upgrade

[m1ck_b87]

Hi all

Am I correct by saying if I install a new consumer unit, like for like replacement with no additions I don't have to upgrade main protective bonding conductors if they are 6mm, aslong as there's no signs of thermal damage. Tnc-s system.
Would I note this on departures on electrical installation cert.

 

[babylonsBurning]

Hi Mick, This is from ESC best practice guide for "Consumer unit replacement in domestic and similar premises"

"A 6 mm main protective bonding conductor size could be

deemed adequate where the minimum size required by

Regulation 544.1.1 of BS 7671 is 10 mm if the bonding conductors have been in place for a significant time and show no signs of thermal damage"

 

[bartkusal]

Hi all

Am I correct by saying if I install a new consumer unit, like for like replacement with no additions I don't have to upgrade main protective bonding conductors if they are 6mm, aslong as there's no signs of thermal damage. Tnc-s system.
Would I note this on departures on electrical installation cert.

It is not like for like is it? So this reason is wrong. But yes you can leave 6mm in place for other reasons you stated and if it satisfies adiabatic equation and 10mm protective bonding is in place for TN-C-S