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john hoffman 10-26-2009 18:57:17 67.236.89.71 250768 Report to Moderator	Wondering how you like a tractor driven generator if you have used one for a while. I would need about 25kw and would like to use the 1000 pto to drive it at 540 so I dont have to listen to a roaring tractor. Tractor is an 85 hp diesel. Also have a 50 hp gas tractor with 540 pto for a back up. [Reply]   [No Email]
Mazemeister 10-27-2009 18:23:45 24.188.81.230 250869 Report to Moderator	Re: PTO Driven Generator in reply to john hoffman, 10-26-2009 18:57:17   we have a 25kw 1800 rpm gen. geared to run on 540 pto. usually we'll run it with the 806D running the 1000 pto at half speed. not disagreeing with the others, just sayin that's what we do and it seems to work so far. sometimes that's a pretty good load since we've got 3 houses and the barn wired together on the backup system, but the 806 has a good governor and i've never seen it max out the generator. only problem comes in when you try to start several large motors all at once.   [Reply]   [No Email]
john hoffman 10-28-2009 19:25:19 67.236.78.91 250969 Report to Moderator	Re: PTO Driven Generator in reply to Mazemeister, 10-27-2009 18:23:45   Thanks a lot for all the ideas. We have a house, pumps, out bldgs but no hi-hp motors to start so nothing coming on should trip a generator off. This is for whole farm back up when REMC power gos down - probably have to do some load sheding to get it on line but should be fine after that. Hadnt thought out the 1800/3600 generator speeds but expect the 1800 is the long life choice. Getting a 540 gen. would allow the big tractor to run at higher power just by switching ptos if its needed. I have checked the hp/torque curves for the Diesel and at 1/2 speed its making a lot of rated power. Thanks again.   [Reply]   [No Email]
RodInNS 10-27-2009 19:17:16 216.118.158.123 250874 Report to Moderator	Re: PTO Driven Generator in reply to Mazemeister, 10-27-2009 18:23:45   When you max out the generator, you'll find the problem... We run a 25 KVA and it makes a 50 hp tractor snort. The 70 and more get along fine but I wouldn't want to try it at idle speed with a 1000 shaft. It's a pretty basic torque calculation. If you take the engine speed that the tractor must run at, then figure out what torque the engine is making at that speed, you can quickly figure out what power it's making. It would also generally be below it's peak torque so it's not likely to have much response... Rod   [Reply]   [Send Email]
VaTom 10-28-2009 06:35:35 216.12.124.38 250897 Report to Moderator	Re: PTO Driven Generator in reply to RodInNS, 10-27-2009 19:17:16   Rod, all depends on the load. I sometimes run my 25KW generator off my 1000 PTO, and that's from only a 25 hp tractor. Nice and quiet. When my load's heavier, I use the 540 rpm/high engine rpm. I can't draw 25KW with the small tractor, but never been a problem. Mostly it powers a 12 hp planer and 5 hp chip blower, not on 1000 PTO, and started sequentially. Mazemeister has the right idea: if it works, use it. I've got a substantial mismatch between tractor and generator, no problem. Generator was ridiculously cheap, so I bought it. Suits my needs.   [Reply]   [No Email]
RodInNS 10-28-2009 10:22:25 216.118.158.123 250916 Report to Moderator	Re: PTO Driven Generator in reply to VaTom, 10-28-2009 06:35:35   The point is... that with an 85 HP tractor and a fully loaded generator, it won't work unless the generator is overspeeded. Most 85 HP tractors will produce mabey 40 hp at a fast idle, which is where it would need to run for 540 with a 1000 shaft. The 806 might do it OK because it's a 95 horse tractor that in all probability made more anyway without accounting for the smoke screw getting backed out about 20 percent... so couple that with a generator not fully loaded and you get away with it. The fact that you can do anything with a 25 HP tractor on a 25KVA gen tells me you had no laod on it at all. I sometimes run ours on a 45 hp tractor for light loads of short duration and it works it hard. The 50 hp can handle it at full power but it's working very hard. We generally stick our 86 HP rated (turned to 105 hp) for long hauls. Start a 4 horse compressor with some other loads on the go and it wakes her up too. She's not working hard but the sudden load will make her jump. If that was at idle speed she'd be down for the count. Rod   [Reply]   [Send Email]
