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Author Topic: Question about LP Generator  (Read 16839 times)

alann

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Question about LP Generator
« on: August 17, 2007, 06:59:41 PM »
Just wondering how long I can expect it to run on the 23# LP tank?  Also is it a good idea to run the generator and roof ac while driving if the cab a/c does not cool the coach?

Shayne

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Re: Question about LP Generator
« Reply #1 on: August 17, 2007, 08:45:50 PM »
We always run ours when needed.
Old, Stubborn, Opinionated, Set in my Ways, and Independent,  IMHO

Ron

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Re: Question about LP Generator
« Reply #2 on: August 18, 2007, 10:28:11 AM »
Just wondering how long I can expect it to run on the 23# LP tank?  Also is it a good idea to run the generator and roof ac while driving if the cab a/c does not cool the coach?

Having never had a propane genset I can't say from experience.  However, the fuel consumtion will be something more than a similar size gas genset.  Our Onan Diesel burns less than .4 gals per hour when we use it.
« Last Edit: August 18, 2007, 03:43:11 PM by Ron »
Ron & Sam-home is where we park it. Currently located   HERE

Jackliz

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Re: Question about LP Generator
« Reply #3 on: August 18, 2007, 11:27:05 AM »
[quote author=alann link=topic=12803.msg116374#msg116374 date=1187395181..........................  Also is it a good idea to run the generator and roof ac while driving if the cab a/c does not cool the coach?
[/quote]

Sure, we do that in our Wanderlodge.

Regards,
Jack and Liz
Regards,
Jack and Liz Pearce and Oreo the Escape Cat
Fulltiming in a 1993 Wanderlodge WB 40 ft
Dhanis, TX - Winter
Buena Vista, CO - Summer

Gary RV_Wizard

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Re: Question about LP Generator
« Reply #4 on: August 18, 2007, 03:36:41 PM »
Quote
However, the fuel consumtion will be something less than a similar size gas genset.

Are you sure of that Ron?  That would be surprising because propane has substantially less energy per gallon than gasoline (84,000 btus vs 114,000).  And everybody I've ever known who had a propane generator said it literally gulps fuel.
Gary
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Gary Brinck
Summers: Black Mountain, NC
Home: Ocala National Forest, FL

Ron

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Re: Question about LP Generator
« Reply #5 on: August 18, 2007, 03:45:46 PM »
Are you sure of that Ron?  That would be surprising because propane has substantially less energy per gallon than gasoline (84,000 btus vs 114,000).  And everybody I've ever known who had a propane generator said it literally gulps fuel.

You are correct and I was meaning to say less efficient.  Darn just can't seem to multi task very good anymore.   Yes all the comments I have heard from folks that have propane Gensets report they are pretty inefficient.  Thanks for catching that.
Ron & Sam-home is where we park it. Currently located   HERE

Shayne

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Re: Question about LP Generator
« Reply #6 on: August 18, 2007, 03:52:14 PM »
Once had  a friend with a LP Genset and he called it a succarator the way it went thru fuel.
Old, Stubborn, Opinionated, Set in my Ways, and Independent,  IMHO

Gary RV_Wizard

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Re: Question about LP Generator
« Reply #7 on: August 18, 2007, 03:57:03 PM »
Quote
how long I can expect it to run on the 23# LP tank?

Is that 23 lbs or 23 gallons?  The # usually means pounds but standard propane tanks don't come in a 23 lb size (20#, 30#, etc).  A 20# LP tank contains only 4.8 gallons and that would run a typical 5 KW generator no more than 8 hours at 50% load.  But if it is a 23 gallon tank (fairly typical for a large motorhome) then you've got fuel for many hours, probably 40 or so.

These estimates are based on 0.5 gallons/hour at 50% load which is fairly typical for large diesel gensets and somewhat smaller gas gensets.

Yamaha has some estimating tables for their propane generators but the assumptions have a somewhat higher energy content for propane (92000 btu/gal) than I see elsewhere (84000 btu/gal). Using the Yamaha figures, a 5000 watt generator at 50% load would consume about .55 gal/hour of propane. At the lower (84,000) btu/gal figure it would be about 0.6 gal/hour.  [Propane energy content varies with the blend, which is adjusted regionally and seasonally as well as varying from refiner to refiner - there is no standard blend for LPG]

Yamaha propane consumption charts
Gary
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Gary Brinck
Summers: Black Mountain, NC
Home: Ocala National Forest, FL

alann

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Re: Question about LP Generator
« Reply #8 on: August 18, 2007, 05:55:47 PM »
Thank you so much for the replies.  Guess I will have to be careful with generator times. :)

