Electric car charging point - cable size?

leo738

Hello all,


We're planning to get an electric car next year (probably a used Nissan Leaf). I'm probably going to run the cables myself from the consumer unit/ fuse board to a point outside in preparation for the charging point. I understand that there is a grant available but I'd rather run the cables myself & let the installer simply mount the charging point.


My question is what size cable should I run?



I only want to do this once & we're planning to stay in this house for the foreseeable future hence I want to run a cable that'll prove to be too big rather than too small down the road.

• Being able to fast charge would be nice &
• if possible the ability to charge two EV's simultaneously would be useful (not sure if that possible).
  The cable run will be short, less than 4 metres
• We don't have an electric pumped shower in the house.
  

Regards,


Leo

KCross

Two 6mm2 cables.

leo738

Thanks for the quick reply.

Would you wire them in parallel or keep them separate?
Any advantages to using one larger wire?

KCross

leo738 wrote: »

Thanks for the quick reply.

Would you wire them in parallel or keep them separate?
Any advantages to using one larger wire?

Separate feeds from the consumer unit.

I said two because you mentioned two EV's in future so each charge point would get a dedicated cable from the consumer unit.

In the case of two EV's you want both EV's to be able to charge at 32A each but you will likely load share to a max of <50A when both are charging together.

If you had one 6mm2 cable it would do 32A but not suitable for 50A+.
You could put in one 10mm2 cable and it would cover 50A but only in certain circumstances. i.e. it wouldnt want to be inside an insulated slab where heat wouldnt dissipate.

So, its generally better to use two 6mm2 cables as they will both comfortably do 32A each. If it was a longer run you should use 10mm2 but for 4m, 6mm2 is plenty.

leo738

Great, many thanks!

n97 mini

Installer has to do more than mount the CP to qualify for the grant. Various tests have to be done as well.

Run the cables by all means yourself, but the sparks will be going at the consumer unit anyway.

optimal

If you are running a longish distance you will have to run 10 sq. Get some advice on that first.