Outbuilding supply from TT system

[Mr.Black]

What if the earthing conductor is buried..........

 

[robsparx]

What do you mean?

 

[Guest123]

What do you mean?

If the earthing conductor is buried for any length and not mechanically protected then it must be a minimum of 16mm. Table 54.1 page 127 of BS 7671 see also 542.3.1

 

[malcolmsanford]

Isn't the rod classed as the electrode Lenny and the conductor the cable that links the electrode to the MET. So though the rod would be buried the actually conductor connected to the rod is terminated above ground and may run above ground, or am I miss interpreting again

 

[Guest123]

Isn't the rod classed as the electrode Lenny and the conductor the cable that links the electrode to the MET. So though the rod would be buried the actually conductor connected to the rod is terminated above ground and may run above ground, or am I miss interpreting again

Thats right, as long as the actual conductor or cable etc isn't buried than this doesn't apply.

Most earthing conductors to electrodes aren't buried and are terminated in electrode boxes above ground, happy days.

I was just explaining what another poster meant when he asked what would happen if it was buried for any distance,

 

[La Poste]

If you are going to invest in a 100ma time delayed rcd why not use it as the main switch. That way the whole house will be protected by it. It would be a second layer of protection for the whole installation. After having installed it this way you can then take a feed from the main CU, a feed that is unproteced by the 30ma RCD in the main CU. Fuse it at maybe 20A and use this for the supply cable to the shed then at the shed fit 30ma RCD's to protect it. With this method you get the most value out of your 100ma £100 time delayed RCD.