BernieD

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Re: Question about LP Generator
« Reply #9 on: August 18, 2007, 06:32:19 PM »
IIRC, the propane generator (Onan 6.3kw Emerald) used about 1 gallon per hour while running 1 a/c.
Bernie & Marlene Dobrin
Home is Goodyear, AZ
Missing our Travel Supreme

John From Detroit

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Re: Question about LP Generator
« Reply #10 on: August 18, 2007, 07:10:51 PM »
Bernie is close on the Onan suck-a-bility

One thing  you can do if you are going to be there a while is order up a bigger bottel from the local Propane supplier,  The park can provide the supplier's name.  The bottle is professionally delivered.  Usually a 100 lber  Or even larger if you must.
Nothing adds excitement like something that is none of your business
My Home is where I park it.

King

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Re: Question about LP Generator
« Reply #11 on: August 18, 2007, 07:26:40 PM »
The typical automotive air conditioner is actually capable of about 21000 BTUH.  To maximize the cab air, use the "recirc" or "Max" air path setting so you are not cooling outside air, and do not moderate the temperature with the heater.  Move the dash air outlets so they don't blow on the crew.  I have a Class B, and the roof air is only about 7000 BTUH...   the dash air cools the van much faster than the roof air.
Art

alann

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Re: Question about LP Generator
« Reply #12 on: August 18, 2007, 08:08:40 PM »
Wife just asked "Instead of asking why don't you just look it up?"  Again, she is right.  ::)  It is only a 2500 and Onan says at half load it should use about .3gl per hour.  We shall see.  Our maiden voyage (only one night due to work schedule :( ) will be the 26th/27th.

foxxen

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Re: Question about LP Generator
« Reply #13 on: August 19, 2007, 11:29:05 AM »
Hello,

I have over 5 years experience with selling and fixing generators, and can answer your question.

An LPG Generator is a Gas/Petrol generator that has been converted to accept LP Gas. If it has been converted after manufacture it is hard to calculate without actually running it, but it does work out much cheaper and more efficient, but as it is build to use gas, in the long term it can wear the engine differently from gas.

So make sure you regularly service the unit, clean the spark plug and change the oil.

I have made a website about generators called www.whatgenerator.com this might also help you decide.

Thanks

Styles Beagley
www.whatgenerator.com
www.generatorguru.com

King

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Re: Question about LP Generator
« Reply #14 on: August 21, 2007, 08:05:42 AM »
Based on the Onan generator specs for the 2800 (gas) and identical 2500 (propane) and the current prices at the Mill Hall PA Flying J,  the cost per KW per hr. for propane is higher.

Gas $2.799/gal,         0.3 gal/hr half load,    1.4 kW             $0.5998/kw/hr
Propane $2.049/gal,  0.4 gal/hr half load,    1.25 kW            $0.6557/kw/hr

Art


Hit The Road Jack

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Re: Question about LP Generator
« Reply #15 on: August 30, 2007, 03:18:30 PM »
Wife just asked "Instead of asking why don't you just look it up?"  Again, she is right.  ::)  It is only a 2500 and Onan says at half load it should use about .3gl per hour.  We shall see.  Our maiden voyage (only one night due to work schedule :( ) will be the 26th/27th.


How did that  maiden voyage go alann?
2015 Thor Challenger 37 GT

Name?... 'Roadhouse' Navigated By 'Maggie' Our 7200 Street Pilot GPS.

Ron

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Re: Question about LP Generator
« Reply #16 on: August 30, 2007, 03:27:20 PM »
Based on the Onan generator specs for the 2800 (gas) and identical 2500 (propane) and the current prices at the Mill Hall PA Flying J,  the cost per KW per hr. for propane is higher.

Gas $2.799/gal,         0.3 gal/hr half load,    1.4 kW             $0.5998/kw/hr
Propane $2.049/gal,  0.4 gal/hr half load,    1.25 kW            $0.6557/kw/hr

Art



As expected.
Ron & Sam-home is where we park it. Currently located   HERE

alann

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Re: Question about LP Generator
« Reply #17 on: August 30, 2007, 06:45:00 PM »
It was great.  No problems except van need alignment and 2 light fixtures.  Will be done on Sept 6th.  Plan on LOTS more trips. 

Gary RV_Wizard

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Re: Question about LP Generator
« Reply #18 on: August 31, 2007, 05:22:53 PM »
Glad to hear you are happy campers, Alann.  And hope future trips go as well.
Gary
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Gary Brinck
Summers: Black Mountain, NC
Home: Ocala National Forest, FL

 

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