any conductor as protective earth

[stef]

Hi all,

Just lately I have seen this quite a few times: a 4 core SWA (cores brown, black, grey and blue) feeds a single phase distribution board. The spare grey conductor has been taped up with green/yellow
tape and used as an earth conductor. The steel armour has been bonded to the metal enclosure of the distribution board.

According to tha colour coding it is a fairly new installation and certainly not good practise.

I always thought you have to run a seperate (green/yellow) wire for earth if the SWA hasn't got one
and if one is needed at all and you are not allowed to use other than green/yellow cores as an earth.

I couldn't find it in the regs but somehow I seem to remember that you are not allowed to tape up
wires with green/yellow and use it as earth (although I might be wrong)

Can anyone help me with that? It looks like a bodge job to me.

Thanks guys.

 

[Spudnik]

You can use any colour you like provided they are suitably identified as to what purpose they serve.

Havent got my regs with me at the mo, but im sure someone will be able to give the number.

 

[andekoch]

To the best of my knowledge you can designate a conductor as a cpc (usually the grey) and all is well. You cannot however use a green/ yellow (or unsleved) as anything other than a cpc though since that is a specific designated use.

Also below a certian size the armout on a SWA can be used as the cpc so a 2 core would be fine.

 

[stef]

Thanks guys.

 

[benji]

where was the black connected to

yours benji

 

[xraytek]

I seem to recall somewhere that there is a standard for sleeving 3 phase SWA for single phase to avoid black being used as a neutral conductor:
Brown- left as it is
Black- sleeved Green/Yellow
Grey- Sleeved blue
May have even been the NICEIC but could be wrong.

 

[Guest123]

Yes....there was a "de-neutralising the black" article in a connections newsletter when the colour changes first came in.

 

[Darkwood]

Dont forget for the swa to comply if used as earth as well there should be bonding link (fly lead) from the earth ring to the earth block and as for the cores been utilised as earth i agree with the above as long as its correctly marked along its full exposed length.