| Onan question [message #285950] |
Wed, 26 August 2015 20:00  |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
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Senior Member |
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Forthe Gugurs - Mr Miller comes to mind.
Dog show friend has an Onan 7KW Marquis. It failed AC output. Onan shop replaced the brushes and voltage regulator, it operated nmormally for a few uses ( 20 - 30 hours), then became very slow to come up to 120V at startup, but >if started under load< came up properly for a while, then up slowly, now no output. Any ideas as to what might be going on here? All input appreciated.
Maybe an out of round slipring? Loose bearing allowing the shaft to wobble?
--johnny
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
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| Re: Onan question [message #285961 is a reply to message #285950] |
Thu, 27 August 2015 00:32  |
Bullitthead
Messages: 1411
Registered: November 2013
Karma: 5
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Maybe the slip rings need to be cleaned with an ink eraser, the type I use to clean electric model railroad tracks...got an Onan in the garage that had the same symptom, and thought the generator was dead. A meter on the brush leads and hand rotation showed the problem.
Terry Kelpien
ASE Master Technician
73 Glacier 260
Smithfield, Va.
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| Re: Onan question [message #285966 is a reply to message #285950] |
Thu, 27 August 2015 08:15 |
stick miller
Messages: 1036
Registered: March 2010
Location: Americus, Georgia
Karma: 0
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Johnny Bridges wrote on Wed, 26 August 2015 21:00 Mr Miller comes to mind.
--johnny
Surely you mean another Mr. Miller.  I can give you a quick rundown on how to spend $1000 without stopping a leak. I can tell you how to turn a starter bracket replacement into a 12 hour job (thanks for your rescue, Ken), and I can describe frustration, but other than their causing abject misery, I know nothing about Onans.
Yep, there must be another Mr. Miller. Bless his heart.
Stick Miller
'78 Royale - "White Trash" - she left me for another man
'76 Eleganza - "Cousin Eddie" Sold
'84 Bluebird Wanderlodge - "Past Tents"
Americus, GA
[Updated on: Thu, 27 August 2015 13:49] Report message to a moderator |
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| Re: [GMCnet] Onan question [message #286055 is a reply to message #285950] |
Fri, 28 August 2015 16:12 |
Jim Miller
Messages: 501
Registered: March 2008
Karma: 10
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On Aug 26, 2015, at 9:00 PM, Johnny Bridges wrote:
>
> Dog show friend has an Onan 7KW Marquis. It failed AC output. Onan shop replaced the brushes and voltage regulator, it operated nmormally for a few uses ( 20 - 30 hours), then became very slow to come up to 120V at startup, but >if started under load< came up properly for a while, then up slowly, now no output. Any ideas as to what might be going on here? All input appreciated.
Hi Johnny,
I’m not at all familiar with the Marquis. Onan has had many different designs over the years - the Marquis might have a more complex excitation system or it might even be a rotating field machine as contrasted with our rotating armature powerdrawer design.
Maybe I should tweak my signature a little. :)
--Jim "saving the lives of PowerDrawer Onans...one unit at a time" Miller
1977 Eleganza II
1977 Royale
Hamilton, OH
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Jim Miller
1977 Eleganza II
1977 Royale
Hamilton, OH
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| Re: Onan question [message #286065 is a reply to message #285950] |
Fri, 28 August 2015 18:51 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
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Senior Member |
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Hey, they're all green.
I have to go ask, but I >think< when we bought a couple of them, the seller said they were rotating field, and therefore better, cos less current to the rotating portion, yadda yadda.
I think he has a double problem - there's something temp sensitive in the excitation setup; and I think he has a dirty or out of round commutator. His Onan dealer seems to be trying to fix it by throwing parts at it.
The little single cylinder 3600rpm set are famous for losing the rear bearing and allowing the end to wobble enough that the brushes bounce on the sliprings and do Bad Things to the output.
They're based North of Ocala, if anyone knows a competent shop in that area, speak up.
Symptoms am/is/are... Cold start, and the genset usually works properly. Shut it down and restart, it bullds voltage very slowly, over a period of five - ten minutes to accomplish full voltage. When started under load, it either comes on correctly (most times) or not at all (one time in five). Voltage regulator board and brushes have been replaced with new Onan parts by Onan, without noticeable change in the symptoms.
I'd admire to have the set at home for a week or two.
--johnny
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
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