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Genset 100kw ENBA NG to Propane Questions


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  #21  
Old 12-11-2017, 12:50:11 PM
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Default Re: Genset 100kw ENBA NG to Propane Questions

Natural gas set up is going to run a little too rich on propane, at the same settings.
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Old 12-11-2017, 12:53:30 PM
reid070 reid070 is offline
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Default Re: Genset 100kw ENBA NG to Propane Questions

If it was running on NG previously you will be richer running on propane . Be careful as richer with dry fuels can burn valves . Opposite of gasoline

Steve
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  #23  
Old 12-11-2017, 03:11:22 PM
len k len k is offline
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Default Re: Genset 100kw ENBA NG to propane questions.

Generally engines consume fuel proportional to kw rating, ei doubling the rating doubles the fuel consumption ( both no-load and full load).

So with a 100kw gen and only needing a 25 kw gen your about 4X oversized on the gen, that will cost you BIG TIME in extra fuel use. So much that you might save money by giving the 100kw gen away for free and buying a used gen of correct size. ( do need to be oversized a little to start big motors if you have any).

For comparison if had a 30kw gen and only needed 15kw gen then after ~ 2 weeks of cumulative run time the extra gasoline consumption of larger gen would be about the cost of a buying a used 15kw Onan gen. Run your fuel cost numbers, over sized gens only make cost sense if you hardly ever use them, but then again you will have to run them periodically to exercise them .
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  #24  
Old 12-12-2017, 12:06:03 AM
Jonny Hotnuts Jonny Hotnuts is offline
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Default Re: Genset 100kw ENBA NG to propane questions.

Quote:
Originally Posted by len k View Post
Generally engines consume fuel proportional to kw rating, ei doubling the rating doubles the fuel consumption ( both no-load and full load).

So with a 100kw gen and only needing a 25 kw gen your about 4X oversized on the gen, that will cost you BIG TIME in extra fuel use. So much that you might save money by giving the 100kw gen away for free and buying a used gen of correct size. ( do need to be oversized a little to start big motors if you have any).

For comparison if had a 30kw gen and only needed 15kw gen then after ~ 2 weeks of cumulative run time the extra gasoline consumption of larger gen would be about the cost of a buying a used 15kw Onan gen. Run your fuel cost numbers, over sized gens only make cost sense if you hardly ever use them, but then again you will have to run them periodically to exercise them .
Let me clarify, its REALLY only just a mere 66kw at single so it will hardly use ANY fuel right?!!

-I guess this would be a bad time to suggest I was considering a turbo upgrade? I have a spare FP Billet GT3582r that would look AWESOME on this Onan!


Truth is I get that it is more generator than I need....however....the kid in me likes the fact that its ridiculous. If it was just a little to big it would be meh. The fact that it is a mountain makes me laugh. Now, I NEVER said I made good decisions.



Yeah, it will use lots of gas but IMO one can not put a price on awesomeness. LOL

~JH
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  #25  
Old 12-12-2017, 01:09:52 AM
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Default Re: Genset 100kw ENBA NG to propane questions.

Quote:
Originally Posted by Jonny Hotnuts View Post
...Let me clarify, its REALLY only just a mere 66kw at single so it will hardly use ANY fuel right?...
I think you're being facetious, but no. Lightly loaded, it'll still inhale gas as if it were a 100 kW set, even though you'll see only 66kW of capacity.
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  #26  
Old 12-12-2017, 02:28:41 AM
AngrySailor AngrySailor is offline
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Default Re: Genset 100kw ENBA NG to Propane Questions

Johnny, you and I have the same "issues" I would say
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  #27  
Old 12-12-2017, 10:55:05 AM
grif grif is offline
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Default Re: Genset 100kw ENBA NG to Propane Questions

Seems like you'll keep enough tank pressure for liquid delivery way below zero,,, in my mind something like -30F.
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  #28  
Old 12-12-2017, 11:10:37 AM
len k len k is offline
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Default Re: Genset 100kw ENBA NG to propane questions.

Quote:
Originally Posted by Jonny Hotnuts View Post
Yeah, it will use lots of gas but IMO one can not put a price on awesomeness. LOL
Maybe one can't , but the gas company can.....

Bit like driving cross country at 8 mpg in a 1969 Camaro Z-28 with 327 , high lift cams, Holley duel pumpers, headers, chambered exhaust, class winner at the dragway, ( only got to drive it 1 weekend, car sold in 4 days). Dad was a car dealer, we keep couple 55 gal barrels of gas just to make sure we could stay in business, demo and sell the regular cars during Arab Oil Embargo of ~ 1972

Quote:
Originally Posted by Jonny Hotnuts View Post
Let me clarify, its REALLY only just a mere 66kw at single so it will hardly use ANY fuel right?!!
Using post #7 numbers of ~ 6 GPH no-load Propane, 14 GPH full load, which sound reasonable,
I estimate your 100kw gen at 8kw load is 6.6 GPH, at 25kw load 8.
Whereas a 25kw gen at 8kw load is 2.1 , 25 kw load 3.5, big difference!!

