Diesel...Propane..Gasoline... small quiet generator

[luvrbus]

I have a 3800 Onan propane in a RV a nice quite generator it uses about 1 gph under load with the AC running propane is cheap here $ 1.49 for mounted tanks $2.03 for portable tanks with no sales tax.Our van has 2800 Onan gasoline fueled and it is quite too it uses a 1/2 gph under load with the AC.

Now the 20kw diesel running 4 AC units in the bus sucks some fuel the best I can figure is 1.3 gph with out using the diesel fired hot water if we use that much I can add another 1/2 gph

[TomC]

I realize that you're looking at around a 3-3.5kw genset. From my experience of having a 6.5kw Commercial Emerald III gasoline generator on my truck that I put 12,000hrs on my first and 1,500hrs on my second, I highly recommend you NOT deal with gasoline or propane-too much maintenance, although propane would be less, but you'd burn a lot of gas.

Diesel is the way to go. The disadvantage of small Diesel generators is they are usually 1 or 2 cylinder engines running at 3,600rpm. If I needed a smaller generator than my 10kw on my bus or my 12kw on my truck, my number one choice would be the CD8000SI 8kw by Powertech that runs @ 1,800rpm (.4gal/hr 1/2 load, .8gal/hr full load). It is only 34.5"long x 19"h x 25"w and 424lbs. The engine has a sound shield on it and the radiator fan is a squirrel cag fan that pulls the air over the radiator then exhausts it straight down-so that also keeps the compartment cool. I have a truck driver friend that had one of these on his last truck and when he sold it, the generator had over 28,000hrs on it, with only one generator head replacement-and that was because it originally came with a brush type generator. He replaced it with the current brushless type. I know you don't need that big of an generator (you'll be thankful you have a bigger generator if you're in altitude), but the small size, compactness and quiet is worth it. Good Luck, TomC

[luvrbus]

LOL I don't too much about a diesel set being less maintenance I read on F/B the diesel generators give the entertainer guys fits some of those guys have 2 generators 1 for backup looking for shops to repair both  and I know they run 24/7 but it's still a generator  

[belfert]

I've had enough problems with my diesel generator that I now borrow a Honda EU2000 for a backup in case the main generator goes down.  The EU2000 will run everything except the A/C units and the water heater.  The problems have been with the generator head.  Never an engine or starting problem.

[LuckyChow]

It's too bad that nobody is making a small 1800 rpm, water cooled, diesel genset.  Something along the 3500 watt size.  I guess the closest is the Onan 3200, single cylinder air cooled (link shown in an earlier post).  I've not known anyone with one of these and haven't heard anything good or bad about them.  If Honda would put out a diesel unit like the current quiet gasoline models they're selling, it'd be a barn burner in the sales department. 

[belfert]

Powertech makes a liquid cooled diesel 3500 watt generator.  I can't find a price or the specs on RPM.

[eagle19952]

Powertech makes a liquid cooled diesel 3500 watt generator.  I can't find a price or the specs on RPM.

here's one a kubota, not power tech tho ... 3.5 and 5 kw available.

radiator/cooling is on you  

well poop...after further research...it's 2800 rpm 

[eagle19952]

of course they are almost free 

here's a 4.5kw direct coupled kubota @1800rpm   not sure about cooling tho 

http://www.ebay.com/itm/Phasor-Marine-4-5Kw-Compact-Generator-/271773800712

[bevans6]

If I was adding a generator to my bus at this point, I would get a small three cylinder liquid cooled diesel and two 24 volt 160 amp alternators.  I would belt drive the alternators from the flywheel of the engine at an rpm that put them in the middle of their power curve with the diesel at just above idle.  The alternators would power my house bank of batteries and the Magnum 4024 inverter, which would supply the power.  Three cylinders for smooth idle and enough capacity to power the alternators at quite a low rpm, probably around 1200 rpm.  That way I could tune my vibration control and sound dampening to a constant speed.

Big fan of the idea of a DC generator if you already have the big inverter and some decent batteries.

