TT Eathing

[DaveSparks]

Hi All,

I want to provide earthing for a workshop remote from the house and not wanting to export the PME earth I am going for TT. The ground is decent soil but has many stones in it that would make driving rods in it somewhat hit and miss so I thought that I would bury the earth when I trenched out for the services. Would it be OK to use lengths of copper pipe and if so any idea how much would be needed? I would rather over do it than have to provide more later and what would be a good depth?

Thanks in advance for any comments.

Regards,

Dave

 

[RF Lighting]

Why don't you wan't to export the earth?

 

[DaveSparks]

Hi,
It isn't recommended that a PME earth is extended outside of the equipotential area:
http://www.diynot.com/forums/viewtopic.php?t=125007

Regards,

Dave

 

[RF Lighting]

Are there any extraneous conductive parts in your out building?

What size supply are you planning on taking out there?

 

[DaveSparks]

Hi,

Yes there will be a sink and metal fixed benches. The roof trusses are going to be fabricated out of steel.

I will be feeding it with 16 mm SWA and protecting at the CU with 32 Amp breaker.

Regards,

Dave

 

[ban-all-sheds]

Use 16mm 3-core - the cpc is large enough to double as a main equipotential bond.

Would it be OK to use lengths of copper pipe

http://www.jointingtech.co.uk/category.asp?categoryID=304

 

[DaveSparks]

Hi,

So I now have 16mm 3 core SWA in the trench and if I now use the earth to provide an equipotential bond the workshop with the house earth do I still provide a local earth rod/tape? I was just wondering what happens if a workshop socket was used outside as the earth potentials could be different.

Regards,


Dave

 

[Spark123]

Just because you have metal work benches doesn't make them an extraneous conductive part, nor does a sink on its own. Are the pipes feeding the sink metal?

I was just wondering what happens if a workshop socket was used outside as the earth potentials could be different.

Exactly the same as using a socket from the house.