PTO Generator Recommendations

[Bookman]

I have an all electric house without even a fireplace. I do have a couple of generators. One is small 5,000 watt Coleman and then I have an older Winpower 6,000/10,000 watt pto powered one. The 6,000 continuous power is pretty modest for my needs. Therefore, I am thinking of upgrading.

When I look self contained backup ones at 20kw, they look to run over $10,000, plus the propane tank purchase/rental and annual inspections/maintenance

Now I have two tractors with roughly 35 horsepower at the drawbar . A Farmall 340 and a Farmall Super H bored out to be the horsepower of a Farmall 300. I am looking at a Winco PTO generator that produces 15kw (model 99840-004) at both surge and continuous power and is single phase. It runs about $2,000.

I have a cart with the older pto unit, which I will try to sell and keep the cart. Or, I may install the new unit on the fast hitch carrier I have with some adapting for the pto.

I have my power usage from my power supplier. My peak usage usually is between 7.2 to 11.7 kw, but on rare occasions it has peaked at 18.4. I do not know if at the peak if we had the oven and dryer working and electric heaters on in my shop all going in cold weather. Last February with -30 weather in our area, the peak was 15 kw. Will a 15 kw meet my needs if I am careful about usage? It is just for backup in emergencies.

Also, should I install a Murphy switch on my tractors? If so, any idea as to how much they are and how hard they are to install.

Lots of questions and probably some I do not know enough to ask, but I am just not wanting to spend money needlessly, and I want to still end up being happy with the results. Thanks in advance for any advice.

 

[Gibby]

I have a 25KW PTO based generator - It requires a 50 HP at the PTO tractor - so roughly 60 ponies to work at fully capacity. I thought it would be the best solution until I ran it for 10 days on a JD 855
(compact) . It would run for 3.5 hours until it needed a refill... Then comes the governor issues. Older tractors are not responsive enough for good clean power under varying loads. For example my Farmall 300
would sag to 55 hz for several seconds - 460 was a little better but wandered north of 62 hz every one in a while. Granted they were 55 + years old. The 855 was much more steady. I finally got what I was
looking for out of a New Holland 4835.. But I now have standalone units at both houses, I picked both of them up for around 4k - old telco units being swapped out due to age - 202 and 321 hours respectfully -
Ebay. Much happier - good clean power - heavy industrial units. They get their yearly oil change and in better shape than me. The only part I have any issue finding is the mechanical governors - they are
available but really expensive. So I bought an electronic one up as a spare - hooked it up as a test and it was awesome. Very good response - very clean power. So If the mechanical one ever dies, the spare is
on the shelf.

 

[leroy in ne]

For thought and checkout with those that know. I once was told 750 watts equals 1 electrical horse power so 15,000 watts divided by 750 equals 20 electrical horse power.
And every electric HP requires 2 mechanical horsepower of to drive generator so about 40 HP power takeoff rating of your tractor or 40 HP continous rating of an engine
driven unit. Right or wrong I don't know but hope John T and others in the electrical know chime in. Leroy

 

[buickanddeere]

25Kw will cover unbalanced loads . A 20Kw load can be carried with an absolute minimum of 30 PTO HP .

 

[jCarroll]

Will your PTO generator be kept in a building with an electric door opener?
Does your gasoline supply have an electric pump? hand pump? Do you have transfer cans?

 

[Russ from MN]

All electric door openers I have ever worked on have a manual release, but on the big ones you have to pull a chain to open the door.

 

[Determined]

Regarding the Murphy switches

Requirements;

-Oil pressure sensor
-Coolant temperature sensor
-Switching box

If the tractor is a diesel with a mechanical shut down you would also need to add a fuel control solenoid.

Simple system, engine gets too hot or oil pressure gets too low
the engine will shut down.

If you wanted to save some money you could get creative and just install an oil pressure and coolant temp switch (not sensor) wired to a Bosch relay controlling power to the ignition coil and a momentary pushbutton to override the oil pressure switch for starting.

