Planning for Car charger and upgrade to garage circuit

[Windy123]

Hi,

I am having a new patio laid next year, and would like to lay some cable underneath it in preparation for a car charger so that the installer doesn't need to run the cable around the house when it is done (The fuse board is on the opposite side of the house to the garage).

I also have an office in the garage which is powered by a spur from the ground floor ring. The office has building reg's and electrical certification, however the engineer said it was near the limit for the amount of power it could deliver.

I'd like to lay the charger cable, and a cable ready to connect the fuse box directly to the garage on it's own ring, but i am not sure what size and type of cable I would need. i was assuming 2.5mm 3 core armoured cable but if this is not the case can anyone advise?

Many thanks in advance.

Dave

 

[Gavin John Hyde]

2.5MM 3 CORE SWA would not do. assuming a 32 amp car charger, many of which need a 40 amp protective device and then also supplying other circuits in the garage I would run 10mm SWA
it gives ample for a car charger and to improve the capacity for the electrics in the garage.
If you can sort out the loads in the garage you could run 6mm SWA instead.

 

[Strima]

As above, go bigger to give yourself some wiggle room.

When you cut to length roughly measure where you want it and add 2 meters to each end, always better to have too much than too little.

 

[EalingBadger]

Do you have a 60A or a 100A main supply cutout (fuse)?

If the former you may want to check with an electrician and your DNO that you can be upgraded. Especially if you rely on electrical water or room heating anywhere else in the building as adding a high power car charger to the mix can push things too close to the limit.

I heard a rumour earlier today that some DNOs are struggling to upgrade some premises due to looped supplies.

It would be gutting to install a nice shiny new cable and then only find out later that you couldn't actually make use of it.

 

[Windy123]

Many thanks for all the information. The power requirement in the garage are not heavy, it is an office not a workshop and the only big draw item is an electrical heater that is rarely on and never beyond the lowest setting. I'll find a local electrician to have a look.

Thanks again for all the advice, much appreciated.

 

[Dustydazzler]

Might be cheaper to whack some of this in ...

63mm Twin Walled Cable Duct - Black | Univolt (FXKVR 63)

Then the sparks at a later date can pull in the relevant cable

 

[Spoon]

I'd like to lay the charger cable, and a cable ready to connect the fuse box directly to the garage on it's own ring, but i am not sure what size and type of cable I would need. i was assuming 2.5mm 3 core armoured cable but if this is not the case can anyone advise?

Welcome to the forum mate.
I might be reading this wrong but is the intension to run 1 cable from the house CU (Consumer Unit) to the garage and this will supply both the car charger and the new ring?
or is the intension to run 2 cables from the house CU to the garage, 1 for the car charger and 1 for the new ring?

 

[Gavin John Hyde]

Do you have a 60A or a 100A main supply cutout (fuse)?

If the former you may want to check with an electrician and your DNO that you can be upgraded. Especially if you rely on electrical water or room heating anywhere else in the building as adding a high power car charger to the mix can push things too close to the limit.

I heard a rumour earlier today that some DNOs are struggling to upgrade some premises due to looped supplies.

It would be gutting to install a nice shiny new cable and then only find out later that you couldn't actually make use of it.

Around here WPD will give customer option of having looped supply removed at no cost. If not they will permit a charger subject to use of CT clamps which restricts the charger choice

 

[Windy123]

Welcome to the forum mate.
I might be reading this wrong but is the intension to run 1 cable from the house CU (Consumer Unit) to the garage and this will supply both the car charger and the new ring?
or is the intension to run 2 cables from the house CU to the garage, 1 for the car charger and 1 for the new ring?

So sorry for the late reply, I missed the notification.

I plan to run two cables, currently planning 2 x 6mm swc

 

[pc1966]

You could also put in duct so a cable can be pulled through later. Something like this would be fine for up to 10mm SWA or similar along side another for the garage, etc.

50/63mm Class 3 Electric Cable Black Ducting Coil (50m)

50m 50/63mm black ducting coil for electricity cables in Class 3 applications. With coupler and draw cord.

store.jdpipes.co.uk

Also in larger sizes. But whatever you do keep all bends as gentle as possible and runs as straight as practical.

Edited to add: Seems that @Dustydazzler beat me to it!

 

[brianmoooore]

I plan to run two cables, currently planning 2 x 6mm swc

One for the charger and one for the garage? Don't like that idea at all, ever since I fell foul of a similar set up many years ago, after starting work on the wiring in an outbuilding after switching off the supply.
One isolator (and one feed) for one building.

 

[Windy123]

One for the charger and one for the garage? Don't like that idea at all, ever since I fell foul of a similar set up many years ago, after starting work on the wiring in an outbuilding after switching off the supply.
One isolator (and one feed) for one building.

That is probably my description confusing things. One fed will go into the garage. The second feed will also route under the new platoon but will terminate on the side wall of the house and not go into the garage at all.

 

[Windy123]

That is probably my description confusing things. One fed will go into the garage. The second feed will also route under the new platoon but will terminate on the side wall of the house and not go into the garage at all.

Typo platoon = patio!

 

[Midwest]

If you just put in some ducting for the time being, get some thicker rope rather than the silly string thats provided.

 

[brianmoooore]

The string provided is to pull in a proper rope to attach to the cable. The blue stuff you get from BT/Openreach engineers, with their policy of always using a new drum of rope for every job, however little they need.