Is a 14” Duct and 20x20 Filter Enough for Air Return Intake with a 3 Ton AC Unit?

man adjusting filter in large air vent

Most regular homes use a 3-ton air conditioner for central air. This size of AC is perfect for most homes with the capacity to cool even an 1800 square feet space. The only problem is that, when you are installing the AC as a DIYer, you may not be aware of what circuit breaker to use.

Most DIYers are puzzled by what type of circuit breaker to use, given that most manufacturers may fail to provide the accurate information needed.

The simplest answer to the question of circuit breaker would be using a 60 amps breaker for the AC handler. However, different AVCs have different amperage needs. With that in mind, you should remember that each manufacturer has recommendations for their products.

There is no general rule of thumb when it comes to the 3-ton AC, but you can be sure that using the 60amps breaker will work for any 3-ton AC.

However, for some people using a 60amp breaker may seem to overstretch the power needs of the AC. Ideally, reading the manual that comes with the circuit breaker will provide the best solution.

The manual will provide detailed instructions on how the AC can be installed and issue accurate figures of the energy needed to keep the AC running smoothly.

Manually Calculating The Breaker Size

The most ideal way of determining the right size of breaker needed for our AC is by calculation. You can directly calculate the required circuit breaker amperage if you know the wattage of the AC and the voltage of the outlet.

Whether the AC you are dealing with is bigger or smaller than a 3-ton does not matter. You can easily calculate the necessary circuit breaker and install your AC with utmost accuracy.

The first thing you want to do is determine the wattage of the AC. This information can be found in the manual or the AC package. The second data you need is the voltage for your home plugs. In most cases, you can find this information on the primary circuit breaker.

With basic mathematical skills, use this information to calculate the circuit breaker needed. To calculate, simply divide the AC amperage by the house voltage.

For instance, if you are dealing with a 5000 amps AC, and your home has a 110-volt outlet, the recommended circuit breaker should be 5000 divided by 110 which will be 45.5 amps.

Check Data Plates For Amperage Directions

The other source of reliable information in regard to the amperage of ACs is the data plates. Check the data plate if there is no sufficient information in the manual. In some cases, the data plate may be concealed to ensure that the data on it is long-lasting.

Inspect your AC to find any locations where information such as amperage and other details are written. You may find out the exact amperage of the AC just by looking at the data plate.

The fact that the recommended amperage for a 3-ton AC is 60 amps does not mean that all aircon will use the same amount of power. I have seen 3-ton ACs use breakers rated as low as 20 amps. In other words, there is no one standard for all ACs. There are those that will require a bigger circuit breaker than others.

What Is the Right Wire Size?

It is not just enough to know the right circuit breaker for your AC. You must also ensure that you have the right wire size before you start connecting your AC to the house. For instance, if you have a 3-ton AC with a 40 amp circuit breaker, you may need an eight gauge wire.

When it comes to determining the right gauge of wire to use, check the recommended ampacity on the data plate. Unlike all other devices at home, the AC requires accurate use of wires as recommended by the manufacturer.

If the AC recommends a 40 ampacity wire, make sure you find the wire gauge that can handle those amps. Ask your local dealer wires based on ampacity and you will find the perfect fit for your AC.