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Onan Generators

Onan Generator (15KW) 15.OJC-C3R 112471AA


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  #21  
Old 09-26-2015, 01:33:43 AM
Ray Lynch Ray Lynch is offline
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Default Re: Onan Generator (15KW) 15.OJC-C3R 112471AA

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Originally Posted by Janner1 View Post

As far propane consumption goes, I appreciate the warning about the JC being a gas hog. However, this will be intermittent use, and the total hours per year will be low. The average load will be far less than full load, too. So, I'm not real concerned about the consumption. It is more than offset by the dependability of the JC, and its low cost. I'm thinking of using multiple 100 gallon tanks, perhaps 2, or three, connected by a manifold. That way, I can bring them to town for filling, rather than having a deliver truck come to this remote location.

Thanks again!

J
100 gallon tanks? I don't think they can be transported by consumers for filling. Do you mean 100# cylinders? Think they hold a little over 20 gallons.
Ray
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  #22  
Old 09-26-2015, 05:26:40 AM
Janner1 Janner1 is offline
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Default Re: Onan Generator (15KW) 15.OJC-C3R 112471AA

Thanks Ray for straightening me out on that. I was thinking multiple 100 pound tanks. I'll rethink that. There is an old 500 gallon tank at this site, but it is out of date and will need to be replaced. If I buy a new one from the local propane supply company, they will (reluctantly) come out and fill it. Reluctlantly, because the road is rough and about 4.5 miles long. That will probably be the way to go, though. I'll probably use less than one fill per year.
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  #23  
Old 09-26-2015, 10:16:43 AM
Dale Russell Dale Russell is offline
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Default Re: Onan Generator (15KW) 15.OJC-C3R 112471AA

Janner1, Check and see if local regulations would prohibit refilling the old tank. I am not aware of any time limit on refilling old tanks but maybe there are, I don't know. If the tank hasn't been under ground (like the old Butane Tanks were) and has been painted, maybe they would go head and refill it. Just don't mention the date on the Tank. That is probably when the tank was made. My $.02 worth. Enjoy your time in Montana! Dale
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  #24  
Old 09-28-2015, 07:57:10 AM
Doug Reed Doug Reed is offline
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Default Re: Onan Generator (15KW) 15.OJC-C3R 112471AA

Regarding the 100# propane tanks, I'd have said they would be marginal at best for a 15JC. BUT, last year I bought a trailer mounted 15JC with two 100# tanks in the back that had been used by a construction company to provide on-site power before commercial power was installed. They used this to supply power for a work shift, even in the winter, but I assume they refilled the tanks daily.

From everything I read in the Onan manuals, I would not have expected this to work year-round, but it did. My best guess is that it worked because the trailer was fully enclosed with doors and vents that were manually operated and the muffler was also inside and exhausted through the floor. The generator will throw off enough heat to keep the interior and the tanks toasty warm in the winter if you don't open all the doors and vents. As long as the tanks are warm they will provide enough propane vapor to run the JC, even under full load.

In this case, each tank has its own shut-off valve and the hoses ran to a manual 2-way selector valve that fed the fuel solenoid and primary regulator. If you have the option of having a large tank at the site, I'd go that way if you can. I expect it would get very old to haul the 100# tanks to town for a refill every weekend when you use the cabin. With the large tank you can run appliances such as a gas stove and refrigerator too.

---------- Post added at 06:57 AM ---------- Previous post was at 06:07 AM ----------

Regarding the electrical wiring and grounding, I'd say the advice has been dead on. I'd suggest you have the cabin wired as if it were going to be connected to the regular electrical grid, including ground rods at the service entrance panel. Your electrician and electrical inspector will understand that. Then all you do is substitute the generator for the outside electrical service.

As was suggested, put the remote start panel right by the main electrical panel so you can shut off the main breaker before you start or stop the generator. The 70 amp breaker that came with the generator will remain at the generator since its purpose is to protect the generator from overload and shorted wiring. You WILL require four equal size wires for the electrical connection, two hots, a neutral and a ground, standard color coding.

Regarding grounding at the generator, I believe the Onan manual talks about it, and the usual recommendation is to use a ground rod with a portable generator when providing temporary power, but I would prefer not to do so. I recommend using the green electrical safety ground as the remote generator ground, its already tied to the generator frame. My reasoning is that a single ground rod is really not much use for electrical safety and in the case of a lightning induced surge, it may be counter productive. If you want more info, I recommend you check the videos by MikeHolt.com on YouTube. He has a good lecture about auxiliary grounding and an excellent video about Ground Resistance Testing. Although in your case, since you are not connected to the electrical mains at any point, that may change the grounding requirements in NEC 250.54, you'll have to research that....
https://www.youtube.com/watch?v=Yg6G5VUSsWA
https://www.youtube.com/watch?v=WlnFNTay-9Q
http://www.mikeholt.com/freestuff-books.php

That's my two cents....
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  #25  
Old 09-28-2015, 10:33:14 AM
Janner1 Janner1 is offline
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Default Re: Onan Generator (15KW) 15.OJC-C3R 112471AA

So, would you place an "entrance box" on the exterior of the cabin, then go through the wall into the main box, or eliminate the entrance box, and conduit straight to the main box?

I'm not sure my generator has the green ground tied to the frame, but I'll look again. I'll check out the grounding videos. Thank you for your advice.

J
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  #26  
Old 09-28-2015, 12:17:30 PM
Kpack
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Default Re: Onan Generator (15KW) 15.OJC-C3R 112471AA

Quote:
Originally Posted by Janner1 View Post
So, would you place an "entrance box" on the exterior of the cabin, then go through the wall into the main box, or eliminate the entrance box, and conduit straight to the main box?

I'm not sure my generator has the green ground tied to the frame, but I'll look again. I'll check out the grounding videos. Thank you for your advice.

J
Your neutral and ground should be connected to the frame at the gen but is subject to change maybe or not when you tie in. The guys here know the best way just ask questions. Yours should be easy with no poco.
I would leave the gr and neutral bonded at the gen and unbounded at the entrance since you have no poco. If you every get poco you would tie gr and neutral together at main panel.
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  #27  
Old 09-28-2015, 12:44:36 PM
Janner1 Janner1 is offline
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Default Re: Onan Generator (15KW) 15.OJC-C3R 112471AA

My generator just has three wires; two hot, and one neutral.
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  #28  
Old 09-28-2015, 01:01:14 PM
Isaac-1 Isaac-1 is offline
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Default Re: Onan Generator (15KW) 15.OJC-C3R 112471AA

Your generator should have 4 wires, I think you are not tracing them back far enough.

You should have 4 leads coming out of the generator T1, T2, T3 and T4, T1 should connect to make L1 hot, T2 and T3 should be tied together to make L0 neutral (this may also be connect to the frame ground), and T4 should connect to make L2 hot.

Ike
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  #29  
Old 09-28-2015, 01:37:51 PM
Janner1 Janner1 is offline
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Default Re: Onan Generator (15KW) 15.OJC-C3R 112471AA

That is probably the case, but I'll verify that tonight. Assuming that is the case, I'd take the three wires from the generator to my main panel, terminating the neutral to the neutral bar. Then, I would connect my main panel ground bar to my ground rod (or in this case, being the rocky mountains, a ground array, or ground material). Does that sound correct?
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  #30  
Old 09-29-2015, 06:17:04 AM
Janner1 Janner1 is offline
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Default Re: Onan Generator (15KW) 15.OJC-C3R 112471AA

Yes, Isaac-1, as you thought, T2 and T3 are tied together to make L0 neutral (and this is also connected to the frame ground)... Thanks.
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