Smaller Aux Generator wanted

[Jeff Bayley]

I'm a full timer that mostly prefers staying elsewhere than RV parks. There are times when I just want to run one roof A/C at night to sleep (or during the day) instead of "lighting up" the entire coach with the 17.5 kw Powertech Gen Set installed on my 97 Royal. I'm considering buying either a gas or diesel aux generator in the 3000-3,500 range to use for this purpose. The reason for this would be fule economy but one has to consider the cost for the parts compared with the long term fuel savings. Responses could comment on the fuel useage of the big gen set but I seem to be getting data that suggest the consumption is between 1-2 gallons an hour depending on the load. Reucing that to a half gallon an hour (or possible less) would save approximatley $30 a day if you used 10 hours a baseline of running the gen and rounding out at $3 per gallong. The 2nd reason I like the idea (if it is practicle) is lower noise and peace of mind. I had the big generator set almost catch on fire when the turbo burned up about a year ago and now I never sleep as sound with the gen on as I do when staying plugged in at an RV park.

I'm analyzing the feasability of either using a run of the mill portable gas gen that would stow in the bay OR I'm wondering about a compact air cooled diesel gen that might fit in one of the two available spaces at the rear (of a 45' XL) that are extensions of the engine bay. I thought the Prevost service center could run an extension off the main engines fuel line (probabley incorporating a check valve) or the return fuel line perhaps that would eliminate the need to keep refueling and probabley be safer (would prefer not to have fuel tank in the heated main engine bay of course). Disposing of the fuel tank, it might fit in that space.

The other method might work as follows. One of the storage bays (where I keep my medium size tool box) has a 110 volt outlet that I never use. Since this terminates at the main fuse block, I thought of using the existing wireing to that plug in reverse as an input to put power to the fuse block using that outlet as an input obtaining power from the portable gas generator. I might be able to leave the generator run in place inside the bay next to my tool box if I vented the bay properly. With a remote electric starter, it would be convieient to toggle on and off as needed with the only draw back being that I have to now carry gas around instead of tapping into the diesel supply (as in the first example with the diesel gen installed in the engine compartment).
Since this proposed bay to carry the gas gen is in the passenger side instead of the drivers side (where the 50amp shore power cord is), I'm proposing running the power to the fuse block through the 110 volt outlet in reverse like I said. From there, I presume I can toggle what I want to power on an off at will (stove top, either roof airs, one battery charger, etc) by turning everything else I don't want to run off. I don't know if the gauge of wire from that one outlet is large enough to handle the amp load without a possible fire hazard. I don't want to test out my fire extenguishers and it occurs to me that I better check this througoghly before charging ahead. I joined the Prevost Owners Group specifically to put this subject out there.

I'll remain and see if anyone has any comments on this [semi] off the wall idea. Thanks in advance to all.

Jeff Bayley

[win42]

REPEAT: Free electricity any time anywhere. I'm still waiting for you full timers/boondockers to step up and outline a good Solar system for our coaches. Helloooh ! are you out there.

True Solar units large enough to keep up a rack of batteries under load will be expensive one time. Think of the flexability it would afford us.
Harry

[MangoMike]

Hi Jeff,
Welcome to POG. I don't have many answers for you except I've been considering roughly the same thing. When dry camping I just need to get the batteries charged up and the refrigerator running and it seems like a waste to run a 20kw genset to accomplish that. Honda makes a great portable and quiet generator the EU2000 that would meet my needs. The main problem I see is dealing with the gas issue. JW solved his supply issue at OSH by stealing AVgas for his Honda EU1000 from someones plane.

JWGen_1507.jpg

Maybe you can tap into the TOAD gas tank to have a nearby fuel supply.

Now there are others on the board that will say, Suck it up you own a Prevo, just pay the piper and run the generator. But it's always good to talk about options.

Mike

[dalej]

Jeff, I thought I was the only one with this idea, I had ask almost the exact same question earlier this
year, maybe it was last year? on the other forum, maybe this one.

