While connecting a generator to a home’s electrical system is a job for a licensed electrician, it’s good for any homeowner to have a basic idea of what is required, to understand the what and why.

Every home has an electrical panel – the hub through which electricity is distributed throughout your home. Normally, utility power enters through the electrical panel, which then distributes power to the individual circuits on your home. In turn, these circuits provide power to systems or areas in your home. While electrical panels are designed to receive energy from utility lines, most are not equipped to receive power from generators.

So, before a panel can safely receive power, a licensed electrician will have some work to do. Here’s what an electrician will need to install in order to connect your generator to your electrical panel:

Power inlet

The device serves as the generator’s connection to the home; it’s placed on the exterior of your home, usually close to the generator. The generator will connect to the inlet via extension cord; in turn, the generator power inlet will connect to the electrical panel via wiring on the inside of the home.

(While a generator power inlet may look like a typical household power outlet, it isn’t one. Do not consider connecting your generator to a standard outlet.)

Breakers

A new generator breaker on the electrical panel will serve as its connection to the power inlet; this breaker will regulate the power traveling from (and to) the generator. Most panels have enough space to accommodate another breaker; if more spaces are needed, a piggyback breaker can be used. (Think of the piggyback as another version of an outlet expansion you might use when you need another outlet in your home.)

Interlocks/transfer switches

As mentioned above, homes are designed to receive and distribute energy from utility lines. Utility lines are not designed to receive power from homes, or from the generators attached to them; if power travels in reverse up a power line, it’s called backfeed. Backfeed can place equipment, property, and even life in jeopardy.

Interlocks and transfer switches prohibit power from traveling from a generator, through an electrical panel, and up a utility line; they also prohibit power from a utility line from traveling into a generator, which can also can damage.

Both interlocks and transfer switches ensure that electrical panel can’t connect to both the generator and utility line at the same time. In the event of an outage, a homeowner will switch the panel’s connection from the utility line to the generator; when power is restored, the connection can be switched back.

Hopefully now you understand both the means and the importance of properly connecting a generator to a home’s electrical system. While this task is straightforward for a professional, it shouldn’t be attempted by anyone other than a licensed electrician.