Mục Lục

Wiring Colors | Electrical Wire Color Coding Standards

Electrical wiring color coding standard for three phase electrical applications are standardized to aid the identification of individual wire phases. Wiring color codes for AC and DC power distribution circuits have changed on numerous occasions and vary depending on region. For three phase electricity supply, circuits will use five wires: ground wire, neutral wire, live wire, line 2 wire, line 3 electrical wire. This article details the following cable color codes:

– International Wiring Colors
– US Wiring Color Codes
– Old & New UK Wiring Colors

International Wiring Color Codes

Fixed wiring electricity supply requires specific wiring color regulations (bs 7671) to identify different power lines in different countries. The USA has their own wiring colors for electrical circuits, black, red, and blue are used for 208 VAC three-phase; brown, orange and yellow are used for 480 VAC. Australia also has a different wiring color standard. The UK’s new cable colors for plugs are now harmonized with Europe’s power cable colors for AC & DC. Most of Europe abides by IEC (‘International Electrotechnical Commission’) electrical wiring colors code for AC branch circuits.

Region
Ground (G)
Neutral (N)
Line 1 (L1)
Line 2 (L2)
Line 3 (L3)
USA (LV)*
Green
White
Black
Red
Blue

USA (HV)*
Green
Grey
Brown
Orange
Yellow

Europe & UK
Green
Blue
Brown
Black
Grey

UK (Old)
Green
Black
Red
Yellow
Blue

Australia
Green
Black
Red
White
Blue

Canada
Green
White
Red
Black
Blue

*USA (LV) This should be used for 120/208VAC 3 PHASE

*USA (HV) This should be used for 277/480VAC 3 PHASE.

US Wiring Color Codes

In the USA, color codes are usually utilized for power wires in “branch circuits,” the wiring between the last protective device.

AC Wire Colors For 120/208/240 Volts

These are the types of wire colors commonly found in home and office settings.

Phase 1 – Black

Phase 2 – Red

Phase 3 – Blue Neutral – White Ground – Green, Green with Yellow Stripe, or Bare Wire

If one phase of your wiring is at a higher voltage than others, using a high-leg connection, wires should be marked orange for that phase. High-leg connections are typically uncommon in newer installations.

AC Wire Colors For 277/480 Volt

Industrial motors and equipment typically have higher voltage systems. Phase 1 – Brown Phase 2 – Orange Phase 3 – Yellow Neutral – Gray Ground – Green, Green with Yellow Stripe, or Bare Wire

It is very important to have a documented wire labeling system for higher voltage systems. Labels should include information regarding the circuit, and the appropriate disconnection point for lockout/tagout.

Wire Colors for DC Power

DC or Direct Current, is typically used in battery systems and solar power systems, instead of AC or Alternating Current. Positive (non-ground) – Red Negative (non-ground) – Black Ground – White or Gray