Read the manual thoroughly and understand all of the instructions, cautions, and warnings before using this equipment. If any section of the manual is not understood, contact your nearest authorized dealer, or contact Generac Customer Service at 1-888-436-3722 (1-888-GENERAC), or www.generac.com with any questions or concerns. 

 

Understanding an appliance's power demand: watts, amps, and volts

• To determine the correct size generator for your power needs, the first step is understanding the power demands of the appliance(s) you want to run. Usually, this is measured in watts: What Is a Watt?
• To find out how much power your appliance requires, consult the owner's manual. Depending on the appliance, this information may also be listed on a data label or sticker on the device itself.
• Ultimately, the wattage of your appliances will determine the size (in kW) of the generator you need. If you have a larger and more powerful appliance, you will need a larger and more powerful generator.

 

Environment

This article focuses on portable generators, but the same general principles are applicable when sizing a home standby generator. To learn more about correctly sizing a home standby generator for your home, see How Do I Correctly Size a Generator for My Home?

 

A real-life example

Taylor wants to know what size portable generator he needs to run both his furnace and refrigerator during an outage that is expected to happen because of a major snowstorm forecasted later in the week. He is planning to only power his furnace and refrigerator but would like some extra power left over.

He locates the data label on the inside of his refrigerator:

 

 

 

• Because watts are not displayed on the label, he calculates watts using this formula: volts x amps = watts: 230 x 1.75 = 402.5 watts.
• Consulting the owner's manual, he finds that his natural gas furnace requires 1,000 watts to run.
• Adding these numbers together, he finds that his power demands are 1,402.5 watts.

Choosing a generator

• Taylor starts looking for generators with a power rating that exceeds 1,402.5 watts (or 1.4kW)
• He finds the Generac GP2200i, which boasts 2,200 watts of power, and up to 2,500 watts of starting (or surge) power.
• This means he will have additional power still available in case he needs it to charge his phone or laptop.

See also

• Understanding Portable Generator Power Limits vs. Advertised Wattage
• What Is the Power Output of a GB Series Portable Power Station?