Generator fuel types

Depending on the generator model, Generac standby generators may run on liquid propane vapor (LP), Pipeline Natural Gas (NG), or Diesel fuel. Some generator models can also be converted between fuel types. For example, Generac home standby generators 7 kW-48 kW are shipped as natural gas from the factory and can be converted in the field for liquid propane.
 

Diesel generators

Generac's RD series of Diesel home standby generators are mainly used in commercial applications but can be used in residential applications if needed as long as all applicable codes are followed. Generac's RD series generators use Ultra-Low Sulfur Diesel (ULSD) (the “S15” sulfur level in the U.S.), i.e., standard pump diesel intended for modern diesel engines. Refer to your generator's user manual to verify appropriate fuel type.
 

Liquid propane and natural gas

Liquid Propane (LP) and Natural Gas (NG) are the most common fuel types found in residential generators. The two most important considerations when LP or NG are:

• Propane requires a minimum capacity tank of 250 gallons. Gas grill propane tanks should not be used.
• Natural gas requires verifying the capacity of the natural gas meter. This can be done by your gas provider.

Both requirements are needed to provide enough fuel for the generator and other household operating appliances such as gas stoves, furnaces, dryers, etc.
 

Fuel configuration and conversion

Generac home standby generators 7 kW-48 kW are shipped as natural gas from the factory but can be re-configured without additional accessories or equipment. 60 kW and 80 kW models that use the 4.5 L engine can also be configured in the same manner.
 

Note: While other generator models can be converted, they may require EPA paperwork, as well as additional hardware and expertise to perform the fuel conversion.

 

Generator fuel configuration capability

For generator models that can be configured in the field with no additional required parts, fuel configuration steps are outlined in the owner’s manual under the heading: “Reconfiguring the Fuel System”. 

Some of these generators allow configuration between LP and NG by twisting a valve or swapping fuel jets. See these articles for more information:
 

• How do I configure the fuel type on my air-cooled home standby generator?
• Can I Convert a Liquid-Cooled Standby Generator to Run on a Different Fuel Source?

 

Installation considerations

Different regulators are needed depending on which fuel you choose each one has its own installation requirements. The fuel pressure for each is different, so there is different pipe sizing that needs to be used.  All the requirements for each fuel are in the installation manual: How Do I Find a Copy of My Home Standby Generator Owner's Manual and Spec Sheets?

Most importantly, contact local fuel suppliers and local code regulations for proper installation. Local codes mandate the correct routing of gas lines. In accordance with all local codes and regulations, this should help in making the determination as to what fuel your Home Stand By generator uses.