Weathering Storms With a Portable Generator

June 28, 2004


NEW YORK, NY— 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 along the East Coast without electricity.

Expect another tough hurricane season this year: Experts from the National Oceanic and Atmospheric Administration (NOAA) are predicting "above-normal" hurricane activity for the 2004 Atlantic hurricane season. On the West Coast, the seasonal outlook is "near-normal" or "below-normal," but that doesn't mean a major hurricane couldn't still wreak heavy damage if it makes landfall in a heavily populated area.

To prepare for the loss of power that can occur during a severe summer storm, many homeowners are turning to portable generators as backup power sources for their homes. Powered by gasoline, diesel or propane fuel, a portable generator can provide enough energy to run multiple household appliances, such as lamps, electric stoves, refrigerators, and even computers.

The Copper Development Association issues the following guidelines on selecting and safely operating a portable generator for backup residential electric power.

Safety First

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 any location where their exhaust fumes could be confined or drawn into living areas through an open door, window or vent. They should always be located outside.

What You Need to Know

When purchasing a portable generator, you should 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 momentarily can require 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 and round it up to allow for a little buffer.

The minimum recommended generator for powering residential buildings is a 5,000-watt (5-kW) unit. A generator of this size typically costs between $600 and $1,200 and can power multiple appliances for about 8 hours on one tank of fuel. Many can produce either 120 volts or 240 volts of household (alternating current) power. Be sure to check its power rating at the voltage you will be using.

To enable the generator's power to run to your home's outlets and ceiling lights or to powered appliances such as ranges, ovens, furnaces and well pumps, a licensed electrician should install a transfer switch that distributes power from the generator to the home's circuit-breaker 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).

Smaller portable generators may be connected directly to appliances by appropriately sized copper extension cords. However, use caution: Undersized cords could damage the generator and appliances and create a fire hazard.

Consider staggering power use among your major appliances so you don't encroach on the generator's capacity. For example, run the refrigerator for an hour, and 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.

Finally, keep in mind that gas station pumps won't operate during a blackout, so stock enough fuel to run your generator for several hours - and store the fuel in a safe place outside, not inside, your home.

For more information on residential power and electrical wiring systems, visit our Building Wire section.