size of C.P.C

[coatesykid]

I have a old fuse board and a new RCD C.U which are connected through a Henley block my main earth is 16mm and my main bonding is 10mm all going into MET the new CU which is a 4 way is connected to the MET by a 10mm C.P.C and the old fuse board is connected by a 6mm C.P.C does both these C.P.C have to be upgraded to 16mm
its TNCS by they way

second my old fuse box 60amp has 16mm tails is this ok or need upgrading to 25mm

 

[tony mc]

I would upgrade the the 6mm to at least a 10mm because you are TNC-S if its a old fuse board you may stuggle to get a 16 mm in.

Your bonding is fine at 10mm

16mm tails are also fine for 60 Amps

 

[coatesykid]

should the rcd cu be 16mm as it is only 10mm at the moment

 

[tony mc]

Because your system is TNC-S your bonding is going to be based on your DNO neutral.
So if the neutral is 35 mm or less 10 mm is required.

Your earth conductor can be calculated with the adiabatic equation but has to be 10mm or more due to the PME.

If you want a calculation done post the ZE at the origin of the instalation!

Hope this helps.!!!!