I am using 3 core SWA to take power to a garage. The SWA is buried
underground between the house and garage and I am joining it to T+E
inside the house as it is easier to manipulate.

I was planning on using the 3rd core in the SWA as the earth for the
garage. Does the SWA armour need earthing in this case or is merely
used as a physical protection for the cable.

Cheers

Martin
--
Martin Carroll

Martin Carroll coughed up some electrons that declared:

I am using 3 core SWA to take power to a garage. The SWA is buried
underground between the house and garage and I am joining it to T+E
inside the house as it is easier to manipulate.

I was planning on using the 3rd core in the SWA as the earth for the
garage. Does the SWA armour need earthing in this case or is merely
used as a physical protection for the cable.

Hi Martin,

It does need earthing. Ignoring the regs for a minute, the best way to think
about it is: what happens when I stick a fork tine through the cable.

Earthed armour will ensure the spike is earth before it hits the live, thus
blowing the fuse/rcd/whatever safely.

Cheers

Tim

Martin Carroll wrote:
I am using 3 core SWA to take power to a garage. The SWA is buried
underground between the house and garage and I am joining it to T+E
inside the house as it is easier to manipulate.

I was planning on using the 3rd core in the SWA as the earth for the
garage. Does the SWA armour need earthing in this case or is merely
used as a physical protection for the cable.

Cheers

Martin

The SWA Armour should be earthed, even if you are using one of the cores
for the CPC.

See:

http://wiki.diyfaq.org.uk/index.php?...erminating_SWA

and:

http://wiki.diyfaq.org.uk/index.php?...ricity_outside

On Sun, 31 May 2009 12:10:00 +0100 someone who may be Martin Carroll
wrote this:-

I am using 3 core SWA to take power to a garage.

Others have answered the question you asked. However, there is
another more basic question, which is should you be exporting the
house earth to the garage or providing a local one? The answer to
this question depends on how far the garage is from the house and
whether there are exposed metallic items like water pipes in the
garage too.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

Martin Carroll wrote:
I am using 3 core SWA to take power to a garage. The SWA is buried
underground between the house and garage and I am joining it to T+E
inside the house as it is easier to manipulate.

I was planning on using the 3rd core in the SWA as the earth for the
garage. Does the SWA armour need earthing in this case or is merely
used as a physical protection for the cable.

The armour *must* be earthed. It almost defeats the point in having it
otherwise.

--
Cheers,

John.

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