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After replacing the Torch plug and putting in oil and fuel, I was able to capture some waveforms from my new Wen 56225i inverter. First, the inverter:

View attachment 10241
Once you remove the side panel, everything seems fairly easy to get to. It started up without incident and ran very smoothly. I got my DMM out and the inverter tested at 124.5 VAC, identical to my GN400i. Just like with the 400i, I could not lock onto a Hz reading. It jumped all over the place. It's probably a DMM issue. Next was the scope.

Power output was not very smooth at first. It was jumpy and a bit jagged:


View attachment 10242

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I discovered that this Wen has the same issue as the Champion. You have to use the neutral bonding plug. For some reason, that cleans up the signal on the scope. Notice the Hz reading. That will become relevant later.

I was still getting weird readings, even after using the neutral bonding plug. The display was a bit erratic and jumped around. Plus, the Hz readings kept jumping up and down. That was strange. I hadn't seen that before when testing my other generators, even the non-inverter ones. There was some noise in the signal as well, which was also out of place.

View attachment 10244

I caught it on one of the frequent Hz bursts to above 80 Hz.

View attachment 10245

I was a bit perplexed. The other inverters I have don't do that. Hz is always stable, as is VAC. I started brainstorming to try to figure out what was going on. Why was I getting such anomalous readings from this inverter?

I had to run a fairly long power cable from the scope to the wall outlet in the garage. I noticed that the power strip I was using that was connected to wall power looked old. It was yellowed and very worn looking. I wondered if I might be having issues because of that. I removed the old power strip and replaced it with a known-good APC one. After that, the signal seemed to clear up considerably.

View attachment 10247

The Hz stopped jumping up and down as well. It remained stable at 60 Hz, as you would expect.

View attachment 10248

Apparently, from what I saw, the old power strip I was using to power the scope was causing strange readings from the inverter. I'm not sure how that would happen, but once I removed the old strip from the power chain, the readings cleared up and the inverter readings became what you'd see from any other inverter. VAC is off, but that appears to be because my cursors are not set correctly. I did confirm the inverter is outputting 124.5 VAC, though.

I pulled the old power strip out of my rotation since it seems to be causing issues. My takeaway is to make sure the scope is getting clean power from the wall or readings might be wonky.
good one!
also does the apc strip have any protection like surge or filtering?
yea any coils or wire loops affect the readout.
and can pick up rf trash as well...

so did you use the old strip when checking the other gens as well???
you might have to revisit those posts with updated screen shots..
it still has a couple of little spurs of trash. not much but you could see a bad firing gate or a rotor slot slight out of time.
 

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If you're willing, you might won't to conduct one other test to see if it makes any difference in your results. Instead of plugging your scope into one of you home's wall outlets, plug the scope into one of the generator's outlets and then conduct the same test. Of course, if the wall outlet is receiving its power from the generator, then forget what I am suggesting ........ as it won't make any difference at all.

If the wall outlet you utilized truly isn't receiving its power from the generator, then I'd be curious to see if the home's ground conductor was possibly the source of your anomaly .................. anyway, just a thought!
I did plug the scope into the inverter and took more readings. The outlets on the inverter are recessed so I need to use a power strip to properly seat the probe attached to the hot leg. I've taken readings from house power before and it looked okay. So I don't think the wall power was the problem. I think it was the old power strip. It was the first time using that particular strip to power the scope. Everything stabilized once I removed it.
 

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good one!
also does the apc strip have any protection like surge or filtering?
yea any coils or wire loops affect the readout.
and can pick up rf trash as well...

so did you use the old strip when checking the other gens as well???
you might have to revisit those posts with updated screen shots..
it still has a couple of little spurs of trash. not much but you could see a bad firing gate or a rotor slot slight out of time.
The APC strip does have surge protection. I don't think it does any filtering, though. It's not one of their expensive ones. Certainly nothing like the Isobars.

I didn't use the old strip in any of the previous tests. The scope was plugged directly into the wall outlet in the garage when testing the other generators. I used it this time because I was trying to extend the cord out to where the inverter was on the tailgate of the truck. I'm confident that was what was causing the scope to behave a bit erratically.

It's interesting that the other Wen shows an identical spike in what appears to be the same spot. Is a bad firing gate or a rotor slot-time issue adjustable? As is, the signal looks pretty clean from what I can tell. I'm presuming it's clean enough for any appliances that will run from it. My plan is to use it overnight during an outage to power the window a/c units. It's rated at 9.4 hours but only at 25% output. It drops down to 6 hours at 50% which puts me in the same boat as the GN400i. An extended run beyond that is going to require an auxiliary fuel source. Enter the 9 gallon marine tank... although I really just need to be able to run it from dusk until dawn to keep the insects from dragging me off into the woods during refueling.
 

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that has the making for the next S king movie!!
mutant LARGE flying bugs carting folks off...
back in the day with creature feature movies that would to have been a real box office hit!

"i'd pay a dollar to see that!"

try just a T for the outlet extension or a home made short cord.
that way no chance on other electronics to mess with the numbers.
 

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LaSwamp

I guess what I was trying to convey is:

A) if your scope is attached to your home's electrical outlet, then it is also connected to your home's grounding system ....... that is unless you have removed the ground prong of the plug OR are using a cheater plug - which in either case is not recommended!

