I am getting close to finishing my genset install project. Found a not working 7kw onan genset, repaired the broken drive pulley and replaced belt.. converted to propane, runs great. have added the Transfer switch to the FW and wired to the front compartment. Had the metal enclosure built and have the floor cutout template.. now to actually put the genset into the front compartment.. but the thing weighs 300lbs. I can't find any specs on what the floor of the front compartment will hold. (keystone tech support didn't have any specs for the floor weight capacity)also, the floor is 3.5 inches lower than the door opening, so once you get it in there, I don't know how you would ever get it out. (the enclosure is big enough that you couldn't get it out first.so I've been looking at creating a drawer, or at least mounting the genset on risers to get the base even with the front door opening. this only makes the weight thing more of an issue, cause all 300lbs will be sitting on the base of the riser (in either case). lets do the weight math, risers are 3.5in square tube, 24 inches long, and need 2 of them. 300lbs/(24x3.5x2)that comes out to 1.75 psi. not muchthe floor seems to be some thickness sheet metal (haven't cut it yet), resting on the legs of angle iron, which are welded to the frame (I think)if I can get the riser to rest on the (1"?) angle iron lip too, then the pressure on those two would be 300lbs/(1x3.5x4) = 21 psi each end of both risers. (300/4/ 3.5sq in)I have some 3/16 x 7 x 36 strips of flat stock that I could use as reinforcement in the riser area. not enough for the whole floor section as 1 piece. here is a side view of the layout

What access do you need to change the oil and perform other routine maintenance on the generator? On mine (a completely different model), the oil drain is on the underside of the generator, with a little access panel attached to the outer cover. It wouldn't work well to have it installed over an unbroken floor. Likewise, there's the need for the exhaust plumbing to exit underneath. The generator appears to be mounted to an angle iron frame, which is bolted to the undercarriage of the motorhome, so far as I've been able to suss out.I guess I'm suggesting that you consider removing the floor of the compartment and see if you can't find a way to make it able to be raised/lowered from underneath, rather than slid in from the side/front. Of course, for routine maintenance and such you'd just leave it in place.Do be careful to seal the compartment thoroughly from the interior of the trailer, and maybe consider adding some fire/sound insulation.

I would start with a 3/4" plywood base in the floor of the compartment, that will distribute the weight of the riser mounts pretty evenly across the structure and eliminate any pressure points that could overstress the structure. You can add sheet metal on top of the plywood for fire protection and oil spills.If you want to stay with metal, then a pair of 2x2 square tubes that run the full width of the compartment should give you good weight distribution as well.I would also look at a pair of HD drawer slides (like these) that are rated in excess of 400 lbs per pair. Raise the gen up to the level of the compartment door and mount on full extension slides so you can easily roll the unit out for repair and maintenance.Plus, if you need to completely remove, you can support the genset from underneath while you disconnect the slide extensions.

I set it right on the floor- removing really won't be that big a deal. I ran 1 1/2" angle underneath the compartment- frame to frame, right at the mounting holes. Plywood as an outside lining for the sheet metal enclosure.The trailer I installed it in was "generator ready", but I didn't trust the sheet metal to hold it.The hardest part is locating the holes to cut in the floor.

Don't forget sound insulation. As per Onan spec, you should have insulation on all sides (perhaps the door) of the compartment, but not beneath the genset (so fuel dripping on it doesn't cause problems.) You should also have a vent in the front as well.It also can't hurt to rubber shock mount everything (exhaust pipes, fuel and electric lines), and use the Onan resonator. This will quiet things down remarkably.

I installed a Onan Marquis Gold 7000 in our front compartment. The fiver wasn't gen ready which I liked because I "do it my way". I'm like Chris, didn't trust the floor. And the way the Onan cools, it sucks air from the bottom so I just removed the floor and welded some 2" square tubing to the fiver frame. I also made it so it would slide out of the compartment since an Onan is like an old lady, you know, lots of TLC. One thing to remember, make sure the bottom of the genny is above the inside lip of the door frame. So if it has to come out, you don't have to lift and pull at the same time. I have an Alfa, and a friend of mine had an Alfa also with a factory installed genny. He had a problem with the Onan that was covered under warranty and took it to an Onan shop. His genny was below the lip of door and he said the Onan techs came up with new words he never heard!

anyone install Onan genset in front compartment?

sdetweil
Explorer
Mar 26, 2015
coolbreeze01 wrote:
Suggest you look at RV's with factory installed gen sets. I think you will find iron supports with air flow.

