Generac Generators

Why own a generator?


Now you have it. Now you don't. From hurricanes and snow storms to accidents, tens of millions of Americans lose electrical power to their homes each year. No warning - just no lights, no heat, no air conditioning. No refrigerator, no sump pump, no security system. A few hours without power is a nuisance. Losing power for days, weeks or even longer can be costly and downright dangerous.

A Generac automatic standby generator returns your home to full power within seconds, 24/7, even when you're not at home. More convenient than a portable unit, a fully automatic Generac standby generator senses an outage and begins to produce power immediately. There are no extension cords to plug in, gas tanks to fill, or switches to flip. A Generac generator delivers the power you need, the security and peace of mind you want.

Why Generac?

Number 1 in America

When it comes to protecting your family and your property from power outages, you want nothing less than the best. That's why 4 out of 5 homeowners turn to Generac when purchasing an automatic home standby generator for their homes.

We didn't get to be number one by being like everyone else. Power generation is our only business and has been for nearly half a century. Our products provide the highest quality, the best reliability, the most advanced features and the best value in the industry.

While some companies just assemble product, we design and manufacture our own air-cooled engines, alternators, enclosures, control systems, transfer switches and communication software. With Generac, you get a fully integrated standby power system in which every component is perfectly matched.

We control every aspect of the manufacturing process and production test every unit to ensure the highest quality and complete customer satisfaction. High volume production, along with advanced manufacturing technologies and processes, allows us to keep costs under control and to pass the savings along to you in the form of the lowest prices in the industry.

That's why Generac sells more automatic home standby power systems than all other manufacturers combined. With so much at stake, don't settle for less than the best.

How it Works

Generac Standby Generators are completely automatic, helping to ensure that your home or business remain safe from the negative and potentially harmful effects of power loss.

1. The Generac system automatically and continuously monitors incoming power from the utility line.
Generac System

2. When utility power is interrupted, the control system in the generator automatically senses the loss of power and signals the generator to start.

3. The automatic transfer switch safely closes off the utility line and simultaneously opens a new power line from the generator.

4. Your Generac generator supplies electricity to your main distribution panel through an automatic transfer switch. You can elect to back up selected emergency circuits or your entire electrical service.

5. When utility line voltage returns, the system transfers the electrical load back to the utility line. The generator continues to run for an engine cool-down period of several minutes and the entire system stands ready for the next power outage.

To ensure the system is always ready when you need it, your generator will run a 10-12 minute self-test cycle every week.

Frequently Asked Questions

What is an automatic standby generator?
An automatic standby generator is a back-up electrical system that operates whether you are at home or away. It automatically supplies power to essential circuits of your home within seconds of a utility outage. After utility power returns, the generator shuts itself off and awaits the next outage. It operates on natural gas or liquid propane and sits outside just like a central air conditioning unit.

What will it power?
Generac® standby generators supply electricity to the electrical panel circuits of your home through a built-in load center. You select the number of circuits you want to protect and match it to the appropriate generator system. Everything on that circuit will be protected. Generac also powers furnaces, air conditioners, well pumps, water heaters and other appliances that are hard wired into your electrical panel.

Why should I buy an automatic standby generator instead of a portable generator?
While portable generators do supply power, an automatic standby generator produces a higher quality of electricity. It operates automatically and runs a weekly self-test to ensure proper response to your needs. There are no extension cords to plug in and no gas tanks to fill. It operates automatically so it protects your home even when you're away. When utility power returns, the standby generator shuts itself off.

What's the difference between air-cooled and liquid-cooled?
Air-cooled units use engines we design and manufacture specifically for our smaller generators. Volume production helps us to keep cost down, making our air-cooled generators the most affordable for our customers. They cover essential circuits and back-up power needs in most residential applications. Liquid-cooled units use automotive engines for increased horsepower. This makes them ideal for larger requirements such as whole-house power coverage, larger homes and commercial applications.

