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What Size Wire For 220 Air Conditioners [Answered]

Finding out the right wire size for your air conditioner can be tricky. But it’s important to pick the right wire size. Otherwise, the whole thing might not work out the way you’re expecting.

What size wire for 220 air conditioners?

To determine the wire size, know the power supply amount of the AC first. If you know the number, calculate the running current. It’ll give you an idea about the starting current of the AC. Depending on the starting current you’ll be able to find out the wire size.

That was only a preview of the whole process. We’ve explained the whole calculation process step-by-step for you. Read along to find out your answers!

How To Find The Wire Sizing For 220 Air Conditioners?

AC is always a better choice than evaporative coolers. At least you don’t have to deal with running ductworks through trusses. But to enjoy the Air conditioner’s utility to the fullest you must install it right.

To wire your AC properly, there are a few things you should know. It comes with a few steps and it’s important that you know them. Otherwise, you won’t be able to choose the AC wires by yourself. 

This is why we’ll be guiding you through the steps- 

Step-1: Find Out The Power Supply Amount

You’ve to know the power supply of your air conditioner first. It varies from different brands to weights. You can find out the power supply amount from the casing. Almost all air conditioner casings mention their power supply.

Don’t forget to wear safety gear before you start working on the electrical circuits. Here are some recommended safety gears you can use:

Rubber gloves
Safety footwear

Step-2: Find Out The Running Current Amount

To find out the running current, you’ll have to do some small calculations. Don’t worry, it’s not as hard as calculating your evaporative cooler’s duct measurement. Just follow our lead-

Suppose, your air conditioner’s power input is 2500 to 2650 watts. The highest power input is p, which in our case is 2650w. The value of v is 220v. For a single-phase air conditioner, the equation is I=P/Vxcosθ.

The cosθ is the power factor here. 0.9 is the fixed value of it. So, the calculation stands:


The result will be 13.38 amp. This is the running current of the air conditioner.

Step-3: Measure The Starting Current

You’re already familiar with the running current. AC takes more current than running current when it’s switched to On mode. It’s called the starting current. By rule, starting current takes 1-1.5 amperes more for selecting circuit breaker. 

Previously, we got our running voltage to be 13.38 amp. For a 13.38 amp running current, the circuit breaker would be 15 amperes. 

If you calculate the circuit breaker size, it’s nearly 20 amp. For the circuit breaker, you can use a 15 amp switch for a 20 amp circuit.

Step-3: Determining Wire Size

For wire sizes, starting current will be 2-3 times more than the running current. Calculating the wire size for 13.38 amp would be, I= 13.38x 2.5. The result is 33.45.

For 33.45 amps, you can use 4 rm wires. Good quality 4 rm copper wires can take a 30-ampere load easily. 

We’re now presenting you with a table to have a clear understanding of wire sizing:

Conductor’s Nominal Cross-section Area (mm^2)No. Of Wire & The Wire’s Nominal Diameter (no./mm)Conductor’s Max DC Resistance At 20°C(ohm/km)Insulation’sNominal Thickness (mm)Approx Overall Diameter (mm)The Cable’s Approx Weight (kg/km)Current Rating(amp)
Bunched & Enclosed Two Cables Single Phase At 35°CClipped To SurfaceOr On Cable Tray Bunched & Enclosed Two Cables Single Phase At 35°C
0.5 re1/0.80360.62.11079
0.75 re1/0.9824.50.62.312912
1 re1/1.1318.10.72.6151316
1 rm3/0.6518.10.72.9171316
1.3 rm3/0.7514.030.73.1201519
1.5 rm1/1.3812.10.72.9211620
2 rm7/0.5212.10.73.1221620
2.5 re3/0.919.110.83.6302025

Step-5: Choosing Wire

When buying AC wiring, take into account its grade and voltage rating. You also need to have a good idea about proper voltage for operating AC. It’ll help you to have a better idea about the AC circuit.

Hopefully, you’ve got all the steps right.


Question: How many amperes does an air conditioner use?

Answer: Required amperes for the central conditioning unit of an AC requires 204v to 240v. They require a circuit of approximately 15 to 60 amp. But it depends on how many tons they’re.

Question: Are 220 volt and 240 volts the same?

Answer: 220 and 240 have the same voltage level. They have the same electrical outlet. Also, the 240v plug has the same counterparts as the 220v plug. 

Question: Can 2 air conditioners be run on the same circuit?

Answer: Yes, both may work on the same circuit. But the combined power has to be less than 30 amp. It’s best to have individual circuits. If not, the circuit breaker switch might trip.

Final verdict

That’s all from us regarding what size wire for 220 air conditioners to use. Hopefully, you’ll be able to find the right size for your air conditioner.

Until next time!