Can I use a typical 120V extension cord with one end cut off to hard-wire a power inverter & plug it into an outlet?

I bought a 12VDC to 120VAC power inverter and some batteries for a small backup power reserve. It's a Magnum CSW2012-X, if you're wondering.

This inverter has an automatic transfer switch that switches between shore and battery power, but it needs to be hard-wired to shore power to do so.

What I'm wondering is whether it would be possible to just cut the female end off of (say) a 10-gauge, 3-prong, 120V extension cord, strip the wires, connect that end to the inverter, and then just plug the male end into a 120V outlet?

Assuming I connect the right wires to the right slots, wouldn't that effectively be the same as hard-wiring it?

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6 Answers

  • Sky
    Lv 7
    12 months ago
    Favourite answer

    If you're talking about using the inverter as a UPS, where the cord is being installed to supply power (ie. "shore power") when the power is on, but then instantly switch to backup battery power if the power goes out to keep your computer or whatever else running, then yes, you can do that provided you don't overload the circuit. If you're plugging it into a 15 amp outlet, don't have more than 15 amps worth of stuff plugged into it; with a 20 amp outlet, the limit is 20 amps worth of stuff.

    If you're talking about putting a cord on the output side of the inverter so that when the power goes out you can plug it into an outlet to backfeed power into your house outlet and power some of the circuits in the house from the inverter, that *can* be done but you have some major limitations and critical steps to follow. First, you'd have to go to the circuit panel and shut off the main breaker to the house. That will separate the house from the power grid so you won't be generating dangerous voltages on the grid through the transformer that could hurt a power company lineman working on the lines. It will also prevent the inverter from being blown up when the power comes back on and tries cramming voltage back into the output. Second, whatever outlet you'd plug that into is on a circuit breaker connected to a main bus that runs half the breakers in your house. But that one outlet is rated for a maximum of 15 amps (most typically) and the romex cable in the wall is rated for a maximum of 15 amps, and the circuit breaker it's on is a maximum of 15 amps. So everything being used on every circuit of that half of the house circuit panel couldn't exceed 15 amps (or again, 20 amps if it happens to be a 20 amp circuit). You'd just be better off using the inverter as it's intended and only running things you can plug into it directly, or better yet get a whole house generator installed.

  • 12 months ago

    Yes and no. The gauge needs to be calculated for the power draw over distance. The inverter is 2000w/115-120v=17 amps +/-. Assuming the shore breaker is 20 amps, 10 gauge wire will carry 115V at 17 amps about 140'. As most extension cords are no more than 100' you're fine.

  • David
    Lv 5
    12 months ago

    Yes you can. Make sure it's a 3 wire grounded plug cord.

  • Anonymous
    12 months ago

    10 Gauge is rated 30 Amp, if your load is less than that, you should be fine. Are you planning to charge your batteries from shore power?

    I would change that setup a little. I would cut of the male end and connect the wires to the inverter and tie the male end somewhere convenient, outside the van. Maybe have the plug inside a box so it does not get dirty or wet. Then buy another male pug and put that on the longer cord, in effect replacing the male plug on the cord. So you can store the cord(s) out of the way when not in use.

    Or if you are not worried about stealth and want to do it right, install a proper plug on the outside of the van, most boating places and even amazon will have them listed.

    Just be careful stripping the wires, the wires can break under the stress of the constant vibrations when traveling, You might even want to use different wires for that on the inside of the van. (Cut them a little longer than need be, so you can reuse the same wires at least temporarily if the ends fray and keep the strain of the connections.)

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  • Snezzy
    Lv 7
    12 months ago

    "Shore"?? I gather, then, that you are talking about supplying 120 volt power to a boat? In that case you are possibly correct.

    If there is no boat then you might be trying to do something dangerous or stupid.

    It's a bit hard to tell what you are doing. The view from my planet is a slightly foggy.

    PS: Boats I've seen have used 12 volt onboard, or have used "armstrong" for everything.

  • 12 months ago

    I am sure that you would lose a little power (as heat), but it would work fine.

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