LP generator?

[J. Morgan]

This is not field tested yet so I haven't really posted it up on the forum.

This one runs on LPG and is mounted up in the spare tire well of my 72 Sovereign.

It is shop tested, and it seems like it will run everything in my trailer when used with my inverter.

It is by no means off the shelf.


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[r carl]

Originally Posted by rodsterinfl

FLASH UPDATE

So sorry about my bad math. We were just going over the propane versus gasoline usage cost and my father said something was wrong. He was SO right. The reason I use 72% is that is the load of my AC on the generator.

The actual corrected costs are thus:

Propane @$1.69/gal(price last paid) =1 tank 7.1 gallons or 16.3 hours genset on 72% load
Gasoline@3.65/gal = 1.6 gallons on genset tank or 5.16 hours @72% load

Consumption Rates

Propane .43gal/hr or $0.73/hr
Gasoline .31gal/hr or $1.13/hr

That is a $0.40 difference per hour @ 72% load (running the AC)!

The road tax on gasoline is killing ya, need to burn off road gasoline.

[rodsterinfl]

So, would a 2500 watt Yamaha work for that?

The microwave AND the AC are pushing it- opinion.

You would have to know your wattages on your appliances to really know. I CAN run my AC and microwave- together they pull just over 1900 watts and the generator does fine but I do not know about the cycling of the converter, etc. I have a 11K BTU and 600 watt micro. The 2400isHC is designed to run a 13,500 BTU AC up to 110 degrees (per literature) but that may be all as the extra wattage from 11K to 13.5K is anywhere from 200-400 watts.

[rodsterinfl]

The road tax on gasoline is killing ya, need to burn off road gasoline.

Tell me about it! Yeah, all those freeloading electric cars, what a shame!

[Airrogant]

I wouldn't use less than a 3.5kW generator per Dometic's literature.

https://www.dometic.com/b97fb7b3-584...758792f7.fodoc

I advise against relying on the generator manufacturer's "guess" of the power required. It seems that most of the forum's members tie two 2kW generators together to run their AC units. The 2 kW units weigh about 50 lbs. each.

Running a generator smaller than 3.5kW will "starve" the compressor of starting current which will shorten the AC unit's life. It is probably not good for the genny either. Will it work with 2.4kW? Most likely. But it won't be good for your equipment, and you won't have adequate headroom to run other appliances.

[rodsterinfl]

It is shop tested, and it seems like it will run everything in my trailer when used with my inverter.

J.Morgan that is interesting. wow.

@TerryV, I am not sure but I do not believe Airstream would install a generator in the trailer. Someone else on this comment? It is custom for sure but you pose a good question- where. As far as what generator for your 31'. I can tell you that you are beyond a 11K AC for sure. My guess would be a 13.5 minimum. A 2400 watt can continually run only the AC of that type as long as it does not exceed 1600 watts or around 14amps total for compressor and fan. You would have to do the math to double-check but that is about right. The reason that is the cutoff is that you do not want to run a gen at 100% continuously.

wouldn't use less than a 3.5kW generator per Dometic's literature.

@Airrogant, it all depends on how much power you need. You have to look up the wattage or amp requirements of the AC unit. Mine, from the Dometic literature 600xxx.321 is 9.5amps compressor 2.8 amps fan motor at max. So, it is 12.3 amps@115V. Amps X Volts = Watts so, 12.3 x 115 = 1414.5 watts. Following the 80% rule of load for Generators (don't exceed % for extended period), a 2000 watt generator is at 80% providing 1600 watts. In my case, it is enough to run the generator. This particular unit can also run off of a 15amp house outlet as its requirements are 12.3 amps. There is still 300 or so watts left for initial start without overload beyond manufacturer specs.Oh, and just an FYI, the Dometic literature has two different charts on my unit, one based on 110V and the other on 115V so, I took the 115 as it requires a higher wattage to run just for safety.

