Onan generator voltage too high and low

[dpinvidic]

Hey Adam,

Yes, my last statement was a little confusing.
I tried to say that the cut extension cord was likely good, so there would not be any bad wiring in his current set-up.

Adam: Awesome job on finding the service manual.

We are all on the same page....genny is the problem.

Regards,

Dan

[jdwky]

FIXED!!!!!!!!



Before tearing inside the genset, I had wanted to try to tap straight into the neutral wire and bypass the terminal block on top of generator. As soon as I loosened the screw, I knew this was the spot. It had cooked here for some reason, perhaps was never screwed in all the way or inserted far enough inside the terminal block?? As a temporary solution, I stripped the wire back, wire brushed it, and wire-nutted it directly to the output neutral line, bypassing the terminal block.

Who thinks I should dispute the $439 "diagnosis" by the Cummins Onan service center? "Sir your transfer switch is definitely bad".
Wow this was an arduous stressful sweaty expensive journey over one little bad wire tip!

Thank you thank you to all of you who provided assistance and insight here, it was YOU all that taught me it HAD to be a loose or bad neutral wire somewhere! Thank you!!


2012 Entegra Aspire
2013 Wrangler JKU toad
2006 Vans RV-9A

[ShapeShifter]

Originally Posted by jdwky

FIXED!!!!!!!!

CONGRATULATIONS! What a long hard battle it's been!

Who thinks I should dispute the $439 "diagnosis" by the Cummins Onan service center? "Sir your transfer switch is definitely bad".

Definitely! Print out a nice large version of that picture and show it to the Cummins people - explain how much their "mistake" cost you, both dollars paid to them them and for the new transfer switch you didn't need, and for all of the time you had to spend to finally fix it yourself. Escalate to the regional office if necessary.

If you get no satisfaction from them, try writing to one of the consumer advocate columns, like the Hot Line column in Motorhome Magazine. They will write a letter to Cummins, and many times the target company will make a good faith reimbursement if there is any merit at all (and I think that there is.)

Be reasonable, and don't expect them to refund the entire diagnostic fee, plus the cost of the transfer switch, plus payment for your time. But asking for a portion (or even all) of the diagnostic fee is reasonable. Don't give yourself an ulcer about it, don't get upset with them, and don't let it get you upset. But it's worth writing a few letters, you've got nothing to lose.

Thank you thank you to all of you who provided assistance and insight here, it was YOU all that taught me it HAD to be a loose or bad neutral wire somewhere! Thank you!!

You're welcome! It really seemed like it was a broken neutral, but as time went on I was beginning to question that. But I couldn't think of what else would cause the problem. I'm glad you finally found it, and pretty much right where I was thinking it would be in my last post.

Now, before you put all the tools away, get the system running on the generator, and verify that you have the proper neutral/ground bonding (a simple plug-in three light tester will tell you that) and make sure that you no longer have the hot-skin tingle you reported the other day. I'm pretty sure that fixing the neutral has also fixed those issues, but it's best to make sure.

Once again, congratulations. Of course, I do have to mention that it would've been solved two days sooner if you took my advice from Tuesday morning:

Originally Posted by ShapeShifter

It may also help to remove the wires going into the other side of that junction block and see how dirty those are: clean that side up as well.

[nothermark]

Glad you found it. Whoever troubleshot it at Cummins was incompetent and the people who pay him should be shown the problem. The floating ground/neutral bond is a big safety issue their people should understand and understand where it happens.

If I was them I'd have the moron fix it for free but I'm not in business. ;-)

If I was you I would get a new terminal block if the old one was burnt. That is because if anything else fails you do not want a work around in the unit.

[dpinvidic]

Glad to see you found it. All of us feel better fixing this problem through your hands

Options you can try.
1. Remove the new xfer switch and offer it back to them in exchange for your money. You do the labor....
2. At least try to get a partial refund, they should give you the xfer switch at their cost.
3. Sell it on e-bay
4. Keep it for a spare

It is a slippery slope because they spent time on your coach...but full price for bad diagnosis is not fair either.
It is obvious that no load was applied during their testing.

Definitely get Cummins involved...so Cummins is aware of a poor dealer.

Be sure to check you "Hot Skin" condition...to confirm it is also corrected.

