I’ve had customers ask me if they can buy any generator without using a transfer switch. The answer is, it depends.
For example, you cannot use a standby generator without a generator transfer switch because it'd be like ordering an A/C system without the thermostat—nothing would work. On the other hand, portable generators don’t necessarily need a transfer switch to operate, but it would be more convenient and safer instead of running a bunch of extension cords.
Some of you might be asking: “What is a generator transfer switch?” or "What transfer switch do I need for my generator?"
In short, a generatortransfer switch acts as the brains of the generator and connects it to your home for direct power. Our guide explains how this works for both portable and standby generators and steers you to a wealth of additional information.
Connecting Portable Generators
There are three components used to hook up a portable generator with a home’s main breaker: a manual transfer switch, a power cord, and a power inlet box (in many cases).
The manual transfer switch's amperage should match that of the largest outlet of your portable generator. The power cord and power inlet box will also need to be matched to this amperage. That’s why we recommend buying all the components at once.
Manual Transfer Switch
A manual transfer switch lets you power select home circuits with one cord running from a portable generator to your main breaker panel, although sometimes a power inlet box is necessary.
In practice, this means you’ll be able to use whichever circuits the manual transfer switch is wired to during an outage, but you'll need to make up your mind at the time of installation.
Without a manual transfer switch, you would have to run multiple extension cords from your generator to indoor appliances. Also, you wouldn’t be able to backup systems like your furnace or A/C without a transfer switch because they are hardwired to your breaker panel.
If you get regular power outages, I highly recommend having your electrician install a manual generator transfer switch for easier power and convenience.
If you have an indoor manual transfer switch, you need some way to connect the power cord.
That’s where a generator power inlet box comes in. It sits on the side of your house and is hardwired to your manual transfer switch inside. During a blackout, you simply plug your generator into the inlet box with a power cord.
An outdoor transfer switch has the power inlet on the bottom because it's installed outside. In that case, a separate power inlet box is not necessary.
For greater flexibility in what you can power with a portable generator, consider getting a generator transfer panel.
Unlike a manual transfer switch, which is permanently hardwired to select circuits, a generator switch panel can power different circuits at different times because it's connected to your entire panel. So, if you want to power your kitchen and living room during the day but switch to powering your bedrooms at night, you can easily do so.
Just like with an indoor transfer switch, you need a power inlet box to connect your generator with a transfer panel.
Connecting Standby Generators
If you buy a home standby generator, then you need a transfer switch without exception.
Automatic Transfer Switch
Standby generators don’t work with a manual transfer switch. You need an automatic transfer switch, which links your generator with your home.
An automatic transfer switch constantly monitors the power coming into your home from the utility. When a blackout happens, it automatically switches your home to standby power without any manual effort on your part.