UK domestic socket charging

But I've heard, don't know if it's true. That if you go on EV overnight tariff for say 7p.
Your daytime Tarrif goes up? Is that correct?

Yes, you would need to do some maths to work out if you'd be better off !!! Spreadsheet recommended ??

It was discussed in a previous thread somewhere but for me (who has an old dumb 7.4kw wall charger from 2019 and a Smart SMETS2 Electricity meter) I was still much better off on Octopus Go (the non intelligent Octopus tariff !!) rather than staying on a normal tariff. The car has worked flawlessly so far at scheduling the charge for 00.30am every time I need to charge it.

If you have a smart leccy meter I think you can get on any EV tariff with any charger including that Bokman - you may just have to show them your V5 or proof that you have an EV.

Here's the previous thread and link straight to my calcs. Please note these are April 2024 prices so a lot different now. I do around 9000/10,000 miles a year.

 
something like a Matte PEN protection device.
Depends on your house earthing system.. its only applicable to TNCS earthing systems as this is the only one which connects the Neutral conductor, or PEN, to the earth connection. Admittedly it is probably the most common system but eg mine is TT (earth rod), so not applicable for these, nor for TNS systems.
I also wonder why PEN fault protection is a requirement for ev charging but not for any other circuits eg for your lights, cooker or kettle?
An isolator switch for the commando socket is probably a good idea as I think most manufacturers recommend switching off the supply before the car.
 
My OHME ePOD was installed by Octopus last week and uses a 4G connection.. I'm not aware of a limit on the duration of the connection. I assume it's perpetual.

My granny charger does about 2.88 kW @ 12A but I wouldn't leave it for hour after hour doing that. I have now got an OHME charge point which charges at around 6.6kW. If I'd had the space in my consumer unit then a good quality new 15A circuit and socket installation would have been cheaper if slower than using the OHME.
How long did you have to wait for installation? I ordered one last week, did the old survey and it turns out I’m on a looped system so they can’t install until that’s sorted. Had an email from National Grid today saying I need a cut out change then the installation can go ahead, and that they’ll be in touch shortly to arrange it. When that is done, octopus can install the charger. Wish I’d known about this before I started. ? My own fault, impulse buying ?
 
Depends on your house earthing system.. its only applicable to TNCS earthing systems as this is the only one which connects the Neutral conductor, or PEN, to the earth connection. Admittedly it is probably the most common system but eg mine is TT (earth rod), so not applicable for these, nor for TNS systems.
I also wonder why PEN fault protection is a requirement for ev charging but not for any other circuits eg for your lights, cooker or kettle?
An isolator switch for the commando socket is probably a good idea as I think most manufacturers recommend switching off the supply before the car.
It shouldn't apply to TT systems because the property has its own earth - e.g. an earth rod- and there is a verified route to earth. TN-S systems in older properties (say pre 1980) have an actual earth conductor which goes from the property back to source, and (emphasis) SHOULD (end of emphasis) have a verified route to earth. TN-C-S systems do NOT have an earth conductor. Instead, the earth & neutral are combined, and this by magic SHOULD provide a route to earth.

PEN (protective earth & neutral) faults arise in a TN-C-S system when the neutral/earth develops a fault - the system is live. Anyone standing on the ground and touching a conductive part - such as the metal body of an EV - becomes the path to earth, and potentially gets a severe shock. Thus PEN fault detection should be part of an EV charging system on a property with a TN-C-S system

The problem seems to arise in TN-S systems - the ones with an earth conductor which SHOULD provide protection against such a shock. Say the electricity networks perform a repair and replace a section of cable on a TN-S supply. Nowadays, they seem to replace the section with be live & neutral only, with earths either side connected to the neutral. That is, what had been a TN-S supply to a housing estate has been converted to TN-C-S. There is no longer a separate earth cable; it's been made a Protective Earth & Neutral which can have a PEN fault. In an individual property, it's impossible to easily tell if what appears to have a separate earth does or does not actually have one. Thus ALL systems (other than TT - the property has its own earth rod) have to be considered to be TN-C-S, susceptible to PEN faults, and should have PEN fault protection included in the EV charging system.

"circuits eg for your lights, cooker or kettle" - these are safe, because they’re within the property and earthed through the combined earth & neutral. it’s only conductive parts outside (which aren't separately earned) that become dangerous - e.g. caravans, metal sheds, etc. … and EVs. There is scope for them to become dangerous in the event of a 'diverted earth & neutral' fault, which is an entirely different story.