Seems that the little guys 2000-3000 watt run so loud that you don't want to be around them. They are
used for construction. I had talked to a couple of manufacturers and that’s what they said. Seem you
should be able to quite them down.

After a month or so I just let it go. If you are at all like me you want to be as efficient as you can, not
counting the cost of the little generator, Its just a challenge to me. I was going to put it next to the
Wabasto so the fuel would be right there.

Let me know if you find a jewel of a generator for this. Thermo King has one for truckers so they don’t
have to run the big block for heat.

[MangoMike]

Dale,

I've heard this Honda EU2000


Extremely quiet only 55db. Again it's the fuel issue.

MM

[rfoster]

Jeff: I too don't like the idea of running a 20kw gen set to run one cruise air in the bedroom. I purchased a couple of mini type (110v) fans that I can place on the window sill inside the bedroom, open the window and let it run all night off the house batteries..(makes a nice low hum) Now - it has to cool down at night for this to work, if you are in the deep south or Fl in the summer -it just doesn't cut it. Maybe Harry can keep up the push for solar power with batteries. Or better yet JDUD can train the prairie dogs to power a treadmill generator.

[Jon Wehrenberg]

I wish Peter answers this also.

The fuel you burn relates primarily to the power you generate.

Obviously there is some consumption related to just keeping an unloaded generator spinning, but as you add load you increase the fuel burn. I am shooting from the lip here, but it is probable that your generator will burn somewhere around 1 GPH (more or less) heavily loaded, and with a light load substantially less. I will be so bold as to suggest to run a single air and the refrigerator and battery charger you may be burning 1/2 GPH.

There is a direct correlation between HP, Watts produced, and fuel consumed. Because I am sore from spreading mulch I am too lazy to look in the manual, but I suspect the generator manual has a fuel consumption chart or listing.

Adding to that, I see no downside to running the generator all night, but with a reservation. If it cools down and the batteries are charged and the AC cycles off, the generator has little or no load, and at some point to keep the injectors and the cylinders clean you will need to load the generator because running a diesel at low power is generally not good for them.

[garyde]

Here are a few additional items to consider;
1. Gas Generators have self contained tanks which need to breath, they also will heat up much more than the diesel generators.
2. Gas is extremely flamable
3. To run a typical 120 volt A/C unit , you will need a 1800 watt or larger Generator, to accomodate start-up and cycling.
4. Gas Generators are not designed for full load , 8 hour use in the smaller sizes.
5. Gas tanks are limited in size; 2- 5 gallons.

These Generators need a lot of Air for cooling purposes because they do not have radiators.

Now, I am sure there are exceptions to all of the above, but you should be well informed before you make a decision.

[Jeff Bayley]

Wow. What a pleasant surprise to sign on and see 7 replies to my first post and all within the first day. Interesting comments. My further reply follows.

Before replying to the thread, I would like to invite comments on the idea of installing a small, air cooled, diesel generator in the engine bay area on either the passenger or drivers side of the 45’ XL. This was one thing nobody commented on yet. There is an access door for either side. I saw where I missed something worth looking at in one of the bays at the recent rally ( http://www.prevost-stuff.com/santafe-2%20109.jpg ) What’s in there ? I’ve yet to determine if there is a diesel generator small enough and economical enough to fit but its close enough to keep investigating until someone shoots this down. This solves the dual fuel issue and eliminate the carry gas if we can make it work. I’m getting the feeling (as a first time generator shopper) that the small diesel sets are a bit larger than their gas counterparts. By taking an open frame model and hacking away at the frame and possible eliminating the fuel tank (will tap into the main fuel supply to the engine) then this compacts it a bit. I invite critical comments on the idea. Does anyone thing this could be a fire hazard? I’m a bit paranoid of this unproven (evidently first time) idea and I don’t want you all to ready about me in the funny fire papers. I’m quite certain I don’t want to introduce a gasoline generator into this compartment. That seems like an accident waiting to happen.

