AC wire colors

The wiring from your circuit board to your AC should form part of a color code and will differ based on the voltage of your air conditioner.

When it comes to the electrical wiring in your home, there is a color-coding system that needs to be followed to ensure your safety and to assist professionals to do their jobs.

This is also true for the electrical wires that run between the circuit breaker and your air conditioner (AC) as these wires have their own color code system in the US that has been widely adopted by professionals and novices.

The importance of wire color codes

Although wire color codes are not standardized around the world and each country has its own system for designating certain wire colors to specific things, this code remains important in every region.

These wire color codes are important because they streamline and standardize the processes of professionals in each region and they protect homeowners and appliance users.

Wire color codes can help engineers, electricians, technicians, and homeowners distinguish between the functions of different wires, without having to trace every wire individually.

This code also helps to make sure that appliances function as they should and that the electrical wiring of the unit meets the safety standards that prevent shocks or fires from occurring in a home.

AC wire colors

In the United States, engineers, technicians, electricians, and homeowners follow the wire color code as it is set out by the National Electrical Code (NEC).

This wire color code is usually employed for power wires in branch circuits, which run between the circuit breaker and the appliance or tool. Air conditioners are some of the appliances in most homes that draw a large amount of power to start up and run.

As a result, many homeowners and professionals want to ensure that the wiring of their air conditioner is done correctly, so that the unit can run without causing damage to the house’s electrical equipment.

The NEC only really specifies that neutral conductor wires need to be white or gray and that ground wires should be green or bare copper wires. As far as the other power conductor wires to appliances like air conditioners go, any color wire can be used.

However, in this case, these power conductor wires may not have a specifically required color code, but there are some widely accepted colors that are used in the United States.

This has created an informal color code that is followed by most professionals when it comes to residential 120/208/240 Volt air conditioners, and larger 277/480 Volt industrial air conditioners.

How much power does an AC use?

Air conditioners require power to run their fan motors, compressors, and other electrical components so that they can lower the temperature of your space.

As a result, air conditioners that have a larger cooling capacity also use much more power, for instance, small window air conditioners may only require a maximum of 500 watts per hour, but central air conditioning systems require up to 3500 watts or more per hour, depending on the condition and the age of the system.

Air conditioners also require more power to start than they do to run, but they often operate for entire days or even for weeks on end. Therefore, your air conditioner requires power for every cycle that it completes, and this can add up over time.

For this reason, it is vital that the wiring of your air conditioner is done correctly, so that it can work safely and effectively in your home, regardless of the size, age, or type of air conditioner that you have.

The wire color code adopted for residential air conditioners

Houses in the United States are usually wired for 120, 208, or 240 Volt circuits and it is common that residential air conditioners fall into one of these categories.

If you have an air conditioner with a 120V, 208V, or 240V voltage, the common wire color code used for the electrical wiring to your air conditioner should be as follows:

Function Common wire color
Phase 1 (L1) Black
Phase 2 (L2) Red
Phase 3 (L3) Blue
High-leg Orange
Neutral White or gray
Ground Green, green with a yellow stripe, or a bare wire

The wire color code adopted for industrial air conditioners

Higher voltage industrial systems that may be on a 277 or 480 Volt circuit have their own color code. In this system, the wire colors for the neutral and ground wires remain the same, but the color code system adopted for the power conductor wires is as follows:

Function Common wire color
Phase 1 (L1) Brown
Phase 2 (L2) Orange
Phase 3 (L3) Yellow

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