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?

 

[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

 

[madmac]

Just to add my penny's worth....... I agree with all that has been said before with regards to the regs. however, I also think it is bad practice and the regs. should be clearer and go further and ban this practice.
It was mentioned that as long as the equipment or termination point has been earthed by another means then there is no need for a cable to have an earth and this leaves open the option to use the cpc as a line conductor, however again, it is in the regs. that all circuits must have a cpc for the full length of that circuit regardless of whether it will be used or not, so a bit of a double standard there and now things get a little bit confusing!
I'm feeling a bit lazy today boys, so I'll leave it up to one you fine detectives to find the said reg. I'm talking about, and it is in there.

 

[malcolmsanford]

Just to add my penny's worth....... I agree with all that has been said before with regards to the regs. however, I also think it is bad practice and the regs. should be clearer and go further and ban this practice.
It was mentioned that as long as the equipment or termination point has been earthed by another means then there is no need for a cable to have an earth and this leaves open the option to use the cpc as a line conductor, however again, it is in the regs. that all circuits must have a cpc for the full length of that circuit regardless of whether it will be used or not, so a bit of a double standard there and now things get a little bit confusing!
I'm feeling a bit lazy today boys, so I'll leave it up to one you fine detectives to find the said reg. I'm talking about, and it is in there.

Are you referring to reg 412.2.3.2 concerning a CPC at each point in an installation ??

I think you are refering to my post # 10 when I inferred that a CPC may be at that point being their via another conductor.

If you look though at my post #7 I did say that the assessor may have failed it due to the fact that the cable did not have a CPC inside and therefore the cable would not have a protective earth if it was damaged.

 

[madmac]

Cheers malcolm, that's where I read it, and that's all I'm thinking that if the regs. state that a cable must have a cpc for the length of the circuit then guys that are saying they would use the cpc as a line conductor not adhering to this reg. even though the other reg. says it's only the colour G/Y that can't be used for any other purpose than earth. I think I need a lie down and a wee dram!:confused5:

 

[Spudnik]

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.

I didnt say i agreed with it.

Great thread though chaps!!

 

[Deleted member 9648]

Jason....didnt think you did mate...sorry if I gave that impression...unk:

 

[grimysparks80]

I go to a lot of heating jobs where the earth on a twin has been used as a live conductor. Bit of red sleeving on the end and jobs a good un. Id say it was pretty standard practice based on the amount of old jobs ive seen it on.

 

[Risteard]

the regs. state that a cable must have a cpc for the length of the circuit

It's not the cable that requires a cpc - it is every point in the installation, e.g. accessories.

 

[Sparky Ninja]

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?

As long as the time clock is class II and the multicore cable's sheathing is at full integrity throughout the run, then the cable will have both fault protection and basic protection and so no cpc will be necessary. The sleeved G&Y conductor will need to be identified at every termination.

 

[Marvo]

One problem is if you use the G/Y as a part of the current carrying circuit, you can sleeve it at both ends to indicate this but what if somebody splits the cable somewhere in the middle to run a radial circuit off it?

 

[davelerave]

definitely surprising this is allowed (on dom final ccts anyway)

certainly we can't do it over here(ireland) and with good reason

 

[madmac]

Bad practice, bad design, lazy installation,cheap and nasty..........anybody even thinking of doing this should hang their head in shame, what next?.........allowing the bad and dangerous practice of "borrowed neutrals"?

 

[steve.b]

Totally agree wirepuller----- C.P.C = C.P.C----- END OF.