# Tractor PTO Powered Generators



## Slippy (Nov 14, 2013)

A while back I looked at buying a PTO Powered Generator instead of a larger "whole house" Gasoline or LP Gas Generator. I may have asked the forum but I don't remember. So, I'm looking at them again and want some input.

The upfront cost is cheaper per KWh than a larger stand by gennie and being able to run it with my diesel powered John Deere was an interesting option. Not having to mess with the internal workings of an engine is also a Pro and being able to mount it on a wheeled cart of some sort and move it around my place was also a Pro.

Does anyone use a PTO Generator and if so, what are the Cons? Obviously not having it as a "stand by" but what else?

PTO Generator - Tractor-Driven PTO Generator, 16,000 W Max


----------



## Smitty901 (Nov 16, 2012)

You see them in farming sometimes to run Milking equipment and coolers. You need a good tractor to run it but they work. Bother in law used one for years.


----------



## 8301 (Nov 29, 2014)

PTO driven backup generators are fairly common in this area for the industrial chicken houses during power outages. Losing 12,000 chickens (one average size pullet house) because the grid power went down is bad for business.

The one's I've played with were 10 kw and larger and to keep the frequency at 60 hz it's important to run the PTO at exactly (within 4%) of the correct rpm so know your PTO speed (usually either 540 or 1000 when the tractor is at 1750 rpm) Not too hard to do with a static or lightly changing load but major load changes (such as a large well pump kicking in) may require some throttle adjustments. You want the tractor throttle to be very smooth and need at least 2 or 3 hp per kw capacity. If you've got a little 24hp tractor I wouldn't get more than a 8 kw generator.

I've seen stationary generators (back the tractor up to the generator and park) and generators that use the 3 point hitch (drive the generator around) which seem to be easier to use although sometimes tough to hook up.

Here is a site that discusses PTO generators Tractor-Driven Generators: Producing Quality Power


----------



## hag (May 19, 2016)

Slippy we use one at the dairy during power outages to keep the bulk tank cool and also to milk and feed if it's that time of day. I don't know the power output of it but it will run the entire milk barn, cooler, pumps vacuum receivers as well as two silo unloaders at the same time. Very efficient and makes alot of electricity but takes a 150+ hp tractor to run it. I will try to get out to the shed tomorrow and get some numbers off of it if you would like


----------



## Slippy (Nov 14, 2013)

hag said:


> Slippy we use one at the dairy during power outages to keep the bulk tank cool and also to milk and feed if it's that time of day. I don't know the power output of it but it will run the entire milk barn, cooler, pumps vacuum receivers as well as two silo unloaders at the same time. Very efficient and makes alot of electricity but takes a 150+ hp tractor to run it. I will try to get out to the shed tomorrow and get some numbers off of it if you would like


Thanks @hag,

I'm looking at a much smaller Generator like the one below from Harbor Freight, something that my 30hp JD can run. The one that you use at the Dairy sounds like a Beast!

PTO Generator - Tractor-Driven PTO Generator, 16,000 W Max


----------



## 8301 (Nov 29, 2014)

Slippy said:


> Thanks @hag,
> 
> I'm looking at a much smaller Generator like the one below from Harbor Freight, something that my 30hp JD can run. The one that you use at the Dairy sounds like a Beast!
> 
> PTO Generator - Tractor-Driven PTO Generator, 16,000 W Max


Your 30 hp tractor may not be able to pull that generator under full load. But I doubt you'd ever need to, 15kw is a lot of power, 125 amps at 120v.


----------



## Slippy (Nov 14, 2013)

John Galt said:


> Your 30 hp tractor may not be able to pull that generator under full load. But I doubt you'd ever need to, 15kw is a lot of power, 125 amps at 120v.


15kw is a lot, probably more than I need. Here is my next choice, a 7800 surge/7200 rated watt PTO generator.
NorthStar PTO Generator - 7800 Surge Watts, 7200 Rated Watts, 14 HP Required | PTO Generators| Northern Tool + Equipment


----------



## 8301 (Nov 29, 2014)

Either generator should run any loads you'd have including the well pump although the 7200 watt generator probably couldn't pull your home's central AC. Since the larger generator only has one 30 amp 240v outlet it also may not be able to pull the AC although it certainly has enough electricity to do so.

