Vol. EE Reference
Chapter 2 Color Codes

Wiring Color Codes Infographic

Wiring Color Codes Infographic

Wiring Color Codes Infographic. Released under the Creative Commons Attribution-ShareAlike License

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Basic Wire Color Code Information by Region

Many of the wire identifications standards rely on color codes. Which standard should you be using for your project? It depends on your location, voltage, and other important factors. Note: Older installations may use different color codes.  It is always a great idea to document the color code that's being followed. This makes work safer, and any future maintenance needed, easier.

U.S. Wiring Color Codes

In the USA, color codes are usually utilized for power wires in “branch circuits,” the wiring between the last protective device like a circuit breaker and the load (like an appliance).

AC Wire Colors For 120/208/240 Volts

These are 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

International Wiring Color Codes

International wire color codes are often specified by law depending on your location, though most rely on common practice, below we cover Europe and Canada.

Wire Color Codes for Europe (IEC)

The International Electrotechnical Commission (or IEC) has established a wire color code for most European countries for AC “branch” circuits.   Phase 1 - Brown   Phase 2 - Black   Phase 3 - Grey   Neutral - Blue   Ground - Green with Yellow Stripe

Canadian AC Wiring Color Codes

Wiring Color code standards are set in place by the Canadian Electric Code (or CEC) in Canada. The color code is very similar to the U.S.A’s color code.   Phase 1 - Red   Phase 2 - Black   Phase 3 - Blue   Neutral - White   Ground - Green with Yellow Stripe

When are Color Codes Applied to Wiring?

The manufacturer of most narrow wires will color code them, utilizing insulation of different colors. Wires that are manufactured with black insulation are typically larger than #6 AWG. Color coding should always be added during installation with color bands that wrap around the wire. Self-laminating wire wraps and heat-shrink tubes should be utilized to create clean and professional labels for your projects.