Switched Live sleeving when looping at switch

[flameport]

Twin brown is not a rare or unknown product - even Toolstation and Screwfix have it.

What is rare and unknown is 3C&E with three browns, rather than the nonsense of brown/black/grey, which is entirely useless in every situation it's used for.

 

[SUNRAY]

Twin brown is not a rare or unknown product - even Toolstation and Screwfix have it.

What is rare and unknown is 3C&E with three browns, rather than the nonsense of brown/black/grey, which is entirely useless in every situation it's used for.

Except where it's used for 3 phase...
The last time I tried to buy twin brown, which would have been well before 2012 [when Bush house closed]) it seemed to be like hens teeth, Screwfix is one of my go to's so I'd have thought I'd tried them. I don't recall the availability detail other than it wasn't easy so I had it delivered to site rather than over the counter.

Personally I like having the selection of colours, it really assists when wiring complex systems and makes the options easy. I find I often need 2 brown and 1 blue or 2 phases & neutral (and not always brown and black) so that makes at least 4 different requirements.

Additionally I don't see the requirement (other than regs) to oversleeve phase colours when used on a single pase system.
Within controls systems a selection of different colours blackare used to denote different purposes and core identity is done with numbers. Many control panels are wired with one colour for one voltage so for example red for 230/400V, yellow for 110V, purple for 24V and white for 12V etc. These colours are manufacturer specific and it's not uncommon to find 2 interconnected panels side by side with different colour schemes... and do you know what it doesn't cause many problems as long as the numbers don't dissappear.

 

[Risteard]

It's all that matters in terms of BS7671 'conductor identification', but it certainly can matter in terms of the practicalities of wiring (EFLI has mentioned one example).

What do you do with '2-way switching' - do you perhaps have "triple brown" cables (I've never seen that)?

Kind Regards, John

With 2-way switching you could either sleeve other phase colours as single phase, i.e. brown (with no blue which is neutral), or you could wire it in the traditional rather than conversion method (which is what most would do). Then everything is brown already. Twin brown for strappers and single browns for the commons (one permanent phase, and one switched phase). At least one of these would usually be a brown & Earth to ensure that the switches are also earthed (but it could come from elsewhere depending on the precise switching arrangements).

 

[Risteard]

In what language? - I cannot find any English language dictionary online which recognises that meaning.

It's used in common parlance - as Apprentices the term was used frequently.

 

[bernardgreen]

I saw a house wired completely in purple singles of various sizes. Each wire had an alpha-numeric identity and there were accurate wiring diagrams of the installation. I cannot recall if the Earths were green/yellow or purple with green/yellow sleeves.

 

[SUNRAY]

With 2-way switching you could either sleeve other phase colours as single phase, i.e. brown (with no blue which is neutral), or you could wire it in the traditional rather than conversion method (which is what most would do but not in England). Then everything is brown already. Twin brown for strappers and single browns for the commons (one permanent phase, and one switched phase). At least one of these would usually be a brown & Earth to ensure that the switches are also earthed (but it could come from elsewhere depending on the precise switching arrangements).

The massive issue I encounter with all of the single(&E) cables is the mains interference which is becoming a big problem with the way houses are crammed into developements these days.

 

[SUNRAY]

I saw a house wired completely in purple singles of various sizes. Each wire had an alpha-numeric identity and there were accurate wiring diagrams of the installation. I cannot recall if the Earths were green/yellow or purple with green/yellow sleeves.

This sort of thing is not uncommon in 'caretakers flats' in commercial buildings where similar 'higher class' wiring has been done instead of regular house bashers.

Chances are being purple is will have been a foreign contractor. I encountered a big property in Sussex built by a maderian company, from memory I think as follows: power circuits brown/light blue, lighting circuits black/dark blue, purple SL and white/wellow strappers. All earth wiring Red.
Some in t&e, rest in singles.
All wires had numerical markers to match circuit number and documented. It made fault finding/alterations nice and easy

 

[bernardgreen]

DIYnot refreshed my failing memory. As I posted way back in October 2014

An old house which is being demolished to create a new access road has all the electrics wired in purple single cores. The ends of the cores appear to be identified by various coloured cotton tied round them. Even the CPC is purple with green cotton.

Several very ancient reels of the same cable were found when the building was cleared.

The previous owner was a recluse described as a "mad professor" type who had been a government scientist during World War II

 

[JohnW2]

The last time I tried to buy twin brown, which would have been well before 2012 [when Bush house closed]) it seemed to be like hens teeth, Screwfix is one of my go to's so I'd have thought I'd tried them. I don't recall the availability detail other than it wasn't easy so I had it delivered to site rather than over the counter.

Hens teeth must have become more common in the subsequent 7+ years ...

TLC stock it. My local Screwfix (about 12 mins away) has some in stock for collection today ...

... as does my local Toolstation (almost next door to Screwfix) ...

Having said that, I've never used the stuff (nor twin red)!!

Kind Regards, John

 

[JohnW2]

What is rare and unknown is 3C&E with three browns ...

As I asked, does it exist at all, even in Ireland, let alone over here? I've certainly never seen or heard of it.

Kind Regards, John

 

[scousespark]

I've always looped at the ceiling but was recently replacing a switch where the loop was done at the switch. In this configuration, is the cable in L1 known as the "Switch Live" and should it therefore have a brown/blue sleeve to denote this like we do when looping at the ceiling?

View attachment 168884

This is the actual question.

Jupiter, when you loop at the rose the blue conductor in the cable linking the rose to the switch is not acting as a neutral conductor and The brown sleeve shows this. When you loop at the switch, as in flameport’s picture, all the blue conductors are neutrals so sleeving is unnecessary.

 

[JohnW2]

This is the actual question.

It is - and I answered it in the first two replies to the OP (msgs #2 and #4) back on page 1. I wonder why it was felt that there was a need to repeat the answer, 4 pages and 50+ messages later.

Kind Regards, John

 

[scousespark]

I posted because in the middle of this thread, Jupiter again asked about sleeving in brown or blue. I was trying to help.

 

[JohnW2]

I posted because in the middle of this thread, Jupiter again asked about sleeving in brown or blue. I was trying to help.

Fair enough - there is no harm in repetition/re-enforcement. I am reminded of the regular Army Sergeant Major who, when I was in the school cadet force "taught us how to teach". He said ...

"First you tell 'em wot you're going to tell 'em. Then you tell them. Then you tell them wot you've just told them. Then you ask them wot you've just told 'em and, if they get it wrong, you tell 'em again, and put them on a Charge"

 

[Jupiter01]

It’s the OP here again
Thanks for all the responses. Can’t claim to have understood everything but here’s my summary.

When looping at switch, the brown wire in L1 is the switched live and since it is brown, it doesn’t require (regs) any additional identification.

That said, some may want to use their personal identification method for their own convenience. Yellow was being suggested and in the same vain brown over sleeving can be used as I suggested? May not be very clear as it’s brown on brown but clearly the oversleeving would be much smaller. Blue over sleeving cannot be used as it suggests that this is neutral.

As suggested by these “personal” methods, there is a risk of incorrect identification and hence, should always test the wires if working on a unknown system.

Any major omissions with the above?