An excellent explanation of this (much better than mine) is here:

 
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How long did you have to wait for installation? I ordered one last week, did the old survey and it turns out I’m on a looped system so they can’t install until that’s sorted. Had an email from National Grid today saying I need a cut out change then the installation can go ahead, and that they’ll be in touch shortly to arrange it. When that is done, octopus can install the charger. Wish I’d known about this before I started. ? My own fault, impulse buying ?
I only had to wait 2 weeks. A friend gave up waiting after 6 months. He was told Scottish and Southern electric had to make some changes first and they weren't forthcoming.
 
circuits eg for your lights, cooker or kettle" - these are safe, because they’re within the property and earthed through the combined earth & neutral. it’s only conductive parts outside (which aren't separately earned) that become dangerous - e.g. caravans, metal sheds, etc. … and EVs.
No that's not correct.. an ev is just as much a class 1 appliance (ie connected to earth) as anything inside the house. Its coming off the same neutral bus bar which is live, at least when any appliance is switched on which is a certainty..
The fact that its outside is irrelevant... it is now the circuit protective conductor wires (connected to the live neutral bus bar at the fuse box) which becomes live in the event of an open PEN fault, its the earth wire connected to a now live neutral AND to the appliance which actually makes its metal chassis live. There IS no path to earth on a tncs remember, as its been cut off in the street somewhere! So you may well earth it when you touch the metal chassis, depending upon the floor covering and footwear.

As JW says in the vid, evs have rubber tyres, albeit I think they have a carbon black compound in them to dissipate any lightning strikes but not a good ground contact so the ev chassis would become live.. in fact just like any connected class 1 appliance in the house; hence my earlier statement.

It is indeed a tricky subject and not always clear what the earthing situation may be, as in the case with TNS, which you have rightly pointed out.
 
Hi, you will need an interlocking 32A commando socket for EV charging and something like a Matte PEN protection device.
You maybe better off with an Ohme with a commando plug to get on IOG.

My understanding is that:

IF your electricity supply uses TNCS earthing,
AND is capable of handling the additional 7kw on top of the existing load,
AND there is a spare way in the consumer unit for the necessary dedicated radial circuit,
AND a suitable PEN protection device (such as the Matt:e single phase EV range) is installed to protect that circuit,
then it is possible to install a 32A Commando socket and use that type of charger.

You will need an electrician to inspect the existing setup and confirm that it is suitable for that type of installation.

It may not be cheaper than getting a charger installed, and it won't have any means of controling charging schedules other than iSmart or whatever is built into the car.

But if all the conditions listed are met, it will get you 7kw home charging - it's the setup I have.
 
Depends on your house earthing system.. its only applicable to TNCS earthing systems as this is the only one which connects the Neutral conductor, or PEN, to the earth connection. Admittedly it is probably the most common system but eg mine is TT (earth rod), so not applicable for these, nor for TNS systems.
I also wonder why PEN fault protection is a requirement for ev charging but not for any other circuits eg for your lights, cooker or kettle?
An isolator switch for the commando socket is probably a good idea as I think most manufacturers recommend switching off the supply before the car.
I think whats different on an EV is you need to consider the car itself could backfeed 440V DC at many hundreds of amps.

The car's battery is probably more dangerous for an electric shock than the 240V mains!
 
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I spoke with a local sparky and they said "Granny chargers only used for emergencies".

I am in a modern UK 2014 build, two circuits both with RCD in the consumer unit and still waiting until the 29th Octo for the install of my EV Charger.

I get the car tomorrow and thinking if I get one of those "tough cables" with the built in RCD in the cable to external plug on a 1.5 thick cable to a plug downstairs would be suitable?

Is the sparky just being over cautious (He hasn't seen my specifics and speaking from a general perspective)

Thanks
 
I spoke with a local sparky and they said "Granny chargers only used for emergencies".

I am in a modern UK 2014 build, two circuits both with RCD in the consumer unit and still waiting until the 29th Octo for the install of my EV Charger.

I get the car tomorrow and thinking if I get one of those "tough cables" with the built in RCD in the cable to external plug on a 1.5 thick cable to a plug downstairs would be suitable?