 

[Handsome Devil]

Interesting discussion for me. I bought an older Allis Chalmers 3 ph 14 KW pto generator. I works on my 460/560 IH tractors but you want to start them slowly as the gen gives a work out at top working RPM. You could spin the gen if not careful. For long term power outage I think a commercial Gen set maybe the best answer even with the cost. Mine I bought for temporary power when I absolutely need it. Summer time running reboot fridge/freezer and boost hot water heater and then shut down? Winter for running well system. I have wood heat back up and cook stove. For me 14 KW is overkill for what I would really need. But the gas consumption would be a killer as both my IH tractors when working are not economical. If bad things happen gas stations may not be open or an option. Storing gasoline if your set up is an option but normally storing gasoline is a pain and concern. A fuel efficient gen set maybe a better option even if more expensive? In my case I can usually take care of my needs. If your all electric like OP and want continuous power for extended periods I am not sure PTO gen is the way to go. For reasons already mentioned. LP gen set would be my first choice if I was concerned long term power outage which is very possible for all of us. If your in a heat wave like many of us have been I would miss my AC to keep life bearable. In my case the AC would be put on hold. With a commercial Gen set up properly it might remain an option? My real concern is water. If you have animals you need water and you and the family do too. Both will work, but if one can afford it I think a commercial back up gen set with enough KW to satisfy ones needs is the way to go?

I was offered a nearly new condition Get Set from a local nursing home I worked at. Test run monthly and very seldom ever used. It was powered by Natural Gas and converting to LP would of been a breeze. But that too would of sucked fuel/LP for any kind of extended running. Plenty of KW for my needs and then some. I often think about that or others that are routinely available. Resale on used Gen Sets like this is in the buyers favor. Industry does not normally buy used generators so it is farms and homeowners who are more likely to consider a monster gen set. I think the options are geared to what your perceived needs are going to be? In my case I liked the 3 ph in case I need to operate my shop I can always knock one leg out of the equation and feed my house or other parts of my shop which only require single phase. Reality is I can probably get by with a fairly small generator and my perceptions of covering all my bases is way over kill. But we all have specific needs?

Interesting topic. Regards, John.

 

[Gene Davis (Ga.)]

A 15 Kw set will probably handle the load with some power management. There needs to be a reserve amount for when
you have something that requires a heavy starting load and remember that electric resistance heat is a very heavy
draw on any power supply. Water heaters and stoves are a big load also. If your electric heat is going full blast along with
lights and other everyday things and say your well pump kicks in will there be enough power to start it or will it
burn up the pump motor because it doesn't have enough voltage to bring it up to speed. There are some good buys
in the larger Kw generators if you look. You cannot have too much power available at those times. Fuel efficiency is not a real big concern when the lights go out and it is cold. The best time to buy one is when everything is going good and there have
not been any power outages for a while.
I bought a 1996 year model 20 Kw Onan with the automatic transfer switch
set up for LP gas with only 408 hrs on it. Most of which were recorded and documented test hours from an electric coop because
they replaced them every 10 years no matter how few hours on them for $2500 I installed it myself all but the
final connection as that had to be certified by a qualified electrician to cover the insurance requirements. I did
change the supply regulator on it to use it with Nat.Gas. I lost a little capacity using Nat. Gas but the convenience of a steady supply is worth the slight loss of capacity. It is very nice to know that I don't have to refuel the old 8 Kw
unit I had every several times a 24 hr day in good or bad weather. There is a lot to be said for having it set up on a
permanent mounting pad and ready to go on short notice instead of having to go drag the trailer mounted genset to
the house, connect it to the transfer switch and get it all going in the bad weather if raining or whatever.
I did not use the auto transfer switch in my set up because I already had a transfer switch in the main
line and it was a 200 amp unit where the one with the genset was only 125 amp. It only takes about 3 minutes to
have power going with this unit and it works really nice.

 

[buickanddeere]

Depending on the time of year, time of day and what loads are being used . We either use the 5500W gasser or the 30Kw PTO and one of the tractors. Usually the 435 JD .

