Understanding The Electrical Wire Color Codes
Color-coding standards are not the same everywhere in the world and vary according to the country or the continent. For instance, in Europe, the rules of color-coding are determined by the IEC standards. It is essential not to confuse various standards and adhere to the rules established in the particular country. To nail color-coding rules for your next electrical project, read this quick guide by Nassau National Cable, a top wire and cable marketplace in the United States.
Color-Coding Standards in the National Electric Code
In the United States, color-coding varies according to the voltage of the particular wire and whether it is AC or DC. Color-coding standards mostly abide by the US National Electrical Code, but there are not many rules that determine color-coding. The National Electrical Code particularly states that the neutral conductor has to be either white or grey, and the ground conductor can be either bare, green, or green with a yellow stripe. All of these colors are used only with their respective type of conductors to avoid potential confusion with a love wire that may be life-threatening.
The standards regarding the ground conductor are true for both AC and DC power lines of all voltages, and the standards in the neutral conductors apply to all AC power lines since DC does not have a neutral conductor. As a rule, white is the more common choice for the neutral conductor than grey, even though both can be used interchangeably.
Variations of Live Conductor Color-Coding
For live conductors, there is more variety to the color choice. Possible options are black, red, white with red/black tape, blue, yellow, brown, and orange, with the former two being the most common of all.
When it comes to AC power, the colors used for hot wires depend on the number of lines in a power line. In single-phase power lines, the main hot or live power line is almost guaranteed to be black. The second hot wire is red in most cases. If the power line is three-phased, the common color for the third hot wire is blue.
As an alternative to the most common structure of the live wiring mentioned above, the hot wires can be brown (1st live wire), orange (2nd live wire), and yellow (3rd live wire). This is less common than black-red-blue structure, but rather typical when it comes to industrial equipment and machine motors with the voltage of 480 volts.
Within the DC power system that is fairly common for batteries and solar panels, red is typically a color of the positive wire, black is the color of the negative wire, and the ground wire is either white or gray according to the standard National Electrical Code specification.
In 99 percent of the cases, color-coding is done at the stage of cable manufacturing. However, if you find that the old wiring in your house is not color-coded for one reason or the other, it is essential to have the wiring color-coded by a professional in order to avoid electrical incidents.
