I am about to install 4 sockets in 4 separate stone enclosures, housed within a large stone outbuilding. They have stone floors and are completely weatherproofed. They may be having small animals in them, goats, sheep etc.
The existing set up is TN-C-S.
BS7671 doesn't go into much depth with regards earthing. 705.411.4 just says a TN-C system shall not be used. Does this mean just TN-C, or does it also mean TN-C-S? It's a little confusing as the title to this regulation is TN system.
Is the thinking that there may be some potential between the PME earth and actual earth and that this potential could become lethal to livestock? Is this more likely in muddy, wet, earth floored barns or is it just as relevant in my situation above (all stone).
The existing electrical system has been very well installed, which leads me to think this has been thought out, as it must have been installed whilst this regulation was in practise...... making me think perhaps it doesn't need a TT for some reason. Here is a picture of the supply...
![[ElectriciansForums.net] PME on a farm?...........](https://electricians.s3.eu-west-1.amazonaws.com/data/attachments/68/68814-e982a946bea31f83fae924d2f34f6d76.jpg "[ElectriciansForums.net] PME on a farm?...........")
The existing set up is TN-C-S.
BS7671 doesn't go into much depth with regards earthing. 705.411.4 just says a TN-C system shall not be used. Does this mean just TN-C, or does it also mean TN-C-S? It's a little confusing as the title to this regulation is TN system.
Is the thinking that there may be some potential between the PME earth and actual earth and that this potential could become lethal to livestock? Is this more likely in muddy, wet, earth floored barns or is it just as relevant in my situation above (all stone).
The existing electrical system has been very well installed, which leads me to think this has been thought out, as it must have been installed whilst this regulation was in practise...... making me think perhaps it doesn't need a TT for some reason. Here is a picture of the supply...
