Using cable tubing

[OlmoLP]

Hello there,

I was trying to post this question in the routing article, but after a few successfully attempts I am asking in the forum.

I have a little project at home and I am seeking some experienced advice on it.

I am originally from Spain, and since there houses are build of blocks cable tubes are used to run cables throughout the hose.

I live now in the UK and I am in the process to change plug sockets that were originally installed using daisy chaining from the main ring circuit, to be back on the main circuit. I am doing the donkey job and later I will get a professional to check and connect.

Does it make any sense to use cable tubes? I know that here the cable is ran directly and nailed to the joists. But would it be good idea run it using the pipes, so cables can be run without lifting floor boards in the future?

My point is that I can leave all the runs from plug to plug, and carry on decorating and add the carpet, once the electrician is available it would be a easy job to run the cables.

Thansk for your help/advice in advance.
Olmo.


PS: By cable tube I meant this kind of pipe:

http://www.thetoolboxshop.com/0-330...duty-convoluted-un-split-tubing-75nw-855.html

 

[sparkwright]

No reason why you can't, though I expect the electrician would appreciate a draw wire left in each conduit.

Always best to get the electrician there before the decorating and carpet is done in an ideal world.

 

[OlmoLP]

Thanks for your answer sparkwright, That would be ideal but it has been difficult enough to get hold of him. I need to get that room sorted.

 

[JohnW2]

Does it make any sense to use cable tubes? I know that here the cable is ran directly and nailed to the joists. But would it be good idea run it using the pipes, so cables can be run without lifting floor boards in the future? ... My point is that I can leave all the runs from plug to plug, and carry on decorating and add the carpet, once the electrician is available it would be a easy job to run the cables.
PS: By cable tube I meant this kind of pipe: http://www.thetoolboxshop.com/0-330...voluted-un-split-tubing-75nw-855.html[/QUOTE]
Even with a draw wire/cord, it would IMO probably be a nightmare trying to get multiple cables through corrugated flexible conduit like that, unless it were enormous (I'm assuming that the inside of that conduit is not smooth). If you want to use conduit, I think you'd be far better off using smooth-walled (preferably 'rigid', not flexible) conduit (again with a pull-cord).

Kind Regards, John

 

[sparkwright]

That flexible conduit is all the rage in Europe - you only have to look in a Spanish hotel to see it everywhere.

I don't suppose the rest of Europe use ring circuits, but imagine it could be difficult running six 2.5 mm2 single core wires through it.

Would like to think three single cores would pull through very nicely.

Where it looks like say 6 cores may be needed, perhaps you could run two flexible conduits.

If you do run the rigid conduit like John suggested, you do need to make sure you don't have too many tight bends.

Rule of thumb is that each conduit should have no more than two 90 degree 'sweeping' bends.

The good thing about flexible conduit is you can form your own gentle bends to suit very easily, though you must remember to prevent any sags, as these just cause further obstructions for drawing in cables.

 

[JohnW2]

That flexible conduit is all the rage in Europe - you only have to look in a Spanish hotel to see it everywhere.

Yes, I know (and not just Spain), but that doesn't make me any more keen to try to get multiple cables through it!

I don't suppose the rest of Europe use ring circuits, but imagine it could be difficult running six 2.5 mm2 single core wires through it. ... Would like to think three single cores would pull through very nicely.

Possibly - but, as above, I don't think I would personally be all that keen to try. I've frequently used flexible conduit for short, accessible, runs, for which is fine (one can always 'waggle' the conduit to aid the passage of the cable!) - but would be much more nervous about long 'hidden' ones. Maybe I'm being pessimistic, or just inadequately experienced!

If you do run the rigid conduit like John suggested, you do need to make sure you don't have too many tight bends. ... Rule of thumb is that each conduit should have no more than two 90 degree 'sweeping' bends.

Agreed.

Kind Regards, John

 

[RF Lighting]

The stuff in the link has an internal diameter of 6.7mm and would be neither use nor ornament.

