Generator Adjusting voltage on 3PT generator?

[petegoud]

I recently got my Northern 12,000 watt generator hooked up and running using my L245Dt Kubota has a power source. It may be just a little underpowered to get the maximum wattage from it, however I doubt if I'll ever need all 12,000 watts. The one problem I've noticed is that when I am running it with, say a 5,000 watt load (heater)+ an additional 1,000 watts (lighting), and adjust the RPM to maintain 240/120 volts, when I switch off the heater the voltage will climb to upwards of 270/135 volts. Knowing that this could damage some electrical systems, I wanted to know if anyone else out there has experienced a similiar problem? Does yor tractor's governor self-adjust to make up for the differences, or am I expecting too much from my antique? Any advice as to what to watch out for? Thanks, Doug

 

[johnray13]

I believe it is because your generator doesn't have a voltage regulator- not so much your tractor. As a general rule, most appliances can handle +/- 10% voltage. You do seem to be slightly higher.

My 5500 watt Coleman generator produces almost the exact same (high) voltage when not under load (also does not have AVR).

 

[groundcover]

Looks like you are going to have to keep near the throttle any time there is a big load change. It is a little more noticeable on a tractor that is smaller. The big ones don't bog down unless you are really sucking down the KW's.

 

[BobRip]

You might want to get a frequency meter. Set it at about 62 Hz with no load and see what it drops to. 58 Hz is about right for a bottom end. Your voltages don't sound real bad, but if you get the frequency to far out of line then you can also damage stuff. A lot of equipment has gotten damaged from frequency shifts. If you can monitor it in your house then that goes a long way to protect your appliances. Radio Shack and others sell a "Kilowatt" meter that measures frequency and voltage among other things. Try them out.

 

[JB4310]

Doug,
What your experiencing is typical and should be expected, You have to do what Bob said, with no load, (nothing drawing power) set the rpm's to the upper acceptable limit on your gennys meter, whether it' a HZ or volt meter.

Then when a med to large load is turned on the meter will drop, but hopefully stay within the lower acceptable limit, if not or a very large load is drawn then manual throttle input will be required.

There aren't any now but there's usually a generator thread going on, there have been some very informative ones, try searching for them, or someone can link to them.

Good Luck,
JB.

 

[harwill]

Sounds like your governor isn't governing very well - does the tach indicate an rpm drop? And if your generator has transformer regulation as opposed to AVR electronics the regulation will be looser too. The Kill-A-Watt is a best buy; I've seen them as cheap as $17.95. It measures voltage, amperage, wattage, power factor AND Hertz, which equates to RPM - a cheap tool. Another thought: any chance some of your voltage drop is occurring over connections or too-small gauge wire? Just a thought. Good luck.

 

[petegoud]

I've checked both Hz and voltage with a Fluke 87 meter, so I know where I stand there. I suspect that my tractor may be too underpowered to absorb the fluctuations in both, or my governor isn't working as well as it should be. When any of your tractors are running with loads on your PTO generators, do you notice any changes in the sound of the engine as loads are applied and taken off? I don't on mine, so that's what makes me suspect something.

 

[JB4310]

I've checked both Hz and voltage with a Fluke 87 meter, so I know where I stand there. I suspect that my tractor may be too underpowered to absorb the fluctuations in both, or my governor isn't working as well as it should be. When any of your tractors are running with loads on your PTO generators, do you notice any changes in the sound of the engine as loads are applied and taken off? I don't on mine, so that's what makes me suspect something.

May not notice when a load is taken off as much but if you are applying a 6KW load to your genny from zero load and you don't hear your tractor squat and grunt a little then somethings not right IMO.

What's your tractors rated pto horsepower?

The short answer is no, with a pto genny that is closely matched to tractors pto HP output the gov will not keep volts/hz within tolerance thru out the full range of gennys out put.

see post #49 in this thread.

http://www.tractorbynet.com/forums/owning-operating/113740-hp-needed-genny-5.html

JB.

 

[petegoud]

JB Thanks for directing me to that #49 post. I'm probably facing the same thing you were with your Ford. My tractor puts out 22 PTO HP, so I know I'm pushing the limits with the setup I have. An interesting side note is that I also have a Coleman 12 KW generator powered by a 24 HP Briggs Vanguard engine. It has exactly the same generator head as the Northern model. However it will easily adjust to the different loads. But does it burn through the fuel. The reason I'm trying to use both generators is that one will be used for powering a house/garage, while the other would be used for powering a shop which also powers my well. I suppose this means I need to go out and get a new tractor! Now to convince the wife!

 

[djradz]

I recently got my Northern 12,000 watt generator hooked up and running using my L245Dt Kubota has a power source. It may be just a little underpowered to get the maximum wattage from it, however I doubt if I'll ever need all 12,000 watts. The one problem I've noticed is that when I am running it with, say a 5,000 watt load (heater)+ an additional 1,000 watts (lighting), and adjust the RPM to maintain 240/120 volts, when I switch off the heater the voltage will climb to upwards of 270/135 volts. Knowing that this could damage some electrical systems, I wanted to know if anyone else out there has experienced a similiar problem? Does yor tractor's governor self-adjust to make up for the differences, or am I expecting too much from my antique? Any advice as to what to watch out for? Thanks, Doug

I think you would probably see the frequency increase as well because the tractor RPMs goes up too. If this is not the case, you may be seeing a case of voltage drop in your cabling, which is much easier to fix - bigger cable!

My tractor does exactly as you describe and it has nothing to do with the tractor's ability to drive the load. Apparently the governor is just not sensitive enough. Too bad, as it otherwise is a great setup.