PTO Generator Question

Looking for a smaller back-up generator for outages and decided not to get a genset. The gas ones don't seem to last long and often don't start when needed, the diesels are out of my price range.

Decided to look at PTO generators, Northern tool has one that is 10kW. I have a Deere 5105 (50hp). To get 540 RPM from my PTO, the tractor needs to run at about 2300 RPM. My question is, if I don't need 10kW can I run the tractor at say half of that, 1200 RPM and get 5000 kW? I'd hate to have my tractor racing to produce extra power that I don't need.

Thanks

The simple answer is NO.

You need 60 cycles per second (or pretty close) for most AC motors
to work OK, and this is controlled by the generator speed.

Don't know if your tractor has a 1000 rpm PTO option - or build a
jackshaft on the generator frame to speed up the PTO by 2:1 so
you could operate at lower tractor engine speed.

You must run the tractor at PTO speed to produce 115 to 120 Volts. Running at 1/2 speed will burn out your refrigerator ,AC, freezer ,etc. It won't hurt the tractor to run at pto speed for an extended time .If it will you better get a better tractor . I ran my JD 2155 (50HP) for 5 1/2 days 2 winters ago 24-7 with no ill effects.

As the others said.. output frequency is controled by pto speed and the gear ratio on the genhead, and the number of poles. Sets made for 540 machines need to turn at 540 or thereabouts to make correct frequency power.

Also.. your machine -SHOULD- be able to run at pto speeds delivering full pto power for extended periods of time.. and if not.. get rid of it and get a real tractor.

soundguy

You are not saving anything unless your are running the generator for 1000+ hours per year.
As previously stated several times, run 540 rpm 60hz equipment at 540 rpm.
At the factory they inject electrical equipment with electricity and seal it in with insulation. Running 60hz equipment at half speed, 30Hz and reduced voltage. Will make the electricity leak out. Leaking electricity looks and smells like smoke .
A 540 adapter shaft on a 1000rpm pto and the engine operated at 1242rpm will work fine.

The only gensets that can be run at any RPMs and still make 60 Hertz AC power are DC units with built-in full-wave inverters. Plenty around for sale but pricey. Anything else must be run at one set RPM. And, when it comes to fuel efficiency, they all need to be load-matched to come anywhere close to being efficienct. So, a 10,000 watt generator will be terrible when run at a 1000 watt load, etc. The most efficient way to use a big generator for mixed loads is to have a battery bank, inverter, and genset. Then, only run the genset at full load for a short time to charge the battery bank when needed.

For the kind of part-time, ad hoc use you are looking for - seems like fuel efficiency isn't a big consideration. If you have NG or propane - why not just get a genset that runs on it? It will be less efficient then gas or diesel - but you won't have any long-term fuel-going-bad issues.

You can also get a PTO powered DC generator hooked to an inverter - and run it at any speed you'd like. This way, you get AC at 60 cycles at any speed or load.

I still prefer using a PTO AC generator when needed. I have several diesel tractors - and this way - I never have to worry about starting an engine that's sat for years. If I was shopping for another PTO generator - buying new would be the last thing I'd do. There are plenty of HD generators for sale from farms that have either gone under - or gotten larger and subsequently can't get by with a small 15-20KW generator. I come across many for under $1000. The 17KW unit I have was bought for $500.

It's all kind of moot point with my place now - since I've got solar electric and a huge stand-by battery bank.

Thank you all - I figured that it was like that. I'm not worried about the tractor handling it, just was hoping to save some wear & tear. That tractor is the one thing that has never let me down. It has plowed snow on our near vertical driveway on top of ice without a slip....

We don't have NG or propane now but I do have a 125 gal diesel tank. I think that I'll go for the PTO gen.

You are going to spend in the range of $1500 to $2500 on a PTO unit and probably regret it.As much as people actually use a generator you can buy a really nice quite honda or yamaha gas one that is very reliable, electric start and very user friendly. Also has resale value and the pto unit does not. People spend $2500 on a pto job and try to sell it on ebay 10 years later after using it 3 times for $600 bucks.

Not being able to crank after sitting for years is one reason I never bought a generator. Now I'm glad I bought a Honda for Katrina since it cranked 1st pull after Gustav 3 yrs later. I kept stabilizer in the gas and cranked it once every 4 or 5 months in between. It is very fuel efficient compared to others.

what size generator do you need. i got a coleman gen 6kw from lowes on sale cheap $600. its great. i can run all the nessacary stuff in my house. like any engine, it does need to be ran once a month to keep the system tested. i also have a gas valve on mine to keep the carb dry so it dont varnish up and i use a gas stabilizer. i have had it for 8 years now and runs great. it is there every time i need it. thought i dont get to use it much. but once a month i do attach it to the house.

2 options on tractor engine speed.
1. what we do- for our dual pto tractors- get a spline adaptor to run the 540 gen (actually 1800 rpm with a gearbox) on the 1000 spline, run the tractor at ~1200 rpms.
2. what my neighbor does- i think all his tractors have only 540 pto. so he built his generator trailer with multiple v-belt drive, 2 different stub shafts. so hook up to 1 side and run the tractor at rated rpm (for the smaller tractors or heavy load where you need the power) or move the shaft to the other side and run at slower speed- for big tractors or low load situations

generally, a generator is designed to run at either 1800 or 3600 rpms. depends on the number of poles. then a gearbox to match the 540 rpms from the pto.
an 1800 rpm unit generally costs more but will last longer. not much of an issue if you don't use it much.

Go to www.external_link & look at Tigerpower Generators. I have the 15 kw pto generator & wouldn't trade it for any other kind. We can run the whole house except the air conditioning with it. And the lights don't flicker, either.

I bought a 65 KW in June for our hog barns you need 2 horsepower for every 1 KW and figure it to cost $100 per KW on the price is what I found looked for a year for a good used one no luck you need to run the PTO one about every 3 months for 15 or 30 minutes or the magnets can go haywire is what they told me I hook it up every so often Mine is Tigerpower has reed yellow green light for speed on the cycles and digital read out on volts easy to operate