Electrical Wiring Colours — Old vs New
Electrical Wiring Colours — Old vs New
BS 7671 — mandatory changeover 31 March 2006
Single Phase
| Function | New (from 2006) | Old (pre-2004) |
|---|---|---|
| Live | Brown | Red |
| Neutral | Blue | Black |
| Earth | Green/yellow | Green/yellow |
Three Phase
| Function | New (from 2006) | Old (pre-2004) |
|---|---|---|
| L1 | Brown | Red |
| L2 | Black | Yellow |
| L3 | Grey | Blue |
| Neutral | Blue | Black |
| Earth | Green/yellow | Green/yellow |
Rules to Remember
- • Mixed colours in one installation? Must have warning label at consumer unit / distribution board
- • Any core used as a switched live MUST be brown-sleeved at terminations
- • Blue core used as switched live in old wiring? Must be sleeved brown at both ends
- • Black core in three-phase new wiring is L2 (live) — not neutral
Warning Label Wording
"CAUTION — This installation has wiring colours to two versions of BS 7671. Great care should be taken before undertaking extension, alteration or repair that all conductors are correctly identified."
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