Both have good reviews so roll the dice and take your chances. I think either one would cover things if the power went out for a week.

And for people who don't think AC is essential his wife has diabetes and FL can be very hot with it's high humidity. Unless a person is acclimated to FL weather without AC it can be very tough during the summer.


----------



## tley10 (Nov 26, 2016)

I have worked in generators for years now. Worked on a good bit of PTO generators... PTO gen sets are good for farming use mainly. They tend to sit for a while, and loose residual magnetism. If you want a whole house unit go with Cummins 20gsbb with automatic transfer switch. I have an automatic generator system at my house and I believe that is one of the best decisions I ever made. A farmer friend of mine has had a PTO for years and had issue with horsepower of his tractor. I sold him a Cummins unit and he was blown away 

Sent from my SM-N920V using Tapatalk


----------



## Mad Trapper (Feb 12, 2014)

If you have a generator that looses it's magnetism it's easy to "polarize" with a tractor/truck/car battery and jumper cables. This happens on the old tractor gennies. You just flash it with the cables and you are good to go.


----------



## tley10 (Nov 26, 2016)

This is very true. You can also use a drill.... pull the trigger and spin the drill backwards. Flashed windings quite a few times. I wouldn't have a PTO gen unless I was using it on the farm. They are not meant for residential use

Sent from my SM-N920V using Tapatalk


----------



## Mad Trapper (Feb 12, 2014)

tley10 said:


> This is very true. You can also use a drill.... pull the trigger and spin the drill backwards. Flashed windings quite a few times. I wouldn't have a PTO gen unless I was using it on the farm. They are not meant for residential use
> 
> Sent from my SM-N920V using Tapatalk


.

I forgot about the drill trick, you basically turn the drill motor into a generator


----------



## Slippy (Nov 14, 2013)

tley10 said:


> This is very true. You can also use a drill.... pull the trigger and spin the drill backwards. Flashed windings quite a few times. I wouldn't have a PTO gen unless I was using it on the farm. They are not meant for residential use
> 
> Sent from my SM-N920V using Tapatalk


Why are they not meant for residential use?


----------



## tley10 (Nov 26, 2016)

Slippy said:


> Why are they not meant for residential use?


I had a customer one time that hooked his up to his house based on the rpm of the tractor and never paid attention to the voltage meter, it was running way over 60 hz because something was wrong with the computer on his tractor make rpm Gauge malfunction. Also most of them don't produce clean power(sine wave) causing lights to flicker and fan motors to hum. Read the link below. I'm not saying they won't work.... I'm just saying I don't advise it. Home standby units come on automatically and will shut down automatically if there is a problem. They produce clean power.

I tried to share a link.... look up( pto generator lights blinking.) (Do pto generators produce clean power)
It wouldn't let me share the link

Sent from my SM-N920V using Tapatalk


----------



## Slippy (Nov 14, 2013)

Thank you, I'll check that out.



tley10 said:


> I had a customer one time that hooked his up to his house based on the rpm of the tractor and never paid attention to the voltage meter, it was running way over 60 hz because something was wrong with the computer on his tractor make rpm Gauge malfunction. Also most of them don't produce clean power(sine wave) causing lights to flicker and fan motors to hum. Read the link below. I'm not saying they won't work.... I'm just saying I don't advise it. Home standby units come on automatically and will shut down automatically if there is a problem. They produce clean power.
> 
> I tried to share a link.... look up( pto generator lights blinking.) (Do pto generators produce clean power)
> It wouldn't let me share the link
> ...


