Wiring Color Codes Infographic. Released under the Creative Commons Attribution-ShareAlike License
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.
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).
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.
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.
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 wire color codes are often specified by law depending on your location, though most rely on common practice, below we cover Europe and Canada.
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
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
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.
by Luke James
In Partnership with NXP Semiconductors
In Partnership with Eaton Electronic Components
by Robert Keim