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PME vs TN-C-S

AncientMariner
Are PME and TN-C-S supplies exactly the same?  Or does PME also have requirements regarding the number and relative location of suppliers earthing rods?

I am thinking here where the DNO replaces a length of failed 4-core (3-phase + Neutral) PILC cable with Wavecon or similar cable which has a combined Neutral and Earth conductor.  The average consumer would not know that their electricity supply's method of earthing had been changed.

Clive.
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    Also PNB might be either TN-S or TN-C-S - depending on where the N-PE link is compared to the source electrode connection.


    If the N-PE link (or links) is downstream of the source electrode's connection to the supplier's N conductor then it's TN-C-S and you have the risk of some diverted N currents (whether you have one customer or many).


    If the N-PE link is upstream of the source electrode's connection to the supplier's N conductor then it's TN-S and should be immune to divertedn N currents even if there are multiple customers (like a TN-S supply to a single customer with 4 submains).


       - Andy.
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  • 0
    Also PNB might be either TN-S or TN-C-S - depending on where the N-PE link is compared to the source electrode connection.


    If the N-PE link (or links) is downstream of the source electrode's connection to the supplier's N conductor then it's TN-C-S and you have the risk of some diverted N currents (whether you have one customer or many).


    If the N-PE link is upstream of the source electrode's connection to the supplier's N conductor then it's TN-S and should be immune to divertedn N currents even if there are multiple customers (like a TN-S supply to a single customer with 4 submains).


       - Andy.
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