TT system - main bonding +

[Freetrader]

Hi

Went to look at a possible consumer unit change,

when I got there is was a TT system, The customer want the consumer unit upgrading.

Q1, It has an 100A 1ma RCD unit between tails and consumer unit.

He wants this removed, as the replacement consumer uint will have RCD protection.

I am advising to keep it, and have the additional 30ma RCD as well.

Iam thinking the 100A 100ma unit can be used as an islotion switch as well.

Q2, there doesn't seem to be any sign of main equipotential bonding to incoming services.

What size would be recommended, and can it be run out side the house and back in again if that is an easier route?

Thanks Simon

 

[M107]

1. I take the 100mA rcd's out & put a dp 100A mainswitch in for isolation, mainly because unless trhe 100mA is S type you'll run into tripping problems, along the lines of the 100mA tripping & you loose all circuits.
   
2. 10mm & yes you can run it externally if required.
   

 

[binky]

1. 10mm & yes you can run it externally if required.
   

Think 6mm is still fine, but I carry 10mm so tend to use that.