Are you looking for a power source to fuel a camp site, job site, business or home?  Consider your energy needs when deciding whether a portable or standby generator is right for you.

Versatile portable models can be used to power a few key appliances such as lights, tools, a sump pump, a refrigerator and a radio during a black-out or moved to locations without electrical power. They require no installation and will go to work right out of the box.

Permanent standby models are connected to the electrical panel of a building and use it’s natural gas or propane supply to keep lights, refrigerators, air conditioners, pumps, furnace fans, and other major appliances running without interruption for extended periods of time.

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Sizing Your Generator

Generators are rated in kilowatts (amps x volts = watts; 1000 watts = 1 kilowatt).  In an average home, key appliances run on 5,000 to 7,000 watts of power. To determine the size of the generator you need, add up the total wattage of the appliances you want to run simultaneously, making allowances for the surge wattage requirements of motor-run appliances, and bearing in mind that a generator is most efficient when operating at 75 percent capacity.


The following table lists the approximate wattages of some commonly used appliances.

For a precise estimate of your power needs, refer to the wattage information provided on your appliances, verify wattages with a tester, or have a professional electrician provide you with a household reading.

Choosing the Right Model

Once you establish the amount of power you require, you can decide whether a portable or stand-by model is best for you.  Some important factors to consider include:

FUEL SUPPLY: Portable generators require frequent refueling with gasoline, diesel or propane and will only accommodate as many appliances as they are equipped with outlets for. Stand-by models can run directly on your home’s fuel source and will power as many appliances as they are rated for.

MOBILITY: Portable generators are smaller than fixed, stand-by models and are often equipped with wheel kits that allow for easy transport between home, job and recreation  sites.  

VOLUME: Generators can be very loud, often exceeding 100 decibels, or the equivalent of a lawn mower running non-stop. If you plan to run your generator in an area with noise restrictions, check the decibel rating or consider an inverter generator, which runs more quietly than a conventional one. Select generator models feature Quiet Test technology or operate at lower RPMs for reduced noise levels.


Portable generators can be used to supply power during an outage, to run lights and appliances during camping trips and other outdoor recreational activities, and to power tools on construction sites where there is no electrical service. Most portable generators run on gas, diesel or propane.

Small generators (800-2,000 watts) are a popular choice for portable electronics such as laptops, power tools and camping equipment. (NOTE: Standard generators are not recommended to run computers. Inverter generators, designed to run at varying speeds, are more appropriate to the power requirements of sensitive electronics.)      

Mid-sized generators (3,000-5,000 watts) can be used to simultaneously power a sump pump, refrigerator and other key appliances. A 5-kilowatt portable generator can power a heating system and a few other essentials.

Large generators  (6,000-9,000 watts) will power key appliances and energize several rooms in a house.

X-Large generators (10,000+ watts) will maintain vital appliances and central air-conditioning during a summer black-out.  


A standby generator will automatically restore power to a home if power is interrupted and will continue to run until power is restored. Standby models are available in a variety of power outputs ranging from small units rated at 6,000+ watts that can simultaneously run a refrigerator, sump pump, furnace fan and other vital appliances to large units producing 40,000+ watts that can run and cool a business or large home.

Standby models are sized in accordance with a building’s power capacity. The maximum amount of electricity a building can consume is determined by looking at the electrical panel.  If the panel indicates 100-amp service, the building can take up to 100-amps and a properly sized generator will be capable of powering up to 100-amps. Optimum wattage, however, depends on the amount of the electrical panel that will be energized.

Home standby systems usually have weather-proof exteriors and can therefore be mounted on concrete slabs outside of the buildings they serve. They connect directly to building electrical circuits via automatic transfer switches that start the generator during a power outage. Home standby units are commonly connected to a home's natural gas line, eliminating the need to fill fuel tanks. 

Large industrial generators often provide back-up power for grocery stores, hospitals and other large commercial or industrial operations that depend on a constant power supply. These heavy-duty units are generally powered by water-cooled diesel engines and can generate up to 200,000 watts of power. 


Transfer switches are required by many city and state electrical codes. When using a generator, a transfer switch will provide back up power for vital appliances, such as a boiler and furnace, that are directly connected to a building's electrical circuits. A transfer switch can be set up to power only a few circuits or an entire home. Some transfer switches allow for prioritization of circuits powering heating and cooling equipment. Large backup generators are often equipped with complex emergency switches that seamlessly transfer and regulate power flow from the utility grid to generators and back.

Transfer switches are available in manual and automatic models.

Automatic Transfer Switch 

Automatic Transfer SwitchDuring a power failure, an automatic transfer switch will transfer electrical circuits from utility power to the generator. When power returns, it will automatically switch back to utility power. This eliminates having both power sources on the selected circuits at the same time, protecting the generator from surge damage when power is restored and safeguarding utility workers who expect lines to be dead.

Automatic transfer switches are available in a variety of amps. As a general rule, the amperage of a transfer switch should correspond to the amperage of the main breaker in an electrical panel. A 100-amp main breaker will therefore require a 100-amp transfer switch.

Automatic transfer switches are available with load centers that connect to 8-16 mission critical circuits in small homes with 100-amp inbound service and a service disconnect design that will energize an entire electrical panel in larger homes with 200-amp power supplies.

Manual Transfer Switch 

A manual transfer switch is installed next to a main electrical panel and connected to critical circuits. Most transfer switches are pre-wired with the circuit breakers already selected.  When the power goes out, a power cord is run from the generator directly to the transfer switch. Circuits to be energized can be manually selected using switches. Built-in wattage meters keep track of power usage, preventing system overload and damage to  generator and appliances. Manual transfer switches are sized to accomodate a power cord. A 30-amp transfer switch corresponds with a 30-amp cord.


A power inverter converts direct current (DC) power from a car or boat battery to alternating current (AC) electricity that will power appliances.

Inverters are a popular choice for powering radios, coffee pots and precision electronics such as laptops and portable DVD players in  areas where electricity is not available. Because they can run off of charged automotive batteries, inverters can also provide temporary power for lights, radios and other essential applainces during a power outage. An inverter is most economical for running low load appliances under 1000 watts.

Power inverters are available in modified sine wave and true sine wave outputs.

Modified sine wave inverters deliver power that is consistent and efficient enough to run most devices adequately. They are affordable, small and highly efficient.

Some laptops, variable speed tools, A/V equipment and medical devices require a true sine wave, which delivers the highest quality wave output.  Any AC device will run on a true sine wave inverter.

For detailed specs, manuals and reviews of the generators we stock and ship nationally, visit our product pages at or call us for details: 1-800-429-0800.