Generator NorthStar PTO Generator Question

N1ST · Jun 8, 2007

I'm wondering if a MF GC2310 (PTO HP 18.7, 13.9kw) will handle the Northern Tool "NorthStar PTO Generator — 13,000 Watt, 24 HP Required" OK? The generator has good reviews and I've read good things about it here on TBN.

Does the generator have to be mounted about level with the PTO, or can the PTO shaft assembly be at nearly any angle necessary?

I'm not sure at this point what I'd mount the gen on/in. Perhaps a pallet staked to the ground with some sort of plastic enclosure over it. Would this handle the torque or could it flip? Does it need much ventilation or would a dog-igloo work as an enclosure?

Thanks.

jsborn · Jun 8, 2007

N1ST said:
I'm wondering if a MF GC2310 (PTO HP 18.7, 13.9kw) will handle the Northern Tool "NorthStar PTO Generator — 13,000 Watt, 24 HP Required" OK?

Thanks.

Tractor = 13.9KW ...Gen = 13 KW not counting losses. therefore I would think that your answer is a NO it will not power it .

BUT just because the Gen is rated for 13KW does not mean you have to load it to that! If you only load the Gen to 10KW or so (less than 13KW) you can probably drive it with your tractor.

You do need to remember that as the rpm of the tractor slows so does the frequency of the power and your household appliances wont like that if it goes too low.

JerryK · Jun 8, 2007

Most PTO driveshafts horsepower rating and life expectancy go way down if you use it at more than a 15 degree angle. And most limit their use for 30 degrees or less. The straighter the better. Best to make a stand that keeps the thing fairly in line during use. Somethings, like a rototiller or snowblower, you can't help having some angle.

RichNJKubota · Jun 8, 2007

I have a generator that came with a 3 point mount. That seems to be the easiest way to do it safely. If the generator is not on something with a wide enough base it will flip over.
I was saving a small trailer someone gave me for the purpose but now I don't need it.

windy acers · Jun 8, 2007

I muonted mine on a carryall from tsc. Added swivel wheels to the bottom works great. north star pto 7800 kw on a 2000 yanmar (20 hp). Get your pto shaft from agri supply.

John_Mc · Jun 8, 2007

N1ST said:
I'm wondering if a MF GC2310 (PTO HP 18.7, 13.9kw) will handle the Northern Tool "NorthStar PTO Generator — 13,000 Watt, 24 HP Required" OK?

A good rule of thumb is to allow 2 HP (at the PTO) for every KW of generating power. The rule doesn't work so well once you get into very large generators, or very small. From a couple of KW up into the farm-sized units, it's a decent estimate.

So you should be able to count on 9KW of output if you put that ubit on your tractor. Load it down much more than that, and the engine will start bogging down. 9KW should be plenty for emergency home use, unless you've got a huge air conditioning system (not an issue for me up here in Vermont) or some other major load.

N1ST · Jun 9, 2007

Only heavy load is a 1/2 hp 240v well pump. I dont know if the 7kw model would handle this. It doesn't have much headroom above continuous rating for surges.

Soundguy · Jun 9, 2007

Look at it like this.. your genny has extra 'reserve', and won't be running at max.. should help it live longer.. and if you get a bigger tractor later.. you are set.

I have the 13kw genny northern sells. it's a decent unit.

Soundguy

SPYDERLK · Jun 9, 2007

The way I look at ityou will be able to power 9 or 10kW constant drain. For quick surges tho, you will still be able to apply the higher power the gen is capable of for the fraction of a second needed to carry through startng a motor. Theres a lot of rotating mass to act as a flywheel and help limit rpm drop.
larry

BobRip · Jun 9, 2007

jsborn said:
You do need to remember that as the rpm of the tractor slows so does the frequency of the power and your household appliances wont like that if it goes too low.

This is a very important point. People have burned out many appliances running them at the wrong frequency. Get a frequency meter to put in your house and watch this. I think Kilowatt, sold by radioshack is $39. It plugs into an outlet and gives voltage and frequency.

I start a 1.25 HP well with a 5 KW generator (but it is marginal), so you should be OK. If necessary turn off your other loads before starting the pump. I have an extra large surge tank (40 gallons), and can go many hours between running the well if we are careful with water use.

AndyMA · Jun 10, 2007

BobRip said:
I start a 1.25 HP well with a 5 KW generator (but it is marginal), so you should be OK.

At 746 watts/hp a 1/2 hp pumpis draws only 373 watts or .373 kw. Even assuming 10x starting current (which is overstated) that's only 3.73 kw surge. There's also a difference between generators driven by high hp diesel engines where you have excess hp available vrs small 5 KW gas driven generators which typially have very little if any excess hp. A 5 kw generator 5,000/746 = 6.7 hp at 100 efficiency.

