NICEIC allows use of green/yellow conductor as live

[JohnW2]

If you feel strongly, maybe you should suggest to those who write the regs that 514.4.2 (or some other regulation) should be revised such as to outlaw the use of any over-sleeved G/Y-insulated conductor as something other than CPC/earth?

Perhaps we should suggest that it should be oversleeved (or otherwise identified) over it's whole length lest someone tap into the cable to (for example) add an extra light. I'd like to see someone try that

To be serious, that, of course, is one of the concerns - but it applies, at least to some extent, to any over-sleeving (e.g. over-sleeving blue/black with brown/red). Although the regs currently say that 'identification' throughout the whole length of a conductor is 'preferable', it nevertheless also says that 'identification' only at terminations is acceptable. It also says that over-sleeving is an acceptable means of 'identification'. As the regs stand, that is as true of over-sleeving a G/Y-insulated conductor as it is of over-sleeving a conductor with any other colour insulation.

Since it would (IMO) be impractical/unrealistic to forbid termination-only over-sleeving of other colour conductors, as I said, I think the only thing that Bernard could realistically suggest to those that write BS7671 is that, specifically, any over-sleeving of G/Y (for uses other than CPC/earth) should be forbidden.

Kind Regards, John

 

[mfarrow]

A sheathed (but otherwise bare) conductor is not the same as an insulated and sheathed conductor, which is not the same as an insulated conductor.

In my opinion if I see a green/yellow core with brown sleeve over it going to the S/L, L, L1, C, L2 terminal of an accessory, it's pretty clear what it's doing. If the same core has a blue sleeving and going to the N terminal, it's pretty clear what it's doing. If there's a grey core with g/y sleeve going to the earth terminal, it's pretty clear what it's doing.

 

[JohnW2]

In my opinion if I see a green/yellow core with brown sleeve over it going to the S/L, L, L1, C, L2 terminal of an accessory, it's pretty clear what it's doing. If the same core has a blue sleeving and going to the N terminal, it's pretty clear what it's doing. If there's a grey core with g/y sleeve going to the earth terminal, it's pretty clear what it's doing.

That is all true, certainly when you have the added confidence of seeing what terminals the over-sleeved conductors are connected to. Indeed, as I have admitted before, I have in the past occasionally over-sleeved the G/Y of 3-core flex (probably with red in those days).

However, there clearly are some potential hazards. Despite what some have suggested or implied, 'breaking into' the run of a cable is far from unknown - and there is also the point made by Bernard that some people who get used to over-sleeving a G/Y cores of flex may, if stupid enough, think that they can therefore do the same with a 'bare and sleeved' CPC of T+E.

Don't forget that, as has been said, the regs already explicitly forbid the over-sleeving of G/Y singles.

It's not something I personally loose sleep over, but I suppose I would probably sleep even better if people did not use G/Y-insulated conductors, even if over-sleeved at terminations, for anything other than CPC/earth.

Kind Regards, John

 

[333rocky333]

I think the only thing that Bernard could realistically suggest to those that write BS7671 is that, specifically, any over-sleeving of G/Y (for uses other than CPC/earth) should be forbidden.

I thought thats what the first line of 514.4.2 means

edit
oops sorry, think i may have misread, i thought you was relating to the sleeve colour g/y

 

[westie101]

'breaking into' the run of a cable is far from unknown

So we have a length of flex going from an FCU or similar to a specific piece of equipment, say a time delay fan.

Why would anyone wish to break into that piece of flex which I struggle to see how it could be described as a run of cable.

In the greater majority of cases we are talking of a very obvious piece of flex that will be mostly visible between specific items.

 

[JohnW2]

I think the only thing that Bernard could realistically suggest to those that write BS7671 is that, specifically, any over-sleeving of G/Y (for uses other than CPC/earth) should be forbidden.

I thought thats what the first line of 514.4.2 means
edit: oops sorry, think i may have misread, i thought you was relating to the sleeve colour g/y

It sounds as if you have seen the light The first line of 514.4.2 simply says that the colours green/yellow should not be used 'to identify' anything other than a protective conductor - not that I can think of why even stupid people would ever dream of doing that! It does not preclude over-sleeving a G/Y-insulated cable with sleeving of some other colour, thereby 'identifying' it as having a function other than that of a protective conductor.

Kind Regards, John.

 

[JohnW2]

In the greater majority of cases we are talking of a very obvious piece of flex that will be mostly visible between specific items.

Quite so - I totally agree; I would probably even say 'vast majority'. However, 'the greater (or vast) majority' and 'all' are not necessarily the same thing.

As always, it all depends on how improbable a risk one wants to guard against - as I often ask, how probable is it, for example, that any harm would result from a 1.5mm diameter hole in the top of an enclosure?!

Kind Regards, John

 

[ericmark]

I do see that the regulations to the letter only says single core cables should not be over sleeved.

411.3.1.1 says as you read down (A circuit protective conductor shall be run to and terminated at each point in wiring and at each accessory except a
lampholder having no exposed-conductive-parts and suspended from such a point.)

So an earth is required a fan is not a lampholder so it does require an earth running to it even if not connected. So I can see how with for example a central heating junction box with multi-cables being used between controller and box one of the earth wires could be over sleeved where there was an earth in one of the other cables. Although I would not personally do that.

