How to wire an extra garage power socket?

[saladdays]

Hello All,

Currently the consumer unit and double socket are on the end wall in my detached garage. I'd like to move the socket to the middle of the garage and install another on the opposite wall. So two sockets opposite each other about 3m from CU.

How would you do it?
Option 1: wire in the first socket and put the other in series with the cable over the joists.
Option 2: use a junction box above CU to split the supply.
Option 3: Put another 2.5mm cable into the CU using the same terminals as the other socket.

I use power tools in my garage. The biggest is a 2kW grinder.

CU:

CU from above

Thanks.

 

[EFLImpudence]

It doesn't really matter which method you use, although the sockets will be wired in parallel, not series.
It depends on the location of the sockets and how you want to route the cables.


There is no over-current device for the socket in the garage (assuming the socket is not on the 6A MCB) so it must be in the house.
Is the supply run from an MCB in the house consumer unit or just taken from the socket circuit in the house?

Where does the green wire go?

 

[saladdays]

Thanks for your reply. The 6A MCB is for the lights. The detached garage must be on a spur from the lower ring circuit.
Kitchen CU:

The green wire goes to an earthing rod outside.

I'm now off to Screwfix to buy the bits.

 

[EFLImpudence]

Ok.

As it is supplied from the ring circuit there should be a (switched) Fused Connector Unit at the beginning of the garage circuit.
Is there one?

 

[saladdays]

No FCU anywhere, eek! Before you ask, it wasn't me! The garage power was installed sometime before 2004 (red and black wires).

 

[EFLImpudence]

Then, as the protection on the house ring is 32A, if you want more than one socket in the garage, the spur should be protected with either -

an FCU on the supply cable to the garage unit, anywhere will do. like just above the garage CU although in the house would be better,

There are various other options (like relacing the garage CU) but it would be more complicated and expensive.

 

[winston1]

The garage power was installed sometime before 2004 (red and black wires).

Maybe. Or somewhat later by someone who had old wire left over. You can still find red/black on a certain auction site.