Generators, sizes and fuel options?

[ning]

My well - ¾hp pump 160' down - required all other loads to be disconnected from my 3.5kW generator, and then it was still a 50/50 chance that it would pop the generator's breaker on pump start-up; I think if you're expecting to rub other things at the same time as the well pump start, 5kW may be small.

Remember also that initially everything is likely to try to start together, but you don't have to let this be the case. When we used that 3.5kW generator I would first turn on the well, flush necessary toilets, wait a minute or two, then connect the other loads.

 

[Sawyer Rob]

I can get away with a small generator because I have an artesian well,

It's the same water we have for the house, so I can go out and get a pail for flushing the toilet, or get some for cooking or just drinking.

Once you get past that big load, you really don't need a big genset for lights ect... My little Honda inverter generator can easily take care of those small loads, it's quiet and doesn't burn much fuel at all.

SR

 

[stumblinhorse]

My well - ¾hp pump 160' down - required all other loads to be disconnected from my 3.5kW generator, and then it was still a 50/50 chance that it would pop the generator's breaker on pump start-up; I think if you're expecting to rub other things at the same time as the well pump start, 5kW may be small.

Remember also that initially everything is likely to try to start together, but you don't have to let this be the case. When we used that 3.5kW generator I would first turn on the well, flush necessary toilets, wait a minute or two, then connect the other loads.

Hmm, I don’t have my 20 amp breaker popping normally for my well pump so 6000 should be fine I would think.

I would think your non generator breaker would pop sometimes if you‘re pulling that much…

 

[crashz]

Minus my well, I was able to run nearly everything off of my Harbor Freight 3500Watt inverter generator. That was a fridge (not freezer or second fridge), furnace, pellet stove, a few lights and the TV at times. Left on Eco -Idle, it only sounded like it was working when all of the items were running at once.

That little genny ran from Friday the 22nd in the afternoon to early Christmas morning without a break. Was quiet enough even on our front steps, and used maybe 5 gallons of gas. The thing ran beautifully.

The only "problems" are that if I'm not home, my wife has no way to connect and get it running. Second big one is that I cannot run the well on this system.

 

[ning]

Hmm, I don’t have my 20 amp breaker popping normally for my well pump so 6000 should be fine I would think.

I would think your non generator breaker would pop sometimes if you‘re pulling that much…

Are you sure it's on a 20A? Mine is a 30A.

Pulled this off the web, 240V @ 20A is 4800W. This question is probably pretty dependent on the specific equipment.

 

[stumblinhorse]

Are you sure it's on a 20A? Mine is a 30A.

Pulled this off the web, 240V @ 20A is 4800W. This question is probably pretty dependent on the specific equipment.
View attachment 777933

Yes, definitely a 20 amp double. A 240/20 amp breaker is supposed to be 80% of the 4800w, that is the 3800 number I put. Maybe because mine is 3 wire single phase? But here is another chart.

 

[Hoss710]

Also you need to take into consideration the size wire and the length of the run .

 

[stumblinhorse]

This is why I started this thread. It seems to be voodoo to figure out the wattage you need. Many people have 4k units and then the other crowd says you need 10k. I pulled the trigger on a 6250 inverter. We’ll see if it works I guess.

 

[newbury]

Many people have 4k units and then the other crowd says you need 10k

And then compound that with:
Are the 4K and 10K running 4K, 10K? or PEAK 4K 10K??
What fuel is the rating for?
Are they running a soft start device?
From my readings a 4K rated running with a soft start in the loop may beat a 10K PEAK w/o soft start.
And what elevation? Temperature?

 

[ponytug]

This is why I started this thread. It seems to be voodoo to figure out the wattage you need. Many people have 4k units and then the other crowd says you need 10k. I pulled the trigger on a 6250 inverter. We’ll see if it works I guess.

And then compound that with:
Are the 4K and 10K running 4K, 10K? or PEAK 4K 10K??
What fuel is the rating for?
Are they running a soft start device?
From my readings a 4K rated running with a soft start in the loop may beat a 10K PEAK w/o soft start.
And what elevation? Temperature?

I think that perhaps a reason for the "voodoo" aspects, is different motors have very different peak currents, and different generator models can have extremely different abilities to handle the peak draw of a motor starting that gets into the details of the generator bull, windings, insulation, and its control circuitry. There is also the detail of "do you want to be able to start your well once, ten times, or five times a day for a year, or for twenty years"? You get the picture.

I think well pumps are amongst the most demanding motors to start because the have a head of water on top of the pump that the motor is attached. A relative has a well pump that is 700' down, that's over 300psi. So in her case it isn't so much that the motor is a 3HP, it is the back pressure on the pump.

Net result: I think that you get a lot of folks saying "Hey, I can/can't do it with my XXXXwatt generator...." both can be true.

One of my engines is used in over the road trucking where the recommended rebuild time is 500,000 miles, or fifteen thousand hours, which ever comes first. The marine use is rated at a full rebuild in 1,000. The marine engine is tuned up to double the horsepower...

All the best,

Peter