My plumbers sparky has installed my heating system, but has used the green/yellow wire in one cable as a switched live. The core has been marked, (with red rather than brown tape, but that is another issue!). Previous posts in this group seriously depricate this practice - in my opinion with very good reason. The question is though, can anyone point me at a specific regulation that prohibits using a sleeved green/yellow cable as a live? Note: this is a flexible cable so the 'earth' has the same CSA as the other conductors. I'd like to be able to throw this back at the plumbers with a definite regulation to quote at them... Mike
"The bi-colour combination green-and-yellow shall be used exclusively for identification of a protective conductor and this combination shall not be used for any other purpose."
snipped-for-privacy@googlemail.com coughed up some electrons that declared:
Then he's not a proper sparky. You never EVER use green/yellow for anything other than an earth/CPC. Andy's already quoted the regulation, but AFAIC that's a reportable offence because all right thinking people expect G/Y to be safe.
Should someone come along later, unwire it and put it back from one end only, it would be quite easy for them to connect it back to an earth terminal, possibly rendering some extraneous conductive part live.
Also - if he's used the CPC for live, is anything providing an earth to the thing on the end of the cable?
That's something I suppose, but it is still unacceptable.
I suggest you call the plumber, and ask why you shouldn't be phoning (most probably) the NICEIC. That should concentrate his mind.
If he doesn't get over PDQ and correctly rectify the issue, then your options would include:
If you have electricians name, it would be a case of phoning the NICEIC, NAPIT and the rest of the half dozen scheme providers until someone finds his name on their list. They'll take it from there.
Failing that, Building Control would be my next port of call. Even a non sparky BCO should realise that's wrong, especially if you quote the regulation at them. They have channels for following this up.
Trading Standards is another, but I think the BCO will be more use in the first instance.
Normally I'm in favour of giving grace to genuine mistakes and keeping it diplomatic, but this is a serious safety issue and, given he attempted to re-identify the conductor, it goes beyond a mistake to pre-meditated laziness. It's not hard to obtain multicore control cable.
Hopefully you won't have to get heavy handed, but you have some options if you need them.
That refers only to the colour, so if the wire is sleeved red or brown it should be OK - until someone breaks in to it elsewhere! I prefer red for switched Live as it identifies it.
You are right to say that only refers to the colour but sleeving in another colour does not make it ok. There is a separate requirement that current carrying conductors require basic insulation on the conductor and supplementary insulation (the sheath). Using a bare protective conductor as a switched live (or neutral) will breach this. Sorry, no access to regs to provide the cite, but it will be there somewhere.
I must disagree Peter. The difference betwen this and sleeving a black or blue as phase, is that black or blue are to be regarded as "live" at all times anyway, even if they are a neutral. The consequences of wiring a neutral conductor to phase is most often that something doesn't work, or a short circuit which trips the breaker.
The CPC is a special case, because if someone breaks into it later (as you mention) or the sleeve falls off, then the consequences of mis-identifying it are "unsafe", rather than "doesn't work".
Others have given the appropriate regs - but it really does show a lack of pride in workmanship and or penny pinching given that suitable flex is so easily available.
========================================= I'm a bit confused by the OP's post. Can you actually buy three core cable with the earth wire separately insulated in the same way as the other two cores are insulated? I understood Fred's post to indicate that the earth is always a bare conductor in twin and earth cable whereas the OP's post suggests that his cable includes a fully insulated green/yellow earth.
It's probably flex, based on the fact that heating is involved. I suspect it the flex going up to either the hall stat which probably wants E, L, Switched-L *and* neutral for the bias heater.
Or it could be the flex going to the programmer and the bloke only had 4 core, when he needed 5 or whatever.
I agree it's not allowed and is bad practise, but it is extremely common, particularly in heating circuits, and there are clearly a large number of electricians who don't think there's anything wrong with it.
I came across it in some streetlamp circuits which would have been professionally wired too -- standard 3-core had been used to the NEMA photocell socket, with the earth used for the switched live return in all of them.
Also, if there's no earth in the cable, accidentally slicing through the cable might not blow a fuse/RCD and disconnect the supply.
Sorry for the confusion - It is flex! The wiring in question is approx 2m length between the wiring centre and the boiler. I guess the guy didn't have any multi-core cable and so has used 2 x 3 cores instead. One carries L/N/E from the wiring centre to the boiler. The other carries SWITCHED LIVE to the boiler and L/N from the boiler to the pump (via wiring centre). IIRC it is the pump live that is carried on the green/yellow wire. Incidentally the boiler manual is here;
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. Page 34 shows the pump L & N fed from the boiler, but I can't see any reason why the N couldn't be taken locally from the wiring centre... or is there normally some reason why both L & N would need to be fed from the boiler PCB? Mike
Common plumber's trick when wiring boilers. Why buy two reels of cable when one will do. And why change the habit of a lifetime. It works, doesn't it? ;-(
This bad practice is very very common. (50% of all installations?) Given that the boiler has provision for more than one cable entry the installer could have used a second flex to provide the extra signal.
Why should the good guys carry multi-core control cable around to do a proper job when this guy thinks he can bend the rules. It's not as if he had to do significant extra work to get it right.
When we had our boiler replaced a while ago, I took the opportunity to fix the rather bad electrics that were there before. By the time the guy arrived to fit, I'd already downloaded and read the manual, and started on the new permanent cabling.
The difficult bit was getting cable with the right rating and number of cores. In the end I went to the local plumbers merchant, and even they struggled. In the end they found me a 'reel end' and I got it for a pound!
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