# Extension cords for 10000 watt generator?



## newtopreppin (Jul 25, 2021)

I was looking at generators that could run a full size window a/c and it seems you need one of the better portable generators, like in the 8-10k watt range.
My question is what kind of extension cord to use to. I see that most of the "good" ones at home depot will say something like "10 gauge/1875 watts outdoor cord"... if your running 6000 watts, dont you need a extension cord rated for that many watts? I dont even see anything like that. Anyone been running the more powerful items with the off the shelf cords? Thanks.....

actually, I think a big window a/c runs at like 1600 watts but needs about 5000 watts to start.


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## Demitri.14 (Nov 21, 2018)

What type of A/C is this ? Most A/C units run off of standard 15 or maybe 20 Amp service, That's only 1800 - 2400 Watts

House wiring would be 12 AWG. If that is the case then you should be safe with 10 AWG extension cord. The Wire size determins how much current you can draw before it starts to heat up and melt. The 5000W starting power is only a second or two so you don't need to consider that for the power cord. Length is also an issue. How long will it be ?


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## Back Pack Hack (Sep 15, 2016)

10 gauge/1875 watts is the 120 volt rating. 

If you're running a good-sized genny like 5000 watts and up, you're generally going to be using the 120/240 outlets. So, 240 volts pumping out 5000 watts is 20.833 amps. A 12-gauge cord will handle that for short periods of time, while a 10-gauge would be perfect.

Once you start getting into 7000w loads and up, Home Depot isn't going to have any cords for you. Towards that end, you're not going to just be plugging in one item at a time. You should be running through a proper transfer switch to power your main panel.


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## paraquack (Mar 1, 2013)

Check the A/C unit for the required wattage. That's the running wattage. Unfortunately it can take 3 to 3-1/2 time that to start the A/C unit. So, let's say the spec lable on the A/C says 5,000 watts. Once it's running, it uses the stated wattage, in this example, the 5,000 watts. But to start it ( the compressor), you need 15,000 to 17,500 watts. In case your A/C gives you amps instead of wattage, multiple the amps by the voltage to find the number of watts the A/C uses.
That said, I had a camping trailer that had a roof top A/C that would start and run from a 2,600 watt generator, because it had a 4,000 watt surge rating. Generators usually show a running watts and a surge watts. The start up of the A/C is the surge. When I moved up to a larger camper, it came with a bigger A/C. My 2,600 watt generator would simply bog down and stop running when I tried with the new camper's A/C. I had to buy a larger generator. I went to a 3,600 watt/ 5,000 (surge) generator. 
If you can find friends who have a generator, borrow it and see if it can start and run your A/C unit. BTW, let the generator warm up first and don't use the automatic idle feature, it may bog down when the A/C compressor tries to start. 
Extension cords are not recommended for window A/C units. If there is no other way, purchase an APPLIANCE extension cord. Keep it as short as possible. Distance is the enemy of electricity. Small wire is the other enemy. Go a minimum ONE SIZE LARGER, than needed to supply the required watts or amps to the A/C unit.
REMEMBER THE CARBON MONOXIDE DANGER. Lots of people in hurricane zones die every year from CO2 poisoning.
PLEASE POST THE SPECIFIED VOTAGE, and WATTAGE OR AMPERAGE of the A/C unit, if you want more info.
If you're really looking at a 8,000 to 10,000 watt generator, you might be better off having an electrician put in a transfer switch and feed the whole house. But you are talking $$$$.


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## 7515 (Aug 31, 2014)

I can not add anything to what has been already said - excellent advice 

BoF


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## AJustice (Aug 4, 2021)

I would suggest using a wire size calculator, it will help you figure out what wire size you need, as well as what the NEC code requires (if you care about that sort of nonsense).



http://www.paigewire.com/pumpWireCalc.aspx?AspxAutoDetectCookieSupport=1


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## newtopreppin (Jul 25, 2021)

i just got one of the better cords from home depot, it was a 75ft 10 ga outdoor 1850watt cable. Ive had this generator a while but only realized recently that I didnt have a good extension cord to use if something happned!!!! I got the wen 2250 watt inverter generator so far and a stanley beast that looks like a lawn mower motor that says it puts out 2500 watts., hope to get a more powerful one soon that will spike at least 8000 watts. Today I got a thing you plug into a wall outlet that lets you know how many watts something is pulling, this little window unit runs at 914 watts it seems, its a 120volt though. I think it would be a good idea to get a solar generator also so you can use it inside the house so that neighbors won't know you have one.


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## AJustice (Aug 4, 2021)

newtopreppin said:


> .... I think it would be a good idea to get a solar generator also so you can use it inside the house so that neighbors won't know you have one.


My neighbor has a gas generator and when the power goes out for a while, other neighbors show up looking to charge electronics. Nobody knows that I have a large, silent, battery system in our house, and nobody comes knocking.

You can also use excess generator power to charge batteries, then shut off the generator when the batteries get full so you don't have to run a noisy piece of equipment all day and night. 

You can build a LiFePO4 battery for incredibly cheap from raw cells. I made a 12 volt, 250 amp hour battery for under $500. If I bought a preassembled battery of that size, it would have easily been $1-2k.


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