Brian

[luvrbus]

There are tons of small 1800 rpm 12 hp water cooled diesel on the market Kubota,Cat and others anyone can take a 5 or 6 kw turn the HP down not the rpm and depending on the head you can have a small generator.All the manufacture use the same head for 3 or 4 different kw rating just by changing the HP.

FWIW Subaru/Robin builds the small air cooled engines for Cummins/Onan ,gasoline,propane and diesel both my 1 cylinder gasoline and propane engines are Robins

[robertglines1]

I did a use Question on the PC board. How Many Hrs does your gen set have on it? The typical response was  250 hrs in 10 years in a bus conversion.  This makes the type of gen set fuel a little less of a factor.  Any gen set is going to cost bucks. So $$ per hour of use should be considered. I have luck finding take outs at my local generator dealer. My latest is a 7.5  propane unit for $1200 dollars. With cabinet. While I do agree diesel would be great. When you do the math of how much per hour it actually cost you the savings on the lp unit with 34hrs on it offsets cost of more efficient diesel at prob 3 times the price. The reason the set had so little hrs on it was the previous owner bought a bigger diesel gen set.(to save $$$ on fuel)  FWIW   Bob

[belfert]

Almost 1,000 hours on my diesel generator since 2006.  The yearly usage is a bit less now since I hooked up the alternator to power my inverter on the road.

I didn't want to add a big gas tank to my bus.  It would be a harder decision now as the same diesel generator has gone up at least 50% in cost over what I paid.

[Oonrahnjay]

Looks like fuel consumption is about the same if you factor in the higher cost of diesel fuel.lol 68db@10 feet. The Honda idles down when load is lifted in the one switch position. Won't work when running ac though.

     Chessie, what are they doing to you up there in the Peoples Republik of Pennsylvania?   I drove I-84, I-81, and I-83 last night border-to-border across PA, I was seeing diesel $.55 - $.60 more than regular.  In NC, I occasionally see diesel lower than regular, usually it's higher but the average is $.06 - $.12 cents.  But don't feel too bad -- up in the Socialist Workers' Paradise north of you, I was seeing diesel prices $.60 to $.75 higher than yours!

[bevans6]

For the first time in living memory it cost me less to fill up in Canada than in the US.  I think PA was the most expensive on my trip, I paid up to $3.25 a gallon, as low as $2.45.   In Nova Scotia I paid $.99 a litre, at 3.8 litres per gallon and the 75 cent exchange rate, that works out to around $3 a US gallon, in US funds.

Brian

[sledhead]

I just installed a 4024 hybrid inverter with a new set of 4 x  trojan t-105 re batteries . I have a split unit a/c up front and a r/v roof shaker in the bed room . when driving at 60 mph with the split unit on it uses 48-52 amps when only using the inverter and with the bogart 2025 it shows only 1.5 amps coming from the bank of batteries . no visual change in engine power or any extra heat on the 6v92ta . when using both a/c,s off the inverter it was using 122-128 amps with only a slight loss of power on full acceleration on a on ramp until up to speed ( 60 mph ) same draw on the bogart 2025 ( 1.5 amps from battery bank )

I tried it with my inverter 3100 generator ( 23 amp max out put ) and set the 4024 hybrid to only 20 amps on input a/c power and using the 4024 hybrid inverter to top up the power for the 30 amps ( 120 volt ) that the 2 a/c,s use . the 4024 only used 10 amps from the battery bank  and when the compressor on 1 of the a/c,s cuts out the 4024 would start recharging the battery bank.

now that I know this works my next generator will be a yamaha ef3000iseb inverter generator with the boost control ( 25 amp max ) as gene,s go it is as quiet as the honda 49 db - 59 db and uses very little gas or propane .

the 3100 gene I have now on full is 69 db . that is 2 times as load as the honda or the yamaha gene at 59 db

I have looked at lots of diesel gene,s from 3 k to 6 k and would love to have 1 but I hate the noise  ( min. 69 db )

most of the time we are in the coach the 1 split a/c unit will keep us cool and if I run it only on the 6v92ta I will not be using the gene that much .
so with the help of my new 4024 hybrid for me my set up should be complete

sorry about the long winded post but I have looked at doing this for a long time and because my old batteries were 10 years old now was the time to up grade 

dave