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Here's how to charge with 32A commando in UK
- Thread starter Fraank
- Start date
Back in the day Tesla used to pay for commando sockets to be installed and they didn't have PME fault detection fitted as the regs didn;t require it at the time. I had one installed and a few years later I swapped the commando socket for Tesla wall charger.. and still no PME fault detection. I am sure I am far from unique on this. Regs aren't generally backdated and the PME thing is relatively recent (maybe 3 years).
My current (no pun intended) understanding is if you already have a 32A commando you can use it, you can even have a commando socket installed without PME if the expressed intention is not to charge an EV, but if you want a commando socket installing with the intention of charging an EV, the regulations are more strict and (I'm no electrictian) I believe that includes PME extra fault detection. I kind of think its craze the same socket can have two different levels of protection with no obvious indication and the only difference is the expresed intention at the time of installation.
Am I worried about not having the extra protection? No, not really, and I'd argue its a lot safer than people using extention leads out of hotel windows and a 3 pin plug and other dubious arrangements.
The issue for me is largely compliance, that said I wouldn't condone trying to circumvent the regulations for new installs, I'm just personally not feeling compelled to retrofit to the latest regulations when the law doesn't require it.
MrBadger
Badger out
My understanding is, that its more as to whether you intend to charge an EV whilst it is outside (so connection inside garage can still be liable to this but if its only in reality capable of charging an EV inside the garage than its not so strict. I believe that it also now includes any socket outside the property, whether it is for EV charging or not. But none is retrospectively applicable although an electrical inspection would likely mark it as NCS (Not to Current Standard) which, from past experience, may well put off any potential purchaser if you came to sell the property. If its anything like gas, NCS may well have gone now, and what was previously NCS may now be categorised as the more alarming AR (At Risk) - depending on the Gas inspection and whether they just want to drop an item previously on NCS, or promote it to AR. Based upon previously experience with reporting a gas leak to British Gas, they are too quick to condemn an installation - our new boiler was incorrectly condemned even though they found no evidence of a gas leak until a few days later when it was discovered that our next door neighbour had left their gas cooker on and that was the cause of the smell. It was alot of effort to get our boiler 'un-condemned' - required a safety inspection which would have been at our cost. IIRC we just moved the service forward.
English regs at least. I know Scotland is different.
But throughout the Tesla era, PME faults have been a concern - with the historic solution being to use TT earthing instead on the chargepoint/socket (plus a variety of alternatives, most of which were impractical). This was in the 1st edition Code of Practice for Electric Vehicle Charging Equipment Installation (2012), and made explicit in the regulations in Amendment 2 to the 17th Edition (2013). That amendment was the one introducing section 722 with specific rules for EV charging; the same principle already applied to some of the other special situations (eg. horticultural - greenhouses), so this wasn't new.
The PME fault disconnector option wasn't introduced until 18th Edition Amendment 1 (2020).
Personally, I think the TT earthing is a better option in many cases - while the PME disconnector is a useful option for the cases where TT is impractical, installers seem to have adopted it across the board.
WannabeOwner
Well-Known Member
I'm shocked! I'd -never- do that!Oh dear, are you looking at me?
Now an airb&b OTOH...
More on topic, if you are installing a primary charging circuit, then PEN protection is required by specs and probably advisable, safer is better, right? If it's occasional use (all our grandparents have simple 16a commandos now) or for your own backup, then I'd happily skip it.
The PEN protection is not for now. It's for 10 years time when the next owner has rolled over the cable lots of times with his cyber truck and still insists on using the charger in the rain. You will probably not have a problem because you are sensible and wouldn't use equipment in that state. The regs are designed to protect others who wouldn't know better.
WannabeOwner
Well-Known Member
Pah! Only 'coz you've never stayed in one where your hotel room was directly above the car park, and there was a space in just the right spot!
But, yeah, I have more typically used a 13AMP socket I found somewhere around the car park - probably to plug the jet wash into when washing the car park
That was all a while ago, Car has more range now so I often don't need to bother, or there is a facility on site / near by and that is good enough, or better. Back then all forms of charging were rare.
Not really. More like when the local DNO has skimped on maintenance of their 50+ year-old cable plant, or some plonker with a JCB is digging down the street.
The broken PEN problem arises entirely outside your installation, and (if it occurs) will bite you even if all your equipment is in 100% top shape (assuming that it doesn't include an open-PEN detector and does use a TN-C-S earthing system). Damaged cables within your installation don't give rise to the problem.
PEN protection
The PEN conductor is used in the supply cable in the street - combining Earth and Neutral in a single wire (which you aren't allowed to do within your installation, ie. downstream of the meter earth and neutral are separate wires). This is only one of several earthing systems, but it is by far the most common in the UK. The snag is that if the PEN gets broken in the street, your neutral and earth wires - so including the chassis of your car if it's plugged in on charge - can end up at the same voltage as the live wire. So the net effect is it seems like there's a power cut - L is at 230V compared to true earth, but so is N, hence the voltage between L and N is zero. All your earth wiring is also at 230V above true earth.
