WEMC Generator Guide

New homebuyers are installing permanent whole-house generators during construction and rolling the cost into their mortgage. Poultry farmers know that one prolonged outage can pay for a generator when it saves an entire flock of chickens.   Businesses find that generators keep them going even if it's storming outside. And portable generators can pull double duty by helping with recreational activities or work beyond the reach of extension cords.

How do you choose the right generator?   First, look at what you want to power.   Then consider your budget, special features desired and fuel source.

Permanent Generators

If you want to provide uninterrupted power to your entire home or business, a permanent generator is the answer.

These power plants are mounted on a concrete pad outside and hardwired into the building's electrical system.   An automatic transfer switch senses the loss of grid power and brings the generator on line without any effort from the owner.   Automatic transfer is a must if you're away from the location frequently.

Permanent generators automatically run themselves at regular intervals to keep the starting battery charged and all systems ready to go.   Warning indicators let you know if there's a problem so it can be fixed immediately.

They also have a fuel supply that's connected to a large tank or pipeline so constant refueling is eliminated.   Typical fuels for permanent generators include diesel, LP gas or natural gas.

Permanent generators are large and complicated to install.   You should consult a professional.   Costs may run $10,000 or more for units to power large homes, livestock facilities or businesses.

Portable Generators

If you can live without the entire building having power during an outage or want to watch your budget, a portable generator may be the answer.

If you can rotate the devices powered by the generator, you can get by with a smaller unit.   For example, instead of powering the freezer, refrigerator, space heater, microwave, lights and television all at once, you run one or two devices at a time.   That may cut the generator size required by one-half or more.

So how do you decide what size portable generator to buy?   It's not that difficult.

Every electric appliance has a nameplate that lists its power requirements.   Add the wattage of the appliances you want to power.

Next, look at the rating of the generator to determine peak and rated load capacity.   Peak load is the amount the generator can supply for a short time for the extra demand of motor starting.   The generator can't run at peak output continuously.

Rated load is what the generator can comfortably handle for extended periods.   Usually a 3,000-watt generator can handle loads like freezers, refrigerators, lights, TVs and microwaves.   If you live in the country and want to power a well pump, you'll probably need a 5,000-watt unit.   Prices of generators above 5,000 watts usually climb quickly.

A rule of thumb is to plan for about two horsepower of generator engine for every 1000 watts of electrical load.

Most portable generators use gasoline, although a few diesel models are available.   Prices run from $300 to $600 or more.   Be careful of brands that sprang up during the Y2K scare–they may already be out of business.

Portable Generator Features

Depending on the application, look for these features in portable generators:

•Extra quiet-some models have additional sound proofing for use in close quarters.

•Electric start-eliminates hard starting with pull cords.

•Easy transport-wheels and handles installed to help with mobility.

Maintenance

A few simple steps will make sure your generator is ready when you need it.   First, start and “exercise” the unit monthly.   This keeps the battery charged and circulates the oil in the engine.

Drain the fuel tank if you won't be able to exercise your generator for more than a couple of months.   Then run the engine until it uses the fuel left in the fuel line and carburetor.

You may also want to consider connecting a trickle battery charger to the unit to keep the battery at full charge if it's an electric start model.

Operating Your Generator

Here are a few tips when operating a backup generator:

•If you're powering a computer from a generator, it's a good idea to use an uninterruptible power supply.   You won't loose valuable data if the generator runs out of fuel and the computer goes off.

•Be careful of voltage spikes and electrical frequency variations.   Most new generators have electronic governors that regulate both voltage and frequency to within a six percent range.   Older generators may not provide the quality needed to run sensitive electronics.

Generator Safety

•Isolating your generator from the main power grid is a must!   There are a couple of ways to do this:

1.   If you're running small loads or just one or two items at a time, plug the device

      directly into the generator; or

2.   If you want to power entire circuits inside the building or if you have a permanent  

      generator, install a transfer switch.

Transfer switches work by opening the connection to the

utility before closing the generator connection.

•Why is it so important to isolate your generator from the power grid?   The main reason is to protect anyone who may come in contact with our power lines.   Just as electricity flows into your home from power company generators, it can also flow out of your home from your generator!   The 120 or 240-volt output of your generator is “amplified” through the transformer outside to as much as 14,400 volts.

This situation, called back feeding, can electrocute anyone coming in contact with power lines, including workers trying to restore your power or children playing outside.

The other reason to isolate your generator is to protect it from damage.   Your generator can be destroyed if it's connected to our power grid when the lights come back on.   And chances are your homeowner's insurance won't cover any damage or liability that results from an improperly connected generator.

If you're building a new home and think you may one day use a generator, go ahead and install a transfer switch now. It costs a fraction to install during construction compared to retrofitting later.

•Be careful with gasoline.   Allow the engine to cool before refilling.

•Don't run a generator in an enclosed space.   Deadly carbon monoxide can build up inside garages or basements and find its way into living spaces.   Generators also need enough intake air to run properly and keep the engine from overheating.

•Don't overload the generator.   Stay within designed output ratings.

•Use properly sized extension cords when using the generator to power appliances or devices.

•Read the owner's manual.

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