How to Select the Right Generator

It’s easy to feel left in the dark when it comes to knowing what to look for in selecting a generator. Will it be used in a small business, big house or small home? Does it matter? What if it needs to power computers during a power outage – would that require anything special? Surrounded by loads of choices, many consumers feel powerless to make the right decision.

Don’t accept an across-the-map recommendation when looking to purchase or rent a generator. Each individual’s specific needs dictate the load size and type of generator that would work best in a given situation. The challenge comes in identifying those needs and matching it to a generator with similar capabilities. Overcoming that challenge places consumers in a position of power at all times – whether they’re weathering a storm at home or keeping a small business going.

Shhh! Do You Hear It?

Technology advancements have made generators quieter and cleaner than ever, but there are still several degrees of “quiet” and “clean” – 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.

Quality components aimed at reducing 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, with a regulator controlling the voltage level and thus keeping the power more stable, or “clean.” Sensitive electronics run best on clean power since 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 power tools and air compressors, but would not be recommended for powering electronics for any considerable length of time.

The difference between generators’ “cleanness” can be found 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 up to 10 percent, making conventional generators a good fit. Capacitor-style generators can have sine-wave distortion up to 40 percent, which is adequate for tools and other less-sensitive equipment. Inverter generators provide the lowest sine-wave distortion of all styles with less than 2.5 percent, making them the cleanest of the three.

Signs of Quality

The next power trip stop will make it apparent that a quality generator helps ensure that you won’t be faced with another power emergency should the backup power source fail.

A number of components indicate a well-built machine. First, a quality generator needs a quality engine – it won’t matter how well the rest of the generator has been constructed if the engine isn’t sound. Look for a company with a strong reputation for engine and generator reliability and a solid warranty program.

Furthermore, 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 since the engine will lower to an idle when power is not being drawn from the system.

A quality generator needs to be made with quality components. 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 — will there be enough to power everything adequately?

An expansive control panel also will indicate a better quality machine. An hour meter will help keep track of maintenance checks and services, while a voltage meter on the generator will eliminate guesswork. Looking for the largest fuel tank available will lessen time spent refueling, and finding a generator with a fuel tank gauge will simplify checking the fullness of the tank. Additionally, a low-oil shutdown will guard against letting the lubrication level drop too low, which may result in engine damage.

While it may not be the first thing to come to mind when looking for a generator, it also is important to ask whether it is OSHA and EPA compliant. The Environmental Protection Agency has established three levels for emission control standards – Tier I, II and III – with deadlines for each tier of increased standards to be reached.

The Occupational Safety and Health Administration sets regulations for GFCI receptacles. Ground fault circuit interrupters will help protect operators from electrocution when used on a generator with a frame that 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. While the GFCI will not protect against short circuits and overloads, conventional generators 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 once the load was lessened.

On the Move?

At the next stop on the power trip, it becomes clear that a generator’s portability features may be as unique to the user as the load size. 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 could be moved easily around the garage.

Someone looking to have a more permanent generator 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.

With a manual transfer switch system, an electrician will need to have 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, pulling the lever on the box will switch power away from the public utility and over to the generator. This type of system eliminates running extension cords to the generator when the power is out since you would only need to flip a switch to restore power to certain appliances.

Automatic home standby is essentially a smarter version of the manual transfer switch. A box similar in size to a central air system is mounted outside and connected to a natural gas line. When the power goes out, the generator will automatically start and, when it gets up to speed, transfer 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 due to the installation costs and size – most are at least 8 KW but can exceed 20 KW for those looking to maintain power throughout a large building. The advantage of the automatic home standby system is that a home or business will never go without power to essential appliances or sump pumps, even when the house is unoccupied.

Professionals should install both the manual transfer switch and automatic home standby to ensure there will be no connection between the generator and public power supply. A back feed occurs when electricity from a generator flows back into the main electrical utility lines. Back feeding makes wires “live” again and can injure or kill any utility employees working to repair the lines.

With that, the bulk of the power trip has come to an end. The lessons learned at each stop should offer a guide through the steps to finding a generator that’s a perfect fit for your home or small business.

With this map in hand, feel free to proceed to the final destination – a generator manufacturer, rental center or local hardware store. Complete the trip empowered with the knowledge of how to find the right size and type of generator to meet your needs.