BS 7671 also known as the IET Wiring Regulations provides standards for electrical installations in the United Kingdom. Here is the wire colour coding specified by BS 7671:
| Wire | Colour |
|---|---|
| Live Conductor (Line) | Brown |
| Neutral Conductor | Blue |
| Protective Conductor (Earth) | Green and Yellow |
| Phase Conductor in Three-Phase Systems | Brown (L1) Black (L2) Grey (L3) |
| Control Wiring (Single-Phase) | Black (Switched Line) Blue (Switched Neutral) |
The colour coding is essential for identifying different conductors and ensuring consistency in electrical installations. It promotes safety by providing a standardized way to recognize the function of each wire.
It's important to note that these colour codes may vary in different countries and compliance with local regulations is crucial for electrical safety.