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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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    PME systems do indeed have extra requirements to be considered PME,  such as electrodes just before the end of the PME run and part way along at defined intervals if the run is more than a certain length, PEN conductors must have double crimped joints or an equivalent measure to make sure neutral is less likely to break then live...

    Equally nothing stops TNS or PNB having extra electrodes or extra NE bonds, and still not being PME.

    Much of the DNO paper work avoids the saying "PME" altogether, and refers instead to CNE  (Combined Neutral and Earth) and SNE (Separated Neutral and Earth).

    IF only there were labels that could be fitted at the intake position that told you what was going on, like this but ideally with the addition of a small white square to the right hand side for writing in a Zs result and a PSSC in crayon.


    .

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  • 0
    PME systems do indeed have extra requirements to be considered PME,  such as electrodes just before the end of the PME run and part way along at defined intervals if the run is more than a certain length, PEN conductors must have double crimped joints or an equivalent measure to make sure neutral is less likely to break then live...

    Equally nothing stops TNS or PNB having extra electrodes or extra NE bonds, and still not being PME.

    Much of the DNO paper work avoids the saying "PME" altogether, and refers instead to CNE  (Combined Neutral and Earth) and SNE (Separated Neutral and Earth).

    IF only there were labels that could be fitted at the intake position that told you what was going on, like this but ideally with the addition of a small white square to the right hand side for writing in a Zs result and a PSSC in crayon.


    .

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