Approved Contractors and Domestic Installers will appreciate that conductors throughout an installation need to be identified, generally by colour, to indicate their function (and, for live conductors, their polarity), as required by Regulation Groups 514-03 to 514-06 and Appendix 7 of BS 7671.
However, a separate requirement of BS 7671, to which installers sometimes do not pay sufficient attention, is that:
“As far as is reasonably practicable, wiring shall be so arranged or marked that it can be identified for inspection, testing, repair or alteration of the installation.” (Regulation 514-01-02 refers.)
This requirement of Regulation 514-01-02 is particularly relevant at distribution boards and consumer units, although it also applies elsewhere throughout an installation. Where practicable, the wiring within a distribution board or consumer unit should be identified by arrangement.
To read full article please see attachment...