Woodwalker
Keithville, La.
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With the help of a Flight System tech. I was able to determine I have to change the voltage regulator. He advised me that before connecting the new regulator to check the OHMS across PINS 7 and 9. Afterwards I got to wondering, how long I can safely run the gen. with the regulator unplugged. I tried to contact him again but have not been able to. Hope that someone on the forum can answer the question. Thanks for the help.
I hope I have my generator issues corrected as of today. I have worked on the issues numerous times since my first post on 2/15/09 and my second post on 8/23/09. With the help of Generator Jim and others on this forum and a Tech at Flight Systems I have cleaned the slip rings, changed the voltage regulator, and adjusted the choke. I actually cleaned the rings twice. After the first time the OHMS were not what Jim, the Flight System tech, or the Onan Repair Manual stated. My, Electrical Engineer, son was here and suggested that I clean them again. Then the reading was correct and after starting the generator the voltage and frequency are as they should be. With that happening I would tell anyone who cleans their generator slip rings and thinks they are clean, to clean them some more. Thanks to all who responded to my posts.Tommy Munds
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stevesandidge
kingsport tn
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you don't want to run it while you are checking it on ohms, or resistance, it'll blow your fuse.
steve
steve sandidge
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Generator Jim
Conway, SC
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Woodwalker
The NHM (Marquis) can be run for 4 or 5 minutes with the regulator unplugged. The voltage across the generator windings will be less than nominal 120 due to the control board furnishing field flash voltage to the rotor. If you let it run too long and there is a rotor problem, the control board fuse will blow and stop the unit without damage. Insure circuit breakers are OPEN prior to testing.
Ohms are usually checked with the engine stopped as a multimeter furnishes the only voltage signal necessary to check ohms in a circuit.
Your NHM will stay running after you let go of the start switch because the Marquis does not require generator voltage to run the control board.
An Emerald (NHE) will shut down if you let go of the switch and there is no voltage on the generator.
JimL
Jim & Jane Latour
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05 Wilderness Advantage AX6 365 BSQS, Onan 3.6KY
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Woodwalker
Keithville, La.
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I have a TYPO in my original post. The correct pin numbers are 9 and 10.
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gunny357
North Carolina
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If you have to clean slip rings with any regularity, something else is wrong and needs to be addressed. Most of the time an Onan will run thousands of hours without the need for this to be done.
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Woodwalker
Keithville, La.
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Thanks for the information Gunny. This is the first time since I have owned the MH the rings have been cleaned. It has 550 hours of run time,so I am at a loss as to why it needed it this early. I will moniter the OHM reading of the brushes from time to time. What is considered a high OHM reading? When we decided to clean the rings the second time before connecting the new regulator we were getting readings at pins 9 and 10, of 50+. I did not check the reading before the first cleaning. When I posted my problem in my first post in Feburary this year, the replies I was getting said to clean the rings. I never thought about taking a reading before hand. Thanks again for the help. The experts on this forum, such as yourself, do a really good job in helping us "PUPS".
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