Question on Running Onan onboard Gen on hot days

It's specifically states in the onan microqiet manual that they tested these generators to 120°F ambient using travel trailers that the company owns.

I have experienced overheating shutdowns that were actually caused by the fuel pump. A brand new Onan brand fuel pump solve that issue.

Toy hauler fifth wheel. I didn’t run it, but am finding it is taking forever the the two 15000 btu AC’s to catch up. My infrared heat gun show it almost all areas of the camper over 100° when we parked. Two hours later high 90s. I finally open the turbo cool in both bedroom and in the garage which eliminated the duct system. Hoping to cool those down first and pull the heat out and will then work on the main living compartment as it gets cooler tonight

mrad wrote:
I guess I left out a few details. I meant an onboard generator in a toy hauler. An Onan 5500. We will be heading to our destination in 90-degree temps. The trip will be about an hour and a half

Wait, toy hauler FW or toy hauler MH? The answer would be different. If this is a FW I wouldn't as no one is in the RV to know if there is an issue with it. A MH I would certainly run it while travelling.

That's what the generator is for. To supply power in the absence of shore power. If you can survive on a hot day of travelling without the rooftop air, more power to you (pardon the pun). We ran the genset pretty much the entire time on the road. We had a previous MH that had the genset right behind the engine manifold and sometimes while travelling on 100 degree days, it would go in overheat shutdown mode. It was getting more hot air from the V10 exhaust manifold than fresh cool air from outside. I chalk it up to a MH design flaw. Anyway, I installed 2 HVAC registers in the bin door to allow more fresh air and never had the issue again. Was never a problem parked.

Always leave the generator door closed. As said, it is designed to pull air through a certain pathway. The RV outer access door is not related and can be closed or open. I suppose open it will let more hot air escape from under the coach.
The Onan moves a LOT of air over its cooling fins when running, you do not need to help it. RV outer door open or closed wont matter, there is a LOT of air being pushed across the Onan motor.
Driving or parked has no effect, doesnt matter.

I guess I left out a few details. I meant an onboard generator in a toy hauler. An Onan 5500. We will be heading to our destination in 90-degree temps. The trip will be about an hour and a half

We used to set up RV shows in the Tucson summer without access to a power pedestal. We had to run the gens, on the big diesels, all day for four days. None of them had any problems, that's what they're designed to do.

Only once did my generator go OVERHEAT and shut down
That day when I got back to the ride after shopping the Genturi was so hot (NOTE the generator had already shut down) I had to wear gloves. So with the Genny off what was making that black polycarbonate tube too hot to handle... The SUN of course. only time I've needed gloves to handle it.

The generator specifically warned to NOT open the compartment but keep it closed to insure proper (as designed) air flow... I suspect not all enclosures are proper. But do not open the generator's own access panel .

Yes, running the generator while on the road is common practice. On my 5th wheel trailers I liked to run the generator to cool things off about an hour before arrival. Opening the compartment door won't do much. My current generator is enclosed in a sound insulated box with a vented door and the generator has its enclosure of course. My other larger trailer just had the generator in the front compartment, no sound box and it was less noisy. The difference between the current 4.0 KW and previous 5.5 KW is substantial. Smaller one is a good bit louder, I only run it when I really need to!

Having an air cooled diesel generator (Lambordini) I found that having clean cooling fins helps. I play a strong fan across it on miserably hot days.