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Jun 29

What Is A Generator Transfer Switch?

By: Patti Dinneen


Power outages are unpredictable, can occur at any moment and have the possibility to last for a prolonged periods of time. Any home or business owner that has endured a power outage, especially one that lasted more than a few hours, has good reason for installing a generator to avoid repeating the experience.

Transfer switches are an integral part of all back-up generator systems. Typically, a "transfer switch" is designed to supply power to an electrical circuit from multiple power sources. A transfer switch is necessary in order to isolate the generator from the utility system when you install a back-up generator to your facility/home's wiring system. Transfer switches are absolutely necessary; it is illegal to connect a standby generator directly to any point of the electrical wiring without a transfer switch, because of the possibility of "back-feeding." Back-feeding occurs when electricity runs backward out of the house and through the utility transformer.

Main Types of Transfer Switches

Manual transfer switches are hardwired to your control panel and are used in conjunction with portable or standby generators. As their name suggests, manual switches must be manually turned on and off when the electricity goes out or comes back on. This can become an issue if you aren’t home, or your business is closed during the outage. The switch is wired to essential circuits in your home/business, such as lights or furnace blowers that can’t be run with an extension cord.

Automatic transfer switches are a safer and more effective alternative to manual transfer switches. Automatic transfer switches automatically turn the generator on and switch power to it when a drop in line voltage is detected. When the line power is restored they transfer power back to the utility and turn the generator off. Typically an automatic transfer switch is a great option for businesses. They offer the flexibility of being used with a portable generator (as long as the generator has an electric starter) but are most often paired a permanently installed automatic standby generator.

Transfer Switches For Residential Applications

As we mentioned before, a generator transfer switch is responsible for closing off the utility power line to your home during a power outage and opening a line to the generator. Transfer switches are permanently hard-wired to and installed near the breaker panel in your home, effectively solving any back-feeding issues. Many local state laws require that a transfer switch is installed by a licensed electrician, so it is wise to be sure to check local electrical codes before attempting to install one yourself.

Transfer Switches For Industrial Applications

For industrial and commercial generators, you’ll need an industrial transfer switch. These switches are designed to handle various voltages and are sized appropriately for each generator. The switches for industrial generators usually have a wide range of features including automatic excising, changeable start and stop delay times, changeable cool down times and other features. Transfer switches are available fused and with breakers. There are devices available that allow using more than one generator at a time, such as high end controllers and switchgear. They allow switching between multiple generators, optimizing loads and providing additional redundancy.

Do I Need An Automatic Transfer Switch (ATS)?

Unless you have an existing transfer switch, it is essential to purchase one for your generator system. The large majority of the generators Kinsley Power sells are coupled with an ATS. The remaining projects have equipment provided elsewhere to perform the same function. The automatic transfer switches that we sell are designed to detect any power outage and automatically start your generator, and will exercise the unit on a weekly basis. The exerciser can be set to do so at an appropriate time consistently each week.

It is absolutely essential that your emergency power system run once a week, under load if possible, to ensure that your generator is operational during an outage. If you're away on vacation and your house loses power, your generator will automatically turn on and potentially keep pipes from freezing and pumps working.


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