2 & 4 core armoured

[coombed]

Hi all,

I have conflicting information that I need clarifiying. Is it acceptable to use 2 core armoured cable for a installation and relying on the armour for earth and the same for 4 core, is it acceptable to use this for a 3phase install, using 3 cores for the phases, 1 for neutral and the armour for the earth?

Some people have said it is acceptable and common practice and others have said NO WAY!

Please, can someone advise?!

Thanks

Duncan

 

[RF Lighting]

It depends.

There is a table which shows the copper equivalent CSA of the steel armour, and some SWA does not have a big enough CSA to allow the amour to be used as the CPC.

Also a supplementary earth may be required to lower the EFLI of the circuit.


http://www.diynot.com/wiki/electrics:swa-earthing

 

[coombed]

Thanks for the prompt reply,

Just to clarify, a 2 x 4mm core will be fine to use the armour as earth, and a 4 x 10mm core will also be fine? Would you advise on using 3 and 5 core instead of 2 and 4 for an install using the said core diameters?

Thanks again,

Duncan

 

[GaryMo]

Yes, both are fine to use the SWA as a CPC.

Have a look at the link RF posted. It's very useful.