Know Watts Right and Wrong
by Chuck Woods
TAVARES, Fla.---With seven to nine hurricanes predicted for the current season — including two or three that will hit the United States — sales of portable generators are rising fast, and so are the safety concerns about using them.
University of Florida extension safety experts say common mistakes include operating generators in closed spaces without proper ventilation, overloading them with too many appliances and plugging or wiring them directly into house electrical systems.
“First, if you’re going to buy a generator, don’t wait until the last minute,” said Julie England, a Lake County extension agent with UF’s Institute of Food and Agricultural Sciences, or UF/IFAS. “Buying before demand peaks will save money.”
Before you buy, determine your power needs. She said some people think a generator will provide enough power to run everything in the house. An average household needs 3,000 to 5,000 watts to provide enough energy for basic needs such as lighting, cooking, refrigeration and pumping water.
Calculate the wattage needed for additional appliances that are convenient but not essential for day-to-day living. Then find the right combination of power and price to fit your needs. Most generators in this wattage range sell for $400 to $700.
“When you determine how many watts of generating capacity you will need, calculate running watts and starting watts,” England said. “Starting watts are the extra power needed to start the appliance, and they are usually at least twice the amount needed to operate the appliance. Add the running and starting watts to get the total wattage that will be needed — overloading your generator can damage the appliances and generator.”
England said it’s important to start the generator without the appliances plugged in. Start by plugging in the most necessary appliance and the one that consumes the highest wattage. Add other appliances one at time, allowing the generator to stabilize as each one is added. Stay under the wattage rating, and do not operate the generator at maximum wattage for more than 30 minutes.
“Never plug a generator into a household outlet,” England said. “This may cause a problem known as back feeding, sending a surge of power through the lines that can injure or kill power workers or your neighbors. When your electric utility restores the power, the resulting power could damage your generator.”
She said the only way to hook up a generator to house wiring is with a transfer switch installed by a licensed electrician. This may require a permit from the local electric utility provider.
Carol Lehtola, an associate professor and safety expert at UF/IFAS in Gainesville, said portable generators should be operated in a safe, secure, well- ventilated place. “Generators give off dangerous carbon monoxide (CO) gas that cannot be seen or smelled. Do not place generators near doors, windows, ventilation intakes or any other place that lets gas into your home.”
Generators should be at least five feet from buildings or anything that might catch fire. Protect the generator from rain by placing it under a roof or canopy. Keep children away from the generator, and keep it out of view to prevent theft.
“Be courteous to your neighbors,” Lehtola said. “A generator can be very noisy, so try to place it in an area that’s as far away from other homes as possible. Make sure fumes from the generator don’t enter their homes.”
Lehtola said it’s important to read the owner’s manual before starting the generator for the first time. “Don’t wait until you need the generator before using it. Start your generator every month to help maintain the engine and recharge the battery. If you wait until there is a power failure to start the generator, it may not start or run properly.”
Use the manufacturer’s recommended fuel and oil. Never refuel the generator when it is running, and allow it to cool down before adding fuel. Improper fueling can lead to fire or explosion. Don’t store fuel inside the living area of your home, and only store it in approved containers. Estimate your fuel and oil needs in case of emergency. Most generators use about one- half to three-quarters of a gallon per hour — about 12 to 18 gallons per day.
Lehtola said there also are 15,000-watt generators that can provide back-up power for small homes. These stand-by units, which automatically start when there is a power failure, are usually wired directly into the house electrical system. Local utilities require a permit to install and operate this type of system.
Family and Consumer Sciences Agent III