Neutral current diversion
In simple terms a neutral current diversion can occur when the combined protective earthing and neutral conductor in an electrical system fails. The current in that system may itself then be diverted by making a haphazard circuit via exposed metal workings in the surrounding, in buildings this might also including gas, water and oil pipes which can be highly dangerous.
In technical terms the Electrical Contractors Association describe neutral current diversion as "the event of a lost protective earthed neutral (PEN) conductor on a TN-C-S (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. One common route is through shared metallic pipework, such as gas and water pipes."
Definition from "ECA Members: Help us research neutral current diversion" The IET, Electrical Contractors Association (ECA), Electrical Safety First (ESF), NAPIT, NICEIC and SELECT are working together to investigate the prevalence of Neutral Current Diversion (NCD) incidents across the UK.
[edit] Related articles on Designing Buildings
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