Hiller Know-How: Wiring Color Codes


Each electrical wire in a circuit has a specific function.But did you know that in order to identify which wire serves which function, the wires are color-coded? 

It’s important to know the different colors and function of each electrical wire not only to correctly configure an electrical system (less of a concern for most homeowners), but also for your safety. If you’re going to embark on a home project like changing an outlet, it’s worth knowing which color means what. Even if you aren’t, we think it’s good knowledge to have. 

Below is a simple breakdown of the color-coded system 

  • Black: Black wires are considered “hot,” or live, wires, and are for power in all circuits. They are used as the power feed for a switch or an outlet. Black wires are also often used as a switch leg in a circuit, connecting the switch to the electrical load. Black wires should never be used for a ground or neutral wire.
  • Red: Red wires are use as hot wires in a 220-volt circuit, representing the secondary live wire. They are also used as switch legs in items such as 3-way switches, ceiling fans, and as the interconnection between two or more smoke detectors that are hard-wired.
  • Green: Green wires, as well as bare copper wires, are used only for grounding. In an electric circuit, if one of the live wires happens to touch metal, or any conductive material, the green wire is the electric current’s path to ground. Green wires can only connect to another green wire. Treat green wires with caution because they can carry a significant electrical current if a fault occurs.
  • White and gray: White and gray are neutral wires, although white is the most commonly used for a neutral wire as gray is very seldom used in a residence. The neutral wires connect to the neutral bus bar of an electric panel. Only connect white/gray wires to other white/gray wires. While a white/gray wire indicates a neutral wire, they can still carry a current, so as with all electrical wires, remain cautious.

Dealing with electrical wires can be tricky business, so if you are still uneasy about dealing with them, please get in touch with us by phone at 402-339-0524 or via the contact page of our site. We’d love to answer any of your questions!

photo credit: Neeta Lind via photopin cc