Wire size for 55' distance from a generator to house?

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drabina

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I have a small portable generator (2200W / 120V). It is only used for emergencies (heat and lights in the winter and fridge and lights in the summertime) when the power goes out (which thankfully doesn't happen very often). I would like to wire a small manual transfer switch (up to four circuits) but my electrical panel is about 55 feet from an exterior wall where the generator will be running. What wire size should I go with? I have about 50 feet of wire to run inside the house and I am adding about 5 feet for the extension cord between the generator and the outlet in the wall.
 

Sparky617

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Ohms law would say your generator puts out 18 amps. I = p/e (I= current, P=watts, e=voltage) 12/2 would be sufficient for this small generator.
 

Snoonyb

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Although it's not mentioned, are we to assume you have a transfer switch, or that you are intending to install separate circuitry to accommodate the transfer?
 

drabina

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Although it's not mentioned, are we to assume you have a transfer switch, or that you are intending to install separate circuitry to accommodate the transfer?
Yes, I will have a manual transfer switch (I did mention that in my original inquiry). The switch will only have 4 circuits as I really need to just run fridge and heat.
 

kok328

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Ohms law would say your generator puts out 18 amps. I = p/e (I= current, P=watts, e=voltage) 12/2 would be sufficient for this small generator.
1200Watts/120Volts=18.33Amps. #12 is good for 20Amps but, I like a 10% buffer and would personally run 10/2 due to the amperage not necessarily the length of run. Also allows for a larger generator down the line.
 

Snoonyb

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Yes I saw the "manual transfer switch", and I should have questioned, why not an automatic, to protect the equipment?
 

drabina

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Yes I saw the "manual transfer switch", and I should have questioned, why not an automatic, to protect the equipment?
I have a small portable generator which I have to take out of the garage, start and connect to the outlet in the outside wall. I don't think automatic switch would be worth for that.
 

bud16415

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Hopefully your house is wired to suit the idea of a 4 switch transfer without back feeding other circuits around the house.



I have thought about doing this same kind of thing here as I really can’t justify a unit just for backup for the house but something small enough to use for other things as well seems like a plan. I have been thinking what I would like to have on for an extended outage. Furnace, fridge, freezer, microwave, internet, maybe a couple LED bulbs, kitchen TV, Laptop, Cell charger, etc

Thing is they all wouldn’t need to all work at the same time.



Kind of wonder if a combination of switching and extension cords and some new outlets that are dedicated to the gen.

I would also most likely go heavy on the wire gage for future proofing for a larger unit. Wire is expensive but labor is also.
 

drabina

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My small generator puts out 2300W of constant power (2500W peak). I haven't done any calculations but it should run refrigerator and heat (furnace) which is gas and needs little power for the electronics and igniter. With a four circuit transfer switch I will still have two circuits to use for any lights I may need.

As to the other items like lights, TV, internet, etc, I am fine with not having them for a day or two. Those are the days when the whole family gathers together in one room and plays board games under a battery powered light.

I will run the wire myself but you are right, may as well go with a higher gauge.
 

Jeff Handy

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Your puny generator makes no sense, you can get 4000, 5000, 6000 watts for such good prices nowadays.
Cheaper than replacing spoiled food, frozen pipes, etc.
You need to be able to run multiple things at once.
Juggling plugs and cords gets very old, very fast.
Sump pumps, microwaves, small air conditioner, hair dryer, would take up the entire capacity of your little generator.
Bigger is better, in your wire gauge AND generator.
Keep that little one for backup, or rent it to the neighbor who comes begging for power at every outage.
 

drabina

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Your puny generator makes no sense, you can get 4000, 5000, 6000 watts for such good prices nowadays.
Cheaper than replacing spoiled food, frozen pipes, etc.
You need to be able to run multiple things at once.
Juggling plugs and cords gets very old, very fast.
Sump pumps, microwaves, small air conditioner, hair dryer, would take up the entire capacity of your little generator.
Bigger is better, in your wire gauge AND generator.
Keep that little one for backup, or rent it to the neighbor who comes begging for power at every outage.
I do not have sump pump or a microwave. No need for a hair dryer or "multiple things at once" for the few hours the power goes out once a year. I am also not going to be juggling extension cords or wires if I have the transfer switch all setup. I did have a big generator and to be honest, it was pain in the neck to get it out of the garage so I have never used it. Sold it, bought the portable one and at least I am using it. Pipes won't freeze if I have heat on the generator. Really I do not see why bigger is better for my application.
 

Hamberg

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I'm with @kok328 on this one, 10/2/3 minimum, also assuming you are using NM copper and not AU.

(again, we are assuming you have gas/oil heat) It's the heat circuit, on start-up, that would worry me, especially if the other 3 circuits are loaded. May even consider upgrading the wire to 75°C or 90°.
 

Eddie_T

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@drabina I agree with your analysis. It's both quieter and more economical to run a generator sized for your needs. I have a 5000 watt just because I need 240v for a well pump. When I replace it I am going to try a 3500 watt unit and use an auto transformer to get 240v.

A 3500 watt unit would also be more mobile and maybe I could get it into my woods so I could use my electric chainsaw.
 
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