Electrics to garage

[TimW]

I have a falling down old double garage a little way from the house and when I rebuild it I should run the electric out to it. If we are all going to be driving electric cars a garage without power in not going to be any use.

Previously you might have thought a few KW for lights and a heater, maybe a hoover, a drill, that sort of thing would be a fair guess of the requirement, and a battery charger would be a trickle only, but are car batteries going to have a fast charge facility. That's going to take a lot of power, what sort of wattage might I need in the next 20 years?

TW

[Andy Burns]

Unless you're going to spend six-figures on an EV, I'd say 7kW should cover what you'll need for charging.

[Theo]

I'd run a 32A circuit (7kW) for the car charger, unless you have three phase when it would be 32A three phase. I'd then run another circuit for random sockets, power tools, etc - ideally 32A but maybe you can only provide 16A, depends on what capacity you have. The car charger should have its own feed, rather than shared with other things (although I think you could fit a secondary CU).

I'd be tempted to throw a data connection in there as well. There are combined EV power and data cables:

although you might consider running fibre for future proofing: Theo

[ARW]

I am generally fitting 40A supplies to garages now on newbuilds/rewires.

32A for the charger (even though it might be 10 years away) and the spare 8A for the other stuff.

The extra cost of the thicker cable when doing the install is very little.

[The Natural Philosopher]

That was the recieved wisdom when wiring up CAT5 cable. The cable cost is irrelevant - its all the labour, so always lay 2-3 at once in case...

[Adrian Caspersz]

Best make it few strands of Fibre, to be safe.

When it becomes possible to have a personal home teleport installed, ye will need some extreme bandwidth to transfer over ya whole being in whatever standardised format comes about. Error corrected of course, don't want DNA dropouts ...

[Brian Gaff (Sofa]

More like 30, if single phase. I think Electric cars will be forced on people but then not many car owners will exist when autonomous pods roam the streets. Brian

[Andy Burns]

kilowatts or amps?

[Tim+]

I think Brian is confused. A typical home EV charger is 7kW/32amp.

Tim

[ARW]

Teleportation is the future

[Davidm]

A single cable, or separate for the 32A and 8A? What size cable if the garage is about 50m away from the house CU?

[Andrew]

expensive size

[ARW]

A 40A or 45A supply to a separate DB.

At 50m then 16mm (a guess based on experience) or subject to calcs 25mm for a 63A supply (I am guessing the 16mm will drop more than 3% at 63A)

[Vir Campestris]

Run a duct.

I've4 got cat5e out here to my mancave. It's good enough for now, I get gigabit back to the house. When that isn't fast enough I'll run whatever it is I need next through the duct.

I've only got 32A though - the cable fed the old garage, and replacing it was too hard. Direct buried.

Andy