Transfer Switch for Portable Generators

  • Generac IQ 2000 Generator
  • Transcript

    LESLIE: Well, when power outages strike without warning, they’re unavoidable, indiscriminant and more than a little inconvenient. When the electricity is out, it only takes a few hours for food to spoil and your home to turn bitterly cold in the winter or uncomfortably hot in the summer.

    TOM: And that’s why portable generators have become almost an essential household appliance. Now, one downfall of a portable generator is having to string extension cords throughout the house to use it. The good news is that there’s a way to increase the versatility of portable generators. And here to tell us all about that is Scott Caron, the electrical contractor on TV’s This Old House.

    Welcome, Scott.

    SCOTT: Thanks for having me. Boy, it’s nice to be here.

    I’ll tell you, those cords are a pain in the neck. What happens normally, you have a portable generator, you roll it out of the garage, you start it up and then you look around where to plug it in. There’s no place to plug it in. So you run cords through windows in the houses, you run them through your garage. It’s just a mess and it’s not safe.

    LESLIE: Alright. But there’s got to be a solution, so what can we do to get rid of those cords?

    SCOTT: There is, Leslie. The correct way to do it is a transfer switch. Now, this transfer switch with a portable generator has to be manual. That’s really the only way you can do it.

    TOM: So that means you have to actually plug the generator into the portable transfer switch. But all the other circuits that you’re feeding off of it can be connected directly to that transfer switch as if it was, say, a mini circuit-breaker panel?

    SCOTT: That’s one way of doing it is they have a 6-circuit, 10-circuit, 12-circuit little transfer switch. And you’re able to switch these circuits manually so that if you want 1 or all 12 of them on at the same time, you can do it. And it does the exact same thing as an automatic one. It isolates the utility power from the generator power so that there’s no cross-contamination. You can’t send it one way and they can’t get it back the other way.

    TOM: So is a transfer switch really meant, Scott, then to power every circuit in the house?

    SCOTT: Not with the portable ones. With the automatic ones – with a full-house standby generator, they do a really good job of covering almost anything. And you know what? With the right amount of money, you can buy a generator big enough to power any size home. But with these portable ones, you need to pick the circuits very carefully. So if you want your refrigerator on or your heat or a sump pump or a well, then that circuit is tied directly to that manual switch on that transfer switch.

    LESLIE: Now, what about grounding? I don’t think people really think, when you’re using a portable generator, that you have to ground to things that you’re connecting to it.

    SCOTT: It is often overlooked. The ground in the electrical panel inside your house usually covers what needs to happen. It’s tied into the water meter, it’s tied into the neutral. However, the secondary ground needs to be tied to a great ground source.

    Now, if you have a copper water pipe in your home that you can get to easily with a wire or copper wire, we recommend that. Or you could drive a copper ground rod out by wherever the generator is going. But you need an earth ground for any sort of a fault that would happen.

    TOM: And of course, we can’t talk about portable generators without having a cautionary note about the issue of carbon-monoxide poisoning. It happens every winter, sometimes more than once, when folks run these generators in enclosed spaces, including even open garages where the doors are open. That combustion gas can get into the house pretty easily, right?

    SCOTT: It’s not a good thing. What happens is they’ll roll the generator out of the garage, open the garage a little bit, and they’ll start the generator up. What happens? The carbon monoxide just drafts right back into the house and it just creates a really toxic situation.

    TOM: So always use that generator outside and of course, always, always, always have a carbon-monoxide detector in your home.

    Scott Caron, the electrical contractor from TV’s This Old House, great advice. Thank you so much for stopping by The Money Pit.

    SCOTT: You bet. It was good to be here.

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