question on pto driven genertor

[roc-n-goats]

I have one that is 100 amp output.
Says it needs a 45 hp tractor to drive it.

Could I get by with less hp if I don't use the full amp load?

Thanks

[plowjockey]

Depends on how small of tractor, IMO.

The generator takes a certain amount of PTO power just to run it.

Using something much less, may cause too much strain on the tractor.

That's why tractors have a PTO HP rating, also.

[farmerj]

will it do it? Sure....

Should you do it...

Not good to overload the tractor that way.
And definitely not good to underpower the generator that way.

[||Downhome||]

you did not give all specifics, how much less HP?

is the gen output of a 100 amp at 120 volts 240 volts.

I have to assume its 220 volts, 24 kilowatt output. which should be right based on the horse power rating.

takes a little less then 2 hp per 1 k of generator (Alternator) output. you can figure two to be safe.

as long as you are spinning it at the proper RPM's and not over loading it should not be a problem for the generator..

More load the harder it will be on the PTO and Engine.

if it where me I would figure the safe zone, and install a appropriate breaker between the head and the load. that way your guaranteed you wont exceed it.

say you go with 24 hp = 12k x .20% =(12k - 2,400 watts) 9,600 watt safety range.
9,600 / 240 = 40 amps. you can get either a 220v/40amp breaker or two 220v/20 amp breakers. either way the breakers will not let more then that 9,600 watts pass.

[poorboy]

The load doesn't become so big that the engine can't hold it's rpm with the governor open. Engines under load tend to last longer than engines freewheeling.

[ace admirer]

as rpm drops also will gen voltage. more than 5% loss could make life hard on some electrical motors. you might consider auto cut off on temp and oil pressure for unattended running (murphy gauges)

tractors generally were born to run hard....in the old days anyway...

[moldy]

your problem is not with the tractor----won't hurt it to bad, your problem is with the genny. as your rpms drop due the load on the tractor--your frenquency on the genny could get wacky and cause serious damage to your electrical stuff. a genny needs to run at a certain rpm to make "clean" electricity, to small a motor and it could cause a lot of expensive repairs.

[roc-n-goats]

Thanks for all the replys.
I'm looking for the proper size tractor now.
Somewhere between 40-50 hp.
Maybe more but not less than 40.

Thanks again

Bruce

[Old Vet]

Don't know where you live but I have a MF 150 in the 50 hp range that I will sell for $4k.