MISSISSIPPI STATE -- Use caution while operating generators in the wake of Hurricane Katrina to avoid further damage to homes and health.

Herb Willcutt, safety specialist with the Mississippi State University Extension Service, said generators can be an invaluable resource after a disaster, but improper use can be deadly.

"The first thing to consider is that a portable generator should be grounded properly, according to the operator's manual instructions," he said. "This usually means you should use wire to connect a metal water pipe or ground rod 8 feet down into the soil to the generator chassis. Otherwise, if something causes the generator to short out, it can literally be a live wire -- typically generating 240 volts -- and deadly to anyone who touches it."

Treat extension cords with care when using them with a generator. Do not allow an extension cord to be pinched between a door and threshold. Also avoid placing cords in high-traffic areas because repeated wear can damage the insulation and possibly cause a short or electrical shock when contacted.

An alternative to cords routed through doorways may be to remove a window screen, run the cords through the window and close the window to the cord.

"Never wire a generator into the circuit breaker panel of a home so that it will 'feed power back' to the electric utility line," Willcutt said. "This is dangerous to utility workers who may be working on a line and not know that a portable generator is connected."

Be sure the generator is adequate for the job it is being used for.

"A gas- or diesel-powered generator will tell you real quick if it's overloaded by stalling," Willcutt said. "Appliances that are on the line when the generator stalls may suffer damage because appliances with motors require extra amperage to start. A low voltage situation may cause the appliance to try to start repeatedly, never reaching full operation; this will cause damage."

Similarly, a generator that has poor speed control or is surging in revolutions per minute will damage most appliances in a short time.

Before using a generator to power electronics, refrigerators or deep freezers, check the frequency on the generator to protect appliances.

"The generator's frequency should be 60 cycles. Less than this may damage refrigeration equipment and electronics," Willcutt said. "You don't have to have a large generator to stay comfortable. Run items alternately a few at a time."

Check the operator's manual for instructions on setting the RPM of the engine for proper speed -- usually 3,600 RPM for smaller generators. Use surge protectors for computers, televisions and other electronics.

When motor loads are being operated on a generator, start the largest motor first, then add smaller loads. This allows the generator to adjust to each new load before an additional load is applied.

Provide adequate ventilation for the generator. Avoid running it in a utility room, garage or carport, and especially inside the home. Carbon monoxide fumes from a generator are deadly, especially in a confined area.

When refueling a generator, always allow it to cool first. If fuels are spilled, clean them up and get rid of the fumes before trying to restart the generator.

"Check fuel and oil regularly and power-down all the electric load to the generator before shutting down for refueling," Willcutt said. "Allowing a generator to run out of fuel may damage electronics and appliances because power may surge several times as the generator runs out of fuel. Check the operator's manual for estimated run time before predicting when refueling will be necessary."

Willcutt said generators are an efficient means to power items necessary for comfort. However, they are poorly suited where heavy, resistive loads, such as water heaters and stoves, are connected. Consider a small hot plate or camping stove instead of a full stove. Heat water for bathing in pots on a camping stove or a fish cooker fired by propane.

A more obscure issue when dealing with generators is security.

"In times of disasters such as hurricanes and ice storms, people have been known to borrow generators, never to return them again," Willcutt said. "It might be good to secure them in some way to reduce the risk of theft."

Also remember to be a good neighbor when operating generators.

"Plan to power down generators that are noisy after normal bedtime hours. Also, share your good fortune of having a generator with your neighbors, who may need to keep a freezer of food from spoiling," Willcutt said. "Remember the elderly, who may have electrically powered medical equipment they depend on."