Home charging query for incoming Tesla

Home charging query for incoming Tesla

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Hammy98

Original Poster:

857 posts

99 months

Wednesday 24th July
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Hi all,

I'm planning to buy a Tesla Model 3 Performance in the next week as someone's left a deposit to buy my current car.
I've switched over to Octopus energy in preparation for their intelligent EV tariff, however I've got a couple of potential sticking points...

My house was built in the 1950s and is an end terrace. My main fuse is in the house 2 doors up from me.

In preparation for the Octopus tariff, they said I'd need a smart meter installed. An engineer came out last week but my neighbour wouldn't let them in to turn off my main fuse despite me warning them a couple of days prior. I've rebooked it for next week and spoke to the neighbour again, so hopefully that wont be a problem this time. When the engineer was here, he did mention that I could have issues with the meter being an old style (rotating disc) and the consumer unit being old looking as well. He also implied that my main fuse may be 60A which could cause problems when the charger is running. A few questions...

My understanding was that the charger is installed before the meter - connecting into the supply but presumably having it's own meter. Is this correct? I'm struggling to find any actual installation info.

If I do infact have a 60A main fuse, is it as simple as my supplier changing this out or does this impact the actual feed into the house - new cabling needed?

Additionally - am I asking for trouble getting a 7kW charger fitted without upgrading the consumer unit etc?
I'd rather not if possible but wouldn't want to risk a fire.

Lastly - and as much as I know nothing about electrics I probably know the answer to this one... We have an outdoor socket on the side of the house which was wired into the livingroom ring circuit. I assume charging on this for the interim period until a proper charger is installed is a big no-no?

Cheers!

TooLateForAName

4,841 posts

191 months

Wednesday 24th July
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I'd be concerned that if the fuse is two houses away you might be on a looped supply. You need an electrician to look at the install.

quinny100

960 posts

193 months

Wednesday 24th July
quotequote all
The charger is installed after the meter. The preferred way to install, especially for old or dubious installations is to split the meter tails - cables between the meter and the main CU and drop a small dedicated CU in for the charger. This keeps the high current stuff away from an old CU.

Upgrading your fuse might be as simple as changing the fuse, or it might require fairly extensive work including digging to install a new supply. Impossible to say without assessment and is a job for the DNO.

The socket is probably your best option for now provided it’s properly installed. You can reduce the charge rate in the app very easily to 5A, although that’ll take 60-75 hours to charge from 0-100% but in reality you would top up as you need.

How many miles a day do you routinely do.

Hammy98

Original Poster:

857 posts

99 months

Thursday 25th July
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TooLateForAName said:
I'd be concerned that if the fuse is two houses away you might be on a looped supply. You need an electrician to look at the install.
Understood, the smart meter installer is coming back next week so I'll ask him about this...

Hammy98

Original Poster:

857 posts

99 months

Thursday 25th July
quotequote all
quinny100 said:
The charger is installed after the meter. The preferred way to install, especially for old or dubious installations is to split the meter tails - cables between the meter and the main CU and drop a small dedicated CU in for the charger. This keeps the high current stuff away from an old CU.

Upgrading your fuse might be as simple as changing the fuse, or it might require fairly extensive work including digging to install a new supply. Impossible to say without assessment and is a job for the DNO.

The socket is probably your best option for now provided it’s properly installed. You can reduce the charge rate in the app very easily to 5A, although that’ll take 60-75 hours to charge from 0-100% but in reality you would top up as you need.

How many miles a day do you routinely do.
Great, thank you. I was searching for this online yesterday but there's not a lot of actual installation info about...

Re the main fuse - my nextdoor neighbour had theirs moved to their own house (from the neighbour's where mine's is) a few years ago, so I'm hoping that means there's no extensive work required. I have no problem with the work myself however I suspect that the neighbour whos house the main fuse is in could be difficult about this if it's not something that can be done quickly.

I do 1k a month usually, however I only commute 2 days a week (100 mile round trip).




dreamcracker

3,257 posts

224 months

Thursday 25th July
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Hammy98 said:
Understood, the smart meter installer is coming back next week so I'll ask him about this...
The installer probably won't know anything, as they are only trained to fit smart meters.

Hammy98

Original Poster:

857 posts

99 months

Thursday 25th July
quotequote all
dreamcracker said:
The installer probably won't know anything, as they are only trained to fit smart meters.
Ahh okay, I thought they'd be able to tell when they get a look at the main fuse. Cheers!

Road2Ruin

5,492 posts

223 months

Friday 26th July
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When you book the EV charger install, the company will ask you loads to questions with regards to suitability. Ours also wanted photos of the consumer unit etc. They can advise whether fitting is possible, without upgrading anything.

quinny100

960 posts

193 months

Saturday 27th July
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Hammy98 said:
I do 1k a month usually, however I only commute 2 days a week (100 mile round trip).
100 miles will need about 25kWh. 10A from 3 pin plug will do that in about 11 hours, so you should be able to cover your commuting off a 3 pin plug until you get sorted.

Note that is advantageous to use a slower charger with Octopus Intelligent Go because they will extend the cheap rate window, during which your other home usage is charged at the cheap rate. When you set it up in the app set the charger to 3 pin even if you have a wall charger (assuming IOG is controlling the car rather than the charger, which is fine with a Tesla).

blueacid

483 posts

148 months

Tuesday 30th July
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Hammy98 said:
Ahh okay, I thought they'd be able to tell when they get a look at the main fuse. Cheers!
If you're able, could you post a photo of the meter / consumer unit / surrounding area? Feel free to cover any serial numbers or barcodes on the meter with a piece of paper if you wish, but the wiring and surrounding area would be very helpful to see & advise you.

I'm doing a 2x 80 mile round trip each week, doing it on the 3-pin at 10A is going fine. If I'm back from a road trip late on Sunday night then I can't charge enough for Monday morning, but I'm ready for Tuesday,

ashenfie

846 posts

53 months

Thursday 1st August
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The smart meter in my case is the electric meter and the gas meter sends data to the electric meter. The data is then send to the electric company and your smart display. That means the gas and electric meters need to be close enough to transfer data. So moving your meter maybe a good idea.

In terms of the 60amp fuse. You could get this upgraded quite simply to a 100a one. The car charging alone runs of a 32a spur.

The current socket as you suspect is not up to modern standards and should have is own consumer box and rcd etc.

Sadly smart meters are a shockly bad design and I am on my 3rd in as many years. So if your neighbour is a pain about having workmen access the meter, maybe time to move it.

Other things you should consider arethe earthing arrangements and rcd which mostly like are not up to modern regs