NEW WIRING COLOURS

The IEE published Amendment 2 to BS 7671:2001 (the Wiring Regulations) on the 31st of March 2004. The amendment species new cable colours for all new fixed wiring in electrical installations in the UK. These new colours are sometimes referred to as "harmonised" colours, as they will bring the UK more closely in line with practice in mainland Europe.

Electrical installations work commencing after 31st March 2004 may use the new harmonised cable colours or the pre-existing colours but not both. Work commencing after March 2006 will be required to comply with the harmonised cable core colours and must not use the old colours.

Full detail on the change can be found in amendment No2. (AMD 14905) to BS 7671:2001 - which is a free download from the IEE web site. They are also within the new version of BS7671:2001 (incorporating Amds 1&2) to be published on the 31st of March 2004; this new version of the Wiring Regulations can be identified by its brown cover. The cable colour changes are summarised below.		 BS7671

Single-phase installations

The fixed installation colours of red phase and black neutral are replaced by brown phase and blue neutral, respectively. These are the colours that have been in used in appliance flexible cables for many years. The protective conductor is still identified by the colour combination green and yellow.

Existing

 Twin flat 6242Y

New (harmonised)
Triple Flat 6243Y

Extensions or Alterations to existing single-phase installations

Alterations or additions to a single-phase installation do not require marking at the interface between old and new cabling providing that they are correctly coloured. However a warning notice must be fixed at the distribution board or consumer unit like this:

CAUTION

This Installation has wiring colours to two versions of BS7671

Great care should be taken before undertaking extension, alteration or repair that all conductors are correctly identified.

Three Phase Installations

For three-phase cables the colours are brown, black and grey, instead of red, yellow and blue respectively and the neutral colour is now blue instead of black. Again the protective conductor is identified by the colour combination green and yellow. Alternatively all three of the phase conductor cores may be coloured brown and marked L1, L2, L3 at the terminals.

Four core
armoured

Extensions or alterations to existing three phase installations

For alterations or extensions to existing three-phase installations it is recommended that old and new cables are marked at the interface L1, L2, L3 for the phase and N for neutral. The marking should be made to both old and new cables and is preferred to the use of coloured tape. A caution notice is again required at the distribution board.

Schematic of alternative interfaces
REMEMBER - you will need to use the new cables in order to comply with BS7671 (the Wiring Regulations), from the dates shown. The new harmonised cables will be available from your stockist now

For more information, consult the industry's agreed web resource centre:
www.iee.org/cablecolours
where you can find detailed information on the changes practical articles, FAQs and more.
Organisations across the industry have agreed to these changes and efforts to promote them, coordinated through a BSI/BEC national safety committee. This leaflet has been supported financially by the following organisations.

This information is also available as a pdf. All information in this page is obtained from IEE who retain the copyright.