PTO Generator - which one to choose

[JB4310]

AVR does not have the ability to adjust frequency.

Well they do move in some kind of relation to each other don't they?

If AVR helps to hold a certain voltage, I would think it would help with the HZ as well ???

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A little hijack, kind of related. I bought a little Chinese Kipor 2kw inverter (1.6kw continuous) generator off craigslist yesterday. The guy told me it was in an estate sale and he didn't know anything about it, but it did not run.

Judging by the picture it looked like new, so I figured someone bought it and never used it. Probably just needed the carb cleaned. I offered $150. for it and got it. Well Now I think I have a nice yellow China anchor, the thing started right up first pull after I replaced some very old gas, only problem is no AC output

I fiddled with it but no luck, found out the generator is putting out the high voltage ac required for the inverter to do it's thing but nothing coming out of the inverter except 16 to 20 volts DC. Could use it to slow charge 12 volt batteries I guess.

Found an inverter for $350. but am not going to invest that on it. It's to bad since the little thing looks and runs nice. supposedly these are total rip offs of the Hondas. found a storey where Honda won a judgement and seized a boat load of kipors and had them destroyed a few years ago.

Was gonna start a new thread asking for help with it but there is really no use it's just a sad china syndrome

JB.

 

[tsteahr]

Well they do move in some kind of relation to each other don't they?

If AVR helps to hold a certain voltage, I would think it would help with the HZ as well ???


JB.

For alternator based generators, frequency is determined solely by the speed of the rotor (ie the tractor pto speed). The AVR has no control or impact on frequency. The AVR is able to maintain output voltage more closely to 240, over a wider range of loads and rotor speeds, than a capacitor based voltage regulation. So unfortunately if you are having a issue with maintaining frequency the AVR is not going to help. It will only keep the voltage closer to 240. The AVR provides the most benefit when starting large motors as it reduces voltage droop during current inrush.

Hopefully that makes some sense, as I'm not really a electrical guy.

 

[JB4310]

For alternator based generators, frequency is determined solely by the speed of the rotor (ie the tractor pto speed). The AVR has no control or impact on frequency. The AVR is able to maintain output voltage more closely to 240, over a wider range of loads and rotor speeds, than a capacitor based voltage regulation. So unfortunately if you are having a issue with maintaining frequency the AVR is not going to help. It will only keep the voltage closer to 240. The AVR provides the most benefit when starting large motors as it reduces voltage droop during current inrush.

Hopefully that makes some sense, as I'm not really a electrical guy.

It kinda does. I just thought they were both (volts and HZ) dependant on the rotor speed?

JB

 

[Soundguy]

doesn't matter much about the volts where thy have it set to produce,.. since hertz is HARD locked / determined by rpm and poles. you run it there and that's it. vreg takes care of the voltage regulation as best it can based on it's design.. passive or active, and the loads it encounters.

soundguy

 

[tsteahr]

It kinda does. I just thought they were both (volts and HZ) dependant on the rotor speed?

JB

You are right. But voltage is only dependent on rotor speed to a point. As I increase RPM up from idle voltage increases. I have to get my PTO speed fairly close to 540 before the output voltage reaches 240V. But the voltage stays at 240V even if I change the tractor engine rpm by a couple hundred revs either side of PTO speed. However changing tractor speed directly changes the frequency. So if I bump the engine rpm over pto speed by 100, the frequency will increase linearly but the AVR will keep the output voltage at 240. Same if I drop the engine speed 100 rpm below pto speed.

 

[90cummins]

I bought a new Generac PTO 25 in 1999 prior to Y2K it has seen very little use but I do run it on occasion for 30 minutes or so with an 8kw load to verify operation & drive moisture out of the windings, it is also stored indoors.
It was said to be prone to failures and not recommended.
Could anyone share some details?



Thanks Tim