How certain are you it is a PME system, TN-C-S is not necessarily PME.
It’s a very large installation with its own substation clearly labelled PME. Also the installers who fitted the Distribution board have noted it as PME.How certain are you it is a PME system, TN-C-S is not necessarily PME.
An Earth electrode/pit in a TN-C-S installation should be encouraged! In fact many (most?) countries mandate it! A large installation may need a fairly low impedance to be effective though.Let’s open an old thread.
looking fo4 a brief answer. Wishful thinking.
on a pme system having an earth rod as an addition is perfectly ok in my opinion.
im working for and under a new electrician at work.
we have had a distribution board fitted by outside contractors. They have earthed via a 16 mm earth conductor within the 3 phase SWA supplied from a PME system. They have also popped an earth rod in at the new distribution board. We are going to run feeds of this board for various stuff.
the new electrician wants to convert to TT or get rid of the earth rod As he thinks it’s wrong because of “potential differences” I disagree.
Am I wrong? I’m willing to accept this If I am,
but I know earth rods where proposed as additions in PME in the 18th. So I’m sure it’s OK.
I would agree with you on a properly maintained, regularly checked system but one or multiple earth rod issues could become dangerous as I have seen in the pastAn Earth electrode/pit in a TN-C-S installation should be encouraged!
And they all have different regs and network topologyIn fact many (most?) countries mandate it!
And that is the difference between an earth rod and a properly installed and tested earth rodA large installation may need a fairly low impedance to be effective though.
With a private substation it could be TNS despite it being labelled PME just because the star point of the transformer is referenced to earth it is only there to keep a stable neutral point and doesn't necessarily make it PMEBut as pointed out TN-C-S could be either PME or PNB.
It’s a very large installation with its own substation clearly labelled PME. Also the installers who fitted the Distribution board have noted it as PME.
Surely you can if you have multiple earth rods connected to the PEN conductor before the main isolator (origin of supply)??If it has its own dedicated feed from a substation then it can't be PME. For a supply to be PME there needs to be multiple N-E connections along a distributing main, it's not possible to achieve that multi earthing on a dedicated feed.
Surely you can if you have multiple earth rods connected to the PEN conductor before the main isolator (origin of supply)??
To be fair, I am not certain myselfI don't think so, I'd have to look up the rules and regulations around PME to be sure though.
It just wouldn't make sense for a dedicated feed from a substation.