VaTom 10-28-2009 11:25:04 216.12.124.38 250920 Report to Moderator	Re: PTO Driven Generator in reply to RodInNS, 10-28-2009 10:22:25   OK Rod, if you call my industrial planer and chip blower "no load at all"... They remove 3/16" off a 24" oak board in one pass. No idea what your problem was with 45 hp, but something's amiss. You apparently weren't getting much PTO hp. I'm generating 17KW, with a Mitsubishi compact. Yes, running hard- without complaining. Been happy with it for over a decade. The planer's loud enough, the tractor isn't a problem. If I needed 25KW, I'd need a slightly larger tractor. Or a 540 rpm hydraulic motor to run off one of my Cats. Bought one a few years ago, haven't bothered to plumb it. When I need portable power it's usually small enough tools that I can get by with 1000 rpm PTO. A lot closer to that "no load" you were talking about. My PTO generator came already on a trailer, very convenient. There really are a lot of options available. Depends on what one has and how much load. Strikes me as unusual that anyone would always need the maximum 25KW. Maybe you do. Certainly the guy I bought mine from, who was using a 45 hp tractor, didn't. He sold it only because neither he nor his "electrician" could figure out which legs wouldn't blow up his expensive cash registers, even though there was a sign just over the plugs identifying what voltage you get on which plugs, color-coded. A $3 voltmeter would have sufficed. Otherwise, it powered his commercial coolers fine. That load varied a lot. They went to single phase and were happy. As am I.   [Reply]   [No Email]
RodInNS 10-28-2009 15:01:11 216.118.158.123 250935 Report to Moderator	Re: PTO Driven Generator in reply to VaTom, 10-28-2009 11:25:04   We draw the absolute maximum from our 25KVA when we use it. That's 100 amps/250V. We should have a 50 KVA for proper backup to allow normal motor starting instead of having to do sequential starts all the time and shutting half the farm off. When you add up a 4 horse compressor, a pair of 1/2 horse fan motors, 2-1/2 horse pump motor, and various other resistive loads that add up to the 100 amp mark or very close to it. It's often the well pump cutting in that trips the breaker on us if I forget to shut it off. That 25KVA electrical load is equivelant to 37 hp load. If you figuered a drive efficiency of 85%, a fairly typical figure in many drive systems.... That puts you at 43 HP required to drive that 25KVA... so yes, that's pucking my 45 horse pretty hard considering the tractor probably doesn't make quite that power at 540. The 52 HP might, but it's still running at full power. I'm not saying that our generator is highly efficient. It's an 1800 RPM, model MAGNATE MKII made by N.J. Fromnet. Rod   [Reply]   [Send Email]
VaTom 10-28-2009 18:45:53 216.12.124.38 250964 Report to Moderator	Re: PTO Driven Generator in reply to RodInNS, 10-28-2009 15:01:11   Yeah, Rod. I was wondering if there was something less than my Winpower's efficiency with your generator. Not that I think Winpower's necessarily the answer, but this one's working well here with my small tractor. My load is determined by both motor specs and my induction ammeter, which agree. I'm getting 68% of my generator's rated output with 25 hp, which would lead me to expect full power at well under your less-than-successful 45 hp. My Mitsubishi seems to do well at full power, don't know about others. Well, my Cats do the same. I doubt that my 20 yr old Mitsubishi is putting out more than its rated