Help On Using Earth As live?

[6ft2]

Hi Im currently working for a company wiring heating systems up I have had a Job Pulled up By a QS for the company we contract for
Saying it Failed due to Earth conductor being used as a live and seriously dangerous. Ill explain , I had to run a cable in for The Heating time clock and it was a fair run , I needed Live, Neutral, and 3 switch lives ,making 5. I used 1x 5 core flex as I thought that as the timer control was double insulated then I could Sleeve the earth with Brown sleeving and use it as one of the Switch lives. Am I wrong to do this?

 

[malcolmsanford]

Yes that is exactly what it means. Table 4F3A gives us the current carrying capacity of the flex and Table 4F3B give us the mV/A/m.

You would then do all other tests as per normal ir IR R1 + R2 etc.

 

[truckster]

Cheers Malcolm

Still think it's wrong tho

 

[malcolmsanford]

I cannot believe anyone would even consider using a conductor intended to be a cpc as a live conductor....even if sleeved at the ends,the dangers are all to obvious. I'm not convinced of your interpretation of 514.4.2.
IMO in order to comply the entire conductor would have to be sleeved over....clearly impossible if the G/Y is contained within a sheath......I disagree with the above, it is not permitted to use a G/Y within a sheathed cable as a live conductor.

Sorry wire I can,t see how your interpreting these regs any other way than they are written.

You can't use the colour G/Y for any other purpose than for a protective conductor. It clearly sates that a single core cable can not be sleeved at it's termination if it's entire length is G/Y.

How do you interpret that to mean a mulit core flexible cable.

I'm in total agreement as I said in a previous post that it is something I would never considered doing just because IMO it is bad practice, the same as non grommit of a back box IMO is bad practice and not fitting fly earths to back boxes is also bad practice but none of above are demanded of us in the regs.

 

[Deleted member 9648]

Malcolm, these regs can be interpreted in various ways...which is what keeps forums like this going!
514.4.2 states
"The bi-colour combination green and yellow shall be used exclusively for the identification of a protective conductor and this combination shall not be used for any other purpose".
If contained within a sheath it remains green and yellow,therefore IMO must only be used as a protective conductor...if the cable was cut for alterations to be made it would not be apparent that the G/Y was not a cpc....Having re-read the single core bit I accept that it does appear open to interpretation and that it could be taken that a sheathed cable could have the G/Y sleeved,but that is not how I see it.

Why the hell dont the regs just say "A conductor coloured G/Y shall be used only as a protective conductor and shall not be energised,or used for any other purpose than a protective conductor"?

 

[mogga]

Thanks Malcolmsanford, that's illegal practice under our local regs, I wasn't sure about the UK.

2 refits on supermarkets iv donerecently were both YY cable for additions DBs looked like a LB of Mince but cheap as chips and within the regs

 

[mogga]

Iv seen hundreds of street lighting installs where the 3 core flex to photocell has G?Y core taped and used as switch wire

 

[Deleted member 9648]

Iv seen hundreds of street lighting installs where the 3 core flex to photocell has G?Y core taped and used as switch wire

Me too......but if there was an accident as a result of using the G/Y in a flex as a live I would not want to rely on the interpretation of 514.4.2 as a defense if I was in front of a jury.

 

[davelerave]

definitely bad practice sleeving the gr/ye-i've seen a couple of near misses


no debate over here-as sleeving and taping of neutrals and earths not allowed at all

 

[IQ Electrical]

Too easy for mistakes to happen here if the G/Y is used as a phase conductor. Its all about using cables with enough cores to do the job in the first place innit?.....

I absolutely agree, poor practice/poor design and I would never dream of doing it but as an academic discussion only, 514.4.2 makes a definite distinction between single and multicore cables so the scenario would actually comply.

 

[T.Glass]

I personally would never gamble on things like this, is it really worth potentially killing somebody just to save running an extra bit of wire in?

Even if the regs say it's ok, if Joe Bloggs cut in to the wire to get power for something else ( yes, I know they shouldn't but they do) it could result in major issues that could have been easily avoided.

 

[IQ Electrical]

Good morning Richard,

Can you please clarify the meaning of 514.4.2 with respect to multicore cables as I believe the restriction on oversleeving a green-and-yellow coloured conductor at terminations only applies to single core cable?

Thanks in advance



Kind Regards,

Peter
IQ Electrical Ltd




Morning Peter

You’re quite right, it’s acceptable to over sleeve a green and yellow coloured conductor of a multicore cable. The regulation you have stated is designed to refer to single core cables.

Best Regards

Richard

Richard Townsend
Senior Engineer
Standards and Compliance
The IET

 

[malcolmsanford]

Good morning Richard,

Can you please clarify the meaning of 514.4.2 with respect to multicore cables as I believe the restriction on oversleeving a green-and-yellow coloured conductor at terminations only applies to single core cable?

Thanks in advance



Kind Regards,





Morning Peter

You’re quite right, it’s acceptable to over sleeve a green and yellow coloured conductor of a multicore cable. The regulation you have stated is designed to refer to single core cables.

Best Regards

Richard

Richard Townsend
Senior Engineer
Standards and Compliance
The IET

Think that is what they call from the horse's mouth Thanks IQ

 

[Deleted member 9648]

OK...admit defeat....but if it is ok to oversleeve a G/Y it damn well shouldnt be!...:freak:

 

[Silly Sausage]

I would possibly extend that to say Neutrals shouldn't be sleeved as Line conductors as well (for the similar cutting mid cable reason).

 

[davelerave]

surprising it's allowed on final circuits for new work-when the correct cables are readily available

surely it encourages the practise

fair enough for larger dist. ccts where the risk is lower-and the cable is more expensive