Electrical Wiring Color Code Standards
What Is Color-Coding ?
In the wire and cable industry, color-coding is the process of assigning a particular color to a wire. Particular colors indicate the place that a distinct wire has in a circuit. The color-coding goal is to inform technicians which wires are ground, hot, and neutral to ensure safety. In the United States, modern wire color codes have been implemented in the 1940s. Electrical wire colors vary country by country, so the information above is only relevant to the United States. Canada and the European Union have different standards of color-coding. The rules of color-coding are defined by the National Electrical Code (NEC) and the industry's commonly accepted practices. The failure to meet these standards is considered a violation. Below are the electrical wire color standards for ground, hot, and neutral wires in the United States.
Ground Wire
In a three-branch power circuit, a bare copper wire is most often used for grounding. However, green cables are also sometimes used for this purpose. Green cables are never used for other goals rather than ground. Green wires can only be connected to other green wires for safety purposes. A hot wire can also be green with a yellow stripe, though this is far less common. You should contact a professional if you see a ground wire connected to anything other than another ground wire, as this is a safety hazard.
Neutral Wire
A neutral wire in the three-branch power circuit can be white or grey, with the former being more common than the latter. These two colors are required for neutral wires by the National Color Code. Neutral wires should not be covered by electrical tape. Please note that no other colors are allowed for neutral wires in the United States. Regardless of the rules in a particular country, there is always a risk that a wire is hot if it is not white or grey, so this should be taken into consideration when performing any electrical work.
Hot or "Live" Wire
According to the rules, hot wires can be represented by many colors. As a rule, black is the most common hot wire color in a house circuit. Black wires should not be used for other purposes rather than providing a live electrical current. If there is only one hot wire in the circuit, it is almost guaranteed to be black.
Red is another standard color for a hot wire. In 240-volt constructions, a red wire can be used as a second live wire in addition to a black one. White wires with red or black tape are also allowed as hot wire, though not as common. If you use white wire, remember that taping is crucial, as the plain white wire can only be neutral. White wire with a tape also commonly serves as a second live wire.
In some rare cases, blue or yellow is also used for a hot wire. In these cases, yellow is used in light switch legs, and plugs that go together with light switches. As for blue, it is most regularly used in three- and four-way switches.
If someone ignored the wire color codes when installing wiring in your house, or the wiring was done before certain standards have been set in place, there is a need to fix this. You can opt to replace all cables, but, luckily, this is not your only option. Since the real goal of color marking is to inform all future workers about the potential dangers, you can mark every wire with written indicators "hot," "ground," or "neutral" throughout its entire length or use color markers.
