Ventilated Generator Compartment Door.

VinCee wrote:
Has anyone checked with Onan directly for this answer? Everyone on the forum will be guessing or using their humble opinion, which isn't so bad either!

My Onan Marquis 7000 NHM installation manual shows no requirement for a ventilated door when the unit is installed per the instructions. Other models may be different.

Has anyone checked with Onan directly for this answer? Everyone on the forum will be guessing or using their humble opinion, which isn't so bad either!

What oil are you using? 15/40?

I have an Onan Marquis 7000 7NHMFA26105F that does the same thing you discribed running /stopping in about 15 minute intervals. Seems to happen while driving with fridge and two ac's on. I was wondering if maybe oil pressure switch is getting weak. I was also traveling in about 90 degree weather in Florida. any one have any idea's what is going on?

I have the same generator. Considering how the cover is made, I doubt that ventilating the door would make any difference as the cooling air is brought up from below and discharged the same way.

I go to Laughlin, Nev in the summer time where I have seen temperatures of 122 degrees. I usually will park at Davis Dam right next to the river where we can use the boat and jet ski's. I run the Onan 7500 Quiet diesel 24 hours a day at times and it never has gotten hot on me. I do have the type of generator that with a push of a button will roll out about 24", but I never have left it out for cooling purposes.

It's an Onan 7000 Marquis. Not too concerned about stopped, but when in motion.

Last summer I was traveling along I-10 In SOCAL between Blythe and Indio and the generator would just stop, for no apparent reason. Oil level good, fuel level good. Running both A/Cs, with no other major electrical draw. After securing the A/Cs I could immediately re-start it. Brought one, the the other A/C back on line and after about 15 minutes, the gen would shut off again. Once A/Cs were on line, there was no "shedding", so never pulled more or close to the generator rating. Did this 3 or 4 times, until I just stepped down to only 1 A/C, and continued with no further issues.

As I said outdoor temp was in the 120 range. Moving consistently (no stop and go traffic).

My thinking at the time was high outside temps, heavy A/C load, heat from the MH exhaust, etc. maybe caused an overload and overheat condition and shut down the gen.

So I guess the answer is that the generator compartment was designed with proper air flow for the installed generator, and additional ventilation isn't necessary.

I think you asked a good question especially when operating at 100-120 degrees. I would bring the genset to operating temperature then take readings with an IR temp gun in several locations including the eng block and generator housing. Then open the door and take readings at the same locations with the door open. I might even try it with a 12v fan in the compartment to see if moving air will reduce the temps.

You need to tell us what generator.. The first two responders hit the nails on the head.

Oh wow.. Watching a TV commercial for the "MicroTouch one" Razor as I type.. it's the original Gillette that used the two edged blade.. Nothing more. and the guy is yammering how much better it is than the modern multi blade jobs.

What will they re-think of next?

Back to topic

My ONAN the way it is designed having louvers in the door wont make much difference. it breaths from the bottom. And in fact it warns not to operate it without it's own cover in place (Save for brief periods such as when re-setting a tripped breaker)

Other generators, Need the ventilation

If you have a way of telling exactly what your generator running temperature is, just leave the door open and see if it makes a difference. This may answer your question.