Joining cable in trunking

[The Jeep]

Guys - I wish to make connections between 2.5mm² T&E and 2.5mm² PVC insulated single core (ring main) and 1.5mm² T&E and 1.5mm² PVC singles (lighting) circuits within steel trunking (which is, of course, bonded to earth).

This is a domestic job that has some circuits - grouping factors taken into account! - run in 50x50mm steel trunking for good reasons.

I am aware of (is it?) Page 104 of the Regs, which lists the different ways that circuits can be connected (at the CU, in a JB, compression fittings, etc), but am wondering if there are any suitable proprietry connectors that would do the job (don't want to fit external JBs)? Are standard crimp connectors with BS mark OK?

Thanks. PS Enjoyed DanThe MainsMan's post immensely!

 

[RMS]

The only problem with crimp connectors and twin and earth is that you have to break the outer sheath in order to joint the cable, this obviously does not maintain the secondary layer of protection but if the joint is enclosed in a suitable joint box or trunkin then you have maintained the secondary protection and with crimps the joint does not have to be accessible as stated in the regs.

 

[Adam_151]

Agree with RMS, but I'd personally apply heatshrink over the insulated crimps, the ends are a bit open otherwise and you never know if anyone is going to poke an unfolded coat hanger down the trunkig to fish a cable through it or anything...

 

[Pensdown]

Crimps in trunking are fine. Although I'm not in favour of using heat shrink, if you do use it make sure you stagger the joints, it's much neater than one big lump.

 

[The Jeep]

Thanks. I'll come clean and admit that I've already made the joints using 'pro' crimpers. Concerned that if a wire worked loose (highly unlikely as there is no mechanical or other stress on the cables, and anyone trying to access the cables would have to unclip the lid with a tool), I then covered the (staggered) joints with the appropriate electrical tape.

Now, this doesn't look very professional (if any future electrician should have cause to inspect it), but , in my view, it does the job. The joints are protected both mechanically and electrically. I was just wondering if a) this was a complete no-no or b) anyone new of a kind of in-line enclosed connector that could be used and which would look more acceptable.

 

[Pensdown]

I hope that you have not used normal "insulating" tape. IMO the only time that should be used is for identifying cores. It used to be know as phase tape for that reason.

 

[Adam_151]

IMO the only time that should be used is for identifying cores.

What about attaching draw wires?!

 

[JohnD]

Wouldn't a large size of heat-shrink have been suitable?

edited - I see Adam already suggested it

I mean, over all the cores to substitute for the sheathing. I have recently seen crimps advertised with heat-shrink incorporated so it covers the join on the core and a little of the insulation beyond the crimp, which I though a neat idea. Never used one though. Otherwise self-amalgamating tape would give a good cover, but look rather unsightly.

 

[The Jeep]

Thanks. I'll search around for those heat-shrink crimps, unless you know where they can be bought, JohnD?

Is regular electricians' insulating tape, suitably wound, not OK? It does claim to be 'insulating', though it does look untidy and suggests that a 'bodged job' may have been done, which certainly isn't the case in any other respect.

 

[Adam_151]

http://www.rapidonline.com/producti...tier4=Heat+shrink+butt+splices&moduleno=63945

Not that cheap, though, mind

 

[Pensdown]

IMO the only time that should be used is for identifying cores.

What about attaching draw wires?!

Smart arse

 

[JohnD]

IMO the only time that should be used is for identifying cores.

What about attaching draw wires?!

And re-attaching handles to poor-quality Pensdown mugs.

It does seem to lose its stickiness and go loose or unravel with age, which is why self-amalgamating tape seems better to me.

 

[plugwash]

never really found the stuff tough or sticky enough for draw wires, gaffer tape is far more suitable.

 

[Adam_151]

never really found the stuff tough or sticky enough for draw wires, gaffer tape is far more suitable.

You must be doing something wrong then, I've had phone cables I've been using as draw wires snap when a cable has snagged rather then the tape separate... *makes note to use nylon cord in future*

 

[Spark123]

I only ever use insulation tape in this instance to cover the wires so they don't snag when being pulled through. I thread the wire through the loop on the end of the draw wire, start with one wire on the draw wire then attach the next wire to the first wire so it grows gradually. The loadsa yella gunk on it