First post, just a quick introduction, my brother and I have a food truck called Brisket Biscuit, so not technically an RV, but I'm hoping I can get some help for a few technical issues here. We bought our trailer pre-equipped, with fridge, freezer, hood vent, water heater, water pump, warming lamp, and ceiling a/c being the main electrical draws. The generator mounted to the front of the trailer is a Generac Gp8000e, rated at 8kW continuous and 10kW surge, going through a PD4560 distribution box via a 2m 10ga 4-prong extension cord. We haven't had any issues with the unit except for the noise level, so I built an enclosure (described below). With the enclosure in place, the generator shuts down after just a few minutes, even with minimal load. Even with only the hood vent (2400W) and some led lights, it'll run for a little bit then shut down. It isn't any hotter than without the box thanks to the beefy fan, and it starts right back up, so I can't figure out what's causing the shutdown. The enclosure is 1/2" MDF with 2mm butyl/foil sound mat inside, then 1.5" acoustic foam panels inside that on the top and long sides. The ends are pretty open, with 3x 120mm fans pushing in the intake end and a 10" radiator fan (~800cfm) pulling out the exhaust end. The exhaust itself is extended outside the box, so fumes shouldn't be an issue, though I'm not sure. The pipe turns 180 degrees and is attached to the side of the box pointing toward the intake end, but I don't think that's the issue. There are also openings for accessing the control panel and fuel filler that I keep open when running.My next step is to change the routing of the exhaust pipe so it points down, but if that isn't the issue, does anyone have any suggestions? This thing is loud and I'm afraid it's hurting our business, and the box makes it significantly quieter, but that doesn't matter if it won't stay running.

Are you getting a code? My guess is it's going into over heat shutdown mode. Open air generators are just that and require passive air around the unit to cool it. By enclosing it you are trapping all the heat. It shuts down as a self protective measure. That's my deduction, since you said it ran fine before you enclosed it and now it doesn't. If they were meant to be enclosed they would have come that way. Even vented, the pics show it's pretty buttoned up and the sound mat and foil is just insulating it's own heat.

I don't know if the generator error light is coming on, because I stupidly didn't cut the access panel wide enough for it to be visible (I actually didn't even know the light was there, the plastic on the control panel is really yellowed and makes it hard to see). I'll check next time it happens. Based on what I can feel by reaching inside, the big puller fan seems to keep the air temp around the unit as low or lower than it is without the box, so I didn't think that would be an issue, unless there's some particular part that's heating up more that is causing the shutdown.

Is it OK with the box off? Point the hot exhaust straight up through the top not down. Shield the serving side only.

CA Traveler wrote:Is it OK with the box off? Point the hot exhaust straight up through the top not down. Shield the serving side only.This. Run it with the box off and you'll know soon if that's the issue. Another simple, free thing to check is to ensure the correct oil level. Very simple thing, but it will cause the issue you're describing.And, based on the name of your food truck, I very much want to try it! Too bad I'm not in your area!

Brisket, I have a newer version of the same generator. I would guess from the pictures that there is a big heat build up in the carburetor area. Put the exhaust heat alone that side of your box. You might think about looking up a Gen-Turi as an exhaust. That won't help with noise much, but it will get the exhaust up over the roof. I can't promise that will help with the shut down. I might be cleaner.Matt_C

Generac shutdown issues, help! | Good Sam Community

way2roll
Navigator II
May 23, 2023
Are you getting a code? My guess is it's going into over heat shutdown mode. Open air generators are just that and require passive air around the unit to cool it. By enclosing it you are trapping all the heat. It shuts down as a self protective measure. That's my deduction, since you said it ran fine before you enclosed it and now it doesn't. If they were meant to be enclosed they would have come that way. Even vented, the pics show it's pretty buttoned up and the sound mat and foil is just insulating it's own heat.
BrisketBiscuit
Explorer
May 23, 2023
I don't know if the generator error light is coming on, because I stupidly didn't cut the access panel wide enough for it to be visible (I actually didn't even know the light was there, the plastic on the control panel is really yellowed and makes it hard to see). I'll check next time it happens.

Based on what I can feel by reaching inside, the big puller fan seems to keep the air temp around the unit as low or lower than it is without the box, so I didn't think that would be an issue, unless there's some particular part that's heating up more that is causing the shutdown.
CA_Traveler
Explorer III
May 23, 2023
Is it OK with the box off? Point the hot exhaust straight up through the top not down. Shield the serving side only.
rjstractor
Nomad
May 24, 2023
CA Traveler wrote:
Is it OK with the box off? Point the hot exhaust straight up through the top not down. Shield the serving side only.

This. Run it with the box off and you'll know soon if that's the issue. Another simple, free thing to check is to ensure the correct oil level. Very simple thing, but it will cause the issue you're describing.

And, based on the name of your food truck, I very much want to try it! Too bad I'm not in your area!
Matt_Colie
Explorer II
May 24, 2023
Brisket,
I have a newer version of the same generator.
I would guess from the pictures that there is a big heat build up in the carburetor area. Put the exhaust heat alone that side of your box. You might think about looking up a Gen-Turi as an exhaust. That won't help with noise much, but it will get the exhaust up over the roof.
I can't promise that will help with the shut down. I might be cleaner.
Matt_C
Grit_dog
Navigator
May 24, 2023
Off the cuff, looks like you have the airflow for cooling pretty well designed (and you confirmed it’s not getting real hot inside).
That said, the mufflers on, well, any engine, but on small engines that run full throttle get VERY hot. Ever see it at night? My home generator (similar to yours) and big mowers will get glowing red hot under sustained load.
Could be some localized heat maybe causing a vapor lock but it wouldn’t restart instantly I think.

Exhaust back pressure could be an issue too. Maybe test the absolute shortest straight run of exhaust pipe to get it clear of the enclosure and see if that helps.
IMO it’s likely heat or backpressure if it runs fine “naked.”
Grit_dog
Navigator
May 24, 2023
All that said, you’re still trying to modify something that really isn’t being used in the right application (with noise concerns).
I’d imagine you’re trying to save money, but for $3-7k you can get any number of generators better suited for your use both noise and applications.
Open frame “contractor” generators are around 90db giver take.
Quiet diesel, gas or dual fuel 10k units from mfgs like MQ, kubota, Kohler are low-mid 60s db rating.
Grit_dog
Navigator
May 24, 2023
For the recent respondents here asking, the OP said in his first post it runs fine without the enclosure….
wnjj
Explorer II
May 24, 2023
Does it run rough before it shuts down? If it does, maybe the circulation fans are pulling the outside exhaust and sending it back to the intake? If it just suddenly stops it’s more likely deciding to (I.e. heat sensor).

It may be a pain to haul and set up but could you instead use some kind of free standing (tethered) wall on the customer side?

I think you need to bring this trailer to my house so I can help with it. :D
CA_Traveler
Explorer III
May 24, 2023
I was wondering about air flow. Recommend 2 or 3 of the large fans on one end, no other openings on that end. large single opening on the other end and no fans. Exhaust straight up through the top and Gen-Turi to cool it.

Also have you weighed the trailer? Looks like a lot of weight on the hitch.

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