OP
Engineer54
Haven't done too much in the way of PME for a good few years now, so i'll have to have a gander at the Reg's on Monday when i get back to the office to see what the so-called official version is. I can't remember sizing the main earth conductor from the bonding conductor on a PME install though.
Personally, i'd stick with the 50% rule, even with a PME installation for the main earthing conductor, especially in these day's of plastic service pipes becoming more and more prevalent in the domestic sector. To be honest, can't think of any domestic PME heads that i've seen, converted or otherwise, that had just a 10mm main earth coming off the heads N/E connection to the MET, (...may be some very early heads had a 10mm connections). It's always been 16mm, (or larger when when the head has been a substantially bigger 3 phase supply on a commercial or small industrial installation).
I'll go along with the 10mm earthing conductor in this instance though, for a known 60A supply!! I certainly wouldn't be leaving the PME connection behind in favour of a typical UK TT system that's for sure!! lol!!
