UK Twin and Earth in metal trunking

[Ryespark]

Hi guys, I had to carry out some alterations to a domestic installation the other day and was pleasantly surprised when having to run a new circuit how neat the CU was. It had 75mm metal trunking installed to the CU with bass bushes installed. A lot of effort had gone in to it to keep it neat. I took a lot of ideas from it of how I could go about it in the future. However the twin and earth had been striped back in the containment so that there was no outer sheaving in the CU itself giving more room to keep the cables tight. I wasn't sure if this is a good idea or would be considered ruff at the time, but on second thoughts I suppose its not much different to running singles in a commercial job. Was just wondering you thoughts? Cheers

 

[James]

I can’t see a problem with it, although it might make identifying 2 cores of the same cable slightly harder if you can’t see them enter the outer sheaf.

 

[telectrix]

as long as the cable with stripped sheath is within containment, it's fine. the containment (trunking) provides mechanical protection.

 

[Dustydazzler]

Is the trunking earthed....

 

[Ryespark]

Thanks guys for your opinions, the cables had been marked with cable markers, and the trunking earthed, also all conductors for each circuit through the same knockouts, so no eddy currents. Looked as if a commercial electrician had done it. Will consider doing the same when cables need to be run in on the surface. I normally use the rear knockouts most of the time. Cheers

 

[ForkEnigma]

Is the trunking earthed....

You would so through the brass bushes

 

[Risteard]

Personally I'm not a fan of twin and skin stripped outside of the enclosure it's being connected into. It's not really what the cable is designed for. By all means use singles in containment (in fact if using containment I would go so far as to state that singles should be used). But I really don't like twin and skin stripped back inside trunking. I don't like it at all.

 

[Simon47]

Can you expand on that a bit ?
Other than the CPC being bare, if you strip T&E you have singles. Singles+ in trunking is OK*, so what's wrong with having singles§ in trunking ?
In a way, having T&E stripped back inside the trunking could be considered roughly equivalent to having used singles and sheathed them for the bit at the other end that's outside of the trunking.

+ As in "real" singles
§ As in cores that are now singles because the sheath has been removed
* Subject to the rules on IP rating - i.e. IP4X or IPXXD

 

[Lucien Nunes]

A bare CPC sleeved with normal G/Y sleeving is not as robust as an insulated cable, and there can sometimes be a gap where the sleeving pulls away from the end of the sheath, therefore a small possibility exists of getting incorrect readings when testing if any CPCs are in contact with the containment or each other, where you cannot see them. Other than that, I think it's fine.