PTO Generator, output 74v AC on 240v

Tom671

Member
Went to use my PTO driven generator today and could not get anymore than 75 volts AC out of the 240 and 50 volts on the 120. Used 2 different volt meters just to make sure one was not bad. Just my luck, the company that made it, sold out. Called around to different place, and no one in my area works on PTO generators. Anyone out there have any idea what is causing the low voltage?
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This is probably a dumb question, and I apoligize if it is, but is the tractor at wide open throttle?
 
Not dumb at all. Assuming the generator creates DC current which becomes AC
using an inverter, that is the first and foremost question. I wonder if he
has hooked a 1000 RPM generator up to a 540 PTO.

He needs to get an electronic tachometer and check that out.
 
I think I see a voltage regulator board. Check the fuse but the board could be bad. Also could have a floating brush. Then the rest of the guesses are for a repair guy to make. You might still be able to download a PDF file on it
 
I hope the actual generator is put together correctly, cause whoever was in charge of making the identification serial number sticker did not know how to spell "generator"
 
Is it for sure an Inverter Generator ?? Several companies make Inverter style but is this one??

John T
 
To answer a question, Tractor was running at 540 PTO speed, and was getting 63 Hertz at that speed. Also, the last time I had to use it was 2 years ago and all worked well.
 
I highly doubt it's an inverter generator. Most likely just a simple dumb alternator style like all the others, especially considering that it's a cheap fly-by-night China brand.

When I was troubleshooting a little Winpower PTO unit a few years back, one of the things suggested was that the "residual voltage" had drained off. The way to fix that was to plug in a hand drill, hold the trigger, and turn it backwards by hand while the generator was running, as I recall. If it worked you had to be careful because the drill would suddenly start running in the right direction.

Unfortunately that did not help my generator. I ended up driving it 50 miles to an electrical shop, then making an extra trip to drop off the PTO shaft because after they told me they had one, it turned out they didn't. Then a third trip to pick up the JUNK generator after they told me it had a bad winding. Since I had only paid $90 for the thing in the first place, not worth fixing. Should have let them keep it but I wanted the cart, tires, and PTO shaft.

So your generator could ultimately have a bad winding, and be worthless junk...
 
A shop that deals with large motors and alternators should be able to check it out. First I think I would undo all of those connections on the regulator board and reseat them. If its been sitting dust or corrosion making a bad connection is a likely problem.
 
I just woke up. Most likely a bad regulator. Since it is producing voltage. The main question is. Was it built by them or for them. Many companies will rebrand a generator. Any numbers on the regulator. Does it have brushes.This is the danger of buying unkown brand of anything. Parts can be hard or impossible to find.
 
Same vote from me, regulator. I see some electrolytic capacitors on the board, seem to be a common thing to go bad in electronics and motors that sit.

A good generator shop can sub in another automatic voltage regulator.

As others said, seat and reseat the connectors and grounds. Fought and fought one recently that was a bad ground from the generator head, it looked fine but the oxide layer was preventing it from properly completing the circuit.
 
You might try these people. They may be able to help you with parts information.
Wanco 800 972 0755

SML may or may not still be in business in the states
 
I agree Ken. Could be just cleaning the connections is all it needs. I hate to guess at things. But with not being there. Guessing is all you can do.
 
I will try and see what I can do this weekend. I appreciate all the help. You guys rock, thank you.
 
I would look at voltage regulator. There should be some adjustment potentiometer that you can turn to see if voltage level moves.
 

Odds are a capacitor has failed on the voltage regulator board . eBay has all
kinds of generic replacement voltage regulators for generators .
Generators are very simple and generic this parts will swap.
It is a bit odd that the line to neutral voltages are different .
 

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