Connecting a Portable Generator to Your House

Portable generators offer the promise of making an extended power outage tolerable, allowing us to continue to use many of the devices we need to stay connected and comfortable. But for many, a portable generator isn’t enough to do the job on its own. That’s because generators can’t plug into electrical panels – and can’t power household systems or electrical outlets – without a little help.

Household electrical systems are designed and equipped to receive electricity from just one source: the utility line. Systems are designed to allow electricity to flow into the home, but not out of it. Connecting an additional power source to a home, such as a portable generator, isn’t part of that design. When a generator introduces electricity into the system, where it can travel backwards up a utility line.

Maybe you’re wondering: Why can’t utility lines handle electricity from a small generator? After all, they’re able to provide power to entire neighborhoods. The answer again lies in the design. Transformers are designed to convert high voltages into much lower voltages that homes can use. When electricity runs in reverse, transformers run in reverse, too: They turn low portable generator voltage into high voltage.

With this in mind, it’s easy to understand why connecting a portable generator to a home without proper safeguards is a major violation of electrical code. In order to connect a generator to a home, you need to start by hiring a licensed electrician.

Generally speaking, your electrician will present you with two options: Connecting your generator through a transfer switch or an interlock kit. Both options keep generator power from running out of your home and into utility lines where they can cause harm. Both prohibit your system from connecting to the utility line and the generator at the same time.

Both transfer switches or an interlock kits have their advantages. Transfer switches require somewhat longer installation times, but offer slightly more ease of operation. Interlock kits take less time to install (which costs less), but require slightly more time to transfer from generator to utility power or back again. The right choice for you depends on your budget, and how often you expect to lose power.

If you like the idea of powering your home (and not just your devices) during an outage, you can do it. Just be sure to contract an electrician to establish a safe connection between your generator and your home.