Regarding fuel consumption, Jon Wehrenberg wrote that the fuel consumption decreases with load and this is true. I would be pleased to find out that it could be a low as ½ gallon an hour. Can anyone comment ? This seems to be something that is all over the board. I found a chart at http://www.mclifts.com/kubota-generator.htm that shows 1.5 gallons an hour for a 15kw and 1.8 gph for a 20kw. These are at between 35 and 40amps load. Wouldn’t you know the field is blank for the 17.5 (like the one I have) so I guess its fair to call it a split at around 1.65 but I don’t know how accurate these estimates are and I don’t care to get out the beaker and eyedropper to confirm.

Regarding the fans that Roger wrote about…….true that. Got two small box fans tucked away in the closet that work sometimes. “Roger that”.

As an aside, I modified my fuse blocks quite easily to run two roof airs while running down the road. I read where the new coaches (mine is a 97) are usually wired to run one roof air off the coach and I thought “I want that”. The modification was surprisingly easy (I’m not an electrician) with a couple of heavy duty toggle switches in line between the shore power fuse block and the inverter fuse block that let me switch between power sources. My inverter fuse block had two empty spots for additional breakers. I found a great use for them and I haven’t had to let the smoke out yet from a fire so I guess I did it right. I had already replaced my bad house alternator with a $1,300 (ouch) 270 amp replacement which makes plenty of power to put back what is taken from the battery bank. Your actually running off the batteries and inverter with this set up, not direct off the alternator of course which is only refilling the batteries as fast as I’m draining them when I have the two A/C’s on. More on this for anyone that is curious. Write and tell or if there is already posting on this let me know (I haven’t browsed the rest of the posting yet).

Back to the small gas generator. Its strange and against my nature to try and spend time on modifying this because I’m not a penny pincher but it just bugs me to leave the generator running night and day and sometimes you need A/C all the time. I would like to not think about it as much as I do now. Running the big generator even at low load has to use at least a gallon an hour (in my gut feeling). Do the math and your talking $75 a day in fuel and more if consumption is over a gallon an hour which I think it is. No wonder I gravitate toward an RV park for half that cost but there are times I want to park where I want to park and I find that I can get a better view on my own than I can from the RV Parks with State Parks being the exception (cheaper and better I’m finding out as a rookie to RV parks). I just want to have power all the time and I find myself cycling the generator on and off now.

Regarding Dales comment on the noise of the small gens, are you talking about the small diesel gens ? The gas ones are quite as a mouse so you must mean small diesel gens are loud. Do you have a link to the Thermo King one you referred to ? I did a few minutes of searching and didn’t find it.

I said in my initial post that I dodged a near fire on the main generator and now I was gun shy about running it at night and getting restless sleep. I spent time and money researching a way to put a fire suppression system in the generator bay and settled on a marine system after I couldn’t find anyone at all who could make a recommendation on one for the bus. I had the company install it themselves only to have the system explode on me like a grenade. They mounted the extinguisher too close to the exhaust and the internal temperature on the propellant evidently likes to expand (a lot) when aggravated by heat. It wasn’t enough heat to trigger the thermostat which requires 240 degrees to release the propellant but evidently enough heat to make it blow. Talk about a safety devise back firing on me. It blew a 1 foot diameter hold in the generator bulkhead to the opposing storage bay. Nobody was hurt but would have been if they were poking around in one of the two bays. More on this later or in a separate thread if anyone has anything similar they want to share. Write and tell if so.

Anyway, you can see why I’m shy about the main generator and also paranoid about unproven modifications after a failed pioneer attempt on the extinguishers.

[Just Plain Jeff]

Hitman Frank, of the 2.8 meter bridge fame, bought an inventory of compact, electric start gennies 1000, 2000, and 3000 watt for the summer season in Maine. I think the brand name is Kipor. They're slick. They are quiet and have the spark arresting requirement for National Parks and BLM, low fuel requirements (gas). They are about the size of a medium-sized suitcase.

If you call him on his cell at (207) 975-6066 and tell him you're a POG person and Jeff sent ya, you could likely get a deal. I believe he has just the 1000, and 2000 watt models left.

We tried the 2000 watt in his shop and it was impressively quiet, unlike the Hondas, etc.

My 2 cents worth and you can keep the change.