Regards,

Dan

[TQ60]

I re read you post about adding cord to generator.

I read it as attaching the shore cord to that point BYPASSING the generator and upon reading second time I understand it as using generator as shore source.

Correct?

Then with the readings you have floating neutral SOME PLACE and the measurement needs to be made at the generator and if bad there then genny is the problem and the folks who tested it failed.

They likely started it and measured unloaded or light load if at all.

Not a clue how your generator is built but others may be aware.

If it is inverter type it could be bad news and if standard rotor/stator type it could be a bad connection.

If you have a good 240 volt load like a welder that you can plug into your cord then you can test the total output.

If total output is good then windings likely good or inverter good and issue is resistance in the neutral path.

You may just want to pull the generator out so you can get inside and look.

Maybe a mouse ate the wire...

[ShapeShifter]

Originally Posted by TQ60

Then with the readings you have floating neutral SOME PLACE and the measurement needs to be made at the generator and if bad there then genny is the problem and the folks who tested it failed.

They likely started it and measured unloaded or light load if at all.

I think it's pretty clear they ran it without a load, as even with the slightest load (the control circuitry in the transfer switch) it gave off bad readings. It seems to me that they have technicians that can read the limited list of troubleshooting steps, but can't think for themselves and don't understand the implications of the symptoms they are given. It was stated that three different technicians worked on diagnosing it - sad.

Given the symptoms (the voltage readings in the first post) it is so clearly a floating (open) neutral problem. It's a pity that there isn't a single technician (or supervisor) there at the Cummins/Onan shop who understands how electricity and split phase power works, when it's such a fundamental part of power generation.

Not a clue how your generator is built but others may be aware.

If it is inverter type it could be bad news and if standard rotor/stator type it could be a bad connection.

It's a standard direct wired fixed speed motor generator, not a variable speed inverter model. My understanding is that the Onan QuietDiesel generators at 10kW and larger are that style where they put out mechanically generated split phase 240 volt power. Smaller QuietDiesel models use an inverter that puts out two in-phase legs of 120 volt power (without having 240 volts between the two hots.)

You may just want to pull the generator out so you can get inside and look.

Maybe a mouse ate the wire...

He did find the burned/broken neutral inside the generator, see the last picture posted in this thread. It was very obvious nice you went looking for it.

[jdwky]

Yea they must've just put a volt meter on the AC terminals with zero load on the generator, like I did, which gave false impression it was fine. Though
the difference is, I'm just a regular joe and they're the "professionals" that should know how to properly load test and troubleshoot...


2012 Entegra Aspire
2013 Wrangler JKU toad
2006 Vans RV-9A

[TQ60]

Missed the fixed part...Many folks helping here.

Just skipped back pages to find the reference we got wrong as the other responses were what they were.

Cummins should have noticed that bad connection and it looks like it has been that way awhile.

Wire and connector should be cleaned well as they usually get a little toasty and replacement better if possible.

Some electrical grease would allow the wires to move as the screw is tightened to allow better connection but that is an opinion from non electrician.

Be sure to get involved with Cummins for some recovery and use the burned wire as leverage as it was a Hazzard to safety.

[jdwky]

For sure. I last spoke to their service manager on Wednesday. Told him transfer switch was not problem, we argued a while, he admitted fault but refused any refund. I said I'd call him back after I confirmed it was the wiring somewhere. His last words were, "you can sure try!". Now he won't call me back. Will look for some corporate # to call...


2012 Entegra Aspire
2013 Wrangler JKU toad
2006 Vans RV-9A

[jdwky]

Originally Posted by jdwky

For sure. I last spoke to their service manager on Wednesday. Told him transfer switch was not problem, we argued a while, he admitted fault but refused any refund. I said I'd call him back after I confirmed it was the wiring somewhere. His last words were, "you can sure try!". Now he won't call me back. Will look for some corporate # to call...


2012 Entegra Aspire
2013 Wrangler JKU toad
2006 Vans RV-9A

Great news, the local Cummins service center branch manager is refunding me the full $439!!

[ShapeShifter]

Originally Posted by jdwky

Great news, the local Cummins service center branch manager is refunding me the full $439!!

Yahoo!

[ChasA]

Fantastic!!