Honda 2000i Inverter generator has intermittent output.

[tcmtech]

I finally got something that came by to be looked at that I have never worked on before, a Honda inverter generator with a odd intermittent output glitch. I am fairly sure its an inverter/control board issue at this point but I figured I would still run it by here and see if anyone has some familiarity with them.

Sometimes when it starts it has no output and other times it works fine and will run for hours without a problem and as with typical stuff like these the manual is less than satisfactory on diagnostics beyond either it works or it doesn't. https://cdn.powerequipment.honda.com/pe/pdf/manuals/31Z07610.pdf

I've been through all the wiring and did not find any real definable issues with connectors or anything else and when it works it works perfectly from no load to full load for any reasonable run time regardless of whether it's in my heated shed and warmed up or has been sitting outside all night in subzero temperatures. The auto idle works fine and it runs well even when cold so it's not a engine speed or obvious temperature or load related issue given when it acts up there is no power indicator light right from startup even when no load was ever applied to it.

So is it a inverter/control board issue or is there some other component that will make it act as such?

If it's the board its a potted non serviceable design and a new one seems to be worth ~$400 (about half of what a new generator goes for) from what I am finding so far and I doubt the owner will pay that much to fix a well used machine.
https://www.ereplacementparts.com/h...-eaaj1170001-parts-c-37657_206860_206875.html

 

[alec_t]

Perhaps a dry joint somewhere in the module? But if the circuit is potted I don't see how you'd ever find the culprit .

 

[Les Jones]

Is it possible to get to the DC input to the inverter ? I have never played with one of these units but my guess would be that the altenator part output is controlled via the field coil (In the same way as a car alternator.) I imagine it's output voltage would be designed to give after rectification the required DC input to the inverter. If you could monitor this DC voltage to see if there were glitches here when the output glitched then you would know it the problem was caused by the generator part or the inverter part. I imagine there is also a control loop that increases the engine speed as the load current rises. this would allow the field current to be reduced to get the same output voltage. Reducing the field current would mean that more current output could be obtained for the same engine torque. Good look with tracing the fault. Intermittent faults are the worst to find.

Les.

 

[debe]

With those Inverter generators theres realy nothing you can do with the inverter module except replace it. The only test you can do is check that theres ac voltage to the module. I have several faulty modules & the generators finish up scraped. The power led function is powered from the inverter If it doesn't come on when you start it then the fault is in the inverter. I had a diferent brand generator that looks the same as a Honda do the same thing. I was lucky enough to find a secondhand inverter from another gen that the motor had thrown the con rod. This at least got it going again.

 

[tcmtech]

Perhaps a dry joint somewhere in the module? But if the circuit is potted I don't see how you'd ever find the culprit .

That would be my guess as well and yep, they made damn sure nobody can work on the inverter boards. They are buried in some sort of epoxy to where only the the tops of a few components stick out.

 

[tcmtech]

Is it possible to get to the DC input to the inverter ? I have never played with one of these units but my guess would be that the alternator part output is controlled via the field coil (In the same way as a car alternator.)

I believe they are PM alternators being there is no field circuit and the units adjust the engine RPM's to compensate for different loads.

They are a neat design but for the $1000+ price tag and total lack of serviceability, no thanks. I will stick with my big old simple gensets I get at auctions for a few $10's of dollars whether they run or not for a while longer.

 

[tcmtech]

With those Inverter generators theres realy nothing you can do with the inverter module except replace it. The only test you can do is check that theres ac voltage to the module. I have several faulty modules & the generators finish up scraped. The power led function is powered from the inverter If it doesn't come on when you start it then the fault is in the inverter. I had a diferent brand generator that looks the same as a Honda do the same thing. I was lucky enough to find a secondhand inverter from another gen that the motor had thrown the con rod. This at least got it going again.

Pretty much what I figured as well given how things checked out. The guy doesn't want to spend the money on it just yet so he's going to run it as is for a while. It's his ice fishing house generator so it's not a critical application unit. He figures that for what he does he can buy one of the Chinese knock offs from Harbor Freight or Northern Tool for way less money.

 

[Les Jones]

This post has put me off even thinking of buying an inverter generator. After reading debe's post I thought the only thing left to check was the slip rings for the field. If it is a PM alternator there is not even that to check.

