Conductor and cable identification7

Identification of fixed wiring conductors

Colour is used to identify the conductors of a wiring system where it is possible to colour the insulation. Where it is not, numbers are used. The requirements for identification of fixed wiring are shown in {Fig 4.21}. There is as yet no requirement to use brown and blue to identify the phase and neutral conductors of fixed wiring, although this applies to flexible cords and cables (see {4.6.3}. The colour green on its own is prohibited, although green and yellow stripes identify the protective conductor. The functional earth conductor for telecommunication circuits is identified by the colour cream.

Fig 4.21 Identification of fixed wiring

Some cables comply with HD 324:1977 and have blue insulation on the neutral conductor. This colour does not comply with BS 7671 and if such cables are used, they must be correctly identified at their terminations by the use of black cable markers or black tape.

Colours for flexible cables and cords

Unlike the cores of fixed cables, which may be identified by sleeves or tapes where they are connected, flexibles must be identified throughout their length. The colour requirements are shown in {Fig 4.22}.

Fig 4.22 Care colours for flexible cables and cords