If all your wiring is inside the house, then this isn't a big deal. Although all your earthed appliances are now 'live' (230V above 'true earth'), other regulations have arranged that everything else you can touch is also 'live' - everything you can touch is required to be either insulated or connected to that same earth terminal, so even if it's now a bad earth terminal, everything around you is at the same voltage, and your body can't touch two things at different voltage to get you a shock.
However, when you step outside your house your feet are now standing on, maybe damp, 'true earth' and your car's chassis is 'live'. This time you do get a shock when you touch the car. Note also that none of the conventional protective devices (RCDs etc) do anything to help you here - it's the earth connection to the car that's killing you, and conventionally earths are all permanently wired, they don't go through switches or RCDs.
The fix is either to put in one of these PEN protection units, which _does_ put a switch in the earth connection to the charging equipment and hence the car and turns it off if the mains voltage is out of spec; or else you use a different earthing system that doesn't connect earth and neutral wires - for example the 'TT' system where the earth wires in your installation are connected to a rod in the ground. There are pros and cons to both these systems.
DNOs are required by the ESQCR regulations to report each time they have a broken PEN incident, so statistics are available and a risk assessment done at the time of writing the Regulations showed that if all cars in the UK were EVs there would be around 6 deaths per year from this cause (range of probabilities from 1 every 5 years to 36 every year). The numbers in there are sufficient to convince me that it's a real problem that needs solving (indeed I think they got their methodology wrong and it's slightly worse than they say).
RCD types
RCDs work by measuring the current in the L wire and comparing it to the current in the N wire - if those currents are different, then some must have "leaked out" somewhere, indicating a fault - maybe it's leaked out through the body of a person touching the live wire and their feet on the ground.
The original type of RCD is known as "Type AC". These are easy to make with a purely electromagnetic design - no electronics. However, at the heart of the design is a transformer and so they only work with pure AC - such as you would get with a person directly touching the AC live wire. However, inside a car charger (and many, many modern devices) the AC gets rectified to DC and so a fault in the car's charger (or someone poking their finger inside) won't give a pure AC leakage current and so won't trip the RCD.
Next up is the "Type A" RCD. This uses essentially the same physical arrangement as the Type AC, with a transformer, but adds some electronics to process the signal coming out. This will respond to not only pure AC but also pulsed DC such as you might get after the rectifier in a charger (or a motor drive, or a solar inverter etc etc). Costs almost the same as the Type AC nowadays.
Top of the range is "Type B". This can detect everything that the Type A can do, but also detects pure DC leakage currents (or anything in between). Unfortunately, the transformer-style design of the other types can't do this and a much more complex circuit is needed. They are usually much more expensive and twice the physical size as a result. If money was no object, that's what you'd be fitting.
For EV charging, there's obviously a very strong argument that Type AC isn't good enough, as there are obvious failure modes (damage to the EV charger) that can give pulsed DC which a Type A will detect but a Type AC will not. The original EV charging regulations (introduced 2011/2012 as mentioned above) therefore required a minimum of Type A and disallowed Type AC.
There's not really any plausible fault scenario that could give rise to a pure DC leakage, so there's not a clear requirement for the full capabilities of Type B, but there is one further snag.
If you've got a permanent DC current flowing (maybe harmlessly) on top of the AC, then that can saturate the transformer in the Type AC/Type A RCDs and stop them detecting genuine faults that they would otherwise be able to handle. To be certified as Type A, RCDs have to keep working even in the presence of 6mA of DC current, but more than that and they are allowed to malfunction (ie. fail to save you when disaster strikes). Unfortunately, the EV charging standards (the specification for how the Type1/Type2 charging connectors work) rely on a 12mA DC current in the earth wire of the charging cable to detect that the wire isn't broken etc. Regulation-makers began to worry that the 12mA DC current could somehow turn into a 12mA leakage current and so disable any Type A/Type AC RCDs - not just in the chargepoint, but maybe elsewhere in the house. Now, it's a pretty outlandish fault scenario for the whole of that 12mA to get diverted into the L or N without the whole thing going bang, and in any case that 6mA spec on Type A devices is a minimum (real ones will typically do better), but it's still a bit unfortunate that those numbers are what they are and this is a forseeable safety risk that can't really be brushed under the carpet.
A Type B RCD would solve the whole problem, but they are desparately expensive, so the original Regulations had some ambiguous wording that let you get away without one. Then it was noted that the problem could be fixed by using a device that specifically looked for that 6mA or more of pure DC and shut down the EV charge circuit; you could then use just a Type A for the main RCD function safe in the knowledge that it won't be defeated. This extra circuit is much simpler (hence cheaper) than a Type B.
So now the regulations have been clarified, and you need a Type B unless it can be shown that >6mA DC can't occur, in which case you can use Type A as before. The >6mA detect circuit can either be built into the chargepoint, or you can get a special RCD that combines the 6mA detect circuit with a conventional Type A - one manufacturer is branding these as "Type EV" although that's not an official designation.
