‘ DE-NEUTRALISING’ BLACK and still i see people using black as a neutral and arguing about it. NO ARGUMENT!!!! black core is not to be used as a neutral Under the new identification colours for fixed wiring introduced by Amendment 2 to BS 7671, black is now used to identify a phase conductor, not a neutral conductor, in new installation work. Of course, for all single-phase applications, it would be preferable to use cables marked for such use, that is with brown, blue and green-and-yellow cores. Breaking the black/neutral association However, where three-core cables marked in the new three-phase colours are used for single-phase applications, it is proposed that, as a convention, the black core is used for the protective conductor, the brown for the phase conductor and the grey for the neutral. This convention is intended to break the association between black and neutral. It would mean that the black core would normally be overmarked green-and-yellow, and the grey core overmarked blue or N. The brown core would not need additional marking. Street lighting The Institute of Lighting Engineers (ILE) intends to introduce such a convention where SWA cables with brown, black and grey cores are used for street lighting applications, the black core being used as a circuit protective conductor in parallel with the armouring to maximise circuit lengt h s . Fire alarm systems Applying the same convention to a flat three-core fire alarm interlink cable, the grey would be overmarked as the neutral and the black interlink overmarked brown.
Posted on: Thu, 18 Jul 2013 14:17:56 +0000
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