I'm looking to setup an option for long-term power outages. Our house was built in the 70s and the circuit layout is nowhere near logical enough to be able to say "these 3 circuits need emergency power". Instead, I'd like to run a standalone circuit with about 8 receptacles on it (4 for critical appliances, 4 for lights/chargers).

By standalone, I mean it won't be connected to the grid or breaker box in any way. It would connect to the 8 receptacle boxes, and have a cord in the garage that I could plug into an inverter connected to our Leaf. If I need emergency power, I connect the inverter and move the required plugs from their normal receptacle to the emergency receptacle.

I know this probably isn't a code-approved setup, but is this a horrible idea for some reason I'm not thinking of? I plan to turn off the main breaker whenever this is in use just to be absolutely sure there's no chance of backfeeding the grid, but this would be very hard to do since the entire circuit is separate.

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  • Pretty sure you would have to use a completely separate panel for this. I don't see how you could have it in your main panel and not have it connected in some dangerous way to the utility grid.
    – TylerH
    Feb 18 '21 at 17:20
  • Most appliances usually use almost 15 amps plus a 15 amp lamp/charger circuit you are looking at almost 75 amps if everything on at a time. Would look into feeding the leaf power to a new box/panel and run four or five circuits off of that.
    – crip659
    Feb 18 '21 at 17:23
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    @TylerH think he was thinking of running one cable with outlets from the leaf, not to the panel, basically a separate system from house power.
    – crip659
    Feb 18 '21 at 17:27
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    Added a picture for clarity. @crip659 is right - it's completely separate. "Circuit" is somewhat a misnomer since it doesn't touch the panel.
    – Drew
    Feb 18 '21 at 17:29
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    Yes! Let's talk interlock. Tell us as much as you can about your service panel, and let's see if there's a way to interlock it. Because that would make this comically easy. Feb 18 '21 at 19:21

Drew there are panels that will do exactly what you want. They use the existing wiring and have a limited number of circuits. These manual transfer of 1/2 dozen or more circuits is really expensive. See generac, reliance 6 circuit transfer switches. These systems cost in the range of 350.00-450.00 I have seen them used with a 2kw generator.

Old school lightbulbs that is 200 not just 1. The house I am thinking of ran there gas furnace. Lighting they needed and refrigerator. When they wanted to run the well they turned off the refrigerator circuit and turned on the well pump.

So it can be done even using your existing wiring. I would suggest a generator interlock kit this locks out your main breaker while turning on the breaker to feed the home from another source whatever it is. You turn off all the circuit breakers you don’t need or cannot power with the new source. A lot cheaper and works similarly for under 100$.

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    Plus if you used an interlocked gas generator you wouldn't risk beaching your Leaf or arriving home needing a charge and having no power available for your secondary system. Feb 18 '21 at 18:21
  • He is using an 1800 watt inverter.
    – crip659
    Feb 18 '21 at 18:29
  • @NoSparksPlease The interlock really doesn't care if it's fed from a smoke belching generator or a Nissan Leaf. Also the smoke matters - go look at fatality counts after natural disasters, very often, the #1 killer is inexperienced people misusing generators. As far as "beaching" the Leaf, you may be underestimating the size of EV battery packs. Feb 18 '21 at 19:30
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    I would strongly favor the last option (sliding-plate generator interlock) rather than the first one (6-8-10 circuit transfer switch). Those old transfer switches have serious issues with MWBCs and irreconcilable issues with AFCI and GFCI (as in, they don't provide it on generator, which is a codevio). Feb 18 '21 at 19:46

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