Inverter problems ...or maybe not?

[John Cortesy]

2018 R25-OB has a separate inverter and charger, not a combo unit. I have already replaced the charger. The inverter is behind the wall near the AC panel I believe. I have tried getting access to it and cannot figure out how to get the wall loose. The inverter is a Kisae model, not sure which one.

After owning the boat for a year I finally came upon a chance to use the inverter to run the microwave for a couple minutes. I turned the remote switch on, got a green light, then turned on the microwave. it ran for a few seconds then shut off. Several attempts had the same results. Three long beeps coming from the power panel then a shutdown. Voltage showed zero for a second, then it reset to 120 volts as it came back online.

When I got back home I tried a smaller load. A 3 speed oscillating fan, which ran fine with no beeping and no shutdown. With both the microwave and fan, there were no other breakers activated so these devices were the only load on the inverter.

Should the inverter be able to handle high loads like a microwave or even a toaster? Could my batteries be weak and need replacing, thus only accepting smaller loads? The microwave test was conducted with the engine running and voltage above 14 volts. Can anyone think of other diagnostic tests I can perform to help diagnose the problem? Or even how to remove that back wall to access the inverter?

Thanks in advance for your input.

 

[cliffm]

I've recalled reading about inverter issues, searched and found these threads. https://www.tugnuts.com/threads/inverter-problem.21215/ https://www.tugnuts.com/threads/inverter-issues.26424/ https://www.tugnuts.com/threads/inverter-problem.5653/
One thing that comes to mind, from working with Martin, is the 2 house AGM batteries don't share a positive bus bar, so the loads don't equally draw. Martin can explain it better, I think its our era of model/wirering design. You may be loading one AGM battery more than another, causing the low volatge cutout. I'll admit that we rarely use the boats inverter, running the microwave on either shore power or from our Bluetti "similating" shore power.

 

[John Cortesy]

Thanks Cliff,
I read every thread that I could find Labelled inverter and found out that I might not have enough battery to support the inverter. A positive battery bus would be a good idea.