A smaller AC unit has its advantages. Less is best. I am always amazed at AC usage and cooling issues I read about. There are formulas out there for matching BTU to room size based on room volume, square footage, insulation factor, etc. A 25' AS is about 145 sq feet. I worked it out on mine using the formula with a worse case scenario insulation factor in direct sun. I came in at around 7000 BTUs needed. Ah but then there are calculations for room type- if a kitchen or stove is present add 3000 BTU- viola. 11K BTU. Yet many owners have 25' units and complain about cooling with their 13.5 units. I can only summize that the pano windows must be a source of a great deal of radiation. That, or it is a low humidity climate they are in and more well suited to a swamp cooler than an AC.

[terryV]

Wow!! I thought you guys would have some good ideas, but never imagined I would get this much information. Thanks, guys, this is great!

Yamaha and Honda both make a light weight genny (2800 for Yamaha, 3000 Honda), recoil start that they both say will run a 13,500 BTU A/C. I'm pretty sure Yamaha has a tri power unit, don't know about Honda.

Usually, I run the air for a short time just to cool down a hot camper that has been setting in the sun, closed up all day. My Southwind had two 13,500 BTU A/Cs and either would run on a 14 amp breaker, but certainly not both.

So, for most of the time, I would be using enough current to run the converter to charge the batteries, nuke something in the microwave, and of course, make coffee.

The converter does what it wants, when it wants, so the genny would need to run it as well as the A/C. Most camper converters are 30 amp, as I understand it, but normally, I doubt they would be pulling that much.

I'm guessing either Yamaha or Honda would be good quality.

[mefly2]

Certainly the propane is less "dirty" on the internals as well and much easier to store ... just need to balance with the "ease" of fuel purchase. I'd like to have a propane conversion but have also read about a lot of problems with the conversions...

[wahoonc]

Originally Posted by terryV

Wow!! I thought you guys would have some good ideas, but never imagined I would get this much information. Thanks, guys, this is great!

Yamaha and Honda both make a light weight genny (2800 for Yamaha, 3000 Honda), recoil start that they both say will run a 13,500 BTU A/C. I'm pretty sure Yamaha has a tri power unit, don't know about Honda.

Usually, I run the air for a short time just to cool down a hot camper that has been setting in the sun, closed up all day. My Southwind had two 13,500 BTU A/Cs and either would run on a 14 amp breaker, but certainly not both.

So, for most of the time, I would be using enough current to run the converter to charge the batteries, nuke something in the microwave, and of course, make coffee.

The converter does what it wants, when it wants, so the genny would need to run it as well as the A/C. Most camper converters are 30 amp, as I understand it, but normally, I doubt they would be pulling that much.

I'm guessing either Yamaha or Honda would be good quality.

I would lean towards Yamaha. The converter on the trailer pulls around 1.5 amps the 30 amp rating is the DC output. I just ran the numbers for an SOB that I own, the power hog is the microwave, believe it or not. This one has an 8,000 btu household style window unit air conditioner and it only pulls 7.5 amps, running. The microwave sucks down 11.5 amps.

Aaron

[rodsterinfl]

Yamaha and Honda both make a light weight genny (2800 for Yamaha, 3000 Honda), recoil start that they both say will run a 13,500 BTU A/C. I'm pretty sure Yamaha has a tri power unit, don't know about Honda.

My advice is to check the actual design and specs of the brand and size you choose to buy. I know a lot of people here own Honda. They are great; however, the 2000 and lower models use a pulley and belt drive with plastic parts. The larger Hondas do not. This may not be a big deal to some but direct drive gears are better. So, if you are buying a smaller unit I would definitely go with a Yamaha. I know that the 2000 and the 2400 are direct drive, I do not know about the 1000 watt model. Thing is, everything can change so check the details. Also, there are specific units that are designed to operate motors. This is more critical for smaller units but a point that the unit has a reserve beyond its advertised size for a burst of power.

Check my link on the propane snorkel. That is available for many brands of generators. The way that was done before was to drill into the carb- not so now. As far as problems go. The gentleman as US carb told me that it was rare to have issues (the drilling method) but the new method took that away.

