Garage Electrics

[Martin Carroll]

I am just doing the garage electrics on the renovation and have a couple of questions.

The (single) garage is only a couple of metres from the house and I have

3 core SWA (2.5mm) running under the path into the garage. According to the TLC calculator this will give up to 5kW power.

On the house side I have not run the SWA all the way to the CU and need to connect it to 2.5 mm T&E somehow. The SWA runs up a wall and will be boxed in so I had planned just putting a blanking plate on the plasterboard allowing access to the cable join. Is it feasible to use choccy blocks for this?

The T&E will run to a spare way on the CU (not RCD protected) and will have a 2-way CU in the garage. The garage will only have a lighting circuit and one (maybe two) double power sockets.

I had planned to export the house earth using 1 core of the SWA.

Presumably at the join to T&E the outer steel protection should be cut away completely?

At the garage end I might try and take the SWA directly into the CU but if this is awkward I could join it to some T&E just before the CU.

Any comments gratefully welcomed.

Cheers

Martin

[dennis]

You buy a SWA gland and follow the instructions on how to terminate it. If its indoors you don't need the waterproof gland, if its outdoors then corrosion guard appear to be the better ones. You also need a box, preferably metal to mount the gland in. The gland clamps the steel wires so it can be earthed properly.

[Mike Clarke]

The SWA cable needs to be terminated properly, see .

There's a lot of information about connecting to an outbuilding in

[John Rumm]

The wiki articles that Mike pointed you at have the full details, but the easiest way to do this is with a waterproof box like:

it to the outside of the wall and drill a hole through from the back of it to inside. Terminate the SWA into the bottom of it. and join it using the terminals to the T&E which can then pass back through the wall.

Use a swa glad like:

tend to use one of these as well:

means connecting the T&E earth is simply a case of crimping a eye terminal on the wire and screwing straight to the piranha nut with the supplied screw.

So you probably want a RCBO in the garage CU for the sockets.

You need to use the armour as well - that's kind of the point of SWA - the fact that the earthed shield encloses the wires.

No, it *must* be terminated with the correct gland, and the glad connected to the earth.

Since you are exporting the earth, using a small metal CU in the garage would be easiest. Most CUs will have a knockout somewhere to allow the gland to be fitted directly.

Read through the sections on exporting earths in the wiki article, and pay particular attention to what type of supply earthing your house has, and the implications it will have for the garage.