Read the manual thoroughly and understand all of the instructions, cautions, and warnings before using this equipment. If any section of the manual is not understood, contact your nearest authorized dealer, or contact Generac Customer Service at 1-888-436-3722 (1-888-GENERAC), or www.generac.com with any questions or concerns. This article is an informational guide to the numerous considerations involved with installing a home standby generator. It is NOT an exhaustive or step-by-step installation manual. 

Can I install my home standby generator?

Installation guides for home standby generators can be found on the product lookup page on Generac.com. While installing your Generac home standby generator as an uncertified installer is possible, the complexity and importance of getting it right make it strongly advisable to work with a certified professional. Generac has a network of Independent Authorized Service Dealers (IASD) who have worked in the industry for decades, which means that they will help you choose the right solution that fits your needs.  They have special planning tools and know how to navigate neighborhood zoning regulations and other local ordinances. By partnering with one of our authorized dealers, you take the guesswork out of a project, saving you time, money, and frustration. Generac IASD installation helps ensure: 

• Compliance with relevant codes and regulations.
• Sizing, placement, and setup for optimal performance. 
• Long-term reliability
• Access to professional maintenance and emergency support. 

For more information on Generac IASD see the following articles: 

• What Is a Generac Independent Authorized Service Dealer (IASD)?
• How can I find a local Generac IASD for installation?

Environment

This article is for uncertified homeowners considering the installation of a home standby generator.

 

Table of contents: 

• Partnering with a local authorized Generac dealer (free quote!)
  
• Codes and Compliance
  
• Generator Sizing 
  
• System optimization and load management
  
• Fuel source selection and sizing
  
• Automatic Transfer Switch  
  
• Site selection 
• Site preparation 
• Fuel system and piping installation
• Pre-startup requirements 
• Special geographical considerations
• Monitoring and Maintenance
• Service Relationships
• Final Testing and Compliance 

 

Partnering with a local authorized Generac dealer

When you request a quote, one or more local Generac IASDs will contact you to schedule a free, no-obligation in-home consultation. The Generac IASD will learn about your unique needs at the meeting and help you weigh available options. They'll also provide you with custom estimates for the total solution cost.

You can expect to discuss:

• Generator placement

• Installation site requirements

• Any necessary system requirements

• Fuel source and connection

• Property restrictions (including HOA or community regulations)

Request a free quote here.
 

Understanding codes and compliance requirements

Federal, State, and Local Codes

Generac IASDs are best positioned to understand and navigate the long list of federal, state, and local codes and compliance requirements. These regulations cover:

• Electrical Code: Proper wiring and connections are critical to safety and functionality.
• Fuel Installation Codes: Correct placement and installation of fuel lines to prevent leaks and hazards.
• Warranty and UL listing compliance: The generator installation must comply with the requirements in the warranty statement terms and conditions. 

Note: Installation must fully comply with all relevant National Electrical Code (NEC), National Fire Protection Association (NFPA), and OSHA standards, as well as all federal, state, and local building and electric codes. 

Key items to consider when installing a generator

Generator sizing 

Accurate sizing helps to provide a generator that meets your current and future energy needs, including peak and seasonal usage, additional appliances, living space expansion, and critical load management.

Note: Sizing requirements may change based on code and jurisdiction.

Factors to consider when sizing a generator include:

• Square-footage: Kilowatt to square-footage requirements may include spaces beyond living areas, such as basements and garages. 
• Motorized electrical appliances
• AC units
• Load management devices - Load shedding devices may impact the required kilowatts for your home. 

 

System design and optimization for load management 

Effective load management systems help determine the optimal generator for your unique situation. Generac IASDs can best design this system, optimizing performance and reliability and, most importantly, reducing the overall cost of your system.

Below are features and accessories that may be considered when designing and optimizing your home backup system. 

• Smart AC Module (SACM) - Integrated, low voltage wire controlled load shedding device within some Automatic Transfer Switches.
• Generac Power Managers - Load shedding devices
• Surge Protection - Required for some installations; consult your authority having jurisdiction for further information.