[terryV]

I did go to the Snorkle site. They were quite informative. However, I am puzzled about one thing. The Yamaha that I think would work for me (it has to fit under my hard tonneau cover) is the EF2800i. However, they show a EF2800iQ. What does the Q mean? I can't find it on the Yamaha site.

[JimGaskill]

Best recommendation for genset is Honda 3000is. If you convert it to lp you will void the warranty. Not worth the chance.


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[Piggy Bank]

Anyone know if/how being in higher altitude would change the burn rate, efficiency, and output available on the gennies, how much, at what altitudes, and differences between propane and gasoline would impact in this scenario?

Good news is one rarely needs AC in high altitude. But might want to run the heat pump if that were available, and also coffee, microwave, etc.

I don't really need to know, I merely thought of it so am wondering?

[Matthew014]

I'm sure it would, but me living in Georgia, I have no idea how much it would affect it.


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[Journalist]

Originally Posted by rodsterinfl

TerryV, I am not sure but I do not believe Airstream would install a generator in the trailer. Someone else on this comment?

Airstream DID install Onan generators in a handful of 1972 models. To my knowledge, those were the only factory installed generators in any Airstream travel trailers. My father owns one of them, a '72 Sovereign International. They were a propane powered battery charger more than a generator, and were 12-volt only. Neat gizmo, but more or less useless only running the 12-volt side of things. The other downside to it was the fact that it was mounted under one of the street side rear twin beds next to the water heater. Imagine putting a mattress on the hood of a large riding lawnmower, and you will have a pretty good idea of the noise level.

[rodsterinfl]

they show a EF2800iQ. What does the Q mean? I can't find it on the Yamaha site.

Terry, call them. I am sure they know. There are two types of 2800 a GFCI and non GFCI model. They are very helpful. The 2600i ,2800i and 3000i are open frame models, a little louder. Note too there is the 3000seb. Get a look at that 2600 model price! It has the same motor as the 2400, is heavier by 20 lbs. The noise factor is the only real drawback I can see being open framed. That is about half what I paid for a 2400. I would probably stay with the encased units. Although it does have the 30 amp plug and offers 2300 watts continuous. hmm.

What makes the snorkel so nice is there is no drilling done.

So, AS did install generators. hmm.

Altitude and temperature impact LP. In higher altitudes there is something called derated propane and orifice adaptation- just looked it up.

[perryg114]

You got a photo of that thing outside the trailer? I see what looks like automotive alternators.

Perry

Originally Posted by J. Morgan

This is not field tested yet so I haven't really posted it up on the forum.

This one runs on LPG and is mounted up in the spare tire well of my 72 Sovereign.

It is shop tested, and it seems like it will run everything in my trailer when used with my inverter.

It is by no means off the shelf. Attachment 215074


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[wahoonc]

Originally Posted by Journalist

Airstream DID install Onan generators in a handful of 1972 models. To my knowledge, those were the only factory installed generators in any Airstream travel trailers. My father owns one of them, a '72 Sovereign International. They were a propane powered battery charger more than a generator, and were 12-volt only. Neat gizmo, but more or less useless only running the 12-volt side of things. The other downside to it was the fact that it was mounted under one of the street side rear twin beds next to the water heater. Imagine putting a mattress on the hood of a large riding lawnmower, and you will have a pretty good idea of the noise level.

They were still listed as an option in 1975. I don't recall ever seeing one installed though.

Aaron

[55AS]

I used to own a SOB diesel motorhome with an LP genny.
Pros:
Quiet
Nearly maintenance free
Fuel does not go bad
Cheaper than diesel genny
Cons:
More expensive than gas genny
Less efficient than diesel genny

For a trailer with a large LP supply it would seem an ideal solution.

[Journalist]

Originally Posted by wahoonc

They were still listed as an option in 1975. I don't recall ever seeing one installed though.



Aaron

I'll be parked next to his next week. I'll try to get some photos of it and post them here.