Not always, depends surely where the origin of that part of the installation is declared.
Zs or Zdb and all that.
A large installation on a farm, or indeed a BN in a block of flats can be in all parts to bs7671, but you can have islands tat are different installations where different rules apply.
The origin of the installation in the stables may well be a pair of bare singles on insulators and gallows brackets fed overhead, but the metering may be at the farmhouse where it comes from, and there it may be pme. You may not want to put that in now, but plenty remain in use and have many years to go.
Similarly in flats, each flat may have a TNS origin at its redlink, but its meter may be there or in the basement, and the basement may be tnc-s.. Bonding to the water main will be done both at the origin in the basement, and again in the flat, to the standards of pme and TN-S respectively.
Not always, depends surely where the origin of that part of the installation is declared.
Zs or Zdb and all that.
A large installation on a farm, or indeed a BN in a block of flats can be in all parts to bs7671, but you can have islands tat are different installations where different rules apply.
The origin of the installation in the stables may well be a pair of bare singles on insulators and gallows brackets fed overhead, but the metering may be at the farmhouse where it comes from, and there it may be pme. You may not want to put that in now, but plenty remain in use and have many years to go.
Similarly in flats, each flat may have a TNS origin at its redlink, but its meter may be there or in the basement, and the basement may be tnc-s.. Bonding to the water main will be done both at the origin in the basement, and again in the flat, to the standards of pme and TN-S respectively.
