The conventional color of a positive wire is red. However, it may not be easy to single out the red wire from an array of color codes used in a given electrical fixture. In rare cases, the positive and the negative wire can have the same colors. That makes colors not the best and the only technique to recognize the polarity of wires.
How can I identify the positive polarity in my electrical fixture or circuit? The color code for the positive wire is usually red. Trace the red wire in your socket or the lighting fixture. That is the positive current wire.
Red wires carry a positive current while black wires carry a negative current. That means the red wires are positive while their black counterparts are negative wires. In DC wire marking, the red wire implies the positive current, and the black denotes the negative current. In the AC phases, phase 1 is black while phase 2 is red.
In that sense, the straightforward answer to this is evident. The red wires are positive.
The Different Types of Wire Color Codes
Coding wires with colors helps one to identify which wires are positive, negative, load, line, or ground wires. Below of the common types of color codes used to label electrical wires:
- Red wires. The positive wires are usually labeled red. These are the wires carrying the positive current.
- Black wires. This color code is for the wires carrying the negative current.
- The green color is used for the ground wires. Copper wires can also be used to label ground wires.
- White or grey wires are neutral. That means they do not bear any current, but you should be cautious since load current imbalance can cause the neutral wires to carry current. The white wires, also known as common or C-wires, are also neutral.
Coding wires with colors helps improve compliance with National Electric Code and limits the number of electricity-related accidents. That is because the employees, or generally anyone who understands wire color coding can easily identify and avoid live wires. (1)
Wire Marking Colors for DC Power
Direct Current flows in a straight current and it is used in solar cells, batteries, and also in fuel cells (in a few cases). It is thus important for the users to identify the DC wires and to differentiate them from the AC wires. (2)
There are usually 3 colors in a DC power:
- The positive current is labeled as red.
- The negative current is black.
- The ground wires are white or grey.
Wire Colors for AC Power
AC is the outlet current coming out from the power outlets of homes and business places. The alternating current is unique because the charge flow periodically changes direction.
The AC power moves further than the DC power because it flows in a sinusoidal waveform. The AC power is therefore the most convenient way of ferrying current to the consumers.
The criterion of labeling AC wires is based on the different amounts of voltages each wire carries. It is important to note that there are different phases in AC wiring; each phase is distinguished by color. The wiring color standards below are used for 120, 208, and 240-volt wires:
- Phase 1 – black
- Phase 2 – red
- Phase 3 – blue
- Neutral phase – white
- Ground wiring can either be green, or green with yellow stripes.
The high-leg connection is a scenario where one phase has higher voltage as compared to its counterparts. To identify the high-leg connection wires, look for the orange-colored wires.
Take a look at some of our related articles below.
- Is white wire positive or negative
- How to tell negative and positive wire
- How to cap off electrical wires
(1) electricity-related accidents – https://www.slideshare.net/
(2) solar – https://www.nationalgeographic.com/environment/article/solar-power