In the event of a lost protective earthed neutral (PEN) conductor on a TN-C (PME) electrical supply, the installation loses its intended connection to neutral and Earth. Current is then 'diverted' and will find its way back to the supply transformer any way it can. There's not a lot of data available in the public domain but that's. In section Shielding and cable entrances, concepts are presented that lead us to realize the need and importance of cable bonding at the point the cables traverse the walls of a shielded structure or the boundary of an installation, even if not shielded, to prevent or minimize the ingress of. Neutral current diversion (NCD) is a term used to describe 'stray' neutral currents that take an alternative or diverted route back to the earth connection of the supply transformer. The faster the protection operates, the smaller the resulting ha-zards, damage and the thermal stress will be.
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