Personally, I think the risk here is rather lower than the PEN case and it's questionable if the extra cost over just a Type A is worth it - but I don't have any proper statistics to prove that, and I have upgraded my own chargpoint installation to have a "Type EV" RCD.
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WannabeOwner
Well-Known Member
I’ve been charging with a 32A commando for more than four years. I decided on this option as I wasn’t eligible for the £500 OLEV grant. I installed it myself and just got an electrician to wire it into the consumer unit and check I’d done it properly. it’s been 100% reliable and saved me a lot of money.
It doesn’t conform to current regs so it would be irresponsible of me to recommend that anyone else does this. But I’m satisfied it’s safe, and it’s every bit as safe as a 3 pin UMC.
It doesn’t conform to current regs so it would be irresponsible of me to recommend that anyone else does this. But I’m satisfied it’s safe, and it’s every bit as safe as a 3 pin UMC.
WannabeOwner
Well-Known Member
Actually, now I think about it ... I have an earthing rod on my wall connector. Perhaps I don't need to upgrade anything to "better"?
Doepke are the ones pushing "Type EV".
Doepke DFS4-040-2/0.03 A-EV 2P 40A 30mA Type A-EV RCCB
Doepke - DFS4-040-2/0.03 A-EV - Doepke DFS4-040-2/0.03 A-EV 2P 40A 30mA Type A-EV RCCB - <P>A Type A EV RCCB 40A 230V 2-pole that is specifically designed for
www.rapidonline.com
There's no such thing as "safe". The only way to avoid the risks associated with EVs is not to have a car - but then you might get run down by a bus. So it's all about relative levels of risk.
Your commando is as you say at least as safe as charging from a random 13A socket with the UMC - indeed safer from the overheating aspect that we haven't been talking about in this thread,. But it's not as safe as the proper job with PME fault protection and DC-sensitive RCDs. Up to you what level of risk you are happy with.
That means you don't need PME fault protection - you aren't using the PME earth.
The question of RCDs is independent. Depending on the age of your Tesla Wall Connector, it might have 6mA DC protection built-in (but if yours is of age to match your first Model S, it won't). Upgrading from a decent Type-A RCD to a Type-EV would give a small improvement in safety (though I am not aware of any statistics to quantify it), debatable as to whether it's worth the money.
kelvin 660
White SR+ with LFP battery
One thing I don't think has been mentioned in this thread, is that you need to inform the DNO that you are fitting a 32A charger, so that they can keep track on how their network is being loaded. If a lot of people start fitting and using DIY 32A commando sockets there might be some unintended consequences...
I've asked my DNO to upgrade my main fuse from 60A to 100A when I installed it, so surely if they're not too stupid, they register the new Amp usage rather than what's behind it?
These are two different things. Your new fuse allows you a higher instantaneous demand. The thing they are concerned about is long-duration demand: your EV charging may well have fitted within your existing 60A fuse, but could still cause them problems.
A 100A fuse is 23kW. A typical EV chargepoint is 7kW. Estates of houses are typically planned for long-term average consumption of only about 2kW per house (even though some of those houses might be drawing 23kW for short periods). If all those houses install EV charging, then there needs to be either some demand management or significant reinforcement of the network: bigger/additional transformers or in extreme cases, new cabling.
The switch to EV charging is a big change in the nature of domestic power loads. Previous provision assumes that peak load will only last for an hour or two, the transformers and other plant can stand a bit of overload for that time - they will start getting hotter, but before they overheat the peak demand will be over and they can cool down again. Also, the worst demand is in winter, and if customers are using more power because the weather is cold, that same cold weather is keeping the plant cool. EV charging breaks these assumptions - charging continuously for many hours, summer or winter.
It's all just about containable if it's only EVs, but if people start installing heat-pump heating on a like-for-like basis (ie. not super-insulating the houses to keep the heatpump size down), then it's going to be a huge problem.
I am looking at the best way of charging at my business premises, we are currently having a quote done for a Zappi. The installer has mentioned that we will need PME near the main incoming supply that will need to communicate with the Zappi located some 15 mtrs away on a seperate RCD Board. We have 3 phase so would like the option to charge at 11kw. I havent received the quote yet but I suspect it is going to be fairly expensive.
We do have a redundant 16A 3 Phase Commando socket located within 6mtr of where I am planning on charging the car. Could I just plug one of these in and start charger from that socket instead?
www.evchargingcablestore.com
Any help would be appreciated.
We do have a redundant 16A 3 Phase Commando socket located within 6mtr of where I am planning on charging the car. Could I just plug one of these in and start charger from that socket instead?
Tesla - Multi adapter Charger. 3 Phase 32A / 16A. 3 Pin and Commando EV Charger. Type 2
Type 2 Tesla 1 Phase to 3 Phase 6A - 32A Multi Socket EV charger. 6A, 8A, 10A, 13A, 16A, 20A, 32ACharge your Type 2 Tesla EV using multiple power sockets including the 3 Phase 32A and 16A Commando (CEE) socket, 1 Phase 32A and 16A single phase CEE socket and the 3 pin mains / household socket. Y
www.evchargingcablestore.com
Any help would be appreciated.
