First, the rule that explains everything
You can never connect a generator to your house in a way that could push power back out to the utility lines. This is called backfeeding— it can electrocute the line crew working to restore your power, it's illegal everywhere, and the "suicide cord" (male-to-male plug into a dryer outlet) you may find on YouTube is exactly as dangerous as its nickname. Every legitimate connection method exists to make backfeeding physically impossible.
Option 1: Manual transfer switch — the guided experience
A small sub-panel mounts beside your main panel. An electrician moves your 6–10 most important circuits into it. During an outage, you plug the generator into an outdoor inlet, then flip each circuit from LINE to GEN. The switch physically isolates generator power from the grid — backfeeding is impossible by design.
- ▸Best for: most homes; the per-circuit toggles and wattmeters make overload nearly impossible.
- ▸Cost: $300–$450 for a kit like the Reliance 306CRK, plus $300–$500 install.
- ▸Limit: only the chosen circuits are available — choose wisely (furnace, well, fridge, freezer, kitchen lights, one bedroom).
Option 2: Interlock kit — the whole-panel hack (the legal one)
A sliding steel plate on your main panel makes it mechanically impossible to turn on the generator's backfeed breaker unless the main breaker is off. Every circuit in the house becomes available; you are responsible for not overloading the generator by managing which breakers are on.
- ▸Best for: bigger generators (7,500W+) and owners comfortable doing load math.
- ▸Cost: $50–$150 for the kit + breaker, similar electrician labor. The Generac HomeLink is the polished 50A version of this idea.
- ▸Caution: the kit must be listed for your exact panel model to pass inspection — check the panel label before ordering.
Option 3: Automatic transfer switch — standby only
Standby generators use a 100–200A automatic switch that monitors utility power, starts the generator, and transfers the whole panel in about 10 seconds, unattended. It's part of every standby installation — not something you add to a portable.
The two parts everyone forgets
- ▸Power inlet box — the weatherproof outdoor socket the generator cord plugs into, wired to your switch. ~$70 for a 30A PB30.
- ▸Generator cord — a real 10 AWG (30A) or 6 AWG (50A) locking cord, 25 ft so the generator sits a safe distance from the house. ~$90 for a quality 30A cord.
What the electrician visit looks like
Two to four hours: mount the switch or interlock, wire it to the panel, mount the inlet box outside, pull a permit if your jurisdiction requires one (most do, and you want it — it documents the work for insurance). Have your generator on hand for the test run. Typical all-in labor: $300–$800.
Ready to pick hardware? Start with our transfer switch & install gear picks.