Onan 5500 keeps stopping

[doit999]

Went to the trailer today and fired up the genny and put it under load by running both a/c, ran good for a while and then the breaker on the genny tripped and shut it all down. I can fire it up ok but after about 1 min it shuts down, as soon as it seem to convert. I can hear a click and then she shuts down. I believe the code is 12 which shows as a over voltage fault. Any ideas would be appreciated! Can it handle both a/c's?? Thanks


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[SAD]

Originally Posted by doit999

Went to the trailer today and fired up the genny and put it under load by running both a/c, ran good for a while and then the breaker on the genny tripped and shut it all down. I can fire it up ok but after about 1 min it shuts down, as soon as it seem to convert. I can hear a click and then she shuts down. I believe the code is 12 which shows as a over voltage fault. Any ideas would be appreciated! Can it handle both a/c's?? Thanks


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New trailer? Has it successfully ran both A/C's in the past and now it will not?

If your Keystone product is like mine, both A/Cs are on the same leg of your 50 amp panel. Which is fine while staying at a park with true 50 amp service.

HOWEVER, your Onan 5500 puts roughly 23-24 amps per leg (x2 because you have leg 1 and leg 2 on the panel).... If both A/Cs are on the same leg, that one leg on the Onan cannot keep up. Keystone wired it - not "wrong" - but stupidly.

If you find what I'm saying to be true (both A/C on same leg on your power distribution panel), move one A/C to the other leg.

Your Onan 5500 can run BOTH A/Cs for hours and hours on end as long as they are wired on separate legs.

[doit999]

Thanks Sad, it's a 2010 fuzion and new to me. So not sure if it has in the past.
But now it won't run longer than a couple minutes. I can hear like a converter or something click and then it shuts down. I'll go check it out next week when I get some time. The generator only has 20 hours on it so can't imagine its a big thing.


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[2014Fuzion300]

Turn off one of the ACs and let's see if it keeps shutting off.

[geo]

Somewhere in the past, I remember seeing a post somewhere about this problem. If I remember correctly, it is a control board issue - the control board needs to be replaced. Have you tried calling support at Cummins-Onan? They are very helpful. Yes, it sounds like the same problem I read about.

Ron

[doit999]

Originally Posted by 2014Fuzion300

Turn off one of the ACs and let's see if it keeps shutting off.

Yes I have tried turning both off but will have a closer look. Some one else suggested to check the oil level. Which is something I should've done prior to firing it up in the first place.


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[randy69]

Sounds like I have same problem. I can run 5 or 6 hours then shut down. It will start back up but shuts down as soon as voltage is applied. Let it set for 2 or 3 hours good to go. Ac on separate leg. Even the voltage converter can shut it down. Change out everthing I could think of . My conclusion crack PC board some where. It gets hot and opens circuit and shuts down

[doit999]

Just for anyone with same issue, geo you were right it was the control board needing replacing


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[geo]

Doit999 -

Glad you got it fixed. You might also want to follow SAD's advice and make sure the ACs are on different power legs. They were not on my Alpine and would cause a main breaker trip if anything else was used on that side of the power board.

Ron

[FusionFZ371]

Thanks for the info doit999,
That may be what they find with ours.
I have had nothing but issues with my Onan 5500 since it was brand new. First it would keep popping breakers when it was brand new so that's another reason to do a thorough PDI. Took it to Onan they said it was in the coach. Took it back to dealer they flipped the breakers a few dozen times until it finally caught and blamed Onan. We actually used it for about 30 hours but it would shut off after 2 hours of run time and flash some error 27 code which is a general fault . Took it back to the dealer and the onan tech worked on it and after that it wouldn't start and run correctly. It would choke itself out until it got warmed up. Now it starts and runs for a few seconds and then shuts itself off. It's back at the dealer now waiting to go to the "Factory" Onan repair shop. I sure hope they get it right this time. This is the third trip to get it fixed and it's over 75 miles one way.

[FusionFZ371]

Here's an update just in case anyone is following this thread that I hijacked. Cummins NW found a faulty govenor spring and when that didn't fix it they replaced the carb as it had a faulty electric choke switch. It starts and runs fine now so fingers crossed it continues.

[doit999]

Lots of reasons things can go wrong, it took a while for my dealer to get it right.