Is the sparky just being over cautious (He hasn't seen my specifics and speaking from a general perspective)

Thanks
1.5?
 
I spoke with a local sparky and they said "Granny chargers only used for emergencies".

I am in a modern UK 2014 build, two circuits both with RCD in the consumer unit and still waiting until the 29th Octo for the install of my EV Charger.

I get the car tomorrow and thinking if I get one of those "tough cables" with the built in RCD in the cable to external plug on a 1.5 thick cable to a plug downstairs would be suitable?

Is the sparky just being over cautious (He hasn't seen my specifics and speaking from a general perspective)

Thanks
Granny chargers are legal and there is advice up thread on taking precautions. Best to assume there is a risk and to manage it.
 
I have only ever charged using the MG supplied granny charger. I do it from 12.00 to 5.00 am with the British Gas EV tariff. And I have never had any problems. Easily the cheapest way to charge an EV. Just like charging a phone.
Exactly the same for me. Granny charger set by schedule in the car 00.00-05.00 on cheap rate electricity. Get around 14% from that per night. It is using the Masterplug EV socket discussed earlier, electrician installed it and upgraded my earth at the same time.

I don't do any signficant distance except at the weekends so it is enough to keep the car topped up.

I have been wondering about getting a 16A command installed; at it would be faster. A proper charger is expensive I just physically don't have £1,000+ to spend on a new charger; plus as we are on looped supply it would mean digging up my neighbours drive, which doesn't make for good relations.
 
I spoke with a local sparky and they said "Granny chargers only used for emergencies".

I am in a modern UK 2014 build, two circuits both with RCD in the consumer unit and still waiting weeks for an install date for my EV Charger.

I get the car tomorrow and thinking if I get one of those "tough cables" with the built in RCD in the cable to external plug on a 1.5 thick cable to a plug downstairs would be suitable?

Is the sparky just being over cautious (He hasn't seen my specifics and speaking from a general perspective)

Thanks
The sparky is right, but, in the circumstances you've described, I don't see any reason not to use the granny at home until your charger is installed. The main issue you're likely to face is the long time it takes to charge. Just be aware that a granny doesn't have the safety features of a proper charging installation.
I've used mine once, with a tough lead extension with rcd, in a holiday cottage which was many miles from the nearest town with public chargers. It worked, but a 10 hour charge didn't give much of a top-up.
On the other hand, my neighbour has just got his first EV (not an MG) and doesn't have a charger. When he uses his granny a breaker in the consumer unit trips out, so he's using public chargers until he gets one installed.
If it works, you could do it until you get your charger. If the plug gets hot or the rcd trips, stop using it.
 
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The sparky is right, but, in the circumstances you've described, I don't see any reason not to use the granny at home until your charger is installed. The main issue you're likely to face is the long time it takes to charge. Just be aware that a granny doesn't have the safety features of a proper charging installation.
I've used mine once, with a tough lead extension with rcd, in a holiday cottage which was many miles from the nearest town with public chargers. It worked, but a 10 hour charge didn't give much of a top-up.
On the other hand, my neighbour has just got his first EV (not an MG) and doesn't have a charger. When he uses his granny the rcd in the consumer unit trips out, so he's using public chargers until he gets one installed.
If it works, you could do it until you get your charger. If the plug gets hot or the rcd trips, stop using it.
Hmm, I think for the two weeks then I have a large grid serve EV Forecourt near me, of course will be more pricy and less great for the battery but might not be a bad idea for me to just use the beefy chargers there to juice it up and it may then last me until EV install date.

As next week I will probably only do 60 miles for work and probably be out in the car as its new and shiny lol.
 
Hmm, I think for the two weeks then I have a large grid serve EV Forecourt near me, of course will be more pricy and less great for the battery but might not be a bad idea for me to just use the beefy chargers there to juice it up and it may then last me until EV install date.

As next week I will probably only do 60 miles for work and probably be out in the car as its new and shiny lol.

IMO that is silly and pouring money down the drain. If you are concerned select 8A, very concerned select 6A. (Keep in mind the car resets this selection each time)
 
I wouldn't. Your sockets will be 2.5mm² csa. I'd be after a cable with that.
As far as I understand, the 2.5mm² cable is a 30A ring main cable. The 1.5mm should be protected by a 13A fuse.
2.5mm² cable may not fit some of the plugs and sockets.
 
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