How do I terminate SWA cable on the outside of a building

[Martin Wiseman]

Hi,

I want to run an underground mains cable to the garden shed (total length of the SWA is about 10m). I've done all the calculations etc. and now I just need to buy the bits.

The cable will be something like:

I terminate it with glands such as: what do I mount the glands to?

What I want is for the SWA to come out of the ground adjacent to the garage wall, run up the outside of the wall for about a foot and then terminate in a box of some kind. The wiring will then go out through the back of the box straight through the wall and continue inside the building in T&E cable.

My question is, what the approved means of terminating the cable?

I found these on the TLC website:

they don't look as if they support cable leaving through the back of the box. In fact I have been unable to find anything which supports a cable entrance in the back of the box.

Can anyone either suggest a suitable junction box or an alternative way of doing it?

TIA, Martin

[Lurch]

On Fri, 23 Apr 2004 23:20:05 +0100, in uk.d-i-y Martin Wiseman strung together this:

Drill a hole in the back of the box, put the T&E cable through the hole.

[Sparks]

Could you not just use a normal box like

a hole in the bottom, and screw the SWA gland in that hole, then drill a hole at the back, and a conduit size hole in the back, then screw a the back, then drill a stuable hole throught the garage wall, using some the hole then use varuous corners tec from this page ) to get to the garage CU?

Just use choccy block in the IP56 box mentiond earlier, as it has a screw front you don't need to use crimps as it is accessible.

You may need to use some

( ) to glue the pieces of conduit together, but as the push fit connections will not be outside, it is probably not really needed...

...I expect this is what I would do if it were me!

Sparks...

[r]

Can't you run the SWA inside the outbuilding? Then you could just terminate it directly into a surfacemounted metalclad box (the glands fit straight into a standard 20mm knockout). I have just done this with my garden shed.

[Andy Hall]

If conduit is used to carry the T&E, then the T&E may need to be of larger size than if it is just openly clipped to the wall

This is because the conduit affects the heat dissipation.

That could be addressed by using 'singles' inside the conduit if it is run all the way rather than T&E.

.andy

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[Pete C]

Hi,

Why not just drill a hole though the shed wall and pass the SWA through, then use a standard junction box on the inside.

Also leave a 'repair loop' on the incoming cable so the connections can be remade a few times without running out of cable.

cheers, Pete.

[John Rumm]

- then use the box (as above) inside the house to connect to the T&E.

[Lurch]

On Sat, 24 Apr 2004 14:19:10 +0100, in uk.d-i-y Pete C strung together this:

Because you can't make SWA off into a standard junction box.

[Lurch]

On Sat, 24 Apr 2004 15:17:30 +0100, in uk.d-i-y John Rumm strung together this:

You'd want to drill the hole at an upwards angle from the outside as SWA is difficult to get through a 'square-on' hole without it sticking out from the wall.

[Martin Wiseman]

Hi,

Thanks for all the replies.......

Oh well, I guess that's a good DIY solution. I just thought there ought to be a ready made solution because it seemed such an obvious thing to want to do.

Martin.

[John Rumm]

Good tip - probably also helps that the OP was talking about 2.5mm sq SWA which is not quite as hard to handle as the larger sizes.

[T i m]

I was thinking (it's ok, I'm sitting down) if you simply drill a hole in the back of a 'waterproof' box then fit it to an outside wall, isn't there a chance of water ingress into the 'sealed' box?

If I ever do similar I ensure there are drain holes in the bottom so if the water *does* get in it can get out again?

Or, do you ever seal the box to the wall or is that what the plastic through-the-wall conduit is supposed to do?

All the best ..

T i m

[Lurch]

On Sun, 25 Apr 2004 12:20:00 +0100, in uk.d-i-y T i m strung together this:

Not if you seal it with silicone.

Yep, you're meant to do that as well.

Either, if you put the T&E straight into the box you only need a 12mm hole for 2.5mm cable, if you use 20mm tube you need a 25mm hole to get the adaptor through the wall behind the box.

[Andy Hall]

There would be if you don't fit it right.

That is recommended.

What I did was to drill a hole in the back of the box and to fit a

20mm threaded conduit fitting into it, sealing with silicone. Conduit was the cemented into the fitting and passed through the wall. As the box was screwed to the wall, a generous bead of silicone was run onto the back of it.

No water ingress..

.andy

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[T i m]

Ah, thanks both.

I didn't see mention of any sealant previously and thought I was either missing something or it didn't matter ..?

All the best ..

T i m