Structural bonding in a BMO

[Rockingit]

What are people's thoughts on exposed structural steel bonding in a BMO where each dwelling is fed from a Ryefield on a private network? Would you bond it once at the main incomer, once at the Ryefield or however many times at each downstream CU?

And I guess, same question for gas!

 

[pc1966]

I would definitely bond the MET of the incoming supply arrangement (is that in the Ryefield board?) to any extraneous things, such as steel building and water/gas pipes. Quite likely the bonding size needed is larger than typically used in domestic flats, etc, so this avoids any overload risk from PME faults, etc..

I also thing each dwelling could also be considered an independent installation (due to ownership, lack of common maintenance body, etc) so they also should have bonding just in case someone monkeys with the main supply arrangement, etc.

That seems to be what is illustrated in Guidance Note 8 in figures 5.15 and 5.16