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What Size Breaker for 3 Ton Ac? (Quick Answers)

Air conditioners are machines that use air conditioning, which refers to removing heat from an enclosed space to make the internal environment cold and more comfortable. You can choose from different sizes of air conditioners available. 

The area of the room best determines the size of the air conditioner to buy.

Breaker size for 3 ton ac

Generally, 3-ton ACs require a 35A breaker. For the wires, you can use AWG 10 wires to provide power. However, if you do not have access to or cannot find a 35A breaker, you can use any breaker rated above 30A but less than 35A. 3-ton AC units generally pull about 18A to 30A.

3-ton air conditioners are large, and you will usually find one in spacious centers or shopping malls. They can cool a large room compared to the residential-sized air conditioners found in homes. 

Since 3-ton air conditioners have to cool a vast area, they pull in significant power and, therefore, need thicker wires and big-capacity circuit breakers.

If you want to figure out the size of circuit breaker needed for a 3-ton air conditioner, you may want to go through the National Electrical Codes (NEC). 

However, most people find it difficult to understand what size circuit breaker will be the most suitable since NEC contains a lot of exceptions. So, read along to find out what size breaker will be appropriate for a 3-ton air conditioner.

A 3-ton air conditioner requires about 18A of continuous current to operate. When it starts, it pulls 7A to 13A current. To calculate the power consumed, you can multiply 18A with 240V to get 4320W or 4.32kW.

To better understand what size breaker will be best suitable, you should look at the label attached to the body of the air conditioner unit. You will see the minimum circuit ampacity value among the numerous pieces of information printed on the label. 

The minimum circuit ampacity will help you determine the wire size you should use to provide power for the air conditioner.

After the minimum circuit ampacity, you will notice a value beside the fuse label. That value tells you the maximum size of the circuit breaker you can use for the air conditioner unit. 

Therefore, you must choose a circuit breaker that has a capacity close to the minimum circuit ampacity value.

Most of the time, professional electricians come across a common problem in air conditioners. The common issue is an oversized circuit breaker. 

If you install a circuit breaker that is too large compared to the minimum circuit ampacity, too much current will flow through the wires and result in dangerous electrical fires.

Can I use a 30 amp breaker for 3 ton AC unit?

Yes, you can use a 30A breaker for a 3-ton air conditioner unit. Generally, a 3-ton air conditioner makes use of 30A-40A circuit breakers. So, using a 30A circuit breaker will not cause any issues to the air conditioner unit.

Although you can use a 30A breaker for a 3-ton air conditioner unit, it is better to check the manufacturer’s recommended ampacity. Moreover, your local electrical codes may require a circuit breaker with a higher capacity. 

Therefore, check the manufacturer’s recommendation and your local electrical codes before installing a breaker for your air conditioning unit.

Also, do not use a circuit breaker too large for a 3-ton air conditioner. Your circuit breaker should be within the range of 30A to 40A. If you install a circuit breaker with a capacity greater than 40A, you may expose yourself to electrical hazards and risk damaging your properties.

How many amps does a 3 ton air conditioner use?

A 3-ton air conditioner uses about 18A to operate. But the current consumption may increase or decrease depending on the usage of the device. Using the air conditioner for too long will result in higher electricity bills.

Usually, 3-ton air conditioners use 18A of current when operational. The starting currents of a 3-ton air conditioner may vary depending on the manufacturer of the machine. The starting currents of such air conditioners is between 7A to 13A.

You should note that not all air conditioners pull the same amount of power. A more efficient air conditioner will make the room cold but use little energy. But a less efficient device will draw more current to lower the room temperature.

4 things that affect breaker size for 3 ton ac

Certain factors influence the breaker size required for a 3-ton air conditioner. Knowing these elements can give you an upper hand while deciding which size of the breaker to use. The following points describe the factors in detail.

Maximum wattage:

The maximum wattage is the amount of power you can expect an air conditioner to use. Knowing the maximum wattage can help you calculate your monthly electricity bill and decide what size breaker will fit best. 

A 3-ton air conditioner uses about 4000W. The maximum wattage may vary depending on the voltage in the circuit and the operation of the air conditioner.

Minimum circuit ampacity:

The minimum circuit ampacity gives the lower boundary of the breaker range. For example, if you see that the minimum circuit ampacity is 18A, you should install a 20A circuit breaker. 

The 20A breaker will allow more current to flow than just 18A but stop the overflowing of current in case the machine malfunctions.

Maximum fuse value:

The maximum fuse value mentioned in the label of the body of the air conditioner is the upper boundary of the circuit breaker range. 

For instance, if the maximum fuse value is 25A, do not use a circuit breaker that has a greater capacity than 25A. In this scenario, you should use a circuit breaker with a rating of less than 25A.

NEC requirements:

The 80% rule of NEC requires you to install a circuit breaker that will allow an additional 80% of current to pass. Abiding by this rule helps prevent the electrical circuit from being overpowered. 

To give an example, if your air conditioner requires 18A, you should install a breaker with a rating of more than 32A.

If you follow the above points, you will face no problems in deciding the most suitable breaker size.

How to calculate breaker size for 3 ton ac?

It is crucial to correctly calculate the breaker size for any device. Failing to decide the most suitable breaker size may result in hazardous consequences and life risks. You can follow the steps below to effectively calculate the breaker size for a 3-ton air conditioner.

Find the maximum wattage of the air conditioner:

To find the maximum wattage, you can try a procedure. Set the maximum power on the air conditioner and record the wattage of the circuit. You will obtain the maximum wattage that the air conditioner pulls when working at maximum power.

Find the voltage:

Finding the voltage is easier compared to finding the maximum wattage. You can use a voltmeter and insert the pins inside a power outlet. The voltage reading will generally be 220V or 240V.

Calculate the current flowing through the circuit:

After you have recorded the maximum wattage and voltage, it is time to calculate the current in the circuitry. The math is simple. Divide the maximum wattage by voltage, and you will get the circuit amperage.

As an illustration, the maximum wattage is 4000W, and the voltage recorded is 240V. To calculate the current in the circuitry, divide 4000W by 240V. You will get approximately 17A, the amount of current flowing through the circuit.

Deciding the circuit breaker:

For the final step, you will choose the circuit breaker size. Following the above example, the current flowing through the circuit is 17A.

We will also have to consider the 80% NEC rule. To do this, we will multiply 17A with 1.25. The product will give the approximate value 22A.

Therefore, the circuit breaker should be more than 22A but not more than 30A. Selecting a breaker with a size greater than 30A may lead to an overflowing of current and hazardous electrical fires.

Final Thoughts

Choosing the most appropriate circuit breaker size for a 3-ton air conditioner is crucial for preventing electrical hazards. Computing the breaker size is simple, and you can do it yourself by doing some simple calculations. We suggest calling an electrician to help install a circuit breaker.