Main incoming earth question

[bobby101]

Hi all I would like to ask if any of you guys have come up against this ... I'm guessing yep.. Having done an adibiatic calc on the install I'm on at the moment I've just realised that the main incomer earth is 10mm smaller than it required could you guys tell me what reg I should use for a eicr and give some advice on how I code also should I contact the supply company and the installers of the installation as the install is not that old any advice would be great thanks

 

[onions1066]

More info would be required, what installation is it and what sizes are we talking? Before you call people back you have to be 100% with your facts and figures because you could end up with a very eggy face

 

[oldtimer]

Bobby a picture would be nice but also you are saying it is 10mm smaller does that me its a 6mm and should be 16mm or is it 10mm. Plus what size is the DNO fuse ie 60A or 100A size is the tails 16mm or 25mm and any readings you have taken . Why ? because it gives us a better picture and at the same time it puts you in a frame of mind to record these thing ie Ze,PFC.PSSC ect all this is good but is this earth big enough question without is basically cryptic

 

[guest119]

The correct sized main earthing conductor would go from your installation to the supply company earth block.
Then the installation would be correct to bs 7671.
The supply company work to different regs and would not necessarily provide an equal sized earth core to the block.

 

[markc123]

The general rule of thumb (or maybe just my rule of thumb lol) is that if the cpc is at least half the size of the conductors then you don't need to fanny on with the adiabtic equation because it'll comply.

Hense 16mm earth for 25mm tails & 10mm earth for 16mm tails.

 

[Phoenix]

The correct sized main earthing conductor would go from your installation to the supply company earth block.
Then the installation would be correct to bs 7671.
The supply company work to different regs and would not necessarily provide an equal sized earth core to the block.

Absolutely! The last rewire I worked on was TNS and the DNO earth was about 4mm, Called them to fit a new meter and to check their earth as I was also worried about the connection to the sheath. They were more than happy with it, which surprised me, but not my problem!