Home charging point

[davyk31]

The person I was enquiring with said

We like to get a cable back for CT clamp back to main fuse so the charger doesn’t blow the NIE fuse.

Doesn’t mean a lot to me but according to what I am reading here it sounds wrong but he is a grant approved supplier so would expect the job would be done right.

 

[mk2driver]

@stevieturbo - I’ll have to get a look at mine when I get home, I do know the RCD for the EV is in the main consumer unit inside the house as it had the capacity to do that and is on the internal wall beside the meter box

So there was an additional run of cable added from outside into the consumer unit - it’s in a downstairs loo so we just added it straight in rather than track walls

Doesn’t look the best but I don’t care when it’s in that room and up high

 

[stevieturbo]

The person I was enquiring with said

We like to get a cable back for CT clamp back to main fuse so the charger doesn’t blow the NIE fuse.

Doesn’t mean a lot to me but according to what I am reading here it sounds wrong but he is a grant approved supplier so would expect the job would be done right.

No, it is right and exactly what I've already said and has been covered in the previous install videos.

If it is a high powered charger it needs a CT ( current transformer, which basically allows the unit to monitor current draw on the entire installation so it can reduce the EV charge if need to to prevent blowing the incoming fuse )

But that is not the same as actually taking the main supply for the charger directly from the meter unit.

It's simply a small low voltage signal wire between the CT and control unit.

@stevieturbo - I’ll have to get a look at mine when I get home, I do know the RCD for the EV is in the main consumer unit inside the house as it had the capacity to do that and is on the internal wall beside the meter box

So there was an additional run of cable added from outside into the consumer unit - it’s in a downstairs loo so we just added it straight in rather than track walls

Doesn’t look the best but I don’t care when it’s in that room and up high

That sounds correct. The supply "should" always come from a consumer unit. And that CU should not be in the external metering cupboard. But as already seen, many do for their own ease of install, whether right or wrong.

it is definitely something that needs addressed pronto with new builds given the push for battery vehicles. And not just provision for a single charger...I'd say at least two on most households. With a suppliers incoming supply to match the potential loads of new stuff, including the likes of heat pumps and other devices that has been mentioned in other topics.

 

[Daviddunlop83]

The person I was enquiring with said

We like to get a cable back for CT clamp back to main fuse so the charger doesn’t blow the NIE fuse.

Doesn’t mean a lot to me but according to what I am reading here it sounds wrong but he is a grant approved supplier so would expect the job would be done right.

The CT clamp is to measure total current coming out after the main fuse. It’s only a small 2 core screened cable.

If nothing else is connected from the main fuse to the consumer unit it can be on the main tail coming from the NIE fuse anywhere on the line.

Interested also in whether 22kW can run on domestic single phase. I fitted a 22 at work and from memory the fitter said it could be either single or 3 phase but that may be different as it’s an industrial setting.



Yes cable costs can be high I’m sure and also as my garage is remote to the house then it involves finding the duct that takes the cables from the house to the garage and feeding back through there which is all under the drive and paths. At least we haven’t tarred yet around the house

No 22KW on single phase is over 100 amps.

Most domestic chargers are 7KW

 

[Coog]

So here's a before and after on our meter cupboard (or whatever the frig it's called). I don't recall anyone coming into the house to the other electrical box I've always known as the 'consumer unit'.

Before:

After:

Yellow circle is the CT. Red circle is headed to the pod point which is a foot or so to the right.

 

[Daviddunlop83]

So here's a before and after on our meter cupboard (or whatever the frig it's called). I don't recall anyone coming into the house to the other electrical box I've always known as the 'consumer unit'.

Before:

View attachment 340196

After:

View attachment 340197

Yellow circle is the CT. Red circle is headed to the pod point which is a foot or so to the right.

Never seen multi core cable like that used to feed a consumer unit tbh.

I think someone said NIE are cracking up with consumer units being fitted into the electrical box. (We have one too as the hot tub takes its feed from the electrical cabinet)

Nothing actually wrong from a safety point of view but NIE don’t like it for some reason

 

[Daviddunlop83]

I’ve only a photo before. Well new cable in there

 

[davyk31]

Never seen multi core cable like that used to feed a consumer unit tbh.

I think someone said NIE are cracking up with consumer units being fitted into the electrical box. (We have one too as the hot tub takes its feed from the electrical cabinet)

Nothing actually wrong from a safety point of view but NIE don’t like it for some reason

I would imagine it is firstly as they don’t like people messing in there but mainly because if the area gets filled with other stuff and they ever need to change a meter there may not be enough room left.

