:slap :slap
Did you miss this part,"PME is a variant on TNC-S, its how the PEN is Constructed that Makes a TNC-S a TNC-S PME, what is it im confusing,please?"
PME is not an Earthing System!!!!
Reg 312.2 Types of Earthing Systems (and arrangementof Live conductors) , Have a read!!
Pme is not a Earthing system, its imposed byESQCR on DNO'S, its function is for when DNO'S use a Supply type of TNC-S (arrangement of Earthing and Live Conductors) to limit the risk associated with a broken PEN, its to limit touch voltage, thats prety much it!!!!
The only exception to TNC-S for the DNO'S is the utilisation of PNB on the PEN, where it serves only the one point, then the DNO may use PNB, the risk of a broken PEN lessened by the fact there is only the one connection.
So PME is imposed on a Public Suply System TNC-S(arrangement of Earthing and Live Conductors) and limits Touch voltage. As ESQCR reqiure PME on mulit point systems, PME and TNC-S have become Synonymous, so if a supply sytem has PME imposed then you know thats because the Earthing and Live conductor arrangement is TNC-S.
So please explain in detail how PME is a "Earthing System" !!!
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