# Questions on maximum recommended portable generator



## whynotme (Nov 23, 2020)

Hi everyone, first time poster here. I'm confused on what size generator I really need. I currently have a Generac GP5000 and can transfer power to the house through an Interlock I had installed a few years back. I don't feel like 5k is enough watts to do what I want, which is to power the well pump for water, the gas furnace, the fridge and a few lights and other small items at the same time. Last time we lost power, the generator just wasn't enough to power the well pump, furnace and fridge at the same time. I'd like to get something like a Westinghouse 12000/9500 unit, but am concerned that the generator cord and interlock have some kind of max wattage rating for them. Does it make sense to buy a big unit like that, or am I wasting money on watts I can't use?


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## tabora (Sep 6, 2018)

If your current cord, etc. uses an L14-30 plug, you're limited to 30Amps. Your generator inlet breaker should also reflect this. The interlock is the same for 30A or 50A breakers.

To use more, you'll need to upgrade to a straight 14-50 plug, cord and 50A breaker, which will get you the full 50 Amps = up to 12000W.








NEMA 14-50


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## iowagold (Jan 22, 2020)

whynotme said:


> Hi everyone, first time poster here. I'm confused on what size generator I really need. I currently have a Generac GP5000 and can transfer power to the house through an Interlock I had installed a few years back. I don't feel like 5k is enough watts to do what I want, which is to power the well pump for water, the gas furnace, the fridge and a few lights and other small items at the same time. Last time we lost power, the generator just wasn't enough to power the well pump, furnace and fridge at the same time. I'd like to get something like a Westinghouse 12000/9500 unit, but am concerned that the generator cord and interlock have some kind of max wattage rating for them. Does it make sense to buy a big unit like that, or am I wasting money on watts I can't use?


hey why not, 
snap a few pix of your setup.
breaker, inlet, inlet cord with numbers on the cord.

if you have a larger inlet setup you can use a smaller gen set for when you do not need a lot of power..
then swap out the generators to a larger generator for when you need the BIG power like summer time for hvac.

I had found i only need less than 1800 watts in the winter time..
that is with everything on!

do you have meters on your current system yet?
take a look at this page
click here for the generator connection page
that meter setup works for the grid as well as the on gen set power.
cool as you can see exactly what you are using live right now power.

yea well pumps can suck a lot of power...
if you have not changed it in the last 20 years have it checked to see if the later models draw less power.
some of the new units draw way less power.
watch the brands etc. and shop for a good one for your application.

make sure you are all led in the house, smart power strips help on power drain..
and check to see if a micro air soft start would work on your well pump.
depending if it is a external suction jet pump it might work to lower the in rush!
they sure work good on the air con units.


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## whynotme (Nov 23, 2020)

tabora said:


> If your current cord, etc. uses an L14-30 plug, you're limited to 30Amps. Your generator inlet breaker should also reflect this. The interlock is the same for 30A or 50A breakers.
> 
> To use more, you'll need to upgrade to a straight 14-50 plug, cord and 50A breaker, which will get you the full 50 Amps = up to 12000W.
> 
> ...


Thanks for the information! My cord and inlet box all say 30A, so I guess I'm limited to how much power I can put through the connection. I would either need to upgrade the cord/inlet to 50A by hiring an electrician or just making due with a 7500W generator. All the generators I'm considering have a 50A outlet, so that's not an issue. Now, off to the phone to call and get some estimates on getting a 50A inlet and cord.


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## whynotme (Nov 23, 2020)

iowagold said:


> hey why not,
> snap a few pix of your setup.
> breaker, inlet, inlet cord with numbers on the cord.
> 
> ...


I don't have any meters other than the standard electricity meter outside. If the estimate to upgrade to 50A inlet and cord is too much, I'll just stick with a 7500-8k watt generator since that's all I can put through my existing 30A setup.

I am all LED in the house, so that's not a big issue. I just want to run water, heat and fridge at the same time. I would think 7500 watts will do the trick, but I'm just always in favor of going big, so that's why I was considering a 12000/9500 watt generator.


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## tabora (Sep 6, 2018)

whynotme said:


> I am all LED in the house, so that's not a big issue. I just want to run water, heat and fridge at the same time. I would think 7500 watts will do the trick, but I'm just always in favor of going big, so that's why I was considering a 12000/9500 watt generator.


