Onan generator shorted (110 side)

That would probably be an ASCO 940 -- right

JimL

I am sorry Jim. I guess that would be a surprise. Kinda like the one I had at an old nursing home. Went into the transfer switch room. Found the switch marked USS Grayfish. Certified for service 1944.

TEXAS said -- What did I do Jim.

People today are use to 2 brushes not a possibility of 12, some ac and some dc.
Thanks for not telling him he might have a reconnectible unit or what those ceramic resistors are for.

JimL

What did I do Jim.

Generator Jim wrote:
Last time I checked, Tampa Armature Works was charging well over two grand for the rotor.

Ouch! And if the stator is damaged, too .....

You can get a rotor rewound for less than half that price if it's not too badly damaged, but the best option is usually to find one with an engine that's shot and do a swap. Often, while looking for a donor, you find a donor in better shape, and just go with it as a replacement generator without doing any work on the damaged gen.

There are a lot of low time generators pulled from old RVs on Craigslist. I'm often tempted to buy them, put them into decent shape and wait for the next hurricane, snowstorm, or whatever when the gen prices seem to triple. I've got two right now, one on wheels that I can lend to the neighbors and one in the RV that I can switch to 120/240 to run my 240 VAC well pump.

TEXAS You are going to scare the******out of that guy when he pulls the wrapper off of the brushes. They don't make stuff like that any more for a reason. Last time I checked, Tampa Armature Works was charging well over two grand for the rotor.

JimL

vacuumbed wrote:
Here is the model #
6.5 NH-3CR/16004K

I have a 6.5 NHD Onan. You said the hot and ground have continuity and " This can't be right". Actually, it is right. The hot and ground are connected together by a winding. The winding has relatively low resistance at DC (The manual has the DC resistance listed). On my gen the stator windings have 0.3 ohms resistance and the rotor winding has 22 ohms DC resistance.

When running, the winding generates AC and this low resistance doesn't act as a short.
If you need a service manual and can't find it with Google, post here, and I'll find one for you.
Edit (Somehow I didn't notice that there were 3 pages in this thread, and only read the first page. Sorry for any duplication)

Also pull the band off the back end. Make sure all the brushes have good contact with the slip rings.

You have two of the best here Jim and Texas . We are very lucky to have there knowledge. Thanks men.

You can buy a Kill-A-Watt meter for under $30 at Home Depot, I think. One of the readouts it's capable of is Hertz (Hz), as well as voltage.

Jim, "I drink coffee for _your_ protection."