Thanks. Never seen one.
coolbreeze01
Explorer
Mar 25, 2015
Suggest you look at RV's with factory installed gen sets. I think you will find iron supports with air flow.
time2roll
Nomad
Mar 25, 2015
Filled my compartment with more batteries, solar controller, 2000 watt inverter.
bobsallyh
Explorer II
Mar 25, 2015
I installed a Onan Marquis Gold 7000 in our front compartment. The fiver wasn't gen ready which I liked because I "do it my way". I'm like Chris, didn't trust the floor. And the way the Onan cools, it sucks air from the bottom so I just removed the floor and welded some 2" square tubing to the fiver frame. I also made it so it would slide out of the compartment since an Onan is like an old lady, you know, lots of TLC. One thing to remember, make sure the bottom of the genny is above the inside lip of the door frame. So if it has to come out, you don't have to lift and pull at the same time. I have an Alfa, and a friend of mine had an Alfa also with a factory installed genny. He had a problem with the Onan that was covered under warranty and took it to an Onan shop. His genny was below the lip of door and he said the Onan techs came up with new words he never heard!
mlts22
Explorer
Mar 25, 2015
Don't forget sound insulation. As per Onan spec, you should have insulation on all sides (perhaps the door) of the compartment, but not beneath the genset (so fuel dripping on it doesn't cause problems.) You should also have a vent in the front as well.

It also can't hurt to rubber shock mount everything (exhaust pipes, fuel and electric lines), and use the Onan resonator. This will quiet things down remarkably.
Chris_Bryant
Explorer II
Mar 25, 2015
I set it right on the floor- removing really won't be that big a deal. I ran 1 1/2" angle underneath the compartment- frame to frame, right at the mounting holes. Plywood as an outside lining for the sheet metal enclosure.
The trailer I installed it in was "generator ready", but I didn't trust the sheet metal to hold it.
The hardest part is locating the holes to cut in the floor.
BurbMan
Explorer II
Mar 25, 2015
I would start with a 3/4" plywood base in the floor of the compartment, that will distribute the weight of the riser mounts pretty evenly across the structure and eliminate any pressure points that could overstress the structure. You can add sheet metal on top of the plywood for fire protection and oil spills.

If you want to stay with metal, then a pair of 2x2 square tubes that run the full width of the compartment should give you good weight distribution as well.

I would also look at a pair of HD drawer slides (like these) that are rated in excess of 400 lbs per pair. Raise the gen up to the level of the compartment door and mount on full extension slides so you can easily roll the unit out for repair and maintenance.

Plus, if you need to completely remove, you can support the genset from underneath while you disconnect the slide extensions.
DrewE
Explorer II
Mar 25, 2015
What access do you need to change the oil and perform other routine maintenance on the generator? On mine (a completely different model), the oil drain is on the underside of the generator, with a little access panel attached to the outer cover. It wouldn't work well to have it installed over an unbroken floor. Likewise, there's the need for the exhaust plumbing to exit underneath. The generator appears to be mounted to an angle iron frame, which is bolted to the undercarriage of the motorhome, so far as I've been able to suss out.

I guess I'm suggesting that you consider removing the floor of the compartment and see if you can't find a way to make it able to be raised/lowered from underneath, rather than slid in from the side/front. Of course, for routine maintenance and such you'd just leave it in place.

Do be careful to seal the compartment thoroughly from the interior of the trailer, and maybe consider adding some fire/sound insulation.

Forum Discussion

anyone install Onan genset in front compartment?

About Technical Issues

Related Content

Bigfoot propane compartment

Front compartment

Anyone install a jackknife sofa?

Propane tank compartment

Flooring Installation