Portable Generator Safety Tips

How to Select the Right One

Portable generators come in many sizes. Following these steps will help you select the right size for your needs.

• Determine the “constant wattage.” A portable generator operates a limited number of appliances and lights. Choose the items you want to run with the generator and add up the wattage they use. The total is your “constant wattage,” or the energy you will need on a constant basis to keep items running. For help determining wattage information, see the “Calculating Energy Usage” section below.
• Determine the “start-up wattage.” Knowing the “constant wattage” of your appliances is not good enough. Appliances with motors, such as refrigerators, freezers, and air conditioners can require two to three times their normal wattage when the motor starts up. The generator you pick must have a surge rating that meets or exceeds your added “start-up wattage” needs. To determine your “start-up wattage,” identify the appliances with motors that you will run with your generator. Double the “constant wattage” of these items, then add up the totals.
• Match voltage rating. Most appliances are rated at 120 volts, but some larger electric appliances, such as ovens, clothes dryers, and well pumps, are rated at 240 volts. Portable generators may be rated at 120 volts only, or a combination of 120 and 240 volts. Make sure the generator you choose matches the voltage ratings of the items you want to run.