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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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    Not in the slightest.


    PME is only PME in a public distribution network.


    PNB is also (most of the time) PME in a public distribution network,


    PNB is almost the same as TN-S in a private installation, where:

    (a) The N-E bond is only made at one point (usually the main switchboard); AND

    (b) The cabling to the transformers / generators have no connection between star point and earth save within the transformer/generator themselves (i.e. the PE between the main switchboard and the transformer/generator is "gapped" at the transformer/generator, making the only items that are TN-C-S the transformers/generators themselves).


    So .. clear as mud, but at the same time, not all that difficult.
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  • 0
    Not in the slightest.


    PME is only PME in a public distribution network.


    PNB is also (most of the time) PME in a public distribution network,


    PNB is almost the same as TN-S in a private installation, where:

    (a) The N-E bond is only made at one point (usually the main switchboard); AND

    (b) The cabling to the transformers / generators have no connection between star point and earth save within the transformer/generator themselves (i.e. the PE between the main switchboard and the transformer/generator is "gapped" at the transformer/generator, making the only items that are TN-C-S the transformers/generators themselves).


    So .. clear as mud, but at the same time, not all that difficult.
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