Earthing on wooden shed

[PeeWee]

Hi all, just a quick one on an earthing arrangement for a radial circuit on a wooden workshop I have just had installed.
I have run a 3 core 2.5mm swa from a consumer unit in a metal shed that has TT earthing in place.
Does this cable need the armoured earthing as well as the CPC or just the CPC earth cable only?
Thanks,Pete

 

[westward10]

The armour will need earthing.

 

[PeeWee]

The armour will need earthing.

Thanks for swift reply westward!
Just want to elaborate on full wiring set up I have at moment:-
I ran a 10mm swa from main consumer unit in garage to consumer unit in metal shed which has got an earthing rod TT system.
I earthed the swa armoured at main consumer unit in garage with banjo fittings and didn't earth the swa armoured at the metal shed consumer unit.
This is the reason why I wasn't sure on the earthing of the swa armoured from the metal shed to the wooden workshop.
So am I right in thinking I need to earth both ends of this swa armoured with banjo fittings?
Thanks,Pete

 

[westward10]

Is the complete installation TT?

 

[PeeWee]

Is the complete installation TT?

The main consumer unit in the garage is on a TN-S earthing arrangement which is for the house.The metal shed is on a TT earthing arrangement.

 

[westward10]

So the SWA from the house you earth the armour to the TN-S system. In the metal shed where it is TT the armour of the supply cable does not connect to the TT but should be contained in an all insulated enclose to prevent simultaneous contact between the two systems which are likely to have a different potential. From there on the armour of the SWA to the wooden shed is earthed to the TT.

 

[PeeWee]

So the SWA from the house you earth the armour to the TN-S system. In the metal shed where it is TT the armour of the supply cable does not connect to the TT but should be contained in an all insulated enclose to prevent simultaneous contact between the two systems which are likely to have a different potential. From there on the armour of the SWA to the wooden shed is earthed to the TT.

That's great westward,thanks for clarifying.I will get it tested on completion to make sure Ze readings etc are all within spec.

 

[MDJ]

I hate it when a shed is TTd, why can they not be extended from the tn system? popcorn ready