Choosing the Right Transfer Switch for Your Briggs & Stratton Generator (Three Scenarios, One Critical Mistake to Avoid)

No single 'right' transfer switch setup exists. Depends entirely on your situation.

If you're installing a briggs-stratton-generator, you'll quickly find out the transfer switch decision isn't one-size-fits-all. It took me three years and about 15 installations (and one embarrassing 12-hour outage in my own home) to understand that.

Here are the three most common scenarios I see—and what actually works for each. I'll also tell you what I'd do today, after making every mistake in the book (literally: I maintain our team's checklist now).

Scenario 1: The whole-home standby install (the 'comfort' setup)

This is what most people picture: a 12kW or larger standby unit (like the briggs and stratton 12kw generator), automatic transfer switch (ATS), installed by a licensed electrician. You want it to kick on automatically when the power goes out. Simple, right?

Well, here's the thing. In 2022, I watched a customer pay $3,200 for a 'standard' ATS install with a 12kW Briggs & Stratton. The electrician used a 50-amp rated switch. The generator could output a maximum of 52.5 amps on natural gas. One amp over, and that switch would trip under full load. They discovered this during the first real outage in September 2022. The homeowner had to manually shed loads.

What works: For a 12kW unit, do not cheap out on the switch. Go 60-amp or higher. The time_certainty of that extra capacity is worth the roughly $150–250 premium. (We paid $400 extra for rush delivery on a 60-amp switch in March 2024. The alternative was missing a $15,000 event. Best money spent that month.)

Also, plan for the time_certainty of the install itself. A standard install takes 2–3 days. An expedited one? Double the labor cost. But if you're facing hurricane season, that's cheap insurance.

Scenario 2: The limited-circuit, hard-wired manual setup (the 'budget but reliable' setup)

This is what I'd recommend for most people. You get a manual transfer switch (like the Reliance Controls or similar), hard-wire it to a few critical circuits (fridge, well pump, furnace, a few lights), and connect it to your portable generator. It's cheaper than ATS, and it's very reliable.

Here's a mistake I made in my first year (2017): I ordered a standard 30-amp inlet box and assumed my local electrician knew exactly which circuits to hook up. He did the whole panel—which overloaded the 30-amp limit when the well pump kicked on and the fridge compressor started simultaneously. (Ugh.) The cost? $890 in redo plus a 1-week delay.

What I do now: Create a pre-check list. I sit with the homeowner and list every circuit. We calculate the draw of each in watts. It's tedious, but I've never had a second failure. The checklist caught 47 potential errors in the past 18 months—that's 47 blown fuses or tripped breakers avoided.

And yes, this is the scenario where you absolutely need to know how to transfer switch data to switch 2 —i.e., how to map your loads from the main panel to the transfer switch sub-panel. Get the manufacturer's wiring diagram (most are available online), and don't trust your memory. Write it down.

Scenario 3: The 'just need power for the essentials' cord-and-plug setup (the weekend warrior)

This is for people with a smaller portable generator (3,000–7,000 watts). You use extension cords to plug in a fridge, a phone charger, a lamp. No transfer switch. The risk here is back-feeding your house circuit, which can kill a lineman.

Warning: Do not do this without a proper interlock kit or a manual transfer switch. Period.

Most people think they can just use a generator cord and a double-male adapter. That's the classic rookie mistake. It's illegal and deadly. I've seen it happen. The consequence isn't just a fine—it's a life.

What I recommend: A simple interlock kit (costs about $50–80 in parts if you're handy, or $200 installed). No, it's not as nice as a full manual transfer switch. But it buys you time_certainty on safety. If you can't afford the manual switch, the interlock kit is the minimum viable option. Don't skip it.

I should add that this scenario also covers the odd-ball requests. Like looking up an air filter for a Kia Optima or a fuel filter for a JCB machine—I often get calls from people who think a generator is just 'plug and play' like a car engine. It's not. And neither is the transfer switch. (Should mention: I also had a customer ask me about a carburetor for a newer generator once. That's a whole other story.)

How to decide which scenario fits you

Here's a quick self-diagnostic that I use with my clients. It takes about 10 minutes.

1. What's your budget? If it's under $500 for the switch and install, you're in Scenario 3 (interlock kit). If $1,000–2,000, Scenario 2. Over $2,500? Scenario 1.
2. What's your risk tolerance? If you can handle a 15-minute manual shutdown during a week-long outage, Scenario 2 or 3 works fine. If you need automatic recovery (you're elderly, have medical equipment, or travel a lot), Scenario 1 is the only real option.
3. What's your timeline? For a Hurricane appointment that's coming in 2 weeks, skip the ATS install (it'll take 6–8 weeks in peak season). Go with a manual switch. The time_certainty of a guaranteed install before the storm is worth more than the convenience of automation.

I made the mistake of going for the 'ideal' setup in a time crunch. Don't be me. Choose the scenario that works for your situation, not your fantasy.

Oh, and one more thing: how to transfer switch data to switch 2 —that's a manual process. Write down the circuit numbers for the old panel and the new transfer switch. Take a photo. Trust me on that one. (I once had to re-do an entire mapping because I'd used 'memory'—cost me a Saturday and a headache.)

Good luck. And check your fuel filter, too. (JCB filter? Get the OEM part. A generic one caused a 3-day production delay for a customer of mine.)