 

[Bookman]

I assume you do not put a full load on your 30kw generator since a John Deere 435 is roughly about a 30 horsepower tractor

 

[Bookman]

Thanks for the information. I talked with a person with my power supplier, and he is concerned about the start up load of my geothermal heat pump. The running load is 12.1 amps, but the start up load is 85 amps. He recommended I talk with an electrician about my kw needs. I suppose I could shut off the heat pump and just use several space heaters, but that would defeat partially the purpose of having a larger backup generator. The other issue is the age of my tractors. One is a 1953 Super H bored out to be the horsepower of a Farmall 300. The other is a Farmall 340 Both have about 35 pto horsepower, which I think is enough for a 15kw pto generator, but another poster expressed concern about the steadiness of the governors in these old tractors with resulting variation in the hz. Thanks much.

 

[Bookman]

Thanks. Both my tractors are older but about 35 horsepower, which is less than your 460/560. I could watch for a used stand alone unit. I suspect one has to be in the right place at the right time to get
one, but never know. Thanks

 

[Bookman]

Great information. Thanks

 

[Bookman]

One end of my pole building has a large door with an opener on it. It, like most garage doors of which I know, can be opened manually. It is a challenge, but doable. The door at the other end is manual and I can get the unit out through it if need be. Yes I have transfer cans. I probably only keep enough gas for a couple of days running, with probably not running it full time, and I could drain gas out of other tractors if need be...so might last 4 or 5 days in a pinch without getting more gas. If situation really bad, I probably would run it enough just to keep pipes from freezing and preserve food in refrigerator. Never know what can happen, but a bad tornado, for example, probably would carry away or damage any generator I might have.

 

[Bookman]

The recommendations run from to 2 to 2.5 horsepower per kw. I have no experience in testing the limits. My 35 horsepower tractors might run a 20kw generator or slightly larger, but probably not a full
capacity. What are folks' experiences with tractor horsepower and generator kw size? Thanks

 

[Bookman]

I think you are very close to being right on regarding your calculations. One Internet source told me 746 watts for one electrical horsepower. So, 15kw is about 20 horsepower, as your wrote. The kicker on a motor is the power needed to get started. According to an Internet source, a one-horsepower motor might require about one kilowatt to run but a surge of five kilowatts to get started. So while my geothermal heat pump has a run load of 12 amps, the start up load is 85 amps. That probably means I need a bigger tractor than I now have to run a large enough generator. ummm.

 

[Bookman]

Thanks for the information. My tractors I have thought about using are old too. The 340 is 1960, and the Super H, which is bored out to be engine size of a 300, is 1953. You have me concerned that neither would hold the rpms steady enough for clean power. In addition, I am not sure they would power much more than a 15 kw generator. That might not be enough to power the start up on my geothermal furnace. It has a running load of 12.1 amps but a start up load of 85 amps. got to do some more thinking as to options. Thanks very much.

 

[jacks]

My 12 kw Onan diesel generator easily starts a 3 ton air source heat pump. You can hear it grunt for about 1/2 a second when the compressor starts but the inrush current very quickly tapers down. I think for home backup which will power electronic equipment and hold a steady 60hz you will be better served with a dedicated generator unit. Personally, I don't like my tractor running at PTO rpm for hours unattended. I don't like the idea of added safety switches on my farm tractor either. As has been mentioned, the governor on older tractors was not intended to provide precise rpm control. For the price of a new PTO generator, you may be able to buy a used low hour propane generator. Availability of parts is something to think about. Cummins/Onan provides overnight delivery of parts to a nearby dealer when I need anything. It is good that you are thinking about which direction to go upfront. Hope it all goes well.

 

[Bookman]

(quoted from post at 22:13:00 06/13/21) My 12 kw Onan diesel generator easily starts a 3 ton air source heat pump. You can hear it grunt for about 1/2 a second when the compressor starts but the inrush current very quickly tapers down. I think for home backup which will power electronic equipment and hold a steady 60hz you will be better served with a dedicated generator unit. Personally, I don't like my tractor running at PTO rpm for hours unattended. I don't like the idea of added safety switches on my farm tractor either. As has been mentioned, the governor on older tractors was not intended to provide precise rpm control. For the price of a new PTO generator, you may be able to buy a used low hour propane generator. Availability of parts is something to think about. Cummins/Onan provides overnight delivery of parts to a nearby dealer when I need anything. It is good that you are thinking about which direction to go upfront. Hope it all goes well.

