Can i wire an outside socket to a junction box located for a car charger?

Jordanntfc · Nov 27, 2023

Hi, i live in a new build house where they builders have left a junction box on the outside of my house. In the junction box there is a 6mm twin and eath cable and what looks like a Cat5 cable. The twin and earth is currently in connector blocks. This cable runs from the junction box straight to my Hager fuse board and is on a 32amp breaker. It is listed at the box as Car Charger which i imagine is done in case we want to add a car charger in the future. I want to remove the junction box and add an outdoor IP66 double socket but ideally would like to use the exisiting cable (6mm twin and earth) and the exisiting breaker (32amp) is this safely possible as i know both are higher than required. From what i have seen outdoor double sockets are normally wired in 2.5mm twin and earth and have an 13amp breaker?

buzzlightyear · Nov 27, 2023

It would be advised to get a spark in to down grade the fuse to a 16 amp in the Cu board and give you a minor test cert,
He can use the 6mm cable with out down grading that.

westward10 · Nov 27, 2023

It's fine to do as they suggest as long as there is 30ma RCD protection.

Risteard · Nov 27, 2023

buzzlightyear said:
It would be advised to get a spark in to down grade the fuse to a 16 amp in the Cu board and give you a minor test cert,
He can use the 6mm cable with out down grading that.

There's no benefit to downrating the circuit protection if there's a 6mm^2 cable there. That said, I'm not a fan of an EVSE being connected to a 32A protective device rather than a 40A as otherwise it's running at the full rating of the protective device for potentially many hours at a time.

littlespark · Nov 28, 2023

I would imagine it’s a 32A type A RCBO.
But agree, 40A would be better.

Is this 32A in the main consumer unit, or in a sub board on its own?

westward10 · Nov 28, 2023

I assume this isn't going to be used for an EV charger.

Spoon · Nov 28, 2023

The OP is only fitting a double socket to it.. It's not going to be pulling more than 32A

Risteard · Nov 28, 2023

Spoon said:
The OP is only fitting a double socket to it.. It's not going to be pulling more than 32A

Granted. My comment relates to how it was installed for the intended use. As such I don't believe that 32A was the correct choice. It is, however, ideal for a socket circuit.

Jordanntfc · Nov 28, 2023

westward10 said:
I assume this isn't going to be used for an EV charger.

No not at the moment anyway, i am just looking to put the outside socket in for December period to plug xmas lights into then after that i will remove and put back original junction box

Jordanntfc · Nov 28, 2023

littlespark said:
I would imagine it’s a 32A type A RCBO.
But agree, 40A would be better.

Is this 32A in the main consumer unit, or in a sub board on its own?

It is in the main consumer unit

littlespark · Nov 28, 2023

Jordanntfc said:
It is in the main consumer unit

Ok... Its not a problem, but as others have mentioned, A 32A breaker would be running at its limit while charging....

You're not using the circuit for car charging, so not really a valid point.

A double socket, although possible to plug in 2 x 13A loads, may only be rated for 20A, so I would advise having the breaker size reduced to 16A, just to protect the socket. (Will never reach that value if only xmas lights)

Spoon · Nov 28, 2023

littlespark said:
A double socket, although possible to plug in 2 x 13A loads, may only be rated for 20A, so I would advise having the breaker size reduced to 16A, just to protect the socket. (Will never reach that value if only xmas lights)

Ok, I don't want to come across like some sort of grumpy old fart.. (which I am) and maybe I need to listed to Marie Carry sing "All I want for christmas is you" 20 more times, while headbutting a wall but....
I know where you are coming from, for safety reasons, but as most sockets are wired back to 32A breakers I don't really see the need and expense in changing the breaker.

littlespark · Nov 28, 2023

if you were designing a circuit from scratch, knowing it was just going to be one outside socket (or two, being a double) then you wouldnt put it on a 32A.
Youde be protecting the cable.... which isnt an issue here, as its oversized anyway... ah... wait a minute......

Ok, scratch that. Im now thinking along the lines of an originally designed 32A radial wired in 4mm with regular double sockets on it. You could have the same 26A load plugged into any of them.

Ok. Just leave the 32A in place. Its not an issue.

"Grumpy old fart"?..... No, i think that particular scouser is laid up at the moment