Note: This list is not meant to be exhaustive but offers insight into some key items that may be considered. 

 

Fuel source selection and sizing

Choosing the right fuel source (natural gas or liquid propane) is an important consideration in the installation process. Each has different storage, supply, and safety requirements. Additionally, the appropriately sized gas meter or propane tank must be installed to meet the fuel demand of the home standby generator chosen. Proper fuel source selection and sizing are essential for efficient and safe operation. 

• Homeowners opting for Liquid Propane require a minimum of a 250-gallon tank for ALL home standby generators.

• All Generac air-cooled home standby generators are field convertible and feature dual-fuel capability (NG or LP). 

  
   

Automatic transfer switch 

Choosing the right Automatic Transfer Switch (ATS) is essential for the seamless operation of your home standby generator. The ATS must be compatible with your utility requirements, which can vary by locality. Understanding these requirements is not always straightforward, as each installation and local utility may have different standards. This is one reason why working with a professional is strongly advised. 

Key considerations

• Utility compatibility: Determining ATS compatibility with your utility service requirements can be challenging. Each utility service and installation is unique, making professional guidance essential.
• Service Entrance-Rated Switches: Installing a service entrance-rated ATS involves connecting utility load-lines. Only a professional should perform this highly dangerous task. 

A local Generac service dealer can assess your specific needs, navigate the complexities of utility service compatibility, and safely install the ATS.

 

Permitting requirements

Securing the proper permits is essential for a legal and compliant generator installation. Every locality has different requirements, which can vary significantly. Additionally, homes in Home Owners Associations (HOAs) may have further regulations and approval processes. 

For more detailed information on permitting requirements, homeowners should contact their local government, such as their city hall. Many cities provide precise, documented guides outlining the necessary permits for generator installation. Consulting these resources is crucial to meeting local codes and avoiding potential legal issues.

Note: All required permits must be secured before installation.

 

Site selection

Choosing the right location for your generator involves balancing multiple considerations with non-negotiable codes and requirements. Since the unit must be permanently installed and cannot be moved, proper site selection is essential for safety, efficiency, and adherence to local regulations.

Clearance requirements and proximity to the house

• The generator has strict clearance requirements for compliance with local codes, including proximity to the house and away from windows, doors, and openings.
• For more information on clearance requirements, see What Should I Know About Clearance Requirements When Installing My Generator?

Note: Home standby generators must be installed in accordance with current NFPA 37 and NFPA 70 standards and any other federal, state, and local codes for minimum distances from other structures.

Note: A unit placed in accordance within NFPA requirements, including the offset reduction validated through testing by SWRI, may still allow CO within the structure. Unit may need to be installed farther from the structure than the NFPA requirements.

 

Proximity to utilities and fuel source

When selecting a site, remember that longer piping or electrical conduit runs increase costs. A Generac IASD can provide expert guidance to reduce costs while complying with all codes and regulations.

Ease of access

The location should allow for easy access for service, maintenance, and first responders.

Environmental protection

Consider protection from environmental factors such as drifting snow, flooding, or debris. 

Site Preparation

The area must be properly prepared, including a stable and level surface, and must comply with local codes. The generator is typically approved to be placed on pea gravel, crushed stone, a concrete base pad, or an approved composite base pad. If a concrete base pad is required, follow all applicable codes. Verify that any base pad meets or exceeds local codes and requirements for wind ratings. 

Site base

Always consult local codes to verify what type of site base is required. All federal, state, and local codes must be followed if a concrete pad is required.

Integrated composite pad

The integrated composite pad allows the generator to be placed on two types of manufacturer-approved surfaces:

• On 5 in (12.7 cm) of compacted pea gravel or crushed stone
• On a manufacturer-approved composite or concrete base pad.

Leveling

• The surface where the home standby generator will be mounted must be compacted, leveled, and will not erode over time. Generators must be level within 0.5 in (13 mm) all around.

