January 2004
Where power failures on a grand scale are concerned, 2003 was a year for the record books. A rolling blackout from Maine to the Midwest stranded millions in the midst of an August heat wave, and then Hurricane Isabel left communities all along the East Coast without electricity. And it doesn't take a hurricane; a severe wind or ice storm can knock out power for long periods.
For untold numbers of Americans, these events meant days, sometimes even weeks, without electricity. But for a few lucky homeowners, power was restored in the blink of an eye - thanks to portable generators.
What You Need to Know
Many people have turned to portable gasoline generators as emergency backup power systems for their homes. The minimum size recommended for this is a 5,000-watt (5-kW) unit, which can power multiple appliances for about 8 hours on one tank of fuel. Relatively inexpensive, a generator of this size costs between $600 and $1,200, and produces 120 or 240 volts of household (alternating current) power, consuming about a gallon of fuel every two hours (at a 1,000-watt output). Portable generators are available as gasoline-, diesel- or propane-powered units.
When purchasing a portable generator, you must match the unit's electrical generating capacity to the power requirements of your most-needed appliances. Certain appliances demand higher start-up or surge wattages. A refrigerator, for example, runs on about 850 watts, but requires perhaps twice as much power at start-up. To calculate your power needs, simply add up the constant and surge wattage figures for all the devices you want to operate simultaneously.
Smaller portable generators may be connected to appliances by appropriately sized copper extension cords. Use caution, however - undersized cords could damage the generator and appliances, or create a fire hazard. Extension cords typically are not used for furnaces, well pumps or ceiling lights. For these, a licensed electrician should install a transfer switch that distributes power from the generator to the home's circuit panel. Transfer switches are safe, efficient, permanent devices that also eliminate the risk of electrical "backfeed" to, or from, the utility power grid (when electricity comes back on).
When operating a generator, consider staggering power use among your major appliances. For example, run the refrigerator for an hour then shut it off and power up the air conditioner for an hour. By doing this, you'll conserve fuel and prolong the life of your generator.
Proper ventilation is critical. Generators, like automobiles, produce carbon monoxide - a potentially deadly gas. For this reason, generators should never be operated indoors or in an enclosed space or in a location where their exhaust fumes could be drawn through an open window or vent. They should always be located outside in a dry location.