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Has a Chonda engine on it.
Was getting about 183V out of the 120v plug. So I removed the adjustment screw completely, and am still getting 130V at about 1650RPM's. I've seen bad AVR's that won't produce any volts. Or IIRC, not enough. But never seen one put out too much.

Is this even possible?

P.S. The governor arm and throttle plate move freely. I don't see a lot of corrosion or debris (like dirt dobbers) in the back of the generator.

Yes, bad AVR can be high volts. You need to check the frequency. I am going to assume it should run at 3600 RPM unless it is an inverter generator.

Here’s the owners manual with a customer support number and parts breakdown. These are what I call throw away units because of their cheap price. They are sold through NorthernTool for less than $400. Most times repairs exceed 50% of new unit. Only have a 90 day warranty, which should tell you the type of quality you are dealing with. https://www.northerntool.com/images/downloads/manuals/504000.pdf

Rivets said:

Here’s the owners manual with a customer support number and parts breakdown. These are what I call throw away units because of their cheap price. They are sold through NorthernTool for less than $400. Most times repairs exceed 50% of new unit. Only have a 90 day warranty, which should tell you the type of quality you are dealing with. https://www.northerntool.com/images/downloads/manuals/504000.pdf

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Yes, I've looked through that "parts list and diagram." It's about as worthless as the generator, I'm thinking. Was looking up the breather vent that mounts into the top of the gas tank. It's labeled something like #32. Scroll to 32 on the parts list, and it's listed as a manual choke. LMAO.
The AVR is pretty cheap ($27) through the Generator Guru. Not so cheap on the breather vent. It's about $30. Just for a darn plastic vent. SMH.
But it's for the guy who owns the property my shop is in. So it all comes off the rent. Including labor.

Hammermechanicman said:

Yes, bad AVR can be high volts. You need to check the frequency. I am going to assume it should run at 3600 RPM unless it is an inverter generator.

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Yes, 3600 is about what I found too. Thanks for the reply.

When you work on generators it helps to have a meter that measures Hz. You will probably want to set the no load speed at 3700 to 3750 and then apply a heavy load and see if the revs don't drop below something like 3575. The AVR will regulate the voltage but frequency is still RPM dependent. You want it running 3600 at near full load. And remember the advertising watts listed on the side is surge watts not running watts.

I set my generators a little different than Hammer. As stated you will need a hertz meter, so if you don’t have one, you should get one somehow before starting. Plus an assistant would be a great extra set of eyes. This would be the procedure I would be following if that unit came to me.
1. I plug a Hertz meter into one outlet. Plug a volt meter into another outlet. Have my tach ready.
2. I am looking for 3600 RPMs, 60 hertz and 120 VDC. This is in a no load condition. This is my starting point.
3. Start unit and observe RPMs, hertz and voltage.
4. Observe all three meters and set governed top speed at 3600 RPMs.
5. Hopefully your hertz on that unit is in between 56.5-63.3, which is the specs for that unit and you have between 118-122 VDC.
6. If not you start adjusting you governed top speed until you get the voltage and hertz within the range posted.
Being a little on the high side is better than low side. I don’t like to ever go over 3700 RPMs to get it into range.
7. Once you are within range, you plug in an electrical device and run it at full speed. I like using an electric drill.
Watch your voltage and hertz to see if they stay in range. If not increase RPMs slightly and test again.
Remember, you are trying to get it within range under load.
8. If I can’t get it adjusted to my liking, I’m more interested in getting the hertz as close to 60 than voltage at 120.
Have a voltage reading out of range won’t ruin a piece of equipment as fast as the wrong hertz.

Others may have a different procedure, this is just the one I used when teaching. One thing is that being a cheap unit with an “Automatic Voltage Regulator” you cannot adjust anything besides your speed, so don’t be surprised if you need the patience of
a saint. Make sure the engine is running as smooth as a top before starting the procedure. Good Luck, you’ll need it if you’ve never done one before.

FWIW I like to use a hot air gun.
Very heavy load applied almost instantly,
And if the Hz drop to low it wont worry a resistace device

I have a hertz meter, but didn't plug it in to this gen yet. With the voltage at 180v ac, what's the point? At least not until I have the AVR replaced.