 

[stevieturbo]

22kw at 230v is 95.6A and yes such chargers are available...but as said, they have CT's to ensure they should never blow the supply fuse. In reality will you ever actually see a full charge current ? perhaps not.

The cable you see is a split concentric, very common supply cable. Similar in design to a SWA, just without the SWA. central brown core, and the outer strands wrapped around it make up the neutral and earth. Just makes for a smaller diameter supply cable .

And what has been done in that meter enclosure as the video discusses, is what should not be done. But is done by many for ease of install.

the video discusses all the reasons why it isn't a free for all in the meter enclosure.

I’ve only a photo before. Well new cable in there

View attachment 340198

WTF is going on there ? 2 main supply incomers linked in some weird way ??

 

[mk2driver]

Just looked at mine and nothing other than the CT clamp is in the meter box for the EV charger

Cable from the consumer unit runs out and down the house and outside the meter unit at the bottom there is a junction box to the fully armoured cable that runs to the charger itself

 

[stevieturbo]

So here's a before and after on our meter cupboard (or whatever the frig it's called). I don't recall anyone coming into the house to the other electrical box I've always known as the 'consumer unit'.

Before:

View attachment 340196

After:

View attachment 340197

Yellow circle is the CT. Red circle is headed to the pod point which is a foot or so to the right.

So they cut the NIE seals on the isolating switch ? then moved it. Pretty sure tampering with the seals without permission is an offence. Live working is another can of worms, although H&S related ( although most sparks do flout those rules all too often and do mess with live stuff when they should not....and in part is why that switch is there in the first place, to allow an electrician to isolate the installation for safe works....however the only way they can have moved that isolator and shortened the tails is by doing it live or by cutting the seals which it appears they have done on the incoming fuse and removing it, again an offence. )
However it is worth baring in mind, live working there is about as dangerous on single phase as you can get, as there is basically zero protection from electric shock.

There are far more wrongs in that enclosure than there are rights.

Although assuming the finished job has suitable protective devices in the new CU....that side of things should be electrically ok and safe. Even if what was done to achieve it is illegal.

 

[Daviddunlop83]

22kw at 230v is 95.6A and yes such chargers are available...but as said, they have CT's to ensure they should never blow the supply fuse. In reality will you ever actually see a full charge current ? perhaps not.

The cable you see is a split concentric, very common supply cable. Similar in design to a SWA, just without the SWA. central brown core, and the outer strands wrapped around it make up the neutral and earth. Just makes for a smaller diameter supply cable .

And what has been done in that meter enclosure as the video discusses, is what should not be done. But is done by many for ease of install.

the video discusses all the reasons why it isn't a free for all in the meter enclosure.


WTF is going on there ? 2 main supply incomers linked in some weird way ??

Would anyone actually try and pull that sort of current on a domestic supply?

I think they have used the other 100amp fuse as a junction from the trip before going into the house? It’s not linked. It’s from meter to trip then that fuse then into house.

There is another one at the other end then goes into the brown blocks before splitting into 2 consumer units too. Can’t really have too many fuses surely? Lol

So they cut the NIE seals on the isolating switch ? then moved it. Pretty sure tampering with the seals without permission is an offence. Live working is another can of worms, although H&S related ( although most sparks do flout those rules all too often and do mess with live stuff when they should not....and in part is why that switch is there in the first place, to allow an electrician to isolate the installation for safe works....however the only way they can have moved that isolator and shortened the tails is by doing it live or by cutting the seals which it appears they have done on the incoming fuse and removing it, again an offence. )
However it is worth baring in mind, live working there is about as dangerous on single phase as you can get, as there is basically zero protection from electric shock.

There are far more wrongs in that enclosure than there are rights.

Although assuming the finished job has suitable protective devices in the new CU....that side of things should be electrically ok and safe. Even if what was done to achieve it is illegal.

Those NIE guys who work live are mad lol a guy I know got a new supply connected to the mains out in the street and he just climbed into the hole and connected the new 3 phase cable up live

 

[davyk31]

I will be fitting my charger in the garage which is remote to the house and meter. There is a separate consumer unit in the garage to feed all the plugs, lights and electric doors in there. Would the charger be connected there in which case it’s not too long a cable run needed and then a smaller one taken back a distance for the CT at the meter board?

 

[mk2driver]

I will be fitting my charger in the garage which is remote to the house and meter. There is a separate consumer unit in the garage to feed all the plugs, lights and electric doors in there. Would the charger be connected there in which case it’s not too long a cable run needed and then a smaller one taken back a distance for the CT at the meter board?

