economy PTO

[wagne223]

Right now I all have is a Honda 5kw gas generator, original cost $2,000. I bought a Honda (not just Honda powered) because ( at that time compared to others), it produced very clean AC. Many things in my house even my furnace, has electronic/ expensive controls, so I felt it was a worthwhile investment over a $500 unit.
Years ago it wasn't uncommon for me to loose power. A few times we were out for around a week. Things have improved and I have only lost power a few times in as many years for maybe 2-3 hours each.
Every year I drain the fuel and replace it with fresh stabilized fuel, run the machine under load and change the oil. The bottom line is that the generator doesn't really require maintenance, the engine that drives it does. This year the engine failed to start. Cleaning the carb solved the problem. I didn't get 100% reliability, even maintaining things the way I do.

My theory is this. With a PTO unit, it can sit covered up in the barn, with almost zero maintenance and still

While this is a great theory and one that a lot of people believe, it does not always work in practice.

In addition to prime mover maintenance, the generator head itself must be exercised. Sitting allows the brushes and armature contact's to corrode or seize, insect's to take up residence and in rare cases a weakening of the magnetic fields.

All this results in an inoperable generator when you need it most.

I exercise my gen sets at least every 4 months by running for 30 minutes with at least 25 percent load.

 

[Notforhire]

Would the amount of fuel used be based on both load and rpm? If so, then fuel used would depend on generator load, it should not require full HP the tractor is capable of making.

Do you know anyone with PTO generator you can borrow for a fuel usage test?

Actual run time is so little fuel usage won't be an issue. While on the subject of fuel, because my present generator burns gas, I store about 8 gal through the winter. I have a 50 gal diesel tank for the tractor.
I don't know anyone with a PTO genset.

 

[CobyRupert]

Sure bet that the generator itself (not its PTO input shaft or the tractor PTO spinning it) spins at either 3600 rpm (2 pole), 1800 rpm (4 pole), 1200 rpm (6 pole), or 900 rpm ( 8 pole) in order to develop 60 hz;
and there is gearing (maybe w/ chain drive) between the pto shaft from the tractor turning at 540 rpm and the generator's input shaft that needs to turn at one of the above mentioned generator rpms.

Example: 540 rpm (tractor) (through gearing) = 1800 rpm (gen.) = 60 hz

It's probably easiest to change the gearing at the input of the generator.

 

[Notforhire]

While this is a great theory and one that a lot of people believe, it does not always work in practice.

In addition to prime mover maintenance, the generator head itself must be exercised. Sitting allows the brushes and armature contact's to corrode or seize, insect's to take up residence and in rare cases a weakening of the magnetic fields.

All this results in an inoperable generator when you need it most.

I exercise my gen sets at least every 4 months by running for 30 minutes with at least 25 percent load.

Good point. I'm a big believer in Murphy's Law.
Both the generator I own and the one I'm contemplating buying, are brushless, but I agree creatures do tend to get into everything.

As I mentioned earlier I have done yearly maintenance on my present Honda unit (your 4 month program is probably better). I did have a failure to start this year. When I disassembled the carb, it looked clean, but must have been plugged up somewhere. I will mention that the generator is about twenty years old and that was the first time it failed.
I do believe that todays gas is the weak link here. I also considered changing the engine over to LP but I'm not sure if the reduction in HP would be a problem. Another thing I could do would be to have a new carb on hand. It can be changed out quickly and the cost is only about $65.

 

[wagne223]

Good point. I'm a big believer in Murphy's Law.
Both the generator I own and the one I'm contemplating buying, are brushless, but I agree creatures do tend to get into everything.

As I mentioned earlier I have done yearly maintenance on my present Honda unit (your 4 month program is probably better). I did have a failure to start this year. When I disassembled the carb, it looked clean, but must have been plugged up somewhere. I will mention that the generator is about twenty years old and that was the first time it failed.
I do believe that todays gas is the weak link here. I also considered changing the engine over to LP but I'm not sure if the reduction in HP would be a problem. Another thing I could do would be to have a new carb on hand. It can be changed out quickly and the cost is only about $65.

You are correct sir, I just wanted to advise on the gen head itself.
Happened to me years ago. Before I knew better. I maintained the engine but not the gen head.

I'm sure the brushless helps.

 

[Notforhire]

Sure bet that the generator itself (not its PTO input shaft or the tractor PTO spinning it) spins at either 3600 rpm (2 pole), 1800 rpm (4 pole), 1200 rpm (6 pole), or 900 rpm ( 8 pole) in order to develop 60 hz;
and there is gearing (maybe w/ chain drive) between the pto shaft from the tractor turning at 540 rpm and the generator's input shaft that needs to turn at one of the above mentioned generator rpms.

Example: 540 rpm (tractor) (through gearing) = 1800 rpm (gen.) = 60 hz

It's probably easiest to change the gearing at the input of the generator.

All the gen-sets I looked at were 2 pole.

 

[CobyRupert]

All the gen-sets I looked at were 2 pole.

Ok, 2 pole means 3600 rpm generator, so the gearbox at the front of the generator converts 540 rpm to 3600rpm; or is 6.66 to 1.

So (say) 2400 rpm (tractor engine) = 540 rpm (x6.66 gearbox) = 3600 rpm (genny) = 60 hz;
but you want to run tractor at (say) 1500 rpm, this means tractor pto rpm will be (540 x 1500/2400=) 337.5 rpm (pto). You still want 3600 rpm at genny, so your genny gearbox now has to be (3600/337.5=) 10.66 to 1.

 

[larboc]

Good point. I'm a big believer in Murphy's Law.
Both the generator I own and the one I'm contemplating buying, are brushless, but I agree creatures do tend to get into everything.

As I mentioned earlier I have done yearly maintenance on my present Honda unit (your 4 month program is probably better). I did have a failure to start this year. When I disassembled the carb, it looked clean, but must have been plugged up somewhere. I will mention that the generator is about twenty years old and that was the first time it failed.
I do believe that todays gas is the weak link here. I also considered changing the engine over to LP but I'm not sure if the reduction in HP would be a problem. Another thing I could do would be to have a new carb on hand. It can be changed out quickly and the cost is only about $65.

For what you're looking to spend on a new 10kw PTO genset, you could buy two complete 10kw gas gensets, to have one for a spare. You could buy a government surplus MEP-803 or similar for the same money and have a liquid cooled diesel genset ready to go anytime. I understand your point about not having one more engine to maintain, but I feel like the advantages of a standalone genset, hardwired into a transfer switch, that I don't have to hook up to the three-point, outweigh it for me. Just personal opinion and observation. If PTO gensets were cheaper I'd probably have a different opinion but right now, the 540-3600rpm gearbox on them is more expensive than a dedicated engine.

 

[Zebrafive]

For what you're looking to spend on a new 10kw PTO genset, you could buy two complete 10kw gas gensets, to have one for a spare. You could buy a government surplus MEP-803 or similar for the same money and have a liquid cooled diesel genset ready to go anytime. I understand your point about not having one more engine to maintain, but I feel like the advantages of a standalone genset, hardwired into a transfer switch, that I don't have to hook up to the three-point, outweigh it for me. Just personal opinion and observation. If PTO gensets were cheaper I'd probably have a different opinion but right now, the 540-3600rpm gearbox on them is more expensive than a dedicated engine.

Do you more info on the surplus generator you mentioned? MEP-803

 

[LouNY]

Quite a few PTO generators are 1800 rpm head units, and as far as being on a 3 pt most of the ones that I have seen have been trailer mounted, out of a few dozen I can only think of 2 that where 3 pt'ed.