Problem is 100kw gen no-load will use ~ 4X fuel of a 25kw gen at no-load.......no-load consumption of oversized engines is wallet killer on long runs (a day or so) . And as you apply a load fuel consumption only goes up from there. Run fuel numbers for a day or week run, costs will surprise you.

Unless your Bill Gates after some run time cost gets so bad you'll want to shut it off and sit in dark. Even with a small 7kw gen cost/KWH of electricity will be ~ 4X that of utility at BEST ( full load), maybe 8X at 1/2 load, don't want to even think what it is at 1/4 load. Your MINIMUM fuel cost will be no-load times hours you run it. For 100kw gen, a one week run 24/7 your minimum cost (no-load) would be ~ 1000 gal, if gasoline that would be ~ $2400 That's why it's awesome if someone can afford to run it.

Fuel tank $$..... ignoring vaporization ability , a given tank will only last ~ 44% as long with a 100kw vs 25 kw gen (assumes 25kw load), this 44% drops to 32 % if load is 8kw. This can become a problem during blizzards or emergencies if a truck can't get in to bring more fuel.

.

Last edited by len k; 12-12-2017 at 05:33:16 PM. Reason: Add info, clarify
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  #29  
Old 12-12-2017, 03:12:42 PM
armandh armandh is offline
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Default Re: Genset 100kw ENBA NG to Propane Questions

propane is a way richer fuel than NG

and YES you must adjust for it.

a generator that is 17.5 KW on gasoline
is 16 on propane 15 on NG

the different BTU density is substantial about 7% greater in your case
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  #30  
Old 12-12-2017, 04:59:21 PM
Max Thompson Max Thompson is offline
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Default Re: Genset 100kw ENBA NG to propane questions.

Quote:
Originally Posted by Jonny Hotnuts View Post
Let me clarify, its REALLY only just a mere 66kw at single
Looking at the rating tag, it is rated at 300 amps 120/240 3 phase. It is rated 347 amps 120/240 single phase (last box, lower right of tag). It looks like a little more than 66 KW in single phase. What am I misinterpreting here?
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  #31  
Old 12-12-2017, 05:16:51 PM
Wayne 440 Wayne 440 is offline
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Default Re: Genset 100kw ENBA NG to propane questions.

Quote:
Originally Posted by Max Thompson View Post
Looking at the rating tag, it is rated at 300 amps 120/240 3 phase. It is rated 347 amps 120/240 single phase (last box, lower right of tag). It looks like a little more than 66 KW in single phase. What am I misinterpreting here?
Onan often derates the single phase kW capability of their 3 phase sets considerably more than the laws of physics dictate. I don't know why - but I do know that a generator end that is capable of 240v/347A driven by a turbocharged 460 Ford will typically carry considerably more than 66kW of load at unity power factor.
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  #32  
Old 12-12-2017, 05:30:08 PM
Jonny Hotnuts Jonny Hotnuts is offline
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Default Re: Genset 100kw ENBA NG to Propane Questions

Quote:
Originally Posted by armandh View Post
propane is a way richer fuel than NG

and YES you must adjust for it.

a generator that is 17.5 KW on gasoline
is 16 on propane 15 on NG

the different BTU density is substantial about 7% greater in your case


I read through the ENBA manual and its recommendations for adjusting mix is under full load.

Ok, guys here is a BS question, I know I shouldnt ask but Im gonna:

-I have no prob in installing an O2 bung/sensor in the exhaust however this will be a little ways down the road; there is no real way I can do a 'sniffer' O2 setup as the muffler has no pipe distance and back pulses will contaminate the reading. When I install a bung it will be within 8" of the turbine outlet and pre muffler.
We can say the generator will be running fat on propane with the NG setup; this I get. IN THE MEANTIME is there a 'ball park' adjustment I can do to the mix to get it running 'safer'? (*take note that I do not know if unscrewing the jet at the base of the mixer translates into leaner or richer). Is it possible to say "loosen the jam, and unscrew (or screw in) the mix adjustment a full turn (or whatever) and re-secure the jam. I understand all these engines are different (and how identical engines can have different settings between them just because of no real explainable reason). I am not looking for perfection, only to get it to a place where there isnt a concern that I will burn a valve.


Thanks!

~JH

Also, I am including a garage shot of a couple old trucks of mine for no reason:



---------- Post added at 04:30:08 PM ---------- Previous post was at 04:27:13 PM ----------



(*pic didnt show in previous post)
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  #33  
Old 12-12-2017, 06:09:22 PM
Sprbob99 Sprbob99 is offline
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Default Re: Genset 100kw ENBA NG to Propane Questions

I have a 20 kw with a 4 cylandar ford.
I got it with the same by setup. The Marlow was pointed up. I turned it over and ran lp.
You have twice the consumption as I do.
Off a 500 gal tank I am using a first stage reg to reduce to 10lb. Then through a second stage reg to reduce to a 9-13 water column. It ran rich so I adjusted the air fuel mixture to lean it out and it runs great..
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  #34  
Old 12-12-2017, 06:31:55 PM
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Default Re: Genset 100kw ENBA NG to propane questions.