We have a 6000/7500W PowerMate and it does the whole house except the kitchen range, dryer and secondary water heater with plenty of wattage left over.


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## whynotme (Nov 23, 2020)

So I guess my only remaining question is what is the maximum wattage generator I should get if I only have a 30A twistlock inlet and breaker?


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## motormonkey (Jul 10, 2016)

30 amps times 240 volts equals 7200 watts.

That will run a well pump, a gas furnace, a refrigerator, some lights and misc. appliances, and even a water heater, just not all at the same time. It's not too difficult to Install a couple of current meters on your genny line and allocate power to those loads as needed.


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## whynotme (Nov 23, 2020)

motormonkey said:


> 30 amps times 240 volts equals 7200 watts.
> 
> That will run a well pump, a gas furnace, a refrigerator, some lights and misc. appliances, and even a water heater, just not all at the same time. It's not too difficult to Install a couple of current meters on your genny line and allocate power to those loads as needed.


Thanks, that's reassuring. I suppose I'll get the 9500/7500 unit I've had my eye on and just run the 30A setup. Fortunately, all of my appliances run on gas, so I don't have a huge electric load for furnace, stove, water heater. All propane. Which now makes me wonder if I should get a dual-fuel unit and somehow get it connected to my household underground propane tank.


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## motormonkey (Jul 10, 2016)

Dual fuel, or even a generator exclusively for use with LP gas, is an excellent idea. None of the usual hassles with gasoline going stale and fouling up your fuel system. Your local gas company should be able to help you plumb it into your tank.


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## Bluwolf (Nov 8, 2020)

I would definitely go dual fuel. I have one. I've only run propane in it so far, and will try not to run gas. Some day I might have to run gas ( I have 5 - 5 gallon cans). But in the mean time I'm not gumming up the carburetor. If you have a propane line you're in great shape. There are a bunch of dual fuels out there. This is the one I have. it's pretty much the size you were thinking about.






7500-Watt Dual Fuel Generator - Champion Power Equipment


Powering Your Life




www.championpowerequipment.com


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## tabora (Sep 6, 2018)

whynotme said:


> Which now makes me wonder if I should get a dual-fuel unit and somehow get it connected to my household underground propane tank.


Just remember that a 7500/9500W generator on gasoline becomes a 6750/8550W generator on propane.


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## iowagold (Jan 22, 2020)

if you had a larger gen set and it had a 30 amp twistlock and 30 amp breaker on it you could use it with the system you have now.
just remember that the breaker will trip if you pull over the 7200 watts.

and yes a larger gen works well on the well pumps.


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## PLX (Nov 22, 2020)

I'm running a Powermate 5000 watt 20amp, it runs my 220 well pump, furnace, sump, freezer & kitchen fridge without any issues. These all do not run at the same time, naturally. I'm surprised what you have now is not sufficient. Have you had the genny tested to make sure it's putting out the amount of power is rated for? Just a thought.


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## whynotme (Nov 23, 2020)

PLX said:


> I'm running a Powermate 5000 watt 20amp, it runs my 220 well pump, furnace, sump, freezer & kitchen fridge without any issues. These all do not run at the same time, naturally. I'm surprised what you have now is not sufficient. Have you had the genny tested to make sure it's putting out the amount of power is rated for? Just a thought.


I just want more power! I need MORE!


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## drmerdp (Apr 10, 2018)

When it come to power. More is More! The problem lies with big thirsty units and storing gasoline. NG and large LPG tanks for the win.


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## whynotme (Nov 23, 2020)

drmerdp said:


> When it come to power. More is More! The problem lies with big thirsty units and storing gasoline. NG and large LPG tanks for the win.


Yeah, I can't wait until my plumber hooks me up to the house propane!


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## iowagold (Jan 22, 2020)

you can always get a smaller gen for when you need less power...
and use it as a spare just in case...
you never know when a gen might fail during a real hard run... like severe heat runs....
yea NG is a cool option where i live..
but in some areas you take what you can get for fuels...
get on an lp plan...
you can buy a block of fuel on the cheap on an annual contract.
and look in to another tank for the future... 1000 would be an ok number..
that might get you 26 days.. or longer if you are careful on your run times..

and be thinking of ways to quiet box the gen.


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