Mini-Trunking cable capacity

[Chris Green]

Can anyone point me at a simple set of "what cables fit in what
trunking" table anywhere? I'd have thought it was a pretty
fundamental piece of information but I can't find anything very useful
anywhere. Even TLC don't seem to have anything.

I'm specifically interested in the very small sizes like the Screwfix
12mm x 8mm trunking, can you fit a 1.5mm T&E in that?

Neither Screwfix nor Toolstation seem to have the (approx) 25 x 10
trunking that I have a bit of, TLC have 16 x 10, would that be better
for 1.5 T&E?

Alternatilve I do have some 1sqmm (I think, it might be 1.5sqmm)
single that I could use as the things I'm connecting (outside light,
all plastic, PIR, timer switch) don't require an earth/CPC. That
might fit in smaller trunking than 1.5T&E.

De-rating isn't an issue, it's only going to be at most two LED lamps
at the end of this, 25 watts total maximum. I'll put a 3A fuse in the
FCU.



--
Chris Green
·

[Chris Green]

Oops, this was meant to be in uk.d-i-y, how did it get here? Sorry
folks.

--
Chris Green
·

[Graham J]

I used to install network cables, and of course cables from different
manufacturers differed slightly in diameter. Bigger difference between
cat5 and cat6.

So what I did was to cut some short lengths (6 inches) and tie them
together to see what would fit into the various trunking sizes. But it
was worth leaving a lot of spare space to take the cables round corners
(also to meet the network cabling specifications).

Power cables such as your 1.5mm T&E never lie flat and twist thenselves
up as soon as your back is turned, so always fit bigger trunking than
you first think of.

I used to buy from cmsplc.com and their sizes started with 16x10mm, then
16 x 16 mm and 25 x 16 mm. The 25 x 16 mm with the correct adapter fits
into the knockouts on standard 8cm square backboxes.


--
Graham J

[Woody]

If you are looking for it to use with an outside light why not use black
round plastic conduit? I did and it looks good and is watertight.

Note that if you are fitting outside lighting wired in then it is
probably liable to Part P inspection. If you are only using a couple of
LED lamps then you can use 0.5mm or 0.75mm flex and plug the lamp in,
then it is only an extension and should not need Part P. That's also
what I did!

If you want decent lamps get some Ledvance by Osram from cpc.farnell.com
which come in white or warm white - if you have other non-LED bulbs
covering the same area then they will be warm white so you need the same
in your LED so that there is no conflict. I have one 50W and three 20W
and they are superb.

[Chris Green]

Woody <harro...@ntlworld.com> wrote:
>
> If you are looking for it to use with an outside light why not use black
> round plastic conduit? I did and it looks good and is watertight.
>

Doesn't help conforming to the new 18th edition regulations. It's
also on nearly white walls and there's already some white conduit
there.

> Note that if you are fitting outside lighting wired in then it is
> probably liable to Part P inspection. If you are only using a couple of
> LED lamps then you can use 0.5mm or 0.75mm flex and plug the lamp in,
> then it is only an extension and should not need Part P. That's also
> what I did!
>

Yes, I know Part P applies to things outside in general.

> If you want decent lamps get some Ledvance by Osram from cpc.farnell.com
> which come in white or warm white - if you have other non-LED bulbs
> covering the same area then they will be warm white so you need the same
> in your LED so that there is no conflict. I have one 50W and three 20W
> and they are superb.

I've really never found lights of different colour/warmth much of an
issue. In fact in some ways I quite like the variety! :-)


(... and all this was meant to be in uk.d-i-y)

--
Chris Green
·

[notya...@gmail.com]

There are two questions - will it fit, which is a question of dimensions. Work it out and / or trial it (as suggested below) .

The other is current in the conduit. I have never done industrial wiring except under instruction, but there are long sections on diversity in the regulations.

[grinch]

As the current per cable will be in milliamps I doubt very much that
current will be a factor at all.

Do the trunking space factor requirements in the IEE regs even apply to
data comms ? Its 30 years since I worked as an electrician.

[notya...@gmail.com]

Not as far as I know, but any circuit carrying mains has to be treated as if it were taking the maximum current of the MCB protecting it.