hp. Good little tractors, but far from great. Today I had my hoe attachment on, worked very well. In fact, I recently had the cheap opportunity to keep a Case 580 hoe I sold for a client, didn't take it. My only other uses for PTO are the generator and splitting a couple cords of hardwoods/yr. My compressor's larger than yours, submersible well pump smaller. Mostly, I need to power large 3 phase machinery, like my planer/chip blower. Awhile back I was looking for a considerably larger farm tractor, 80-90 hp. Not for the PTO, but to avoid tearing up my Mitsubishi (again). Then I bumped into industrial loaders, which nobody much values here. Ended up with a 3 yd 4-in-1 bucket Cat which was the answer to my dreams, except for no PTO. Took no time at all for me to forget about a larger farm tractor. As I mentioned, lots of choices out there. Just a matter of selecting the correct one for the individual situation.   [Reply]   [No Email]
Mike M 10-28-2009 18:51:31 72.251.100.24 250967 Report to Moderator	Re: PTO Driven Generator in reply to VaTom, 10-28-2009 18:45:53   Our suposed 18hp JD 750 puts out 24 or 25 on the dyno. So they can be better then rated for.   [Reply]   [No Email]
VaTom 10-29-2009 03:29:03 216.12.124.38 250990 Report to Moderator	Re: PTO Driven Generator in reply to Mike M, 10-28-2009 18:51:31   That's interesting Mike, thank you. We are talking PTO? Yours is a green Yanmar?   [Reply]   [No Email]
Mike M 10-27-2009 16:25:58 72.251.100.149 250856 Report to Moderator	Re: PTO Driven Generator in reply to john hoffman, 10-26-2009 18:57:17   Get one that runs at 3600 RPM from a 540 shaft and uses gears to do it. Then you won't be able to hear the engine over the gear noise !   [Reply]   [No Email]
Bob Bancroft 10-26-2009 22:29:00 72.173.160.50 250783 Report to Moderator	Re: PTO Driven Generator in reply to john hoffman, 10-26-2009 18:57:17   Have to agree with the others. My 60 HP tractor will start a 10HP motor when used on 540 rpm. 4020 running slow to accomodate the 1000rpm shaft WON'T do it. 40 hp tractor @540 won't do it either!   [Reply]   [Send Email]
JMS/.MN 10-26-2009 21:21:51 209.237.107.155 250782 Report to Moderator	Re: PTO Driven Generator in reply to john hoffman, 10-26-2009 18:57:17   I"ve had a Winpower 25/45 kw since 1977- works fine on a D17 (53hp), or the 3020 (70hp). 3020 is more responsive when the 10 hp motors kick in.   [Reply]   [No Email]
buickanddeere 10-26-2009 19:52:56 216.183.152.225 250776 Report to Moderator	Re: PTO Driven Generator in reply to john hoffman, 10-26-2009 18:57:17   I agree with rodinNS. A 25KW generator uses no less than 38HP under full load and that leave no starting reserve. An 85HP diesel depending on design and if natural aspirated or forced induction. It won't carry the generator. There problems with long term pounding a diesel at max torque load when below it's torque peak. I can see the idea if running 24/7 for months at a time in some circumstances. For nights when only 1 to 10KW load exists with a fridge, freezer, sell pump, sump pump, water heater etc but........ Then again you will burn less fuel running even a gasser 6500W unit at nights. vs the 85HP diesel running at 5-10HP demand. It's a good idea but not practical in any way, shape or form. For the typical outages of 1 to 10 days a year.   [Reply]   [No Email]
RodInNS 10-26-2009 19:26:06 216.118.158.123 250772 Report to Moderator	Re: PTO Driven Generator in reply to john hoffman, 10-26-2009 18:57:17   Run it at 540 on a 540 shaft. Don't use the 1000 shaft at half speed. An 85 HP tractor will not have the torque reserve to hang onto that generator at idle speed if you start a motor or have some other heavy laod start. It just doesn't have the power and it won't save you much fuel anyway. If you have a european type tractor that has the 540E pto (750) rpm, that might be a viable option, but not 1000. If you don't like the noise, get a longer power cable and park it farther away... Rod   [Reply]   [Send Email]