----------



## 8301 (Nov 29, 2014)

The electricity from the grid is called pure sine wave and has a very smooth curve in the waves as the AC polarity changes poles. Most low cost PTO generators make modified sine wave power which is fine for some things but can be hard on some motors and delicate electronics, especially for long term use. A high quality generator has additional electronics in it so it makes a pure sine wave, something most lower cost generators don't do. read this
https://www.altestore.com/blog/2015/10/pure-sine-wave-vs-modified-sine-wave-whats-the-difference/

Keep in mind that many florescent lights will flicker regardless of voltage and hz if fed modified sine wave power. Florescent lights and delicate electronics really prefer pure sine wave electricity. Most motors run better and last longer on pure sine power.

Using a less expensive modified sine wave alternator is fine for occasional use for most things (never run a Plasma TV off modified sine wave electricity) which is all that you are looking for. Pure sine wave generators are much more expensive. If a company claims it's a full sine wave generator and the price seems to way low it may not be a true pure sine wave inverter on that generator. Do your research. Amazon.com reviews are good for this since many reviewers hook up an oscilloscope to the generator before posting a review.

A stand alone generator will automatically increase and decrease engine power (to maintain a set generator speed) as loads change on the generator. This allows the generator to produce a stable 120/240v at 60 hz. With a tractor powered generator as the loads change you need to adjust the fuel to the engine to keep that PTO at 540 rpm. That's how you avoid dimming lights ect, you keep a close eye on the PTO rpm. Some tractors may have the ability to automatically add fuel to maintain a set rpm if needed but the tractors I've used all require the operator to constantly adjust the throttle.

Less expensive stand alone generators make modified sine wave AC which will run must things for a short term emergency (grid down for a week or 2) For long term grid outages and delicate electronics you want an expensive pure sine wave inverter on that generator. @Slippy


----------



## SOCOM42 (Nov 9, 2012)

Mad Trapper said:


> If you have a generator that looses it's magnetism it's easy to "polarize" with a tractor/truck/car battery and jumper cables. This happens on the old tractor gennies. You just flash it with the cables and you are good to go.


Just like the old voltage regulators before alternators.

I have a Honda tractor, I toyed with the idea of making a mobile generator out of it, but passed.

That is the fabricator in me planning another build.

Personally I do not like the idea of multi tasking a thing like this.

To me you are better off with a dedicated genset that is well sheltered ready to run all the time..

One of mine I can hook up to the tractor and tow it around if I need power elsewhere.


----------



## csi-tech (Apr 13, 2013)

There is an optional pulley for the PTO on my Ford 3000. You make your own sawmill, generator, whatever. Very cool. I would have to replace my PTO shaft with a 1000 rpm version evidently for some things. 

We had a discussion about my little 3100W Champion last night. Too much generator is just a waste of gas and power. Mine is perfect for my needs. I was going to upgrade to a 5000w Lifan Energy storm but that just allows me to use the microwave, hot plate and air conditioner all at once. Big deal.


----------



## Mad Trapper (Feb 12, 2014)

csi-tech said:


> There is an optional pulley for the PTO on my Ford 3000. You make your own sawmill, generator, whatever. Very cool. I would have to replace my PTO shaft with a 1000 rpm version evidently for some things.
> 
> We had a discussion about my little 3100W Champion last night. Too much generator is just a waste of gas and power. Mine is perfect for my needs. I was going to upgrade to a 5000w Lifan Energy storm but that just allows me to use the microwave, hot plate and air conditioner all at once. Big deal.


Lots of the old tractors either had permanent pulleys or attachments like yours for the PTO. I've used a circular bucksaw for cord wood and also a huge planer that would do 20" wide and depth as deep as timbers. That planer worked nicer than anything sold now. It was well kept and had nice sharp knives.

With pulleys you can step up or down speeds with different diameter pulleys or using a jackshaft. Most of the old tractors also had governors so the PTO speed does have some regulation under loads.

One other thought on PTO drive. If the PTO shaft is connected to an over running coupler, the generator could be fitted with a driveshaft incorporating a flywheel which will store energy that can be used when a load is applied, and the coupler will allow the driveshaft not to overun engine rpm.

I would still be careful running sensitive electrical equipment off a PTO generator unless it was designed for "clean" AC power. Does anyone know if the military had a PTO powered generator? If so they might be designed for use with electronics?


----------

