Informational Guide

What Size Generator To Run a 5 Ton AC

Running a large air conditioner can take a lot of energy. Learn what size generator it takes to run a 5 ton AC unit.

by Josh M

Having a generator means your life isn’t interrupted if you lose power. But you want to ensure you get a generator big enough to supply power to your house. If you need to know what size generator to run a 5-ton AC unit, read on to find out that and more.

Generator for 5 Ton AC

Watts are a unit of power that tells you how much energy they need to run the appliance. An amp measures the electric current. Most residential circuits carry 15 to 20 amps, which power everything in your home, but not all at once. Turning on all of your appliances at once can cause an electrical blowout.

5000 – 12000 Watt Generator

A 5000-watt generator is at the low end of the spectrum, powering small appliances like lamps, radios, or hair dryers. The appliance must use less than 5000 watts. At 12000 watts, you can keep most of your home powered as usual. These generators are powerful enough to run computers, TVs, and refrigerators.

12000 – 20000 Watt Generator

Generators up to 20000 watts can power the receptacles in your house so you won’t lose any lights. It can even run your 5 ton AC unit. If you have gas heat and hot water, then a 20000-watt generator is enough to keep you on track.

20000 – 50000 Watt Generator

Generators up to 50000 watts can power houses up to 6000 square feet. You can even use them on a job site and for small commercial businesses.

How to Determine The Size Of Generator For An Air Conditioner

A generator is nice to have, but if you don’t get the right size, you’re unable to power your home, or you might overload the generator. Understand how to calculate your 5-ton AC power consumption to get the right generator.

When you know the watts your AC unit uses, you can determine the size of the generator needed. For example, a one-ton central air conditioner uses 3500 watts, but if you use the fan without the compressor, you only need 750 watts.

A 4-ton unit takes 8500 watts, so the generator must produce at least that much power. This is just for your AC unit, so make a list of any other appliances you want to use with the generator and calculate the size of generator you’d need.

Determine Size of Generator for AC

What Size Of Generator Will Run My 5 Ton AC Unit?

A 5 ton AC unit is the largest one that you can power with a generator. That gives you a general idea of how big of a generator you need to run it. A 5 ton AC unit produces 60000 BTU of cooling power, which will cool up to 3000 square feet. That output makes this unit a suitable size for most homes.

Want to know how many amps does a 5-ton ac draw? The wattage required to run a 5 ton AC unit varies from 4000 watts to 8000 watts, which is between 16 and 34 Amps. Since AC units need additional wattage to power up, you want to choose a generator that’s at least 7000 watts.

How to Determine The Size Of Air Conditioner

There are several ways you can find the wattage of your air conditioner, which helps you understand the size and pick the right generator. You can read the specification sheet and find power measured in watts.

The Energy Efficiency Ratio (EER) rating is on the specification sheet but requires some calculations. Divide the AC unit’s BTUs by the EER rating to determine the wattage. The higher the EER, the more efficiently the AC unit runs.

You can also find the current and voltage on the specification sheet. The manufacturer lists the current in amps. To get the wattage of the unit, multiply amps times voltage.

Related ArticleWhat Size Of AC Do I Have?

How Many Watts Does The Air Conditioners Use

Wondering how many watts does a 5-ton air conditioner use? You can determine how many watts your AC unit uses based on the tonnage. This table uses the EER rating of 12.

Central AC Capacity (Tonnage) Watts
1.5 Ton 1500 Watts
2 Ton 2000 Watts
2.5 Ton 2500 Watts
3 Ton 3000 Watts
3.5 Ton 3500 Watts
4 Ton 4000 Watts
5 Ton 5000 Watts

How Many Watts Does The Air Conditioners Use (Estimated By AC Type)

Understanding how many watts your air conditioner uses helps you pick the right generator. You need to consider that each unit needs more watts as it gets started. Once the motor is running, it will use less wattage, but your generator needs to handle that initial surge.

AC Type BTU Range Running Watts Starting Watts
Window AC 5000 – 25000 500 – 2500 2200
Portable AC 8000 – 14000 940 – 1650 1500
Mini Split AC 9000 – 60000 750 – 5000 3500
Central AC 18000 – 60000 1800 – 6000 5100

How Many Watts Does AC Use

People Also Ask (FAQ)

You’ve learned the basics about running a 5 ton AC unit on a generator. You know how to calculate BTUs, watts, and amps. In case you’re still unsure about what you need, check out these frequently asked questions.

What size breaker do I need for a 5 ton AC unit?

The specific size breaker you need depends on the watts your AC unit needs. In general, AC units up to 5 tons need a circuit breaker that has a 45 to 50 rating.

What is the cost of electricity for the 5 ton AC Unit?

Running your 60000 BTU unit for eight hours a day can add up to $200 to your electricity bill, depending on energy efficiency. The cost breakdown shows that large units cost about $0.88 per hour to cool your house.

Will a 2000 watt generator run an air conditioner?

Yes, a 2000 watt generator can run an air conditioner, but it won’t be your 5 ton home unit. This size of generator can power AC units up to 11000 BTU, like the size you’d find in an RV.


Having a home generator ensures you’re never without the comforts of electricity. Use the calculations and tables above to find the size that suits your needs. Remember to use generators safely so you don’t harm yourself or overload the appliances.

Related Article – Watts To Amps Calculator

Related ArticleBest Generator For RV AC

Last Updated on July 15, 2022

Josh M

My name is Josh and I am obsessed with the HVAC industry. I created this website to help HVAC techs of all levels get the best out of their heating & cooling systems. I have spent thousands of hours studying air conditioners, heaters and home air products so you can learn & buy with confidence. Learn more about the team here.