How to Size Emergency Generators

An emergency generator, designed to power essential electrical equipment in the event of a power outage, is a good investment when preparing for emergency situations. Choosing a generator may not be as simple as writing a check or pulling out your Visa card. The type of fuel it runs on and the initial cost of the generator will no doubt factor in to your choice. The size of the generator, though, should carry the most weight in your decision. The size is determined by how you will actually use the generator.

Instructions

Determine Your Power Need

• 1

  Determine the power requirements of each of your appliances. The requirements are usually indicated on the bottom of the appliance itself or on a data tag. Create a list with the amperage in one column and the appliance in the other. Leave a column blank in between for the watts.

• 2

  Remember that appliances can use up to three times as much power to start as it does to simply run. Keep this in mind for your calculations. Also, keep in mind that older appliances use more energy, generally, than what is written on the appliance or the data tag, according to Honda Power Equipment.

• 3

  Convert your amps to watts. The formula is: Watts = Volts x Amps. Most appliances will list their figures in amps; whereas, most generators will list their figures in volts. Enter the volts in the middle column of the worksheet mentioned in Step one.

• 4

  Add up your figures. Your final figure is what you would need to maintain the power throughout the house. Adjust for start-up energy. At this point, you may have to decide which appliances are truly essential.