What do you reckon my chances are in running 2.5mm T&E through existing 16mm OD conduit with an unknown number of bends (but at least 2) ?
2.5mm T&E in 16mm OD conduit ?
- Thread starter Licklieder
- Start date
Impossible
My flat final ring circuit is wired using 2.5mm PVC singles via 16mm conduit buried in the concrete slab (apart from vertical runs up walls to sockets). I'm considering running new T&E where i want to split the ring rather than a hidden maintenance free junction (such as crimp butt joint) - the wall in question will be boarded out (by 50mm). So, am wondering if i will be able to pull 2.5mm T&E through the existing ~ 16mm OD conduit. digging it up really isn't an option - Im upsetting my neighbours enough as it is - and i've got no idea where it runs.
The alternative could be to run conduit along the wall but i need to review reference methods and grouping factors. T&E could be clipped direct which i've previously worked out will be ok
The alternative could be to run conduit along the wall but i need to review reference methods and grouping factors. T&E could be clipped direct which i've previously worked out will be ok
You might be able to pull new singles through.
Not T&E .
if it's got to be that way i might as well get some 2.5mm singles.
or junctions.
there's something in me though that just doesn't like the idea of putting a number of hidden junctions in - even if done properly the regs do allow it, and i've got the kit to test it before and after at every step along the way
or junctions.
there's something in me though that just doesn't like the idea of putting a number of hidden junctions in - even if done properly the regs do allow it, and i've got the kit to test it before and after at every step along the way
Singles are stranded and flexible. T&E is not.
The rule of thumb is that every conduit run should contain no more than two 90 degree bends.
The conduits are usually run the most direct way possible to minimise the amount of beds.
Stranded singles are the way to go.
Don't attempt the twin and earth. It may get stuck, and you will NOT like it.
The conduits are usually run the most direct way possible to minimise the amount of beds.
Stranded singles are the way to go.
Don't attempt the twin and earth. It may get stuck, and you will NOT like it.
This is fair. Is there any reason not to use flex?
I have an interest in this problem because I put 2.5mm T&E though a 20mm conduit for a similar reason to the OP. In one run there was one 90 degree bend and one 45 degree bend. It came through eventually but it was very difficult. So I'm wondering what I could have done differently.
One of the regulars here who, unlike me, knows what he's talking about said in:
https://www.diynot.com/diy/posts/4171551/
that you can wire the whole house in flex.
https://www.diynot.com/diy/posts/4171551/
that you can wire the whole house in flex.
Flex can be used, although it would be a rather expensive thing and for conduit would still need the outer covering removing, but for a short section probably not much difference.
Some places may sell singles per metre, rather than having to buy a whole 100m roll of each colour.
The only other difference is that conduit singles have a small number of strands, 7 typically, and 2.5mm flex will have far more finer strands.
I can't work out exactly what you want to do.
Why do you want to "split the ring?
Ow will replacing the singles with T/E help?
two reasons -
1) I'm battoning out the wall to install insulation / sound proofing and the existing 2.5mm singles in conduit are not long enough to reach the new sockets
2) I'm taking to opportunity to add additional sockets on the ring - thus 'splitting the ring'. with hindsight i missed out the vital bit "to add new sockets"
2) I'm taking to opportunity to add additional sockets on the ring - thus 'splitting the ring'. with hindsight i missed out the vital bit "to add new sockets"
Rather than installing maintenance free junctions that would be hidden behind the new wall, i was thinking i might be able to run a new length of T&E to the previous socket. sounds like 1960's 16mm od conduit is too small for that; so back to heat-shrinked crimping it is. Or i re-think the cable runs.
On that last, if it's two T&E being crimped i understand that the heat shrink needs to cover both the cable-crimp-cable joint and the grey T&E sheaths. If it's T&E to singles, i presume i still need the heat-shrink on the grey sheath.
There shouldn't be any need to crimp any cables unless I'm missing something here.