When installing or working on electrical equipment it is important that all the wires are connected correctly. To make this easier, there are color standards for different types of wiring and what they are used for. This can be helpful in any situation, but is especially critical in equipment where the wires are long and could get mixed up from one end to the other. By following established electrical wire color codes, it is easy to know which ones need to be positive, which are negative, and which ones are grounded. There are also color codes for AC power and high-voltage environments.
In the United States, DC power is used for many types of higher voltage or industrial equipment. This type of equipment requires a positive and a negative wire, and in some cases it will also be necessary to have a ground wire. The standard colors used in these situations are as follows:
- Positive – Positive wires will be red.
- Negative – Negative wires are black.
- Ground – Ground wires are either white or grey.
AC Power – 120/208/240V
For standard voltage wiring, there are several options for AC power. Not all equipment will require all of these types of cables, but it is important to understand what each of the colors means and how they should be used:
- Phase 1 – Phase 1 wires are black.
- Phase 2 – Phase 2 wires are red.
- Phase 3 – Phase 3 wires are blue.
- Neutral – Neutral wires are white.
- Ground – Ground wires are green, green with a yellow stripe, or simple coper.
AC Power – 277/480V
For higher voltage AC power, the colors for the wires change. This helps to keep things organized while also making people aware of the fact that it is a higher voltage system. In these systems you will find the following color wires:
- Phase 1 – Phase 1 wires are brown.
- Phase 2 – Phase 2 wires are orange.
- Phase 3 – Phase 3 wires are yellow.
- Neutral – Neutral wires are grey.
- Ground – Ground wires are green, green with a yellow stripe, or copper.
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