December 7, 2001

Is Your Standby Generator Standing By?

The lights blink and then go off. It’s cold and dark outside. Are you sure your standby generator will start?

"The time to check the standby generator and make sure everything is ready to go is before you need it," says George Maher, agricultural safety specialist with the North Dakota State University Extension Service. "Several factors influence the generator's ability to start, do its job and operate safely. All must be OK if the machine is to be reliable."

The power for a standby generator usually comes from a built-in engine or through the PTO shaft of a farm tractor. Either type of engine must be maintained in a good starting condition, requiring fresh fuel, a strong battery, good electrical connections, clean filters, and maintenance of liquid cooling systems, Maher says. Always follow the manufacturer’s instructions on engine maintenance.

Fuel, either gasoline or diesel, should be fresh at the start of the season. Transfer old fuel to a pickup or tractor where it will be used quickly. Keep the generator fuel tank filled completely during the winter months to prevent condensation moisture that will freeze and plug the fuel line. Also, add a fuel stabilizer to keep the stored fuel in good condition.

The liquid cooling system of the self-powered standby generator needs seasonal maintenance. Test the antifreeze and replace it according to manufacturers instructions. An over-heated generator with a failed cooling system during a power failure can be expensive.

When the generator powered by tractor PTO, the first concern is, will the tractor start? To be dependable, the tractor dedicated for the generator must be in good starting condition and in top operating condition, Maher says.

"You need to be sure you can get to the generator," Maher notes. "Without a plan for parking machinery at the farmstead, it can be very easy to park a seasonally-used combine, planter, or truck in front of the generator. Access to the generator may not be important during the summer months, but beginning in November or December it should be very important. Plan accordingly."

Part of access is availability of the correct PTO shaft. "If you use the generator’s PTO shaft on other equipment during the year, it’s too easy to leave it on another machine and lose track of it. Keep a PTO shaft just for the generator and make certain it has a good PTO shield on it.

If the generator is installed for indoor operation, there are safety requirements associated with the engine and fuel that must be met:

• Exhaust gases must be vented directly outdoors.
• A metal grommet or flange should insulate the building wall from the hot exhaust pipe. where it passes through.
• A supply of fresh air must be provided for engine consumption and cooling.
• Safe storage should be provided for the fuel tank so that vapors are not a hazard.
• Winter-grade fuel should be available and safely stored.

There are electrical safety considerations with a standby generator too:

• A double throw transfer switch must be installed to disconnect the farm from power lines and connect the farm to the generator. The switch prevents the generator from feeding electricity back into the power line, protecting linemen who may be working to restore your service. The switch also ensures that your generator supplies power only to your farm.
• Be sure that all conductors or wires are of sufficient capacity. Overloaded conductors get hot and cause fires.
• Keep in mind the capacity of the generator. Standby generators have a limited capacity. Many electrical systems and appliances operate within a narrow range of voltage. If the generator cannot provide voltage within 10 percent of what is needed, some loads must be shut off. Increasing the speed of the generator past its rated limit will not necessarily increase the voltage and will damage the unit.

Source: George Maher, (701) 231-8288, gmaher@ndsuext.nodak.edu
Editor: Tom Jirik, (701) 231-9629, tjirik@ndsuext.nodak.edu