Generators

[dbs944]

Can someone please explain RV generators to me?

My 7500 Onan Quiet Diesel Generator has stopped working properly with a fault code of 31. This indicates there is a problem with the Overspeed Control. Apparently the engine and generator are fine; it is just a control module of some sort.

Doing some research, I’m finding the repair will be something in the area of $4K. The generator is =~1999 with just over 1000 hours. When checking for a replacement instead of repair, the same generator uninstalled is about $8.5K. It seems generated power is VERY expensive.

So I went to e-bay and new 6-7KW contractor grade diesel generators typically sell for as little as $800 up to <$2000.

What is so special with the Onan that it costs 5-10X more than other generators with similar size/capabilities? Assuming it can fit somewhere, is the cheaper generator a suitable replacement?

[wa8yxm]

gbopp wrote:
Contractor type generators are usually Very Loud.

Naa a six K Contractor would not be "Very loud" it would be much louder than that

On my Onan 5500 I was once standing about 130 feet from the Gen-Turi and the man beside me said "You can start the generator now" it was running.. he could not hear it.. The contractor's job (Smaller, and behind a building and a good 100 YARDS away... We could hear clearly.

There is also a difference in the quality of the power produced. The Onan is fairly clean, the contractors.. may or may not be.

I'd fix the Onan.

[Trackrig]

The MH Onan generator has a radiator on it, I don't think the contractor generator will have one, it is probably air cooled - but I could be wrong. There is nothing wrong with that while sitting on a jobsite or on the contractor's trailer where it has free airflow. If it's stuffed in where the Onan is, it's not going to have enough air circulating around it, especially if you add more sound insulation.

And before getting too far into the idea, check your measurements. The Onan was built for MHs, so it is sort on long, narrow and not very high. Most contractor generators are built more or less in a cube probably making them too high and maybe too wide to fit.

Again the Onan was designed for the MH so the controls, water and oil fill pointrs are on the front. Where are these and the air and oil filters on the contractor generator? If it fits, I'll bet you can't get to half of these once it's mounted in the MH.

I think that by the time you buy the contractor gen set and get it mounted to include new frame supports and hookups so that it will start and modify the electrical connections so that the MH is happy with it, that you'll spend a lot more than $4k. Remember you're talking 120/220 here, not 12VDC so everything has to be perfect.

Let's say $1000 for the gen set, $200 for electrical connections and wiring, and $100 for steel frame supports that's $1,300 for material. Take that from the $4,000, it leaves $2,700. Then divide that by $125 an hour for shop time means they would have to do the whole job in 21.6 hours. Oh yes, if you have sales tax on everything, figure it needs to be done in under 20 hours or 2.5 days.

And then, what will be the resale value of the MH with a contractor gen set in it? And I forgot the cost of the sound insulation and all of the little things like modifying the fuel lines along with the exhaust.

If it actually costs the $4K to fix it, I think that's the cheapest (best) way in the end.

Bill

[dbs944]

My first thought was changing out the fuel filter but I couldn't get the old one out. I have a diesel mechanic friend who is going to take a look at it when the weather dries out some. When I had the spring PM done, they couldn't get the old filter off either and said the fuel line connection was badly stripped and the line should probably be replaced - which requires dropping the generator (the line comes in from the top).

The overspeed problem is a known issue with this generator. If I recall correctly, the generator specialist said it might be a $1000 fix or it could be $4000 - depends. I was hoping a smack with a hammer would solve it.

I checked the specs on some of these industrial/construction generators and they are louder than the Onan. Federal parks have a limit of 60dBs @ 50' and the construction ones were computing out to about 70db but I figured some extra sound insulation would fix that. I just wasn't sure if there was some other reason to not put one in a RV.

Can you even sell a used RV (not that we're selling any time soon) without a working generator? Probably my only use would be to run the house A/C when driving down the road - although the campground we were in last summer lost power during a storm for a couple of hours which is where we discovered the problem.

[Kpackpackkelley]

If your down here in central tx anytime let us know there are several people around that will treat you right and tell the truth about your gen.

[Almot]

smkettner wrote:
How often do you really use the generator?

I've seen people using a generator - and diesel at that - 100% of time when they were not fishing or sleeping. No airconditioner - it was winter. Basically, 5pm to 10pm. Don't know why - no batteries, no charger, or maybe there was something else missing 😉

[time2roll]

Is it too early in the thread to suggest replacing the generator with solar/inverter/batteries? 😉

How often do you really use the generator? Otherwise I would take it into a good shop before you just start throwing expensive parts on it.

[Kpackpackkelley]

dbs944 wrote:
Can someone please explain RV generators to me?

My 7500 Onan Quiet Diesel Generator has stopped working properly with a fault code of 31. This indicates there is a problem with the Overspeed Control. Apparently the engine and generator are fine; it is just a control module of some sort.

Doing some research, I’m finding the repair will be something in the area of $4K. The generator is =~1999 with just over 1000 hours. When checking for a replacement instead of repair, the same generator uninstalled is about $8.5K. It seems generated power is VERY expensive.

So I went to e-bay and new 6-7KW contractor grade diesel generators typically sell for as little as $800 up to <$2000.

What is so special with the Onan that it costs 5-10X more than other generators with similar size/capabilities? Assuming it can fit somewhere, is the cheaper generator a suitable replacement?

See if you can find someone local maybe a retired tech or somebody that works on generators it doesn't have to be a onan tech. Ask around there shouldn't be a lot wrong with a 1000 hrs.

[Almot]

Diesel generators - I believe most of them are contractor grade - are incredibly loud. It's way too loud through the wall of your RV, and you will hear it all around the camp, even half a mile away - and so will everybody else.

[mlts22]

I'd consider a different opinion. A control board shouldn't be that pricy. If the engine was blown or a piston scored, I can understand 4k, but not this.

Fault code 31 -might- be fixable by replacing the fuel filter (as per a thread on the iRV forums.)

[Trackrig]

Your generator as stated is a "Quiet" generator, the contractor's generator is anything but quiet and you wouldn't want it mounted in your MH.

A contractor's generator is basically meant to be used, abused, thrown around, maybe stolen from a job site and then replaced with another one.

I have the same gen set in 2005 and have been very pleased with it. I would have expected yours to last longer. It sounds like you've had it to a shop to be looked at. Since I've never had any problems with mine, I've never priced any repairs on it, but I would get a second estimate on repairs. If you did have an estimate was it from an RV shop that would have to pull it and then send it someplace for repairs or was it from a Cummins/Onan shop?

Bill

[Sandia_Man]

$4K is certainly a pricey repair, take it to a certified Onan repair facility for an estimate as it may turn out to be significantly less. Not sure why Onan generators are so expensive, they are industry proven and have company repair centers in most major cities adding to their overhead. Contractor grade generators are rarely able to be installed onboard, maybe a large portable inverter generator can do the trick. Good luck, hopefully you can resolve what ills your Onan for much less than you assume.

[gbopp]

Contractor type generators are usually Very Loud.