 

[OlmoLP]

Does it make any sense to use cable tubes? I know that here the cable is ran directly and nailed to the joists. But would it be good idea run it using the pipes, so cables can be run without lifting floor boards in the future? ... My point is that I can leave all the runs from plug to plug, and carry on decorating and add the carpet, once the electrician is available it would be a easy job to run the cables.
PS: By cable tube I meant this kind of pipe: http://www.thetoolboxshop.com/0-330...voluted-un-split-tubing-75nw-855.html[/QUOTE]
Even with a draw wire/cord, it would IMO probably be a nightmare trying to get multiple cables through corrugated flexible conduit like that, unless it were enormous (I'm assuming that the inside of that conduit is not smooth). If you want to use conduit, I think you'd be far better off using smooth-walled (preferably 'rigid', not flexible) conduit (again with a pull-cord).

Kind Regards, John

Hi John,

Thansk for chipping in. I have ran cables on this flexible tubes, and it is very easy. There are different diameters depending on your needs. I am certainly no electrician and my experience is very limited, but they are not that difficult as you might think.

Obviously to run cable for more than a few meters you use a cable runner.

Cheers,
Olmo

 

[OlmoLP]

The stuff in the link has an internal diameter of 6.7mm and would be neither use nor ornament.

I used only for the picture, this one is slightly wider 21.3mm:

http://www.thetoolboxshop.com/0-330...duty-convoluted-un-split-tubing-22nw-854.html

 

[JohnW2]

Hi John, Thansk for chipping in. I have ran cables on this flexible tubes, and it is very easy. There are different diameters depending on your needs. I am certainly no electrician and my experience is very limited, but they are not that difficult as you might think.

If the conduit is large enough, it obviously gets easier. As I said, I've often done it with fairly short lengths (up to a metre or two), and fairly small conduit (probably about 20mm), but even then have often had to do a little waggling of the conduit (which would not be possible if it were not accessible) to ease the passage of the cables. However, if you find it easy, that's fine!

Whether it's worth the effort/cost is, IMO, another matter. Whilst it's true that running cables in conduit can make subsequent re-wiring easier, modern cables should last several decades before needing replacement - and, of course, if you wanted to extend/modify the circuits in the future, you wouldn't have conduits in the right place, anyway!

Kind Regards, John

 

[ban-all-sheds]

That flexible conduit is all the rage in Europe

And often comes as conduit with cables already inside it.

I don't suppose the rest of Europe use ring circuits, but imagine it could be difficult running six 2.5 mm2 single core wires through it.

Why would you need 6?

3 surely?

 

[sparkwright]

You've got a point John.

Modern cable doesn't generally need replacing until... well it almost lasts forever.

Very rarely have I re-wired a whole installation utilising the original conduit. Often the conduit boxes aren't in the right place, or there's not enough of them for modern day life.

That said, thousands of post war council houses would have been wired in conduit, and will have been re-wired using the old conduit.

Maybe the op could put the wires in the conduit during installation of the flexi. It could be argued the wires are draw wires - then the electrician could use his discretion in what to do next.

Obviously it would be useful if the op knows how the wiring needs to be.

 

[sparkwright]

That flexible conduit is all the rage in Europe

And often comes as conduit with cables already inside it.

I don't suppose the rest of Europe use ring circuits, but imagine it could be difficult running six 2.5 mm2 single core wires through it.

Why would you need 6?

3 surely?

Because there may be occasion where it's practical to run one conduit, for example horizontally along a wall, and to keep everything on the ring, there may be two lives, two neutrals, two earths.

I gather the existing wiring is being altered.

I do concede though that in a traditional full conduit system usually only three wires will be in the tubes - in a similar manner to a ywin and earth cable.

 

[sparkwright]

That flexible conduit is all the rage in Europe

And often comes as conduit with cables already inside it.

In the UK at least, there was always a lot of fuss about conduit systems being fulled erected before wires were drawn in.

 

[333rocky333]

Why would you need 6?

3 surely?

Im guessing the tube would terminate at the last socket box and not return to the board