Quote:
Originally Posted by Max Thompson View Post
Looking at the rating tag, it is rated at 300 amps 120/240 3 phase. It is rated 347 amps 120/240 single phase (last box, lower right of tag). It looks like a little more than 66 KW in single phase. What am I misinterpreting here?
The power factor. It's rated at 0.8 PF (even in single phase) so that works out to 347A at 240V, which is 83 kVA.
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  #35  
Old 12-12-2017, 08:03:20 PM
Jonny Hotnuts Jonny Hotnuts is offline
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Default Re: Genset 100kw ENBA NG to Propane Questions



I took a closer look at the mixer. It appears the only adjustable element is this screw on the backside of the mixer. Can someone confirm if this is in fact the mix control.



This on the front side does not appear to be adjustable.

.

OT III



Pic of the ATS

Also....

I know its going to use a lot of gas, I am not worried about it in the least.

Quote:
Originally Posted by EricWood View Post

Make sure the plugs are set at 0.035", and timing is at 32 BTDC @ 1800 rpms.
Thoughts on going a number colder on the plugs?

~JH
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  #36  
Old 12-12-2017, 08:08:40 PM
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Default Re: Genset 100kw ENBA NG to Propane Questions

In your second picture in post 35 above, that one that you thought might not be adjustable, is in fact, the power valve. See the embossed "R" next to it? There is a corresponding "L" on the other side. This is a less than 1/2-turn adjusting valve. It don't take much movement to make a change when at full load.

Posting a photo of the style of exhaust adapter I use withe LM2 meter's wideband O2 sensor; it gets in the pipe about 5-6 inches, and at full load, you are not going to have the diluted reading you think you might.
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Old 12-12-2017, 08:18:43 PM
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Default Re: Genset 100kw ENBA NG to Propane Questions

As for the spark plugs, I'd recommend just staying with the original heat range. I've seen many stand-by gassers with 30 year old plugs in them still purr like a kitten. Pull the plugs for inspection. Are the fairly clean/lightly tanned, or a dull gray? Are the back cylinders partially oil-carbon fouled? If so, may need new valve seals. Treat it to a new set of plugs if they're still original, then recheck them after about 20 hours or so, to see how they look. Should still be pretty white at that point yet.
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Old 12-12-2017, 09:22:36 PM
len k len k is offline
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Default Re: Genset 100kw ENBA NG to Propane Questions

On chevys with fouled plugs in rear we just put couple numbers hotter plug in cylinders that had fouled plugs., tends to burn it off. Never had problems, took one car out to ~ 280k before frame got rusty, 5.0L V8 engine was tired but still good.

Last edited by len k; 12-13-2017 at 08:47:51 PM.
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Old 12-13-2017, 12:44:14 AM
AngrySailor AngrySailor is offline
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Default Re: Genset 100kw ENBA NG to Propane Questions

Love the trucks! Yours looks a like '69-71 c-10... attached is my '68 910 which is now my fathers summer ride. It was my daily until it was rear ended by a drunk and needed a box and frame The '67 biscayne is now my summer car. It sat since '81 when the original owner stopped driving it at about 47,000 miles. He logged every fill up, last was 119th tank of gas is '81 then it sat till this spring when I finally plated it again. It's first trip was 1200 miles to my new place. Made it with no issues
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Old 12-13-2017, 09:57:43 AM
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Default Re: Genset 100kw ENBA NG to Propane Questions

Quote:
Originally Posted by Jonny Hotnuts View Post


I read through the ENBA manual and its recommendations for adjusting mix is under full load.

Ok, guys here is a BS question, I know I shouldnt ask but Im gonna:

-I have no prob in installing an O2 bung/sensor in the exhaust however this will be a little ways down the road; there is no real way I can do a 'sniffer' O2 setup as the muffler has no pipe distance and back pulses will contaminate the reading. When I install a bung it will be within 8" of the turbine outlet and pre muffler.
We can say the generator will be running fat on propane with the NG setup; this I get. IN THE MEANTIME is there a 'ball park' adjustment I can do to the mix to get it running 'safer'? (*take note that I do not know if unscrewing the jet at the base of the mixer translates into leaner or richer). Is it possible to say "loosen the jam, and unscrew (or screw in) the mix adjustment a full turn (or whatever) and re-secure the jam. I understand all these engines are different (and how identical engines can have different settings between them just because of no real explainable reason). I am not looking for perfection, only to get it to a place where there isnt a concern that I will burn a valve.


Thanks!

~JH

Also, I am including a garage shot of a couple old trucks of mine for no reason:



---------- Post added at 04:30:08 PM ---------- Previous post was at 04:27:13 PM ----------



(*pic didnt show in previous post)
Jim, nice trucks, the adjustment in the photo is a butterfly valve 1/4 turn from wide open to shut off there might be a R and L on the casting for rich and lean settings..
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