Onan 5500 gas generator issue

[whs9841]

I'm having an issue with my on board Onan 5500 generator. This is in a 2014 Keystone Fuzion. Last Summer we were dry camping in very hot Texas weather. We had both A/C's running, along with other small stuff (tv's, lights, etc). My wife turned on the microwave and it caused one of the 30A breakers on the generator to trip.

I shutdown the generator, turned the other breaker off, turned them both back on, and then started the generator back up. I let the generator run for about 5-10 minutes before I turned on one A/C. I waited another few minutes then turned on the other A/C. Everything ran fine for about 20 minutes.....at which point the generator seemed to bog down. I thought it was going to shutdown, but after about 10 seconds, everything seemed normal again. Both A/C's stayed on and nothing tripped on the generator. Everything ran fine after that.

We are continuing to get this "bogdown" moment about 20 minutes after I have both A/C's running. When it bogs down I normally turn off the back A/C for a few minutes, then start it back up. It normally runs fine at that point. Every now and then the bogdown will occur again.

The generator has about 240 hours on it. The oil has been changed at regular intervals. I just changed the air filter (the old one was a little oily....not sure if that's a sign of an issue) and the fuel filter. Nothing changed with the bogdown issue. I haven't cleaned out the spark arrestor yet....it's on list of things to do.

One other thing that is odd is after the initial issue occurred, the exhaust isn't smooth. When I put my hand in front of the exhaust, I don't feel a smooth flow of exhaust....it feels like small bursts of exhausts at a very fast interval. It is consistent interval, but doesn't seem like the smooth flow of exhaust that I had before the issue.

Anyone have any thoughts? I'm still within the 3 yrs Cummins warranty, so I may just take it to the local Cummins service center and let them take a good look at it. However, if this is something I can do myself I'd prefer to go that route.

Thanks.

[whs9841]

I only get the bog down when both A/C's are running. This last time they were both running consistently for about 20 minutes. The temp in the RV was 90 and I set both thermostats to 72. The compressor/fan had not cycled on/off yet because when the bog down occurred the thermostats showed 81 and 82 for the room temps.

[STBRetired]

Is your refrigerator on Propane or electric? How much does your converter pull? It could also be the compressor start on one of your A/C units. Are they set to continuous fan where you might not notice the compressor start?

To really investigate, turn off all of the circuit breakers in you load center except for the A/C breakers. Let them run for a while and see if you still get the bogging. If not, turn the breakers on one at a time to find which circuit has the additional load that bogs the generator. Once you find the circuit, you can figure out what items are on that circuit to determine the culprit.

[whs9841]

bumping to see if anyone else has any opinions.

[whs9841]

I know it wasn't the electric hot water heater. We always use the propane water heater when we are dry camping.

I thought the battery charger was a trickle charger and was always on. Does it cycle on and off?

[Trackrig]

The only two other large loads are the electric hot water heater and battery charger (besides the microwave which you would know if you used it) which could kick in at any time and effect a 5500 already running two A/Cs.

Bill