Generator Interlock Kit vs. Automatic Transfer Switch: Which Fits Your Minnesota Home?
Every generator that powers your house through the electrical panel needs a way to keep it isolated from the utility grid — otherwise you risk backfeeding the line and putting a lineman working to restore power at real risk. There are two accepted ways to do that in Minnesota: an interlock kit or an automatic transfer switch. They solve the same safety problem in very different ways.
Interlock kits: manual, affordable, portable-generator friendly
An interlock kit is a small mechanical device installed on your panel that physically prevents the main breaker and the generator breaker from being on at the same time. When the power goes out, you shut off the main, start the generator outside, plug it into an inlet, and flip the generator breaker. It’s a manual process — a few minutes of work during an outage — and it’s the most affordable way to safely backfeed a panel with a portable generator.
Automatic transfer switches: hands-off, built for standby generators
An automatic transfer switch (ATS) monitors utility power continuously. When it senses an outage, it disconnects your panel from the grid and starts a standby generator automatically, often within seconds — no one has to be home. This is the standard setup for whole-home standby generators and the only option that will run your home unattended.
- Choose an interlock kit if: you have or plan to buy a portable generator, want the lower upfront cost, and don’t mind a manual step during an outage.
- Choose an ATS if: you’re installing a standby generator, travel often, or want essential circuits — sump pump, fridge, furnace — covered automatically whether you’re home or not.
Ready to add backup power the right way?
Three Rivers Electric installs both interlock kits and automatic transfer switches across the Twin Cities Metro, sized and permitted correctly for your panel and generator. QMerit-certified, licensed (EA761814), veteran-owned, 5.0★. Get a free quote or call 651-418-1476.
