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What Size Generator Do I Need to Run a Refrigerator?

what size generator do i need to run a refrigerator
Written by Jamie Masterson

Although this depends on the size, home refrigerators usually need between 1000 to 2000 starting watts. If you get a generator with a 2000W starting power, then it will be enough to run both your refrigerator and freezer any without problems.

What Size Generator Do I Need to Run a Refrigerator?

First you need to find the watts.

  • Check the owner’s manual provided by the respective company you bought the refrigerator from.
  • If that’s not possible then, verifying the manufacturer label on the refrigerator/freezer can also give you a general idea about the required starting and running wattage.
  • Did you get rid of the sticker/label? No worries, as you can find all the detailed information about the refrigerator online.
  • Even this isn’t working? You can then contact the manufacturer’s company and ask about the wattage.

How to calculate the required watts?

How to Calculate Watts Needed for a Generator

  • You can easily calculate the wattage based on the multiplication of the given Amperes and the VAC (Volt AC Power).
  • You’ll see the Amps in the owner’s manual or even in the stickers behind your fridge. As for the VOC, presume you’re connecting the appliance into a 120 Volts duct/ wall outlet like most of the states in the US.

Let’s do simple math to understand the process. Suppose a refrigerator is of 7.5 amps and 120 VAC. That means the total watts needed are 900.

It will be better for you if you consider much higher wattage than the solved total watts while buying the generator. Why?

The reasons are –

  • You would be in trouble if your appliance if it’s an older version. The older the refrigerator gets; the more power it consumes. And with that generator’s planned watts, the refrigerator can’t run properly to serve first-class foods on your table.
  • The capacity of your fridge (big or small) also acts on its power consumption.
  • If your refrigerator has a built-in freezer, it will consume more power than the normal refrigerator.
  • Supposing you’re going to power some more appliances like phones, laptops, etc. with your refrigerator. Then it will have a 20-30% bigger power supply than before.

Why more watts?

All these issues will affect the compressor of the refrigerator badly if you buy that roughly calculated generator of 900 watts. A generator will give you one hundred percent satisfactory service only if you add a minimum of 1.5 times the previously calculated watts and a maximum of 3 times that calculated watts while purchasing one to run your refrigerator/freezer. We recommend you always go for the higher and average wattage to be on the safe side. So, if you choose a generator between 2000 to 3000 watts, your refrigerators/freezers will be fine in the long run.

Decide what type of refrigerator you’re going to power

  • Present-day refrigerators/freezers consume much lower power (around 300-400 watts) than those of old times. Therefore, if your fridges are of old models they would need a huge power supply (around 300-1200 watts) to start up.
  • When your refrigerator also has a freezer, it will be mandatory to look for a more high-powered generator

Decide what type of refrigerator you’re going to power

How to determine the right generator size?

Starting Watts

The power of electricity a refrigerator, or any other appliance needs to activate its service is the starting watts or surge wattage.

Running Watts

The power of electricity a refrigerator, freezer, or any other appliance needs to run the system and refrigerate the substances (fruits, vegetables, raw fishes, meats, etc.) is the running watts.

How the Starting Watts and Running Watts Work

Starting watts turn on the compressor of the generator to begin the refrigeration process and that’s why surge wattage is much higher than running watts. Once the surge wattage switches on the refrigeration cycle, the required wattage automatically drops to a constant ongoing watt amount.

Why You Need at Least A 2000-Watt Generator

Now you know why I anticipated a generator that can power up a minimum of two thousand watts to a maximum of three thousand watts. Note that you must calculate your desired wattage according to the starting watt number and not the running watts just like I did at the beginning of this article. As generators with that much power can be employed to run most of the refrigerators and some of the freezers easily and sustainably.

So, buy yourself a generator that can turn on the refrigerator between 2000 to 3000 watts.

Manual Transfer Switch and How It Works

The manual transfer switch connects to the circuit board at once. It can physically control your home’s power from the town and over to your generator. The installation of the manual transfer switch is no child’s play. You’ll need expert electricians to proceed with this. The main concern is that it isn’t necessary to insert a manual switch if you’re only powering up your refrigerators/freezers and a few other appliances. When you’ll need to supply power through the whole house, then you must install a manual transfer switch. Ask yourself about it and make a decision.


1. Can a generator damage a refrigerator?

Ans. A generator can damage a refrigerator/freezer most probably in two ways.

a) The generator would harm your refrigerator when its watt allotment doesn’t reach up to the refrigerator’s starting wattage consumption.

b) When you’re looking for a generator for your smart refrigerator, you have to choose inverter generators. The block wave produced by the common generator can cause irreparable damages to that fridge’s programmable units. As smart fridges produce smooth sine waves that are convenient for only microcontrollers.

2. Can a portable generator power a refrigerator?

Ans. Yes, a portable generator can power a refrigerator, or a freezer, or a fridge with a built-in freezer. The matter depends on how much watts all these appliances require and how much power your sought-after generator can supply. That generator has to be powerful enough to produce at least 3500-4000 watts to run the refrigerator.

About the author

Jamie Masterson

With decade-long experience as a generator technician, Jamie has worked with USA’s top generator manufacturers and suppliers as an independent contractor.

The long years of service to the industry has taught Jamie the ins and outs of troubleshooting, repairing, and maintaining all kinds of generators in home, industrial and outdoor settings.

Jamie thinks this platform is a great opportunity to share his tips and tricks with you so you can make the most of such power equipment for better living.

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