Domestic Connection - how many kVA for car charger?

[edent]

Morning,

I want to get my garage hooked up to the National Grid. Have contacted UK Power Networks and they want to know how many kVA I'll need.

Can anyone help me calculate it?

It'll just be for a couple of light bulbs, possibly a garage door opener, and an Electric Car charger.

I'm guessing the lights & opener don't add up to much - but does anyone know how much load an EV charger will need?

Only looking at single phase - think 3 phase may be too expensive.

Thanks

 

[jameseye12]

Do you really need a separate connection off the grid or could a supply be installed as a circuit from the house?

---------- Post Auto-Merged at 10:32 ---------- Previous post was made at 10:28 ----------

And most car chargers are designed to plug into your avereage everyday 13amp socket. Have not yet seen a bigger one. In theory, a 20amp supply would probably suffice

 

[edent]

It's a physically separate garage - so no chance of running my supply over to it.

It's literally next to one of those walled off transformers - so distance shouldn't be a problem.

 

[Manator]

Splitting your house supply and running a cable across to your garage would be the cheaper option, a single phase separate supply for such low usage would be costly both initially and in terms of standing charges.

 

[edent]

Sadly, I think splitting my connection would involve digging up the road - probably not very practical!

 

[sellers]

So would getting a connection from the dno.

 

[Steve3948]

I don't think you can take private cabling across public/council/highway, wayleaves permissions etc.

To them Garage could mean full blown trading garage with ramps the lot, unless you explained it was just a private domestic garage.

You will get 63/80/100A anyway depending on area.

 

[Andy™]

anyone on that side you could get a supply from with a private meter, and you pay them for what you use?

 

[Manator]

I don't think you can take private cabling across public/council/highway, wayleaves permissions etc.

I never thought of that Steve, you could be right there.In fact I am sure it is not allowed due to the requirements for service detailed drawings held by the utilities and given on request to road workers and the like.

---------- Post Auto-Merged at 11:44 ---------- Previous post was made at 11:23 ----------

Back to the op, if you work on the assumption of say 40 amps then the resulting kVA would be around 9, 60 amps would be around 13. It would be highly unlikely you would require any more than that.

 

[edent]

Thanks all - will recommend ~10kVA. Have told them it's for very light use.

 

[a1]

Make sure you sit down when your read the "Quote" letter from them. Even if you get a company to dig the road and lay the duct and nylon rope through it. It's very expensive. At least, it is with SSE/WPD.

 

[edent]

Make sure you sit down when your read the "Quote" letter from them. Even if you get a company to dig the road and lay the duct and nylon rope through it. It's very expensive. At least, it is with SSE/WPD.

Over the phone they quoted around

 

[Steve3948]

Over the phone they quoted around

 

[edent]

Good info to have - thanks

 

[sellers]

When you say the road do you mean your drive/road or the highway? Is there a highway between the your house and garage?

I think you are thinking that the electricity company will come straight off the transformer thats next to your garage, but in reality they will probably come off the existing cables under the road, so they will be digging the road up too be it private or public.

If it's private then you might aswell come off your own existing supply.

 

[SteveT]

Do you really need a separate connection off the grid or could a supply be installed as a circuit from the house?---------- Post Auto-Merged at 10:32 ---------- Previous post was made at 10:28 ----------

And most car chargers are designed to plug into your avereage everyday 13amp socket. Have not yet seen a bigger one. In theory, a 20amp supply would probably suffice

First point

home EV chargers are designed to provide a trickle charge and should be on their own 16A cct (Higher power chargers are coming which will need a 32Amp radial) so the home EV chargers are like having an extra shower fitted at most. That said most EV chargers are used overnight, making use of lower tariffs, when other high KW ccts would not be in operation.

The second is that it is not recomennded that EV chrging should be done with a 13Amp set-up, you should have a dedicated charger and cct. The 13A option is for emergency use only. The dedicated chargers are controlled to limit charging, preventing overheating and other dangerous conditions to arise. I believe this will eventually be written into the wiring regs.

Schnieder Approved Residential EV Link installer.

 

[edent]

First point home EV chargers are designed to provide a trickle charge and should be on their own 16A cct (Higher power chargers are coming which will need a 32Amp radial) so the home EV chargers are like having an extra shower fitted at most. That said most EV chargers are used overnight, making use of lower tariffs, when other high KW ccts would not be in operation.

The second is that it is not recomennded that EV chrging should be done with a 13Amp set-up, you should have a dedicated charger and cct. The 13A option is for emergency use only. The dedicated chargers are controlled to limit charging, preventing overheating and other dangerous conditions to arise. I believe this will eventually be written into the wiring regs.

Schnieder Approved Residential EV Link installer.

So, would you recommend I get 3 phase fitted now so I can fit a rapid charger? If so, how many kVA will I need to ask for?

If I'm just getting single phase, then there'll be nothing else plugged in to the 13Amp circuit, so shouldn't cause an issue, right?

Thanks for all your help on this guys - much appreciated.

 

[wozz]

I cant see you needing 3 phase imagine how limited the market would be if EV manuf needed this. seems like it would be shooting themselves in the foot.

I read a article about the testing of plugs for EV charging and it seemed to point out they were fine for 13A for prolonged amounts of time. I think it was in PE i read it.

 

[edent]

I cant see you needing 3 phase imagine how limited the market would be if EV manuf needed this. seems like it would be shooting themselves in the foot.

All EVs will trickle charge on single phase. Usually 6-9 hours to fully charge. Perfect for overnight, or leaving at work's car park.

3 phase will charge it to 80% in 30 minutes. Perfect for motorway pit stop. I guess I don't really need 3 phase, but if it wasn't going to be much more expense, there's no harm in having it as an option.

 

[wozz]

All EVs will trickle charge on single phase. Usually 6-9 hours to fully charge. Perfect for overnight, or leaving at work's car park.3 phase will charge it to 80% in 30 minutes. Perfect for motorway pit stop. I guess I don't really need 3 phase, but if it wasn't going to be much more expense, there's no harm in having it as an option.

It will all come down to how you use it then, if you can get away with not having to rapid charge you will save money.

out of interest what vehicle are you thinking about?

cheers