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Onan Generators Restoring, operating and maintaining vintage Onan generators.

Onan Generators

Onan 7.5 JB-3CR31/9286T


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  #61  
Old 08-26-2015, 08:27:05 AM
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Default Re: Onan 7.5 jb-3cr31/9286t

Been running the JB it is a power house had 5K on it and it just wants more I was lucky to find a JB in this condition I had been looking for three years and there it was I could not let it get away from me.
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  #62  
Old 08-26-2015, 11:30:43 AM
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Default Re: Onan 7.5 jb-3cr31/9286t

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Originally Posted by Onan Dan View Post
Been running the JB it is a power house had 5K on it and it just wants more I was lucky to find a JB in this condition I had been looking for three years and there it was I could not let it get away from me.
Dan, Maybe you can sell some of that excess power you have back to the utility company. Hey, the SOLAR people do!!!

I am waiting to get to my JB and get some outlets on it.
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  #63  
Old 08-26-2015, 01:01:40 PM
Leon N. Leon N. is offline
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Default Re: Onan 7.5 jb-3cr31/9286t

Motörhead don't laugh. That thought was the first idea I discussed when I joined the Stak back in 2009. In fact, it is more so true today than back in 09 that I can definitely generate 7.5 KW significantly cheaper now because NG is cheaper and electricity has gone through the roof, now at ~ 23 cents/KWH. I went so far as to install a synchronizing light. I am convince I can lock the JB governor just a tad above synchronous speed to push power back into the lines and thus unwind my watt hour meter.

Maybe before I croak, I might try it, but for now, I need the JB as a reliable back up power source, sort of like an insurance policy so I hope I do not start a ruckus over these comments.

BTW, the generator excitation voltage controls the reactive current and the speed controls the in phase current. Fortunately, my JB amp meters measure the total current.

Bye
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  #64  
Old 08-26-2015, 01:10:21 PM
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Default Re: Onan 7.5 jb-3cr31/9286t

I was poking Onan dan with a little humor which we all do with each other here. Knowing the utility companies, they would probably charge anyone doing it a surcharge, tax, tariff, use fee, or about anything else they could do to squash you from doing that.
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  #65  
Old 08-26-2015, 01:50:24 PM
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Default Re: Onan 7.5 jb-3cr31/9286t

In many areas it is possible to sell power back into the grid but it is tightly regulated by the utilities. Usually the sticking point is the cost of the grid tie switching equipment which is so high that it is not worth doing. Using fossil fuel generating equipment to produce power power is usually quite a bit more expensive than buying from the grid so it is not practical. Small scale Hydro is a bit more attractive as is wind and solar. I did a thumbnail analysis a while ago and found it was about 9-10 times the cost of just buying power, and my biodiesel cost is very low. Cheers Dan
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  #66  
Old 08-26-2015, 01:54:34 PM
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Default Re: Onan 7.5 jb-3cr31/9286t

West Penn Power at my home is 7.23 cents a KWH so it is relatively cheap my worst electric bill is like 50 dollars a month so I am not complaining just nice to know we all have the means to supply our homes with electric if we need to .
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  #67  
Old 08-26-2015, 02:02:37 PM
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Default Re: Onan 7.5 jb-3cr31/9286t

So Dan, Seeing that you live in PA. Do you have one of those PA. specific generators? In looking at the Onan parts book on the "J" series sets, it looks like they, the PA gvmt, was specifying genset controls and starters that were explosion proof. All the switch relays and starter were sealed with covers.
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Old 08-26-2015, 03:27:14 PM
Leon N. Leon N. is offline
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Default Re: Onan 7.5 jb-3cr31/9286t

Motörhead, according to Dan's model number, his JB was initially approved and shipped to PA.
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  #69  
Old 08-26-2015, 03:33:55 PM
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Default Re: Onan 7.5 jb-3cr31/9286t

Yes sir I have two approved for Pennsylvania my 7.5 JB and My 5.0CCK
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  #70  
Old 08-26-2015, 03:39:02 PM
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Default Re: Onan 7.5 jb-3cr31/9286t

Production order see PennState on order approved modification 23 natural gas
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  #71  
Old 08-26-2015, 04:32:22 PM
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Default Re: Onan 7.5 jb-3cr31/9286t

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Yes sir I have two approved for Pennsylvania my 7.5 JB and My 5.0CCK
Dan, What was different on the 5.0CCK?
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  #72  
Old 08-26-2015, 06:16:44 PM
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Default Re: Onan 7.5 jb-3cr31/9286t

Motorhead- dont know about dans but my 5.0cck code 31PA only difference i know of is vapor fuel stamped on the plate.

You can see pics under my profile.
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  #73  
Old 08-26-2015, 10:07:54 PM
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Default Re: Onan 7.5 jb-3cr31/9286t

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Motorhead- dont know about dans but my 5.0cck code 31PA only difference i know of is vapor fuel stamped on the plate.

You can see pics under my profile.
Ed that is the way my 5.0CCK is 3CR31/ 8400R need build sheet for it .
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  #74  
Old 08-27-2015, 07:52:59 AM
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Default Re: Onan 7.5 jb-3cr31/9286t

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Originally Posted by Onan Dan View Post
Ed that is the way my 5.0CCK is 3CR31/ 8400R need build sheet for it .
I tried several different ways to find the build sheet for your CCK with no luck. MBB or Onan Parts have to do the tough ones for me.
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  #75  
Old 08-30-2015, 01:13:26 PM
Leon N. Leon N. is offline
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Default Re: Onan 7.5 jb-3cr31/9286t

Hell Dan|

Just curious, but in post #21 your photo shows the generator leads emanating from the control box. Could you remove the cover from the control box and take a picture of the insides? I am curious how the generator power leads were routed up from the stator through the control box and thus out the back.

Leon
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  #76  
Old 08-30-2015, 01:29:18 PM
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Default Re: Onan 7.5 jb-3cr31/9286t

Dan I didnt see Maxes post. Here is your build sheet based on the model in Maxes post.
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  #77  
Old 08-30-2015, 01:34:23 PM
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Default Re: Onan 7.5 jb-3cr31/9286t

Leon here you go
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  #78  
Old 08-30-2015, 01:39:28 PM
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Default Re: Onan 7.5 jb-3cr31/9286t

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Originally Posted by MBB View Post
Dan I didnt see Maxes post. Here is your build sheet based on the model in Maxes post.
Thanks mike
Mike it is all black like I say some open and some does not are phone company is slow when it comes to you tube and downloads .
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  #79  
Old 08-30-2015, 01:57:23 PM
Leon N. Leon N. is offline
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Default Re: Onan 7.5 jb-3cr31/9286t

Dan, thank you. I would never have believed it until now. That explains why Onan located the start solenoid outside the control box and adjacent to the starter as shown in.post 21.
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  #80  
Old 08-30-2015, 02:02:32 PM
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Default Re: Onan 7.5 jb-3cr31/9286t

Leon not much room in the control box
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