exporting pme

[sparkyt]

I know this has been covered a few times but would like opinions on the following.

House with pme supply. SWA from house protected by 30ma rcd to a db in shed 20m away. SWA connected as earth at both ends. oil tank in shed with copper pipework underground back to house. Pipework bonded at house. Does this need TT'ing? all thoughts greatly appreciated.

 

[Evans Electric]

Oh dear here we go again, if it were me I'd do it as described and bond the pipework/tank to the C/unit in the shed. I can't see a problem with that.

Deke

 

[sparkyt]

Oh dear here we go again, if it were me I'd do it as described and bond the pipework/tank to the C/unit in the shed. I can't see a problem with that.Deke

the pipework for the oil is bonded but at the house end i.e 20m from the tank and shed. the SWA feeding the shed be only 6mm.

 

[green-hornet]

the pipework for the oil is bonded but at the house end i.e 20m from the tank and shed. the SWA feeding the shed be only 6mm.

That is the correct way of doing it.

To bond to the garage cu you would have to TT the garage supply.

If I could draw pictures I would but I am too lazy, and old.

PME can be exported providing a full understanding of earthing is shown and calculated for.

 

[Evans Electric]

Surely if you bond the pipework in the shed everything is connected the earth/neutral and is the same potential , or am I missing something here. Would he not have to disconnect his incoming earth to the shed before TT, ing it.

 

[Apache]

Surely if you bond the pipework in the shed everything is connected the earth/neutral and is the same potential , or am I missing something here. Would he not have to disconnect his incoming earth to the shed before TT, ing it.

obviously - unless the SWA could also take the neighbour's fault current.......

 

[green-hornet]

Surely if you bond the pipework in the shed everything is connected the earth/neutral and is the same potential , or am I missing something here. Would he not have to disconnect his incoming earth to the shed before TT, ing it.

They want a seperate earth to run from a metal pipe in the shed/garage back to the main earthing, and not the cu in the shed/garage.

Which is why it is often better to TT the outbuilding.