Mounting 

• Home standby generators come with a mounting template. The template is on the top of the generator carton and can be used to mark the concrete pad to pre-drill the mounting holes. 
• Three mounting holes are available if codes require securing the generator to concrete. Three 3/8 in (M10) lag bolts (not supplied) are recommended for securing the generator to a concrete pad. 

Note: Generac does not recommend covers or enclosures. See this article for more information, Can I put my home standby generator in a secondary enclosure?
 

Fuel system and piping installation 

 

• All pipe sizing, construction, and layout must comply with NFPA 54 for NG applications and NFPA 58 or ICC IFGC for LP gas applications. 

• Fuel pressure must be verified that it never drops below the required specification once the generator is installed. 

• Always contact local fuel suppliers or fire marshals to verify codes and regulations for correct installation. Local codes will mandate the proper routing of gaseous fuel line piping around gardens, shrubs, and other landscaping. 

• Piping strength and connections should be given special consideration for installations in areas at risk for flooding, tornadoes, hurricanes, earthquakes, and unstable ground. 

• Per local codes, standards, and regulations, all installed gaseous fuel piping must be purged and leak-tested before initial startup. 

• The home standby generator should be plumbed directly from the fuel source through an appropriately sized and correctly placed fuel pressure regulator, not off the end of an existing low-pressure system. 

• A certified contractor familiar with local codes should make fuel line connections. Always use AGA-approved gas pipe and approved sealant or joint compound. 

Pre-Startup Requirements

Testing the fuel system for leaks and conducting generator output frequency testing are critical steps before startup. 

• Voltage output test: Check that AC voltage and frequency are correct and within stated limits

• Fuel system leak test

• Building inspection 

 

Special geographical considerations

Placement and protective measures are crucial for areas with specific environmental challenges, such as mountainous regions with heavy snowfall. 

Wi-Fi or cellular monitoring with Generac Mobile Link 

Generac's Mobile Link monitoring feature enables convenient remote monitoring of your generator's status via mobile devices. When considering Mobile Link monitoring, its important to understand that Wi-Fi and cellular monitoring have different requirements. 

Wi-Fi 

• Generac Guardian-series home standby generators 10-26kW come with integrated onboard Wi-Fi. Mobile Link Wi-Fi and cellular monitoring are not currently available with 7.5kW PowerPact home standby generators.
• Wi-Fi requires your product to be within 35 feet of an access point (Router or Extender) and a separated or dedicated 2.4 GHz frequency band network. 

Cellular

• Next Generation Air-Cooled Standby Generators (10-28 kW) come with a Cellular Connectivity Device.

Service relationships

Generac encourages you to establish a relationship with a local Generac IASD, even if homeowners plan to use licensed electricians, gas companies, or contractors for some or all of the installation. This way, you will know where to turn if you need local expert help, repairs, or assistance during an outage.

Key components to consider: 

• Proximity and availability:  Research the distance to your nearest Generac IASD and their availability, including after-hours emergency support. 
• Warranty work: Only Generac IASDs can perform warranty work.
• Local expertise: Generac IASDs bring years of experience dealing with environmental challenges and can provide guidance on optimal performance specific to your locality (e.g., ice storms, heat waves, utility brownouts).
• Service contracts and monitoring: Generac IASDs can offer service contracts and monitoring services (Dealer Managed Account), providing an additional layer of proactive protection. With an IASD-managed Mobile Link account, your generator has a second pair of eyes professionally monitoring its status, quickly identifying potential issues, taking corrective measures, and responding promptly if problems arise. 
• Maintenance and reliability: Proper maintenance by a Generac IASD helps mitigate the need for repairs and maintains reliability and performance. 
   

Final testing and compliance 

 Performing final tests after installation is crucial in confirming that the unit operates safely and that all components function as intended. 

• Electrical Checks 

• Load Testing: Testing the generator under load verifies its capacity and reliability. 

• Automatic operation: Check that the generator and automatic transfer switch operate correctly during utility loss.