On A Power Trip

It’s easy to feel left in the dark when it comes to selecting a generator. Surrounded by loads of choices, many consumers feel powerless to make the right decision. After all, there’s no one-size-fits-all solution; your specific needs will dictate the best size and type of generator for your situation.

The challenge comes in identifying those needs and matching them to a generator with similar capabilities. Here’s how you can meet that challenge and be in a position of power at all times – whether you’re weathering a storm at home or keeping a small business running.

Do The Math

Looking for a generator involves crunching numbers besides your budget and various price tags. However, one number you don’t have to worry about is square footage. Though you might think a 2,000-sq.-ft. home or office would require a smaller generator than a 3,500-sq.-ft. building, it’s the amount of energy used, not the amount of space, which matters.

The occupants in a small house might use a couple of refrigerators and multiple appliances for a home business, whereas a larger office merely needs to keep a few computers and lights on during a power outage.

When considering a generator’s use, think about which appliances you want the generator to power. Begin by listing what the generator should run, such as lights, a computer and a refrigerator. Find the silver tag attached to each appliance to check the wattage; then write that number on the list and multiply it by the number of units to be used (see table below). For example, five 100-watt light bulbs would need 500 watts of power to run.

Some appliances take more energy to start than they do to run. For example, coffeemakers, computers and televisions run on a constant wattage, whereas washing machines, refrigerators and furnaces need more energy to start. Take this surge of wattage into account when determining the total power needed.

Some tools and appliances may have power listed in amps and volts rather than watts, and horsepower might be used for motor-driven equipment. You can convert these numbers into watts with simple calculations.

If volts and amps are listed on the appliance, multiply the two to determine the wattage: amps x volts = watts. When horsepower is listed, keep in mind that 1 hp equals 746 watts. A 1/8-hp motor will draw 93 watts; a 1/4-hp motor needs 186 watts, etc. Keep in mind that motors may need four times as much power to start as they do to run. Speak with an equipment dealer to get the exact specifications for a particular motor.

Consider Noise And Stability

Technology advancements have made generators quieter and cleaner than ever, but there are still several degrees of “quiet” and “clean” (power stability), and the quieter the model, the more it will likely cost.

Inverter generators offer extremely quiet, clean power especially suited for sensitive electronics such as computers. The power runs through an inverter board, producing purely manufactured power. Inverter technology fits well in residential or noise-restricted areas where the resonance from a standard generator may be problematic.

Components designed to reduce noise can lower the decibel level of conventional generators. Look for large mufflers, air cleaners built to suppress noise and automatic idle control, which will slow the engine when power isn’t being drawn.

When it comes to “clean” power, conventional generators use automated voltage — a regulator controls the voltage level and keeps the power more stable. Sensitive electronics run best on clean power; voltage fluctuations can cause computers to reboot or affect components that will later need to be recalibrated.

Capacitor-style generators are better suited for construction purposes. The power level is sufficient for tools and air compressors but would not be recommended for electronics.

The differences in generators’ “cleanness” can be seen on sine-wave charts. A sine wave is one standard cycle of electric current, or 60 hertz cycles per second. Sensitive electronics can handle a sine-wave distortion of 10 percent, making conventional generators a good fit.

Capacitor-style generators can have sine-wave distortion as high as 40 percent, which is adequate for tools and other less-sensitive equipment. Inverter generators provide the lowest sine-wave distortion of all styles (less than 2.5 percent), making them the cleanest of the three.

Evaluate Quality

A number of components indicate a well-built machine. The first is a high-quality engine. Check that the manufacturer has a strong reputation for engine reliability and a solid warranty program. A fuel-efficient engine will cost less to run and prevent frequent refueling and downtime. A generator with automatic idle control will conserve even more fuel, as the engine will slow to an idle when power is not being drawn from the system.

Next, check the thickness of the steel construction as well as the durability of the fuel tank. Look for well-built starting components – either an easy-to-pull recoil starter or an electric start. Count the outlets. Are there enough to power everything adequately?

An expansive control panel also indicates a better-quality machine. An hour meter will help keep track of maintenance checks and services, and a voltage meter will eliminate guesswork. A large fuel tank will decrease time spent refueling, and a fuel gauge will simplify checking the tank. In addition, a low-oil-shutdown feature will guard against engine damage if the lubrication level drops.

Also find out whether the generator is OSHA- and EPA-compliant. The Environmental Protection Agency has established three levels for emission-control standards — Tier I, II and III — and deadlines for each tier of increased standards to be reached. The Occupational Safety and Health Administration sets regulations for GFCI receptacles, which help to protect operators from electrocution. (A generator frame can serve as a grounding electrode.)

The GFCI will compare the amount of current going to electrical equipment with the amount of current returning along the “grounded neutral.” If the difference between the two streams of current exceeds 5 milliamps, the GFCI will trip and stop the current.

Though the GFCI will not protect against short circuits and overloads, a conventional generator will pop a circuit breaker when it becomes overloaded, killing the outflow on the receptacle. On an inverter generator, a digital display will show “overload” and the engine will stop. The generator would need to be shut down and reset after the load was decreased.

Consider Convenience

Different users need different degrees of convenience, and manufacturers recognize this with a variety of options. An elderly person with a conventional generator, for instance, may benefit from adding a wheel kit so the generator can be moved easily around the garage.

Someone desiring a more permanent system might forgo portability in exchange for ease of operation. Two styles of generator systems connect directly to a building or home’s electrical system: a manual-transfer-switch system and an automatic-home-standby setup.

If you choose a manual-transfer-switch system, an electrician will need a list of appliances that would run off of the generator during a power outage. The loads from those appliances will be run through a box to which the generator is connected. When the power goes out, you pull the lever on the box to switch power over to the generator.

Automatic home standby is essentially a smarter version of the manual transfer switch. A box similar in size to a central air-conditioning system is mounted outside and connected to a natural gas line. When the power goes out, the generator automatically starts and, when it gets up to speed, transfers power from the public utility to the generator. It also detects when power is restored and transfers the load back.

This system costs more than others because of the installation expense and size – most are at least 8 kw, but some models exceed 20 kw for maintaining power throughout a large building. The advantage of an automatic-home-standby system is that essential appliances and sump pumps never lose power, even when the house is unoccupied.

Both the manual-transfer-switch and automatic-home-standby systems should be installed by professionals to safeguard against back feeding — electricity from a generator flowing back into the main electrical utility lines — which can injure or kill utility employees working to repair the lines.

Though many considerations are involved in choosing a generator, you needn’t be intimidated. Empowered with the facts, you can find the right size and type to give you peace in any storm.