| Author |
Message |
Jack Conrad (Jackconrad)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 11, 2006 - 7:21 am: | |
I have an Onan diesel generator that I just got running. Engine runs great, but no power from generator. A friend had a similar model and ended up spending 1800 to have the generator end repaired. I have not had the generator checked out yet, but am looking at options. I found a 12 KW 4 pole/1800 RPM generator head on ebay (item # 7579692980). I would like any opinions about this head and especially any first hand experience. Thanks, Jack |
David Hartley (Drdave)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 11, 2006 - 7:30 am: | |
Jack,
What model # is that generator that you got running?
Mine is a DKG and there are two circuit boards that can be a pain to get working if they are goofy. I have a manual for the DKG... |
David Hartley (Drdave)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 11, 2006 - 7:34 am: | |
Oh.. That generator head is the chinese head. I have two of the 10kw. They are extremely heavy and quite large. # 7579692980
Got to watch where you get them as shipping can be expensive. Many sellers don't actually have them in stock and it takes 1 to 3 months for the container order to arrive from china. |
Jack Conrad (Jackconrad)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 11, 2006 - 8:32 am: | |
Dave,
I have not looked at the generator head yet. All I did was start the engine and check the generator output with a volt meter. I will check the model number. I did find out it was manufactured in 6/78. The engine is a 2 cylinder upright cylinder design. Please email me your phone number and I may call you if I have any questions. Thanks, Jack |
John MC9
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 11, 2006 - 8:37 am: | |
Jack -
Check the brushes in the gen head, they may be stuck, dirty,
or too worn. |
Pete/RTS Daytona (Pete_rtsdaytona)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 11, 2006 - 10:10 am: | |
Jack
Because it's a 1978 style Onan - look for a bridge rectifier pack mounted just inside the covers or slots that you can see the brushes thru
In early Onans they were notorious for blowing those rectifiers if you turn off the generator with fully loaded A/Cs running - the back IMF would distroy the diodes
The cure was cheap and simple - Radio Shack or whatever rectifiers with a higher valve reverse voltage rating - _ I think I found them at Skycraft in Orlando for a few $ a piece
The rectifiers were use to excite the field - so they don't take much current themselves
If your genny has the rectifier - just remove it and use an ohm meter to test
How this helps - hope that's your problem |
Richard Bowyer (Drivingmisslazy)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 11, 2006 - 11:18 am: | |
Almost impossible to change generator heads. Possible different rpms and single bearing on Onan connected with a flex plate probably. The chinese heads are two bearing and not usable for replacement of a single bearing unit.
Richard |
waynewland@earthlink.net
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 11, 2006 - 11:19 am: | |
On my gas onan, there is a small box on the top center with a reset button. Check and see if you have one. Press the button and you may have juice. |
Gary Stadler (Boogiethecat)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 11, 2006 - 12:04 pm: | |
Jack, with the generator spinning, see if there is any DC voltage on the brushes going to the armature. If not, it may be as simple as "flashing" the field...ie disconnecting the wires and sparking a 12 volt battery across the field terminals (just a quick flash, on the generator side, not the regulator!!) and then reconnecting and "go". Generators need a tiny residual magnetic field to get electricity started and sometimes it fades away to the point there's not enough to work. "Flashing" re-establishes it.
As John said, check the brushes...
If that all fails all the above ideas also fail you, and you still can't see a DC voltage at the field terminals, it might be that the automatic regulator board is blown. If that's the case, the best way to fix it is spend $85 and get one of these:
http://www.solesco.com/AVRmenu.html
Now these only work on 220, so you'll have to put in a boost transformer also if you don't have 220 windings. It's easy, I'll be happy to help and locate one for you. Even this way it might be easier and cheaper than messing with a new onan board, and definitely easier than changing heads.
The only reasons I can see to change heads is if the actual coils inside are burned or if the bearings have let go and trashed it mechanically. Otheriwise there's probably nothing wrong with the one you have.
Last, if it's the bridge rectifier, I have some really nice ones I'd be happy to send you one... |
Tom Christman (Tchristman)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 13, 2006 - 1:13 am: | |
If your generator is the 2 cylinder air cooled Diesel then you have one of the loudest engines made. I know, I have the DJB (Vacuflo cooling) that I wanted to install on my big rig truck. But was to noisy so used it instead for the house standby. Very dependable, starts everytime, even after weeks of sitting. On your generator, open the end bell. If it is brushless you'll see what looks like a small alternator on the end. This is the excitor that has a permanent magnet so no brushes are needed. What does go wrong is the control board under the top cover of the control box. Mark the way the wires are hooked up, take the board out and take it to an Onan dealer to have tested and replaced it necessary. Good Luck, TomC |