Standby Generator FAQs

AIR-COOLED GENERATORS

…come with engines that use fans to force air across the engine for cooling. For most typical homes, air-cooled models provide exceptional value to homeowners interested in backing up critical circuits. Depending on the model, 8, 10, 12, 16 key circuits in your main distribution panel can be powered by the generator during a power outage. A 22kW air-cooled standby generator offers up to whole-house protection for many homes.

LIQUID-COOLED GENERATORS

…use enclosed radiator systems for cooling, similar to an automobile. Generally, liquid-cooled engines are used on larger kW generators due the larger engines required for the higher power output. For larger homes or small to medium businesses such as convenience stores, restaurants and offices, the solid, reliable, increased horsepower of an automotive-style, liquid-cooled engine provides more powerful options for critical circuit and entire service back up. On breaking the 20KW output barrier, Generac leaves behind air cooled engines and moves on to larger capacity multi cylinder automotive engines which are water cooled. There are advantages to making this leap in size and price.

A standby generator works by monitoring utility voltage and runs off of your home’s existing heating oil/diesel, LP or natural gas supply. When your electricity is interrupted, the generator detects the problem and goes to work.

The controller in the generator monitors incoming voltage through the automatic transfer switch (ATS).
When utility power is interrupted, the controller waits 10-20 seconds, then signals the generator to start. Within seconds, the ATS transfers to generator voltage.

The ATS does this by safely closing the utility line and simultaneously opening the power line from the generator. This will stop any “back feed” of power to the utility line of neighboring houses.

Within seconds the standby system begins supplying electricity to the circuits you have chosen to be powered by your generator. The controller continues to monitor the utility line in order to be ready to transfer back to utility power when it returns.

When the controller senses that utility line voltage has returned at a steady rate, it automatically transfers the electrical load back and resumes monitoring for another outage. The generator will continue to run for another minute to allow the engine to cool down.

Automatic Transfer Switches (ATS)
A standby generator uses a separate device called an Automatic Transfer Switch to connect the generator to your existing electrical system. Most standby generators are pre-packaged with a transfer switch.

Although the generator creates the power, the transfer switch is really the core of your generator system. It is an electrical panel that allows you to safely connect a generator to your home’s electrical circuits and is permanently installed near your main circuit breaker panel. It constantly monitors incoming utility power and determines when a true power outage is occurring, switching from utility power to emergency generator power and back again when utility power returns. Options include transfer switches that provide power to only essential circuits or every circuit for whole-house coverage. Some allow for prioritization of optional circuits or load shedding, such as heating and cooling.

Do not attempt to install a transfer switch yourself. Installation of transfer switches may require local permits – but it always requires a professional electrician. The model of transfer switch will depend mainly on the size of your generator.

Deciding on the correct size backup generator for your need is not an easy question to answer. Ask yourself how many things you’d like to operate during a power outage. Sizing can vary depending on if you’re looking to back up critical power needs (like a sump pump, fridge, basic lighting, and garage door) or your entire home Generac has a generator sizing calculator on their website that can give you a indication, based upon input.

Deciding on the correct size backup generator for your need is not an easy question to answer. Ask yourself how many things you’d like to operate during a power outage. Sizing can vary depending on if you’re looking to back up critical power needs (like a sump pump, fridge, basic lighting, and garage door) or your entire home Generac has a generator sizing calculator on their website that can give you a indication, based upon input.

You’ll want to contact a certified Generac dealer to have your generator installed. Your local dealer will go through a site survey and you’ll discuss scenarios for generator placement on your property that are in accordance with your local codes and ordinances. Ideally, you’ll select a spot that’s close to your home’s incoming gas and electric supply. Finally, your dealer will install the automatic transfer switch and will connect it to your generator.

Your local Generac Generators dealer is a great resource to help you find a standby generator that suits your needs, respond to any questions that you might have, and provide you with a quote customized to your situation.

A standby generator is installed outside your home as a permanent installation. Equipment cost depends on the amount of backup power you need. Installation cost varies depending on your situation. A generator, transfer switch, and installation by a licensed and certified dealers could likely cost between $5,000 – $10,000 total.