Do they have to be maintained?
Just like your car's engine, generators need periodic oil and filter changes. Many customers rely on Generac’s preventative maintenance kits to satisfy routine maintenance requirements. Refer to your owner's manual for routine maintenance procedures and schedules. Kits can be purchased through the business that sold you your Generac generator.

What is the advantage of an aluminum enclosure?
Aluminum is corrosion resistant, so it prolongs the life and look of the generator, particularly in salt air communities.

What is Quiet-Test™?
Quiet-Test is a feature that reduces noise by up to 50% during the generator's weekly self-test cycle. That makes it as quiet as a car idling in your driveway. The generator starts up and operates at a reduced speed, lowering sound output by as much as 12 decibels for units that normally run at higher speeds under load. This allows for near-silent operation in test mode and satisfies all known sound ordinances.

How do I select a generator that's right for me?
The most accurate way is to size a generator for any application is to measure the total amount of electricity required to power the circuits or appliances that will operate with emergency backup power. In addition, certain appliances such as central air conditioners can require up to five times as much power to get them started as they will use when running. When selecting a generator, that additional starting requirement must be taken into consideration. Generac recommends that you consult a qualified electrician to ensure your generator is correctly sized for your specific requirements.

Generac's 10, 14 or 16 circuit pre-wired systems make sizing easy for customers who only want to back up a few essential circuits. You simply connect the circuits you want to back up to matching circuits in the pre-wired transfer switch. For customers concerned with air conditioning, you will need to make sure the kW rating of the generator and the size of the circuit breakers in the transfer switch will meet the A/C startup power requirements. The new 20 kW model, when matched with the PowerManager LTS transfer switch, offers the most affordable whole house protection on the market.

For larger homes that need Generac liquid-cooled models, a licensed electrician must perform a site survey to determine the size and voltage of the unit to meet your backup power needs.

How long does it take to install an automatic standby generator?
Generac home standby and QT Series generators offer the easiest installation in the industry. Our air-cooled models are shipped with a tough composite mounting pad and can often be installed in as little as four hours.

Because of their additional weight, liquid-cooled units must be installed on a stronger mounting surface such as a concrete slab. Our liquid-cooled QT Series generators can normally be installed in 14 hours or less.

Note: Time estimates are based on typical applications. Additional time may be required to run gas conduit or gas piping or to place the unit far from the incoming gas or electrical service.

How much fuel does an automatic standby generator use?

8-20 kW
20-45 kW Liquid-Cooled
60-150 kW Liquid-Cooled
Natural Gas
(cu ft/hr)
LP (cu ft/hr)
LP (gal/hr)
1.3 - 2.8
4.25 7.9
11.0 22.6

Please refer to the individual model's specification sheet for exact figures.

Note: Figures are based on continuous operation at full load. It is unlikely that the generator will run at full load for an extended period, therefore, consumption decreases accordingly.

The generator that I've chosen has a 100-amp automatic transfer switch. What if I have 200-amp service?
Emergency circuits should always be isolated by the emergency load center. An isolated sub-panel helps to prevent overload situations.

What type of transfer switch do I need?
Our air-cooled home standby units and liquid-cooled QT models R-Series controllers require RTS transfer switches (100-400 amps), QT models with the H-100 controller and all QTA models require HTS transfer switches (100-800 amps).

Can a QT Series generator be installed inside my building?
Although our home standby and standard QT Series generators are designed for outdoor installation only, our QTA models are available without an enclosure and can be used for indoor applications. Contact your closest Generac Industrial Dealer for additional information.

Can I get a remote annunciator that will interface with my building management system?
A remote annunciator is available for all QTA models and QT models with the PowerManager H-100 controller.

What type of oil is recommended?
15W-40 is recommended for all liquid-cooled units. The oil should be a SAE rated high detergent oil that meets API Service Class SF requirements for gasoline engines.

Where is my generator made?
Generac generators are made in the United States. Manufactured by Generac Power Systems, Inc. in one of four manufacturing facilities in Wisconsin and Iowa, we design and build our complete product from the controls to the enclosures, to our air-cooled engines specifically designed for generators. This ensures that our products are built to our highest standards.