Buyer’s Guide for Generac Automatic Standby Generators

How Generac Standby Generators Work

A Generac standby generator is permanently installed outside your home and automatically turns on during a power outage. It is connected to your electrical system through a transfer switch, which safely transfers power from the utility to the generator.

Unlike portable generators, standby systems:

• Start automatically
• Power selected circuits or the entire home
• Run on natural gas or propane
• Are designed for long-term reliability

How to Size a Generac Generator for Your Home

Proper generator sizing is one of the most important parts of the project.

Sizing depends on:

• Square footage (as a starting point only)
• HVAC systems (central air, heat pumps)
• Appliances (well pumps, electric ranges, etc.)
• Desired coverage (essential circuits vs whole house)

Larger motor loads—especially air conditioning—require careful planning to avoid overload conditions.

A properly sized system should clearly define what will run during an outage.

Natural Gas vs Propane for Generators

Choosing the right fuel source impacts performance and cost.

Natural Gas

• Unlimited supply (no refueling)
• Requires gas capacity verification
• Lower energy density than propane

Propane

• Higher energy output
• Requires on-site tank
• Needs monitoring and refilling

Fuel availability does not guarantee fuel capacity—this must be confirmed during system design.

Generator Installation Process in New Jersey

A standby generator installation is a multi-step project involving:

• Electrical work
• Gas or propane connections
• Permits and inspections
• Equipment placement and code compliance

A typical project includes:

• Site evaluation
• System design
• Permitting
• Installation
• Inspection and startup

Proper planning is critical to avoid delays and unexpected costs.

Transfer Switch Location and Code Considerations

The location of the transfer switch depends on the system type:

Essential Circuit and Non-Service Entrance Systems

• Typically installed indoors
• Located near the main electrical panel

Service-Entrance-Rated (SE) Transfer Switches

• Installed outdoors
• Located at the point where utility power enters the home
• Must comply with NEC service equipment location requirements (NEC Article 230)

Because SE-rated transfer switches are considered part of the service equipment, they may require additional electrical upgrades.

(See Appendix C for a detailed breakdown of New Jersey grounding and code requirements.)

What Does a Generac Generator Cost?

The cost of a standby generator system depends on:

• Generator size
• Fuel type
• Electrical system complexity
• Installation requirements
• Site conditions

Most systems range from approximately $12,000 to $25,000+, depending on the scope.

Lower-priced quotes may not include:

• Fuel upgrades
• Electrical service modifications
• Grounding updates
• Permit and inspection costs

How to Compare Generator Quotes

When reviewing proposals, make sure they clearly define:

• What will run during an outage
• Generator size and justification
• Fuel capacity verification
• Installation scope
• Permits and inspections
• Warranty and service

If key details are missing, the project is not fully defined.

Common Mistakes When Buying a Generator

• Choosing based on price alone
• Not verifying fuel capacity
• Accepting vague system sizing
• Overlooking installation complexity
• Ignoring long-term service requirements

Avoiding these mistakes can prevent costly issues later.