How Many Amps Does an Air Conditioner Use?

Ever wondered how many amps does an air conditioner use? Knowing the current draw is helps in establishing the power requirements, sizing and choosing energy-efficient units among other things. As a rule of thumb, you don’t choose an AC that requires more amps than your circuit can provide.

AC’s are rated on their cooling properties, which is measured in BTUs or British Thermal Units in full. The larger the BTU on a unit, the more amps it will draw. Most units come with a label with information on their power ratings, under the assumption it is operating in a stable state with the compressor drawing a constant current.

However, this is not always the case. For instance, if your air conditioner features a thermostat and a temperature setting, the compressor shuts off and only leaves the circulating fan working once the ambient room temperature reaches the set limit.

But, there is a way to calculate an air conditioner power draw, which we have shown below using a 3-ton AC as an example.

How to Calculate My Air Conditioner’s Amperage

Using the math formula: P= V* I* Cos phi, you can be able to approximate your electric air conditioner power consumption. As a rule of thumb, one ton AC will use about 1300 watts. Take 0.8 as the value for cos phi.

For example, if you have a 3-ton air conditioner and running on 220 VAC, it will use about 3900 watts. Now using the formula above:

I= P/V * cos phi

I= 3900 / (220 *0.80) = 22.16 Amps

This is the running current. It is important to note that the starting current can be 6 times higher than the running current.

Hopefully, this helps to calculate the amperage of your AC unit so that you can choose the right circuit breakers. Also, refer to the manuals that came with your unit for more information about its power requirements and other details.

Check this too: How to Prevent Mold from Getting into an Air Conditioner