Les.

 

[alec_t]

This post has put me off even thinking of buying an inverter generator.

It's put me off too. I can't see it's really in a manufacturer's interest to sell economically unrepairable kit. It doesn't encourage brand loyalty. If the only option is to buy an expensive new genset/inverter then wouldn't the owner of the failed unit be looking for a different brand?

 

[debe]

After having owned conventional Generators & several Inverter Generators. I have found the conventional generators more reliable & easier to repair in the long run. For those not familiar with inverter generators I will post some pictures & circuit of a Kipor gen that I owned & the inverter failed & it burnt out the 12V windings on the stator that feeds the inverter electronics. Ive found all the Inverter generators are built in a similar way, doesn't seem to be a lot of diference in brand names. Honda use a plastic timing belt on there OHV motors the rest use a timing chain.

 

[Les Jones]

Hi debe,
Thanks for posting that information. Quite a few of my assumptions as to how they work were wrong. Particularly the one about the alternator generating a relativly high voltage.

Les.

 

[tcmtech]

After having owned conventional Generators & several Inverter Generators. I have found the conventional generators more reliable & easier to repair in the long run. For those not familiar with inverter generators I will post some pictures & circuit of a Kipor gen that I owned & the inverter failed & it burnt out the 12V windings on the stator that feeds the inverter electronics. Ive found all the Inverter generators are built in a similar way, doesn't seem to be a lot of diference in brand names.

Rather the same views I came to regarding conventional Vs inverter based welder power supplies back when I was doing welder and like equipment repair work for a local business.

Impressive for their size and function but for the up front prices and high service costs involved and less reliable long term service lives I Just didn't care for them. One 50 cent normally easily replaced component that's buried in epoxy (when a thin conformal coating would have been more than sufficient) goes bad on a board and you can be out half the cost or more of a $1000 - $4000+ dollar unit by the time everything is fixed.

I did that literally daily for my job and I came to hate the blatant waste of good money that it produced.

 

[debe]

Actualy Les, the circuit is for a 240V machine for Australia the voltages for the inverter are. The main 3 phase windings is 350v on each phase & a 12V sub winding to feed the inverter electronics. On this particular machine the inverter developed a short on the 12V circuit, it burnt out the sub winding. I rewound the sub winding but found a new inverter just too expensive, which left me with a good engine & windings & as tcmtech has indicated a waste of good money.

 

[Les Jones]

Hi debe,
Thanks for the update. At least it looks like I guessed one bit of the design correctly although the 350 volts is a bit higher than I expected. I would have expected a voltage that when rectified would give about 240 x root 2 (340 volts DC)

Les.

 

[tcmtech]

At least it looks like I guessed one bit of the design correctly although the 350 volts is a bit higher than I expected. I would have expected a voltage that when rectified would give about 240 x root 2 (340 volts DC)

PM alternators have pretty bad voltage droop right off the top with even a small load applied so I suspect they give them a bit of headroom voltage to work with.

Also, standard utility power is usually allowed around +-10% over/under voltage to be acceptable so given that, if the DC side of the inverter circuit is seeing anything under ~ 375 volts or over ~300 volts its still within utility line voltage specs to run.

Throw some clever PWM based output waveform manipulation and output stage LC tank filtering (the two big toroids on the end in the one picture) on top of that and you can cheat on that DC input voltage even further.

 

[Miho]

My little work.
[link deleted - moderator]
Base - China EGS002 module. Speed control without MCU - no good idea, but too lazy to remake.

 

[Les Jones]

I am confused. You start by talking about a 20 HP engine and then you are taking about almost a 14 MW generator. Even if it was 100% efficient it would require over 18000 HP to drive it.

Les.

 

[JimB]

Les,
dont worry about it, the more I look at that post, the more I am convinced that it is just spam.

And what does JimB like to do with spam?
Press the SPAM button of course, it makes spam go away.
3 2 1 gone!

JimB

 

[schmitt trigger]

Very likely he meant watts.....not kilowatts.

But back to the thread.
In the past I have toyed with the idea of purchasing an inverter generator. But this thread has put me off.