Andy

zzvyb6 · Jun 10, 2007

I run a 50kw pto generator off my 38 hp JD. Used to run it off my 18hp Yanmar, no problems, ever. It was on a trailer, though. Only technical recommendations for the driveshaft angles is that input shaft and output shaft should be parallel in 2 planes for constant velocity. Yes, flipping can be done under 2 circumstances: adding or removing a huge load suddenly. If done gradually you should have no problems. I know of several people who keep their alternators in dog houses. Main concern with these deals is the proper sequencing of putting the device on-line and removing it from the house grid. You can get a "breakout box" installed in your house to prevent lineman from getting fried. This is an "either/or" device to segregate Edison power from tractor power. Other than that, you will find many other uses for a tractor generator: remote welding, hedge trimming, electric pressure washing and other uses that you have not yet dreamed of. You really ought to watch rpm (60 Hz) for any motors, and voltage (110 - 120) for other stuff. I even run the house AC units on this unit (dogs complan otherwise).

Glowplug · Jun 10, 2007

Northerntool does have a trailer designed specifically for the Northstar generators. They bolt down on it so that they don't torque sideways.

What are you planning to use the generator for?

John_Mc · Jun 10, 2007

AndyMA said:
A 5 kw generator 5,000/746 = 6.7 hp at 100 efficiency.

But in the real world, you'll get something like 2/3 efficiency (67%) when converting mechanical HP output from an engine to electrical KW out from the generator, so you are back to needing about 10 HP engine for about 5 KW continuous from a generator (10 HP x 746 Watts/hp X .67 efficiency = 4998 Watts). Hence the "2 HP for every 1 KW of output" rule of thumb.

Efficiencies do vary, and there are a lot of other design considerations which can efect things like surge capacity, but if you look at the continuous (not surge) ratings of most of the generators you see advertised, you'll see that most are pretty close to the 2 Hp per KW of output range. My 4 KW Generac is powered by a 7.8 HP gas engine, for example.

John Mc

Glowplug · Jun 10, 2007

John_Mc said:
But in the real world, you'll get something like 2/3 efficiency (67%). . . . .Hence the "2 HP for every 1 KW of output" rule of thumb.

Northstar's 27.5kW generator requires 48hp. 1.75HP/1kW. You are correct!

ME! said:
Northerntool does have a trailer designed specifically for the Northstar generators. They bolt down on it so that they don't torque sideways.

Northstar PTO Generator Trailer

BobRip · Jun 10, 2007

John_Mc said:
But in the real world, you'll get something like 2/3 efficiency (67%) when converting mechanical HP output from an engine to electrical KW out from the generator, so you are back to needing about 10 HP engine for about 5 KW continuous from a generator (10 HP x 746 Watts/hp X .67 efficiency = 4998 Watts). Hence the "2 HP for every 1 KW of output" rule of thumb.

Efficiencies do vary, and there are a lot of other design considerations which can efect things like surge capacity, but if you look at the continuous (not surge) ratings of most of the generators you see advertised, you'll see that most are pretty close to the 2 Hp per KW of output range. My 4 KW Generac is powered by a 7.8 HP gas engine, for example.

John Mc

The 5 kw generator does have a 10 HP motor. Most generators that I have seen have abouy 2 HP per Killowatt.

bucmeister · Jun 11, 2007

Having the "either/or" switch is the only way to be "in code" and legal. I know of many that don't, however that does not change the issue.

With the gas powered standby gensets I have always looked at the HP of the motor and cut it in half to determine the continuous output and I am guessing that the deeper stronger torque of the diesel engines lets you get by with a bit more on the tractor driven generators.

MarkLeininger · Jun 11, 2007

I have that same generator and run it off my Kubota B2710. I mounted it on a cheap trailer I bought at Menard's for about $75. It turned out to be almost exactly the right height for my PTO output. I have a ball hitch mounted on my tractor that I use to pull the trailer. When the power goes out, I get it out of the shed with the tractor, pull it next to the garage, and run a cord I made from the generator into my power feed.

N1ST · Jun 11, 2007

Thanks for the helpful info everyone. Regarding fuel. I read somewhere to expect .44 gal / 10 hp for diesel. Sounds like the gen needs 540 pto rpm which according to MF requires the engine to run at 2532 rpm (2600 rpm max). Any estimates on the fuel burned per hour for the 22.5 hp engine? Sounds like it should be < 1 gal/hr?

Also, do I need to use a freq counter to know where to set the tractor idle or is the gen very forgiving?