Hammermechanicman said:

When you work on generators it helps to have a meter that measures Hz. You will probably want to set the no load speed at 3700 to 3750 and then apply a heavy load and see if the revs don't drop below something like 3575. The AVR will regulate the voltage but frequency is still RPM dependent. You want it running 3600 at near full load. And remember the advertising watts listed on the side is surge watts not running watts.

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I see what you mean. It's a 4000w generator. that only means it'll surge at 4000. Not actually run 4000w constantly.

Wrong. Hammer is talking about engine RPMs at no load.. It’s rated Wattage is 3250, 4000 is surge Wattage, which means it will jump to 4000 watts quickly when you put a heavy load on it, then drop down to rated wattage. Don’t confuse RPMs and wattage, as one is engine speed and the other is the amount of work the unit can do.

Rivets said:

Wrong. Hammer is talking about engine RPMs at no load.. It’s rated Wattage is 3250, 4000 is surge Wattage, which means it will jump to 4000 watts quickly when you put a heavy load on it, then drop down to rated wattage. Don’t confuse RPMs and wattage, as one is engine speed and the other is the amount of work the unit can do.

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Lower the RPM's and the generator is going to produce less wattage. In my case, even at 1600 rpm's, the generator is creating 130V.

Watts, from what I understand, is sort of the power. The muscle, if you will.
Amps is how much power
Where as voltage is how fast the power is being fed.

The RPM's the engine is turning has a direct effect on the voltage and the power both.

I didn't check the RPM's when I first started the gen. Only the voltage. And seen it was 183v, I reduced the RPM's as far as I could, trying to get close to the 120V mark. As much as I could reduce the RPM's (about 1650rpm), I was still at 130v. With only 1650RPM's, and still getting 130V, then as hammer stated, it must be a faulty AVR.

Have you tested both receptacles on the 120V receptacles as well as both legs of the 220/240 receptacle? Before throwing parts at this unit I would be checking the wiring.

PT said
Watts, from what I understand, is sort of the power. The muscle, if you will.
Amps is how much power
Where as voltage is how fast the power is being fed.

Sort of
Voltage is a measure of potential. Devices are designed to be operated at a specific voltage or voltage range.

Watts is a unit of power. This is the voltage times the amps (current flow) P=E x I. Cuurrent flow is determined by voltage divided by resistance.

Frequency in Hz (hertz) is the number of times per second the waveform changes from positive to negative. Some equipment is very sensitive to line frequency, like some motors. and some could not care less. Such as an incandescent light bulb.

Energy is power (watts) over time. You buy energy from the grid in killowatthours. That is thousands of watts per hour.

My students were told to remember it this way. Amps are the amount you want to push through the wire. Volts are the pressure you are going to push on the amount. Ohms are the back pressure you have. Watts are how much work you want to accomplish.

That is pretty good basic explanation for young students. One of the funniest things to watch was a kid we hired with a 2 years technical degree doing 220v troubleshooting. Lots of theory but not much on real world. He was always quick to point out he had a degree and i didn't.

Hope you left a couple of Briggs condensers, charged and laying around, to teach him that when you assume anything about electricity it can hurt you. My students learned very quickly that you understand and test everything before touching it. When no touch voltage sensors came out, most of my second year students bought one and carried it with them anytime they went into the lab. One day the principal came into our class to observe what we did and touched a low voltage circuit that a student set up showing how electrical fencing work on the farm. He was demonstrating how to change the shock you got by changing the size of the capacitor you hooked into the line. Student thought he was going to be in trouble when he and everyone else started laughing. The principal knew he was in the wring, there was signage all around and another student tried to warn him, but I think he was a little slow on purpose. Student got an A and we were neve observed again.

