Brown sleeving of G/Y core of flex

[securespark]

From 514.4.2:
"Single-core cables that are coloured green-and-yellow throughout their length shall only be used as a protective conductor and shall not be over-marked at their terminations, except as permitted by Regulation 514.4.3 [PEN conductors]"

Thanks, MF. I knew there was another reg, as well as:

regulation 514.4.2

However, to be pedantic, the quote does reference single core cables, not those grouped with other conductors.

 

[matt1e]

This seems to be the compelling part of the argument. As I said, it is quite possible to read 514.4.2 as permitting the use of a G/Y insulated core asa live conductor, provided it is identified as such with brown sleeving.

In what way is this possible?

From 514.4.2:
"Single-core cables that are coloured green-and-yellow throughout their length shall only be used as a protective conductor and shall not be over-marked at their terminations, except as permitted by Regulation 514.4.3 [PEN conductors]"

just to fuel the arguement I've put the first two words of your quote in bold

"Single-core cables that are coloured green-and-yellow throughout their length shall only be used as a protective conductor and shall not be over-marked at their terminations, except as permitted by Regulation 514.4.3 [PEN conductors]"




edit secure spark beat me to it!

 

[JohnW2]

This seems to be the compelling part of the argument. As I said, it is quite possible to read 514.4.2 as permitting the use of a G/Y insulated core asa live conductor, provided it is identified as such with brown sleeving.

In what way is this possible?
From 514.4.2:
"Single-core cables that are coloured green-and-yellow throughout their length shall only be used as a protective conductor and shall not be over-marked at their terminations, except as permitted by Regulation 514.4.3 [PEN conductors]"

I've already discussed that - which (as it says) applies only to to single-core cables, and which is not what we are talking about.

Look at the preceding paragraph (the first paragraph) in 514.4.2. This merely says that one should not use G/Y to identify anything other than a protective conductor - which suggests that a G/Y core of a multi-core cable could theoretically be used as a live conductor if it were 'identified' (per the meaning of Chapter 51 and Appendix 7) with brown sleeving at terminations. The fact that the second paragraph of 514.4.2 singles out single-core G/Y for the prohibition of use as anything other than a protective conductor seems to imply that they did not wish to include a similar prohibition in relation to the G/Y core of multi-core cables.

Kind Regards, John

 

[JohnW2]

However, to be pedantic, the quote does reference single core cables, not those grouped with other conductors.

I wouldn't call it pedantic at all - it's probably crucial to the intended meaning. I would say that the singling out of single-core G/Y for the prohibition of over-marking or use as anything other than a protective conductor implies that the regs did not want these prohibitions to extend to G/Y cores of multi-core cables.

Kind Regards, John

 

[plugwash]

Mind you, the person hacking into a T&E cable in a loft and connecting something to it, expecting the blue core to be neutral could also get a surprise in some cases

They may get a surprise when something doesn't work right but they are unlikely to damage anything or create a shock hazard.

Whereas if a conductor that is expected to be earth isn't actually earth then one could easilly end up with live exposed metalwork.

 

[JohnW2]

They may get a surprise when something doesn't work right but they are unlikely to damage anything or create a shock hazard.
Whereas if a conductor that is expected to be earth isn't actually earth then one could easilly end up with live exposed metalwork.

I can't disagree with that, and concede that the one (and probably only) real hazard created by using (appropriately sleeved) G/Y cores as live arises if someone cuts into the middle of the cable.

However, we are necessarily talking about flexible cables (since one obviously cannot use the bare CPC of T&E as a live conductor) and I would suggest that it would be extrordinarily unusual for anyone to cut into a flexible cable and join anything in. However, I accept that nothing's impossible, so I guess it's better to be idiot-proof.

Kind Regards, John

 

[Stoday]

Remembering back to the 1970's you could buy single core + E cables for lighting, 3X.029 for the red insulated live and 1X.044 for the green insulated CPC, the whole in a grey sheath.

I just can't remember if the 7X.029 TW&E had an insulated 3X.029 CPC core or not. (it was 40 years ago)

 

[seasickstevie]

I've brown (red previously) sleeved G/Y flex many times when linking a PIR to a halogen or similar. But the flex is usually no more than a short length (less than 1m long) from PIR to halogen.
Not a situation where someone's going to be cutting into looking for a CPC since the CPC will be at the halogen anyway.

As well as the 'what to do with the CPC' issue in a Class ll that JohnW2 mentions, there's also the problem I've found that it can sometimes be a struggle to get a four-core through the tiny grommets that some PIRs have.

 

[JohnW2]

I've brown (red previously) sleeved G/Y flex many times when linking a PIR to a halogen or similar. But the flex is usually no more than a short length (less than 1m long) from PIR to halogen. Not a situation where someone's going to be cutting into looking for a CPC since the CPC will be at the halogen anyway.

Indeed, that's exactly the situation in which I have occasionally done it - and I'm sure that, in reality, any risk is vanishingly small.

As well as the 'what to do with the CPC' issue in a Class ll that JohnW2 mentions, there's also the problem I've found that it can sometimes be a struggle to get a four-core through the tiny grommets that some PIRs have.

Again, agreed. I suppose it's a pity that one can't get blue/black/grey flex, but I've never seen it (only SWA etc.).

Kind Regards, John.

 

[JohnW2]

Remembering back to the 1970's you could buy single core + E cables for lighting, 3X.029 for the red insulated live and 1X.044 for the green insulated CPC, the whole in a grey sheath.
I just can't remember if the 7X.029 TW&E had an insulated 3X.029 CPC core or not. (it was 40 years ago)

I've seen a lot of imperial PVC cable in my time, and I have to say that I can't recall every have seen one with an insulated CPC. Red/black 3x0.029 without a CPC was obviously common in lighting circuits (and some of that is still in use).

Kind Regards, John.

 

[Spark123]

Again, agreed. I suppose it's a pity that one can't get blue/black/grey flex, but I've never seen it (only SWA etc.).

Did you mean brown/black/grey?
These are the colours which you get with an additional CPC when ordering bog standard 4c flex.

 

[JohnW2]

Again, agreed. I suppose it's a pity that one can't get blue/black/grey flex, but I've never seen it (only SWA etc.).

Did you mean brown/black/grey?

Whoops. Yet another instance of my typing fingers not obeying my brain - but at least they got the first letter right Yes, I meant brown/black/grey.

These are the colours which you get with an additional CPC when ordering bog standard 4c flex.

Indeed so - but, as I said, I've never seen it in bog standard 3-core flex without the additional CPC, althought that is how 3-core SWA comes.

Kind Regards, John.

 

[ricicle]

And of course the other favourite was/is is the 3 core flex to the cylinder stat (usually with the G/Y used as 'satisfied'.

 

[JohnW2]

And of course the other favourite was/is is the 3 core flex to the cylinder stat (usually with the G/Y used as 'satisfied'.

Indeed, as JameZZ mentioned early in this thread.

Kind Regards, John.

 

[ricicle]

Oops - that'll teach me to fast read