But the pictures shown clearly do not conform with 411.3.1.1 so are not permitted in the way shown.

The Electrical Safety Council seem to be set on finding ways around regulations set by BSi and IET they have done the same with lighting with no earth.

They say things like previous edition but pre-1992 there was no BS7671 so that is the furthest one can go back. As to IET there was no IET before March 2006 so either BS7671:1991 or BS7671:2001 are the furthest one can go back with regulations depending on if BSi or IET but The Electrical Safety Council seem to clutch as every straw to try to do as little as possible to make items comply.

I still ask how two RCD's an a large house can really comply with ((iv) reduce the possibility of unwanted tripping of RCDs due to excessive protective conductor currents produced by equipment in normal operation) my RCD's do trip from time to time and I know really I should use RCBO's to comply.

It seems there is a war on as to how much we can get away with doing and still not breach the regulations this is not the way we should be doing things.

 

[SimonH2]

But the pictures shown clearly do not conform with 411.3.1.1 so are not permitted in the way shown.

The Electrical Safety Council seem to be set on finding ways around regulations set by BSi and IET they have done the same with lighting with no earth.

Perhaps this should be reported to the H&SE ?

If a body is advising it's members to do (or that that they can do) something which is not in compliance with the accepted standards, then that could be construed as a breach of their general duty under H&S At Work rules and also potentially inciting people to break the law as specified in Part P. Perhaps the HSE will just say "Meh, too busy", but if not then the results could be interesting - get the popcorn.

Or failing that, I'm sure the likes of the Daily Wail would love to run a headline "trade body advises it's members to break the law".

 

[mfarrow]

411 is the section for the protective measure Automatic Disconnection of Supply.

If the designer chooses Double or Reinforced Insulation as the protective measure then there is no need for a cpc. Now i know the next jump will be to a regulation talking about replacement of items of Class II equipment with Class I equipment by the user, and therefore not to use plug/socket etc (i forget the exact wording). Some interpret user to be someone undertaking work on the electrical installation, but that is clearly not the meaning of the regulation.

So going back to the cable question: I have cables in my house where either a live core (in 3 core & cpc) is not used as identified throughout the rest of the cable, and in one instance a borrowed neutral 'fix' where I have used the line core as an extra cpc in twin + earth. I would not expect someone to just cut into it and take the core colours as read.

Regarding John's comment that some idiots may see an g/y core identified as a line and apply it to bare conductors as well, they're most likely in the same camp as though who think brown sleeving in B&Q is sold next to g/y sleeving for that specific purpose anyway.

 

[ericmark]

Forgetting about rules we all know that the brown/Red sleeve used in light fittings to over-sleeve is often missing so one must expect this to happen else where.

Of course if it's permissible to over sleeve green/yellow then clearly no problem with bare copper so as long as a plastic back box is used and plastic switch then you can use the bare copper of twin and earth to connect to a two way switch.

It is of course a slippery slope this would open the flood gates there is clearly no difference in the user swapping a fan which was class II to a class I version to swapping a switch which is class II to a class I version.

I had to read again the codes given by the Electrical Safety Council and they award a Code 2 where earths are not supplied to lights so clearly also would be code 2 where earth not supplied to a fan so under there own advice you would fail an installation where their advice is being followed.

 

[JohnW2]

Forgetting about rules we all know that the brown/Red sleeve used in light fittings to over-sleeve is often missing so one must expect this to happen else where.

Indeed - and, I suppose, another point to add to the downsides of over-sleeving G/Y conductors for other purposes.

Of course if it's permissible to over sleeve green/yellow then clearly no problem with bare copper so as long as a plastic back box is used and plastic switch then you can use the bare copper of twin and earth to connect to a two way switch.

Eh?- I think not!! It may be compliant within the box, but the run of cable, with a live conductor only 'single insulated' (in fact, not even 'insulated' - just 'single sheathed') would surely be non-compliant?

Kind Regards, John

 

[ericmark]

411 is the section for the protective measure Automatic Disconnection of Supply.

CHAPTER 41
PROTECTION AGAINST ELECTRIC SHOCK
411.3 Requirements for fault protection
411.3.1.1 Protective earthing

This is the basics before it gets into the nitty gritty and the comment "except a lampholder" makes it abundantly clear it refers to all fixed wiring.

 

[westie101]

makes it abundantly clear it refers to all fixed wiring.

Which I would suggest you would be hard pressed to actually prove that flex between an FCU and a piece of equipment actually is!
Despite how much you wish it

 

[mfarrow]

May I correct:

CHAPTER 41
PROTECTION AGAINST ELECTRIC SHOCK
411 PROTECTIVE MEASURE: AUTOMATIC DISCONNECTION OF SUPPLY
411.3 Requirements for fault protection
411.3.1.1 Protective earthing

But before that:

410 Introduction
410.3.3 In each part of an installation one or more protective measures shall be applied, taking account of the conditions of external influence:
(i) Automatic disconnection of supply (Section 411)
(ii) Double or reinforced insulation (Section 412)
(iii) Electrical separation for the supply of one item of current-using equipment (Section 413)
(iv) Extra-low voltage (SELV or PELV) (Section 414).

The protective measure applied in the installation shall be considered in the selection and erection of equipment.