i have a nh 1520 with 19 pto hp i ran my 25 kw generac pto genset and was able to run a 9 inch angle grinder and a 3 hp air compressor with no problem. when i would hook it to the transfer switch and run the whole house off the generator including well pump[ and washer, i had not problems with voltage or freq stability, if i set the freq at 62 hz with no load, i could flip the transfer switch and it would settle down to 60 hz and run as long as i wanted it to, even with freezer and refrig and well pump cycling off and on. i did not see much voltage variation or frequency variation even with this relatively small tractor. the generac unit was a beast weighing over 500 lbs and that is a lot of spinning weight along with the tractor fly wheel i thing that absorbed a lot of the fluctuation. the tractor would run about 7 hours on a 7 gal fill up.
alex
alex