As I mentioned on another thread, I'm planning on wiring up some
exterior lights and an exterior socket. I'm wondering what to do about
the short lengths of cable that will be exposed in both cases.

Just to summarise what I'm planning:

- I intend to drill through the wall of an outhouse to feed the
socket.

- I am planning two PIR-controlled lights. Again one will be on the
wall of the outhouse, so I will just be drilling directly through
the wall. The other is a few metres away on the side of the main
house and I am planning to run the cable in heavy duty PVC conduit
(the outhouse is attached to the house).

Based on advice I received on this group a few months ago (I'm pretty
slow at getting around to these things!), my understanding was that it
was OK to run standard T&E cable in the conduit as the conduit would
protect it from weather and knocks.

However, now that I have received the stuff I ordered I see a
potential problem - it seems like it is going to be difficult to avoid
having at least a few cm of cable exposed between the conduit and the
PIR entry holes. I can't see a way of getting a good seal between the
conduit and PIR. The lights themselves are less of a problem as I
can see a way to join the conduit to the light housing.

There is a similar problem with the fittings mounted on the outhouse
walls: even though I can drill through more or less directly where the
fitting is mounted, again there will be a few cm between the hole in
the wall and the entry hole in the fitting. (I haven't bought a socket yet
but the ones I've looked at in Wickes have their cable knockout holes around
the sides of the fitting, but none in the back.)

So, in summary:

- Should I be worried about these exposed lengths of cable?

- Is there some way I can weatherproof/protect them?

- should I not be using standard cable after all, but
something weatherproof instead? (This would be a pain as I've
already bought the cable etc. for the job.)

Actually you may (according to the electricians' On-Site Guide) use ordinary
T&E "on exterior surface walls, boundary walls and the like" without further
protection although "protection from direct sunlight may be necessary. Black
sheath colour is better for cables in sunlight". Also "additional protection
may be necessary where exposed to mechanical stress" (common sense really).

I have some ordinary T&E - grey or white sheath, I forget - feeding a PIR
light on a south-east facing outside wall for the past 15 years or so and
it's still in perfect nick; there is about a metre from the hole in the wall
to the light fitting.

On 30 May 2004 11:47:36 -0700, (Ian) wrote:



However, now that I have received the stuff I ordered I see a
potential problem - it seems like it is going to be difficult to avoid
having at least a few cm of cable exposed between the conduit and the
PIR entry holes. I can't see a way of getting a good seal between the
conduit and PIR. The lights themselves are less of a problem as I
can see a way to join the conduit to the light housing.

There is a similar problem with the fittings mounted on the outhouse
walls: even though I can drill through more or less directly where the
fitting is mounted, again there will be a few cm between the hole in
the wall and the entry hole in the fitting. (I haven't bought a socket yet
but the ones I've looked at in Wickes have their cable knockout holes around
the sides of the fitting, but none in the back.)

So, in summary:

- Should I be worried about these exposed lengths of cable?

It isn't a good idea to have exposed PVC cables really.


- Is there some way I can weatherproof/protect them?

How about using a weatherproof enclosure and mounting the PIR on the
lid with the wiring going through the base

http://www.tlc-direct.co.uk/Products/LB9025.html

is one example, but TLC have a range of different ones if you need a
different size.

These have knockouts to take 20mm conduit adaptors.



- should I not be using standard cable after all, but
something weatherproof instead? (This would be a pain as I've
already bought the cable etc. for the job.)

The general alternative id HiTuf.





..andy

To email, substitute .nospam with .gl

On 30 May 2004 11:47:36 -0700, (Ian) strung
together this:

- Should I be worried about these exposed lengths of cable?

No, not at all. PVC is not a problem on external walls, despite what
the books say, it is however recommended to be protected.

- Is there some way I can weatherproof/protect them?

You could run the conduit tight up to the entry point, if that's not
possible then as someone else said an adaptable box can be used.

- should I not be using standard cable after all, but
something weatherproof instead? (This would be a pain as I've
already bought the cable etc. for the job.)

No, PVC is fine.
--

SJW
A.C.S. Ltd

Based on advice I received on this group a few months ago (I'm pretty
slow at getting around to these things!), my understanding was that it
was OK to run standard T&E cable in the conduit as the conduit would
protect it from weather and knocks.

Correct.

(I haven't bought a socket yet but the ones I've looked at in Wickes
have their cable knockout holes around the sides of the fitting, but
none in the back.)

Nothing a 20mm hole saw can't fix!

- Should I be worried about these exposed lengths of cable?

Well a couple of cm probably won't hurt, although the best technique is to
use Hi-Tuf cable, which is UV resistant and can be run in sunlight with
impunity. However, given that you already have the PVC, I'm sure you can
contrive something to protect those few cm from UV and give you that warm
fuzzy feeling from doing it right.

Christian.

Thanks to all who replied.

The consensus seems to be that ideally I should protect
against UV. For the very short lengths of exposed cable
we are talking about, mechanical stresses are not an
issue, so I wondered about this as a potential solution:

http://www.tlc-direct.co.uk/Products/TLSAT19.html

(self amalgamating tape).

Although it isn't described on the tlc site itself, a
google around the web suggests this stuff is suitable
for waterproofing and UV protection. Anyone have any
experience of this or opinions on its applicability
here?

Thanks,

Ian