6mm incoming earth

[DNO1981]

Hi all

This is a follow up from a previous thread I posted about 16mm tails.

Just had two electricians round to quote for a board change, they were both happy to do it with 16mm tails but the incoming earth is only 6mm they have advised me to get onto the electricity supplier and upgrade the earthing and wont do the board change until done. Internal bonding is also 6mm

Sounds right? (not that I don't have faith in the sparks just seeking thoughts on this)

 

[cliffed]

Definitely looks bigger than 6mm…its not usually connected like that,always from the side terminal…

 

[DNO1981]

Definitely looks bigger than 6mm…its not usually connected like that,always from the side terminal…

Definitely a 6mm that's been confirmed funny thing is underneath next to this looks like a chopped earth cable which is much bigger

 

[GBDamo]

Definitely a 6mm that's been confirmed funny thing is underneath next to this looks like a chopped earth cable which is much bigger

Yes, I'm rolling back on this.

Here is a 6mm² in relation to my 25mm² tails and 16mm² main earth.

 

[DNO1981]

Yes, I'm rolling back on this.

Here is a 6mm² in relation to my 25mm² tails and 16mm² main earth.
View attachment 86266

So I guess it wouldn't stop any CU change, they could cut the 6mm earth put in a block then run a 16mm from the CU to the block

 

[Dartlec]

It's the sort of situation that might result in a Catch 22 unless some common sense is applied.

When you go ahead with the fuse upgrade it is entirely possible that the DNO will demand an up to date electrical certificate for the property to show that everything is in place and suitable for 100A, before they do any work. So then you'd end up in a Chicken vs Egg situation.

In most cases (having carefully assessed the situation) I'd personally feel comfortable with doing as suggested, with 16mm earth from the new board to a block near to the main head (and likewise with 25mm tails to henley blocks connecting to the existing 16mm ).

That would be on the understanding that the earth was to be upgraded (or that the DNO would decide they were happy with existing) - as well testing the existing Ze (test of the level of the current earthing) and a quick check with the adiabatic. I'd upgrade main bonding to 10mm too where it was reasonably practicable to do so.