IEC 60446 & HD 308 S2 Wire Color Codes: Phase, Neutral, and Earth
Harmonized conductor insulation colors under IEC 60445 (formerly IEC 60446), CENELEC HD 308 S2, and EN 60204-1 for single-phase, three-phase, DC, and control panels.
Standardized conductor insulation colors prevent phase-to-neutral reversals, wrong motor rotation, and fatal electric shock during maintenance. Across Turkey and Europe, conductor identification is governed by IEC / EN 60445 (which superseded IEC 60446), CENELEC HD 308 S2 for multi-core cables, and EN 60204-1 inside industrial machinery panels.
> Related Category: Filter single-core and multi-core wiring cables by color and cross-section in NYA Cables, NYAF Cables, and TTR Cables.
Harmonized AC power colors: Brown, Black, Grey, Blue, Green-Yellow
| Function | Symbol | Harmonized Color (EN 60445 / HD 308 S2) | Notes |
|---|---|---|---|
| Phase 1 (or single-phase line) | L / L1 | Brown | Standard live conductor in 230 V AC circuits |
| Phase 2 (three-phase) | L2 | Black | Second phase in 400 V three-phase systems |
| Phase 3 (three-phase) | L3 | Grey | Third phase in 400 V three-phase systems |
| Neutral | N | Light Blue | Must not be used for earth |
| Protective Earth | PE | Green-Yellow bi-color | Strictly reserved for protective earthing (30%/70% ratio rule) |
> Safety Rule: Green-yellow insulation is exclusively reserved for protective earth (PE) or PEN conductors. Over-sleeving or taping green-yellow wire to use it as a live or switched conductor is strictly prohibited.
`G` vs `X` designation in multi-core cables (3G2.5 vs 3X2.5)
In NYM, TTR, NYY, and N2XH part numbers, the letter between core count and cross-section specifies whether a green-yellow PE core is present (HD 308 S2):
| Cores | With Protective Earth (`G`) | Without Protective Earth (`X`) |
|---|---|---|
| 2-core | Not applicable | 2X: Brown + Light Blue |
| 3-core | 3G: Green-Yellow + Brown + Light Blue | 3X: Brown + Black + Grey |
| 4-core | 4G: Green-Yellow + Brown + Black + Grey (3P + PE motor) | 4X: Light Blue + Brown + Black + Grey (3P + N) |
| 5-core | 5G: Green-Yellow + Light Blue + Brown + Black + Grey (TN-S) | 5X: Numbered black cores |
Control panel (EN 60204-1) and DC color conventions
Inside industrial automation enclosures (EN 60204-1):
- Black: AC and DC power circuits.
- Red: AC control circuits.
- Dark Blue: 24 V DC control circuits (PLC I/O and sensor wiring; distinct from light blue neutral).
- Orange: Interlock circuits remaining live from an external source when the main isolator is OFF.
- DC power (EN 60445): Brown for positive (L+) and Grey for negative (L−), though red (+) and black (−) remain widespread in battery and PV installations. Always verify legacy wiring with a two-pole voltage tester or digital multimeter before touching conductors.
Frequently asked questions
Which wire is live and which is neutral: brown or blue?
In harmonized 230 V single-phase AC wiring, brown is the live phase conductor (L), light blue is neutral (N), and green-yellow is protective earth (PE).
What are the L1, L2, and L3 three-phase wire colors?
Under HD 308 S2 and EN 60445, L1 is brown, L2 is black, and L3 is grey, paired with light blue for neutral (N) and green-yellow for protective earth (PE).
What is the difference between 4G4 and 4X4 cable?
4G4 includes a green-yellow protective earth core plus brown, black, and grey phase cores (ideal for 3-phase motors without neutral), whereas 4X4 omits green-yellow and provides blue, brown, black, and grey cores.
Do CAT6 Ethernet cables follow the same color standard?
No. Twisted-pair data cables follow TIA/EIA-568 (T568B / T568A) pair colors; see CCA vs solid copper cable and CAT6 T568B pinout.