I had a similar thought but the issue was the consumer unit in the garage was connected to the house consumer unit but cable that was too small for the current draw of the charger. Like you my garage is detached from the house and the opposite side to the consumer unit / meter

Hence why it had to go all the way back to the main consumer unit and the 20m run of cable

Did to the way my house is rendered etc I was happy to run it around the bottom of the house rather than dig everything up

Others wouldn’t be happy with this but our house already had sky cables, fibre broadband cables etc on the outside so it was grand for me

 

[Daviddunlop83]

I will be fitting my charger in the garage which is remote to the house and meter. There is a separate consumer unit in the garage to feed all the plugs, lights and electric doors in there. Would the charger be connected there in which case it’s not too long a cable run needed and then a smaller one taken back a distance for the CT at the meter board?

As above it depend on how the garage is wired/cable size.

When I did the garage I put in a large cable on a 100amp supply for future if I do add a charger etc

 

[stevieturbo]

I will be fitting my charger in the garage which is remote to the house and meter. There is a separate consumer unit in the garage to feed all the plugs, lights and electric doors in there. Would the charger be connected there in which case it’s not too long a cable run needed and then a smaller one taken back a distance for the CT at the meter board?

If it is a high power charger, then the CT's must monitor all current draw on the entire installation.

 

[davyk31]

I think most home chargers are 7kw which aren’t that quick and likely to be outdated pretty soon in the future. Is an 11kw ok for a domestic installation or too heavy a draw?

 

[stevieturbo]

Would anyone actually try and pull that sort of current on a domestic supply?

I think they have used the other 100amp fuse as a junction from the trip before going into the house? It’s not linked. It’s from meter to trip then that fuse then into house.

There is another one at the other end then goes into the brown blocks before splitting into 2 consumer units too. Can’t really have too many fuses surely? Lol


Those NIE guys who work live are mad lol a guy I know got a new supply connected to the mains out in the street and he just climbed into the hole and connected the new 3 phase cable up live

In a normal house chances of exceeding the 80/100A supply is very slim for the most part.

But times have changed. Whilst most devices do use less energy now, lights, various devices in the house....we do have more of them. But generally a normal house wont use much.
EV's can massively change that.

2 battery cars with 2 x 22kw chargers ? Not a chance. Even one 22kw charger....would need to ensure almost nothing else is on in the house during charging if you were to try and fully avail of the maximum charge rate.
And EV's also change things in that they will take a few hours

Normally the heaviest loads might be a shower, cooker etc....but generally they'd be say 30 mins max ?

But say someone taking a shower ( 10kw ), boiling a kettle ( 3kw ) and another with a couple of cooker rings on ( say 3-4kw ).....doesn't leave you much to charge a car at the same time
And maybe washing machine, tumble dryer etc etc, and that's without lights and all the other stuff like phones, Wifi units, computer, TV's etc etc although they'd all generally be small.

I'd imagine most high power chargers would be set to only start charging when you're fast asleep

Can the existing infrastructure handle it ? perhaps....maybe...maybe now it can, EV use is low, most have slow chargers say 6-7kw. If they become mainstream and expect an ability to fast charge at home, with some homes having 2+ cars ?
Very grey area for the future.

I think most home chargers are 7kw which aren’t that quick and likely to be outdated pretty soon in the future. Is an 11kw ok for a domestic installation or too heavy a draw?

Again depends if it is managed or not.

22kw is doable, when it is managed by the controller to not exceed any supplies.

Really, even a 11kw should have CT's to ensure things are not pushed too hard. Because how does it know it is the only charger on the installation ? You fit two...and main fuse blows, NIE replacement only. You've no electric til then ( unless again those seals are illegally cut and fuse replaced )

 

[Daviddunlop83]

In a normal house chances of exceeding the 80/100A supply is very slim for the most part.

But times have changed. Whilst most devices do use less energy now, lights, various devices in the house....we do have more of them. But generally a normal house wont use much.
EV's can massively change that.

2 battery cars with 2 x 22kw chargers ? Not a chance. Even one 22kw charger....would need to ensure almost nothing else is on in the house during charging if you were to try and fully avail of the maximum charge rate.
And EV's also change things in that they will take a few hours

Normally the heaviest loads might be a shower, cooker etc....but generally they'd be say 30 mins max ?

But say someone taking a shower ( 10kw ), boiling a kettle ( 3kw ) and another with a couple of cooker rings on ( say 3-4kw ).....doesn't leave you much to charge a car at the same time
And maybe washing machine, tumble dryer etc etc, and that's without lights and all the other stuff like phones, Wifi units, computer, TV's etc etc although they'd all generally be small.