B) Using the scope in the manner you had described means the scope is now REFERENCED to your home's electrical ground system. And again, I am assuming you were utilizing only the TIP of the scope's lead on L1 of the generator's 120 VAC outlet AND the scope's ground lead was not being connected or had been removed. If this is truly the case, the scope signal was not referenced properly. You would certainly see a sine wave, but I would suspect the voltage would be incorrect ..................... but by how much, I don't know????

Anyway, just trying to understand what you've done and learn myself.
 

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LaSwamp

I guess what I was trying to convey is:

A) if your scope is attached to your home's electrical outlet, then it is also connected to your home's grounding system ....... that is unless you have removed the ground prong of the plug OR are using a cheater plug - which in either case is not recommended!

B) Using the scope in the manner you had described means the scope is now REFERENCED to your home's electrical ground system. And again, I am assuming you were utilizing only the TIP of the scope's lead on L1 of the generator's 120 VAC outlet AND the scope's ground lead was not being connected or had been removed. If this is truly the case, the scope signal was not referenced properly. You would certainly see a sine wave, but I would suspect the voltage would be incorrect ..................... but by how much, I don't know????

Anyway, just trying to understand what you've done and learn myself.
Typically, I plug the scope directly into the outlet. This time was different because the inverter was far enough away that I needed to extend the power cord. I used the old power strip as part of the extension. I had never had any issues before when plugging into the wall outlet, so I don't think that was a factor. The only thing I did different this time was using the old strip. Once I removed the strip, the scope behavior became normal. I think the strip was bad and that was what was causing the scope to behave erratically. I didn't have time to do any more tests but the next time I have the scope out I will plug it directly into the wall outlet and test the inverter again. My guess is the readings will be what I would expect. The only thing I wasn't expecting was the signal to be wonky without the neutral-bond plug. I have a Champion inverter that does the same thing. The signal is distorted until I plug in the neutral bond plug. Then it's clean as a whistle. When I talked to Champion tech support, they told me that was expected given I was only testing the hot leg. My bigger Wen inverter doesn't need the neutral bond plug to give a clean signal, so I'm not sure what using only the hot leg has to do with it. All three inverters have floating neutrals.
 

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Typically, I plug the scope directly into the outlet. This time was different because the inverter was far enough away that I needed to extend the power cord. I used the old power strip as part of the extension. I had never had any issues before when plugging into the wall outlet, so I don't think that was a factor. The only thing I did different this time was using the old strip. Once I removed the strip, the scope behavior became normal. I think the strip was bad and that was what was causing the scope to behave erratically. I didn't have time to do any more tests but the next time I have the scope out I will plug it directly into the wall outlet and test the inverter again. My guess is the readings will be what I would expect. The only thing I wasn't expecting was the signal to be wonky without the neutral-bond plug. I have a Champion inverter that does the same thing. The signal is distorted until I plug in the neutral bond plug. Then it's clean as a whistle. When I talked to Champion tech support, they told me that was expected given I was only testing the hot leg. My bigger Wen inverter doesn't need the neutral bond plug to give a clean signal, so I'm not sure what using only the hot leg has to do with it. All three inverters have floating neutrals.
Fine - I was thinking the different ground reference might be the reason you're getting voltages that you did not expect to see. Anyway, it was just a thought! Then again, it might just be a cursor issue, but unless you have tweaked the setting inside your scope, it is probably still set to <AUTO> .
 

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Fine - I was thinking the different ground reference might be the reason you're getting voltages that you did not expect to see. Anyway, it was just a thought! Then again, it might just be a cursor issue, but unless you have tweaked the setting inside your scope, it is probably still set to <AUTO> .
From what I gather, the VAC issue is due to the cursors not being set correctly. When I adjust the waveform scale, the VAC changes as well. It makes sense that the cursors are reading different parts of the waveform which is what's causing the inaccurate readings. I need to learn how to use the cursors. I wanted to test the waveform on the new inverter before I actually plugged anything important into it. It looks the same as the other Wen unit I have, so it should be good to go. I'll parallel the two Wens together this weekend if I have time to make sure they talk to each other.
 

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From what I gather, the VAC issue is due to the cursors not being set correctly. When I adjust the waveform scale, the VAC changes as well. It makes sense that the cursors are reading different parts of the waveform which is what's causing the inaccurate readings. I need to learn how to use the cursors. I wanted to test the waveform on the new inverter before I actually plugged anything important into it. It looks the same as the other Wen unit I have, so it should be good to go. I'll parallel the two Wens together this weekend if I have time to make sure they talk to each other.
make sure to connect them together before starting any of the gens.
 

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From what I gather, the VAC issue is due to the cursors not being set correctly. When I adjust the waveform scale, the VAC changes as well. It makes sense that the cursors are reading different parts of the waveform which is what's causing the inaccurate readings. I need to learn how to use the cursors. I wanted to test the waveform on the new inverter before I actually plugged anything important into it. It looks the same as the other Wen unit I have, so it should be good to go. I'll parallel the two Wens together this weekend if I have time to make sure they talk to each other.
Bingo. The curser is your issue.
 
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