Nope, the new EV points on the market today come with a PEN monitor (depending on brand, Tesla chargers still lagging) but they have technology that will sense if the neutral- earth path is lost, and shut the charger off, so no need for an Earth Rod 💪🏻 just check the brand instructions to see if the unit has a built in PEN monitor. give us a call or email if you want any advice. www.core7.co.uk
Happy to help
"promo sm"
Yet another reason I'll be holding out as long as possible for not having an EV!
In a twist of fate, this fault helped identify a potentially dangerous fault in the house! Although inconvenient for the driver, it was a blessing in disguise.
😂 oh no my EV charger told me about a fatal flaw in the electic supply to my house that could kill someone.
Boy I wished I didn’t have an EV now so I can stay blissfully ignorant
😂 the newer models are far more temperamental! Il do some more videos of some of the recent faults we’ve had. 😢