I'd imagine most high power chargers would be set to only start charging when you're fast asleep

Can the existing infrastructure handle it ? perhaps....maybe...maybe now it can, EV use is low, most have slow chargers say 6-7kw. If they become mainstream and expect an ability to fast charge at home, with some homes having 2+ cars ?
Very grey area for the future.


Again depends if it is managed or not.

22kw is doable, when it is managed by the controller to not exceed any supplies.

Really, even a 11kw should have CT's to ensure things are not pushed too hard. Because how does it know it is the only charger on the installation ? You fit two...and main fuse blows, NIE replacement only. You've no electric til then ( unless again those seals are illegally cut and fuse replaced )

And then throw in heat pumps and then we really are in trouble.

I think most home chargers are 7kw which aren’t that quick and likely to be outdated pretty soon in the future. Is an 11kw ok for a domestic installation or too heavy a draw?

Is 7KW not ok for majority of people who charge the car all night anyway? Would 7KW fully charge a car overnight ok?

Why such need to charge it so quickly at home? I can understand the massive power ones at service stations etc or public as they are shared.

 

[Coog]

7kw will easily charge overnight. Only really need more than that if you haven’t planned ahead or are doing multiple long trips per day.

 

[davyk31]

Even with a 22kW charger most cars at present will only charge at 10 or 11kw. A 7kw would take 7 or 8 hours to fill my car from empty, many people might like a bit quicker if they have a tariff giving lower cost for 4 or 5 hours at night.

 

[mk2driver]

Even with a 22kW charger most cars at present will only charge at 10 or 11kw. A 7kw would take 7 or 8 hours to fill my car from empty, many people might like a bit quicker if they have a tariff giving lower cost for 4 or 5 hours at night.

I just don’t let the car get down to a low SOC too often

Even if I do I charge it over a couple of nights - 99% of my journeys I dont need anything over 80 miles total range which is 1/3rd of what I get in the I-Pace

Overnight charge for 4 hours on my Octopus Go tariff gets me 28kWh which is 30% of the capacity so essentially matches my typical max daily distance

However even those 80 mile daily coverage is relatively rare so I never gave any issues

 

[stevieturbo]

And then throw in heat pumps and then we really are in trouble.


Is 7KW not ok for majority of people who charge the car all night anyway? Would 7KW fully charge a car overnight ok?

Why such need to charge it so quickly at home? I can understand the massive power ones at service stations etc or public as they are shared.

7kw is probably enough for a "normal" user...and a single car as they don't need to charge up quickly.

Most houses have 2 cars ? So that's up to 14kw....will it have stopped charging by the time you need a shower in the morning ? 24kw boom. Some more than 2 cars, some might have 2 electric showers etc etc.

Existing household supplies never envisaged the sort of power demands that are now presenting themselves. So lots of power management will be needed going forward.

I've seen videos saying the existing grid can handle it ok, as what is used during the day, massively exceeds what is used during the night, that's as far as power stations are concerned. It doesn't really factor in where the power is going and can existing home cabling and road cabling to households can cope with demands that were never expected.
Yes households have 80-100A supplies...but it's doubtful they were ever designed to run at or near this capacity for extended periods, and every single house.

I don't know if the smaller chargers normally have CT's to manage overall power use....if one is available, that is what I would be buying as it will become an issue in the future and nobody wants the hassle of popping the suppliers fuse and leaving you without power. Which requires them to come out and inspect/replace the fuse as it is illegal to cut or tamper with the seals they have fitted....even if it seems a free for all with people cutting them off to do what they want.

Still early days yet though, so who knows.

And yes, heat pumps...don't know much about them myself, but same sort of thing, aircon can use a fair bit of electric. And seems that will be yet another continuous drain of electric, not just a few minutes here and there.

Lots of planning needed for existing houses going forward if you intend to use a lot of electric.

 

[Marc]

7kw is probably enough for a "normal" user...and a single car as they don't need to charge up quickly.

Most houses have 2 cars ? So that's up to 14kw....will it have stopped charging by the time you need a shower in the morning ? 24kw boom. Some more than 2 cars, some might have 2 electric showers etc etc.

The new gen chargers can be “linked” so as to limit power draw in this scenario of 2 cars charging at the same time.

 

[stevieturbo]

The new gen chargers can be “linked” so as to limit power draw in this scenario of 2 cars charging at the same time.

Yes, but then that 7kw, potentially becomes 3.5kw and takes twice as long. So if it was say a 5 hour charge in a reduced rate window....now it will take 10 hours, and you will not get the full reduced rate.

But power management all round will be essential going forward