PTO Generator Question for PPOT Farmers/engineers

[Crowbob]

Say a 15 KW (16 Peak) PTO driven generator requires "at least a 30 HP tractor" to operate. Does this mean 30 HP at the PTO for the generator to operate at full load? I ask because I have a 23 HP tractor and am wondering if it will operate this generator if peak loads do not exceed say 10KW (my house with a well pump and electric water heater, lights. microwave)?

[red-beard]

Originally Posted by Crowbob

Say a 15 KW (16 Peak) PTO driven generator requires "at least a 30 HP tractor" to operate. Does this mean 30 HP at the PTO for the generator to operate at full load? I ask because I have a 23 HP tractor and am wondering if it will operate this generator if peak loads do not exceed say 10KW (my house with a well pump and electric water heater, lights. microwave)?

16 kW is a bit over 21.5 hp. Assuming 85% mechanical to electrical efficiency at maximum load you need about 25 hp. If you are not running peak load, it should work. But, you need to ensure that the pulley ratios are correct as well, so the generator runs the right speed.

[Crowbob]

Thanks, Red. The tractor manual says the PTO is estimated at 17.7 HP (13.2 KW). The gen. requires the standard 540 rpm which the tractor generates @ 3142 rpm.

So, at about 85% efficiency and a peak load of 10KW I'd still be well within the capacity of the tractor?

I can't imagine the well, elec. heater, microwave and a few lights would exceed 10KW. Even then, were I to operate the house off the gen, I could temporarily disable the water heater just to be safe, correct?

[Seahawk]

Originally Posted by Crowbob

Say a 15 KW (16 Peak) PTO driven generator requires "at least a 30 HP tractor" to operate. Does this mean 30 HP at the PTO for the generator to operate at full load? I ask because I have a 23 HP tractor and am wondering if it will operate this generator if peak loads do not exceed say 10KW (my house with a well pump and electric water heater, lights. microwave)?

I have a 1500kw Winco PTO generator that for peak load requires 30hp. I run it with my 23hp tractor. I also have a 35hp tractor but I prefer to use the small units.

I spent a lot of time talking with the Winco folks and the MF dealer before I bought it. Both said it would work fine at less than peak loads. When I had the house wired for the generator to "plug" into the house, I made sure that the maximum circuit load was 2/3's the peak KW, which runs pretty much everything other than the HVAC.

PM and I can go into the details. We average about 5 days without power every year so it has been a blessing.

[red-beard]

Originally Posted by Crowbob

Thanks, Red. The tractor manual says the PTO is estimated at 17.7 HP (13.2 KW). The gen. requires the standard 540 rpm which the tractor generates @ 3142 rpm.

So, at about 85% efficiency and a peak load of 10KW I'd still be well within the capacity of the tractor?

I can't imagine the well, elec. heater, microwave and a few lights would exceed 10KW. Even then, were I to operate the house off the gen, I could temporarily disable the water heater just to be safe, correct?

Again, the efficiency of the generator will be around 85-90% (check with the manufacturer). I think you'll be able to do about 11-12 kW peak.

Playing with the numbers for your PTO, scaling up for a 30hp and comparing that to the generator, I'm getting an efficiency of 87%, right in line with what I'm thinking.

If the generator is 220VAC, you might consider a 50 amp breaker from the generator. This will be both a good safety device (disconnect) and limit the power to your house from the unit.

[turbo6bar]

Originally Posted by Seahawk

I have a 1500kw Winco PTO generator that for peak load requires 30hp. I run it with my 23hp tractor. I also have a 35hp tractor but I prefer to use the small units.

1500 kW, eh?

Looks like bearded one has addressed your question, crowbob. I would like to add that you should not be afraid to run your tractor at PTO speed 24/7. The guys on tractorbynet say tractors can do this work day and night as long as it has clean fluid and air.

I was considering adding an overdrive to the finish mower, so I could run lower rpms and still keep blade tip speed up. Guys were saying I won't save much fuel running at lower rpms. The fuel consumption is related to load and not rpm.

[wdfifteen]

What kind of tractor is this? A "23 hp tractor" should have 23 horsepower at the PTO, since that is where the power is measured from in the official OECD ratings tests.

[Crowbob]

Kubota. The manual says PTO is estimated at 17.7 HP (13.2 kW). 540 rpm at 3142 engine rpm.