Generator not communicating with Inverter

[JohnW2837]

I'm having an issue with my generator not being recognized by the Inverter.

here are the components:
Cummins/Onan 2800watt HGJBB gasoline generator
Go Power IC2000 Watt Inverter/battery charger/automatic transfer switch

The inverter was installed in the spring of 2021 in conjunction with adding solar panels and LiPo batteries. Prior to this the generator worked fine with the old Intellipower inverter/charger.

With my new setup the only thing I need the generator for is to run the AC. The solar setup works fine to run the microwave, keurig, phone chargers etc. We have a 3-way fridge so I run that on propane when not connected to shore power.

Since the installation of the solar system I haven't been able to use the generator. Go Power and the installer said the problem was with the generator not producing "clean" output. Since the installer (who has since gone out of the service business) was not licensed to work on cummins I took it to a cummins service center. They replaced the carburetor and fuel pump and it was running very smooth, putting out a consistent 120 vols at 60Hz without a load. The inverter still will not recognize it.

When on the phone with GoPower they had me check the Grid Fault on the control panel and it says "OFP" which they had no idea of what that means. some online searching and I found that it could mean over frequency protection.

Any help here would be greatly appreciated since the cummins people says the generator is running to specifications and GoPower isn't being very helpful.

[Bones2003]

Does it work ok if you connect to shore power?

[JohnW2837]

Yes, everything works exactly as it should when connected to shore power.

[Bones2003]

Also, if you turn the inverter power switch (located on the front of the inverter) to OFF, the generator power should just pass through the inverter transfer switch and provide power to all your 120VAC appliances. Does that work?

Does the status light on the front panel of the inverter flash/blink/change color?

[JohnW2837]

I haven't tried turning the inverter off when running the generator and i'm not sure it is possible. When I am connected to shore power the inverter will not turn off. If the inverted is turned off it will turn on automatically when i plug into shore power. Normally both lights on the control panel are solid green when running on batteries or shore power. when "connected" to generator the ON/Off switch is solid red.

[Gary Harter]

Since the inverter works on shore power and not on the generator, it sounds like the inverter transfer switch is wired wrong.

[Morich]

I think this is a place to start with the parts you do know about and add to them as you go through the wiring.
Step one is to get which RV you actually have as your profile lists a 24 foot and there are only 25 foot listed!
So which model do you actually have? This should show up on paperwork or there is often a label with the needed info somewhere near the drivers seat.
Which model will let us look at how the OEM wiring was done and how they may have changed it.




Second step is knowing how the wiring is now arranged to get from the generator to the power cord and on into the load center. OEM was to plug the power cord either into the shore power or the box with the wiring from the generator. This is looking at the 25P model, sodo you have this?
Did they leave that in place or remove/replace it some way?
This would be a first place to look as it sounds like it has not been connected to get power from the generator to the load center???

[Bobn1957]

Most likely you are having a problem caused by generator not grounding the neutral as is common in generators.

[JohnW2837]

Thanks for the replies. My RV is a 2015 Winnebago Itasca Viva 23L, SN: 7066T136422.
Since my original post I've been able to do some more trouble shooting by having a friend plug his RVs generator into the plug on mine and the inverter works fine powering everything and charging the battery so I can eliminate the inverter as the source of the problem.
Also GoPower did get in touch to verify that OFP is over frequency protection and must be caused by the generator not producing a "clean" sine wave. The cummins tech said there is no way to change the sine wave.
In addition the GoPower tech said they have run into this problem with older Onan generators.

[Morich]

Was there a significant difference in the age of the two generators to think there is a difference in the sine waves of each?
Your genset being 2015, I would not think it that old to be "over the hill" ??? Certainly lots of genset that are older than that!

Good thinking on trying a different RV!!

[Bobn1957]

If you connected an oscilloscope to the generator output you could measure the frequency accurately, IMHO is you would likely see harmonics or noise as the problem, if there is enough noise the inverter will shut down. There might be a filter in the generator that has failed. The filter would be some sort of combination of components that would include a big capacitor.

[JohnW2837]

The generator that was connected was in a 20 yo RV that with a 20 yo Generac generator. The owner, who is a mechanic, told me that it was well used and regularly maintained. I'm hoping to try it out with a newer onan but that one runs on propane so I don't know if that would be helpful.
I mentioned to each of the 3 places I've taken it for repair that GoPower said the generator needs to output a clean sine wave but neglected to ask any of them if they put an oscilloscope on it.

[Bones2003]

According to the Onan service manual for the HGJBB generator, there are several things that could contribute to the generator frequency being slightly off. There is also a governor adjustment that can be used to fine tune the frequency. The problem is that it requires special tools/meters that a DIY person wouldn't generally have available. The manual does a pretty good job explaining how this all works.

It looks like the frequency drops somewhat as the load increases so the generator frequency is intentionally set a little high at no load. If the inverter checks the frequency of the generator at no load before switching it on, perhaps it is just a little too high? I know you said the Cummins service center said the frequency was 60hz at no load but how did they really check that?

You can do an online search for "onan HGJBB service manual".

[Morich]

Does a Kill-a-Watt meter give the freq?

Or did I just dream that up? I've slept since last seeing mine!!
Cheap lowball test?