Old Onan Genny

[bart]

   Have an old Onan Generator  (m/n 15HQ-3R/1374F) made in the lat fifties.
The Adj. power resister in the voltage reg. quit working, sending the out put voltage to around 350 vac.
It don't sound real good at that voltage.
   Have all the manuals (with blue print wiring diagrams) for it, but all it shows is a dotted line around the "voltage regulator".
This did happen some time ago and after "Sandy" I'm keen on getting it going again.
I did get to talk to an Onan rep. and according to what little he could find out, that resister is 1200 ohm, 50 watt.
Can not seem to find one on the web that reasonable or close to that rating.
   Today I got the idea of soldering across the bad spots of the resister. Had to use the biggest iron we have. The little 40 watt would not do. And still the solder ain't stuck to good, but I can't pick it off. Just not flowed out. 
   Measured the resistance, and it's at 1600 ohms or so. Put the adj. back to about to it was before, and it is running at 220v.
I'm iffy on 1) whether or not the solder will stay on.
                2) questioning the 1200 ohm, 50 watt rating. Don't know what to look for now.
Is there a chance that a electronic voltage reg. will work and where would I find one?
   Thanks in advance, bart

[spottrouble]

Hi Bart

Someone here might be able to answer that question, if not, post it over in the Onan section of www.smokstak.com , they have some pretty knowledgeable old Onan freaks, err,,, enthusiasts over there .

Kristi

[bart]

   Cool! Thanks!

[bergmanj]

Hey!

I'm one of those freaks  ...er, Onan enthusiasts over at SmokStak!!!

Regards,   JLB

[bart]

  Hi!
   Got a post going on over there. And lots of help.
I've got to seriously contain myself in that site. Wealth of great stuff going on in there.

[Flux]

At least you have found the fault and confirmed the value of resistor. It is unlikely that the solder will hold for long , it is probably nichrome wire and it doesn't solder properly. also if it is as big a rating as you suggest it will be running rather hot for solder.

You can probably build it up from several smaller resistors to make the resistance and wattage. It may be worth looking at those aluminium clad resistors that mount on a heat sink. Not sure where you are or what suppliers you have but Farnell, RS, Mouser, Digikey and similar have places in a lot of areas. Failing that mail order fron the good old internet should get you something.

Replacing by an avr from something else could be possible but not for someone with little knowledge , those old alternators were quite cunning to regulate volts and they used a lot of cunning tricks, some were very specific to certain manufacturers.

Flux

[bart]

   Thanks for your reply.
Yes, there is little faith in the solder holding and is not going to be relied on. Have some resistors on order from Newark.
We'll see what happens. There are some AVR's available, but for now going the cheaper route. And easier.
  I would like to ask a question though, could the running of a welder off of this generator have caused the power resister to have failed?

[bart]

Got the new 1000 and 2000 ohm resistors in. Ran both to see how the old girl worked with them. She loved them and some how got lucky on setting both the first time as the 1000 came in at 238 v, the 2000 at 243v. They were both hot after a welder load test. I could touch them with out getting burnt, but not comfortably.
 Thanks for all your help and comments

[thirteen]

I have an old Onan generator that bin junked out motor wise. The motor is toast there is no head and it has bin sitting for at least 14 years and has gathered the nice red  flaky stuff in each cylindar. Is there any numbers on the gen portion that could be used for reference. I'v never taken a good look at it, but I do not want it. I'll take the cover off and see what it looks like inside. It has a 4 cylindar engine which I assume was gas.
13

[bart]

   If your offering to me, I've got my hands full. Might try the SmokStak site as there is lots of interest over there in the old Onan's and about anything else.
http://www.smokstak.com/