The big printers i worked on in the old day job had things called corotrons. A metal sheild with a wire inside the center wire has about 50,000 volts applied to it and bias voltage around 1000 volts applied to the shield. There was enough energy to applied to the center wire it glowed purple. The current leakage to the sheild through air was measured in amps. If you f###ed up and got hit with the center wire your arm goes numb for a few minutes then your entire arm aches to the bone for days. One guy got hit and luckily the customer called 911 because he turned white couldn't stand up. He had gone into arryhthmia. He spent a couple days in the hospital. It also had a flash lamp power supply that flashed 4 massive xenon flash lamps at 2 times a second. The power supply had 6 capacitors that were 1000 farad each. Had lethal caution stickers all over it. New guys learned real quick where not to put your fingers or screwdriver.

Rivets said:

Have you tested both receptacles on the 120V receptacles as well as both legs of the 220/240 receptacle? Before throwing parts at this unit I would be checking the wiring.

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I've checked both 120v recepticacles. They're both 183.
Are you saying it's possible that the factory hooked up two 120 wires?

There are different ways to manufacturers wire up portable generators. If engine is running at approx 3600 and you have 183v at the outlet most likely the AVR is bad. Have you checked the 240v outlet voltage? Across the 2 hots, each hot to the neutral.
Most portable generators with 240v will have 2 separate 120v outlets with each one using a hot leg of the 240 to neutral so you can utilize all the generator's power into 2 120v circuits. Looks like that one only has one duplex receptacle so they are either just using one leg of the 240 or they have split the outlet with a different leg to each socket. You can test it by measuring between the two hots of the receptacle. Zero volts on one leg. 240v means the receptacle is split using both 240v legs.

Hammermechanicman said:

There are different ways to manufacturers wire up portable generators. If engine is running at approx 3600 and you have 183v at the outlet most likely the AVR is bad. Have you checked the 240v outlet voltage? Across the 2 hots, each hot to the neutral.
Most portable generators with 240v will have 2 separate 120v outlets with each one using a hot leg of the 240 to neutral so you can utilize all the generator's power into 2 120v circuits. Looks like that one only has one duplex receptacle so they are either just using one leg of the 240 or they have split the outlet with a different leg to each socket. You can test it by measuring between the two hots of the receptacle. Zero volts on one leg. 240v means the receptacle is split using both 240v legs.
View attachment 55198

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Checked the 220v legs and got the same 180V.

Got the new AVR installed. And it drastically reduced the voltage. But brought it down too much. At 3,600 and 3700, the voltage is the same. 105 to 106. Under a load (heat gun on high) and it increases the one circuit to 112. But drops the other to about 97v.
I'm testing the L1/2 & R1/2 in the back of the generator.

This gen only has one 120 outlet, with two plugs. And the 220.

Customer say he put too much of a load on it a couple of times and it through the switch. I'm not sure what he meant by switch. It doesn't have a circuit breaker. Unless the on/off switch doubles as one.


BTW, I was watching a video earlier. (It looked home made) But the guy says you can turn the tiny screw on the back of the AVR clockwise, and it'll increase the voltage. I don't trust the guy, so I thought I run it passed you guys.

When you install a new avr on most generators you need to adjust the voltage. Different folks do it different. Usually same result. Screw is uaually on the back of the avr. Let it hang on the wires. Hook up a voltmeter and a tach or meter that does frequency. Start it up and no load should be running at 3750 rpm. Adjust avr screw to 120v. Clockwise to oncrease voltage. Apply a load close to the max of the generator's running watts. Rpm should drop to about 3600 or 60Hz and voltage should still be 120v. If not tweak avr to 120v. Then check 240v outlet voltage. Should be double the 120v outlet. Just the way i do it.

Hammermechanicman said:

When you install a new avr on most generators you need to adjust the voltage. Different folks do it different. Usually same result. Screw is uaually on the back of the avr. Let it hang on the wires. Hook up a voltmeter and a tach or meter that does frequency. Start it up and no load should be running at 3750 rpm. Adjust avr screw to 120v. Clockwise to oncrease voltage. Apply a load close to the max of the generator's running watts. Rpm should drop to about 3600 or 60Hz and voltage should still be 120v. If not tweak avr to 120v. Then check 240v outlet voltage. Should be double the 120v outlet. Just the way i do it.

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I turned that screw a full turn and nothing changed. Then my parts came in for a commercial customer and had to leave it for the day.

Thanks for the info on this.