Conductor Colors in Electrical Installations

NEN-EN-IEC 60445 specifies the color coding for conductors in low-voltage installations.

Main Categories

Points of Attention

• Green/yellow is exclusively for PE (protective conductor). Never use as a phase or for any other function.
• Blue marks the neutral (N). If a circuit has no neutral, a blue conductor may be used for another function, but never as PE. In very old installations, blue may be used as a phase — replace or clearly mark.
• For multi-core cables (>5 cores): numbered cores (black with numbers) according to the cable standard.

Common mistakes

1. Brown used as neutral — risk during later work.
2. PE conductor cut through or used as a spare — prohibited.
3. In horticulture: color loss due to UV — use UV-resistant cable types and follow the manufacturer's specifications and the installation conditions (external influences, NEN 1010).