Thanks, good to know. Maybe I just need to be patient and find a good used stand alone unit. I am not sure how to go about doing that except through local Craiglist and asking around Thanks

 

[buickanddeere]

A hard start kit will reduce the starting demand on the generator . The bigger the better regarding the capacitor size .

 

[buickanddeere]

(quoted from post at 12:52:02 06/13/21) I assume you do not put a full load on your 30kw generator since a John Deere 435 is roughly about a 30 horsepower tractor

33HP on the PTO according to the 435s Nebraska test.
This one could be on the high side of that .

 

[Bookman]

Not sure where to start as to looking for a used stand alone, but I will start asking around. Thanks

 

[buickanddeere]

A Koehler or B&S autostart on LP or NG ?

 

[BarnyardEngineering]

Good lord, the overthinking and worry-warting is strong in this thread.

I mean, do you HAVE to have EVERYTHING on and running at the same time? Do you really need to bake cookies, dry your laundry, take a long hot shower, and heat the shop all at the same time while the power is out?

If it's a problem with the rest of the family, then they will learn after they overload the generator and trip the breaker a few times.

 

[buickanddeere]

(quoted from post at 09:01:21 06/16/21) Good lord, the overthinking and worry-warting is strong in this thread.

I mean, do you HAVE to have EVERYTHING on and running at the same time? Do you really need to bake cookies, dry your laundry, take a long hot shower, and heat the shop all at the same time while the power is out?

If it's a problem with the rest of the family, then they will learn after they overload the generator and trip the breaker a few times.

Too often a cheapskate adds the wattage required to operate the minimum critical equipment .
However when Mr Cheapskate rolls out the extension cords or plugs in the suicide cord into the clothes dryer receptacle. He discovers that he should have used Volt amps instead of watts and he should have allowed for 3X to 5X inrush current demand for starting motors.
There are a lot of people wishing they had bought a larger generator. However there are very few persons wishing they had bought a smaller generator.

 

[Dusty MI]

(quoted from post at 06:01:21 06/16/21) Good lord, the overthinking and worry-warting is strong in this thread.

I mean, do you HAVE to have EVERYTHING on and running at the same time? Do you really need to bake cookies, dry your laundry, take a long hot shower, and heat the shop all at the same time while the power is out?

If it's a problem with the rest of the family, then they will learn after they overload the generator and trip the breaker a few times.

X-2

 

[Bookman]

I appreciate what you are saying. However, my problem is enough watts for the startup on the geothermal heat pump I have. The running load is 12.4 amps but the start up load is 85 amps. It probably needs more watts than a generator powered by a 35 horsepower tractor can handle. The other issue is simply how well the generator output is regulated by the governor of an old tractor (1960 Farmall 340 or a 1953 Super H...bored out to 300 Farmall power....so both about 35 hp at the PTO). Thanks mucn.

 

[buickanddeere]

I installed a hard start kit on my parents 6 ton heat pump . Hardly Dims the lights when starting while on the 20Kw Briggs and Stratton auto start generator .

 

[Bookman]

Interesting. I do not know what a hard start kit is but I assume if I ask around some electrician or someone else will tell me. That might solve the problem of getting enough amps to start my geothermal
furnace. Thanks again.

 

[wore out]

(quoted from post at 14:18:26 06/16/21) Interesting. I do not know what a hard start kit is but I assume if I ask around some electrician or someone else will tell me. That might solve the problem of getting enough amps to start my geothermal
furnace. Thanks again.

GOOGLE "compressor hard start kit".

 

[buickanddeere]

(quoted from post at 17:18:26 06/16/21) Interesting. I do not know what a hard start kit is but I assume if I ask around some electrician or someone else will tell me. That might solve the problem of getting enough amps to start my geothermal
furnace. Thanks again.

This is the highest uF rated hard start kit that I can find . It provides the highest amplitude and greatest phase shift in the start windings vs the run windings .

5-2-1 CSR-U3 Compressor Saver AC Hard Start Capacitor by Blue Stars - Compatible for 4 to 5 Ton Units, Hvac Hard Start Kit