Generator not putting out enough wattage...I think

[NoJive]

Newbie here, but I am posting because I cannot find my exact problem anywhere else. All I am finding is low voltage or no voltage issues.

I have a Harbor Freight 4000 watt (3200 watt running) generator that we use for camping, and power outage purposes. I've had it for around three years, and it has given me no problems except for noise (it is loud!). Anyways, we are camping on our river property this month, and I noticed the generator running faster than it normally does. We use it to run the A/C as needed, and it seems to idle down once the compressor kicks in, and then speeds up once that kicks off. That seems like the opposite of what it used to do. I also found out that it now no longer runs the microwave, which it used to do fine. Now, the generator bogs way down, and the microwave barely runs.

I did call Harbor Freight, and they seemed to think the voltage regulator was going bad, so I bought a new one, but that didn't seem to help any. I'm getting 116v on the outlets, so it doesn't seem to be a voltage issue.

Is there anything else I can check?

[NoJive]

I think I am giving up on this generator, and am now looking at Champion inverter types.

[NoJive]

I think you may be right. The first thing that got my attention was it seemed like the generator was running way too fast while not under load. I did check this evening, and I do see the governor moving, but not enough to raise the speed.

[PaulJ2]

NoJive wrote:
Ok, finally got to do some testing. With no load, I get around 117 volts, with a hair dryer running on max, I show 122 volts. Here is a video I took:

https://youtu.be/283RcOO75mo

After hearing the audio the generator's governor is not controlling the engine speed properly. It should stay at 3600 with increased load. The voltage increasing with the rpm decrease is the regulator over compensating for the speed drop off.
I believe the problem is with the engines governor.

[NoJive]

Did this, and got 117 volts from short receptacle slot to ground/shiny spot.

MEXICOWANDERER wrote:
Root
Mean
Square

Deals with AC voltage -under curve- and has got nothing to do with Hz.

One step at a time

Slip on a set of kitchen gloves

Now take your meter which is set to AC volts...

And verify voltage at the receptacle.

Then from the SHORT receptacle slot to a shiny spot on the generator motor

What do you see?

[NoJive]

Ok, finally got to do some testing. With no load, I get around 117 volts, with a hair dryer running on max, I show 122 volts. Here is a video I took:

https://youtu.be/283RcOO75mo

[MrWizard]

there is no way that generator can run at speed to produce 161 hz
that is a faulty reading
engine would destruct before getting that fast
it would be screaming

[wa8yxm]

Inverter generators typically speed up when the load increases

Classic genrators do not, or are not supposed to. however if I were desiging the controls I'd have a system where the throttle is operated in part by the load (Load anticipation) the idea is to reduce the lag time between an increased load and the opening of the throttle to compensate..

Now I don't know of anyone doing that, but I also don't know that they do not.

161 Hz is a bit high.. I'd see if it can be adjusted.

[MrWizard]

that generator will always run at 3600 RPM. 60hz
if the freq is correct the speed is correct
it will get louder and use more fuel with a load
but it is still the same speed plus or minus 2hz / 120rpm

if it won't carry the load
A: the load is too big
B: the generator is failing

open the end of the generator head and check the field brushes on the slip rings

[NoJive]

I will do more testing this weekend. When the fan was plugged in, the gen was running pretty faat, and I was getting 117 volts from the other socket. I think I mis-spoke when I said idle speed, I actually meant the spped the generator runs at with no load.

This is what I have, non inverter:

[MEXICOWANDERER]

"Also, I did adjust the idle speed, as like I said, it was running very fast, but slowing it down did not lower the frequency"

Fascinating. Therefore an inverter generator. This one?

[Chum_lee]

You still haven't answered the most important question. What is the voltage when running at +-75% load? Is the test voltage you post the free running voltage, the loaded voltage, or something else? It makes a HUGE difference on how to diagnose your specific problem.

Chum lee

[road-runner]

Many of the non-inverter generators have a poor waveform that throws off a frequency meter. At 161 Hz. the engine would be turning close to 10,000 RPM and it would self destruct before getting to that speed. A different frequency meter might work ok, and an oscilloscope definitely would. If you can find an old motor-driven clock with a sweep second hand, it makes a perfectly good frequency meter because the motor speed is based on the frequency.

[Tom_M1]

The generator should run at a constant 3600 RPM regardless of the load. It should never run at idle speed. The fan running slower than normal is an indication the generator is running slow. Make sure the throttle linkage is clean and moves freely. Adjust the speed until the voltage is a bit on the high side with no load. Plug in a fairly heavy load such as a hotplate or toaster. The throttle should open up to bring the speed back up to 3600 RPM. Check the voltage to see if it is close to 120 volts.

[MEXICOWANDERER]

Root
Mean
Square

Deals with AC voltage -under curve- and has got nothing to do with Hz.

One step at a time

Slip on a set of kitchen gloves

Now take your meter which is set to AC volts...

And verify voltage at the receptacle.

Then from the SHORT receptacle slot to a shiny spot on the generator motor

What do you see?