| Author |
Message |
Michael Lewis (67.160.12.18)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 11, 2004 - 12:46 am: | |
We have been looking for a decent affordable genset for some time, so when a Onan propane 3600W came up recently on ebay we bid and won. Went over to eastern WA to pick it up and are very happy. My one concern was if this would provide sufficient power long term for our minimal 110V needs. That's a household refrig and some lighting and computer equipment. My calculations show that if we don't add an A/C and toaster oven simultaneously, we will probably be ok. We will also use a 3000W inverter and yet undetermined coach battery bank. Figure we could also add a second inverter later, if necessary.
Since we purchased the propane generator, two things have happened. First, we were given an Atwood marine 11 gal hot water heater. Very nice little box, 110V, 1500W. Today, I answered an ad on a local "for sale" board and came home with an almost new (hours wise) Onan 3000W gasoline generator. For the princely sum of $70.00!
All of which brings me to the question....what if I install the second genset as a backup or dedicated to say the hot water heater, air conditioner and refrig?
Can I run the second gen direct to my existing converter/panel? In other words, how should I wire this?
Someone in this group must have either done this or planned it in the past. Wife says sell both, get one bigger diesel, by the way. I kinda like the idea of having a spare. All advice is appreciated!
Michael Lewis |
CoryDane RTSII (66.155.188.228)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 11, 2004 - 1:48 am: | |
Everyone does it Their way, wether it be correct or not.....
That said,
The gen sets weigh about 300# each, so it is unlikely you will want to carry two heavy gensets everywhere when one will suffice.
Carrying Gasoline means you will have to carry a separate gas tank if you are a diesel conversion.
If you are total electric then you probably do not have a propane tank, so the weight between gasoline tank vs propane will probably be the same.
The Propane Gen runs cleaner, and I am told are somewhat quieter. The difference will be the consumption propane vs gasoline. The propane tank will take more fuel to generate the same current. but if you install removable propane tanks, you can fill them fairly easily.
The fact that you sound like you are near or total electric may sway you toward the gasoline unit if you plan to park in the boons for long periods of time.
The weight of decision will have to be on your shoulders. Propane is cleaner, wont leak from the tank when you fill it like gasoline can and if the tank is installed properly, a safe fuel for the gen.
Gasoline seems to always find a way to leak from the tank, it always smells of gasoline when you fill a gas can then you have to transfer to the main gen tank.
I installed the propane gen HOWEVER, I also have solar panels to help the battery keep charged or to help supply the inverter when in use. I have propane appliances and I installed energy efficient lighting. I also considered energy efficiency with any electrical appliances as best I could.
The gentleman I bought my Propane Genny from felt that the differences between the two fuel wise is very different so the choice will be made between if a coach is all electric, partial or energy efficient and if you will only park in a campground, do a little short booning or plan to boon a lot.
The others that have the Propane and / or gasoline will chime in with more helpful info.
Hope you were helped along your decisions.
"Imagine"
cd |
TWO DOGS (63.156.216.4)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 11, 2004 - 5:48 am: | |
The idea of a backup genset is neat...I'd wire the propane genset into the system,and have the gas unit on a switch..where either propane unit can be used,(OR) flip the switch & the gas unit is online & propane is mothballed..
(OR) sell me the gas unit) |
John that newguy (199.232.240.57)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 11, 2004 - 7:56 am: | |
Switching between battery converted AC, to generator provided AC,
to shoreline power, takes switching circuits. Adding a second generator
further complicates the switch array and the electronics involved. Is it
worth the hassle?
One 6.5 or 7.5 kw genset will provide all you will ever need, and
you still have the batteries as back-up. That new Onan "quiet diesel"
is quieter than any propane genset I've heard. It's pricey, but really,
really nice! But any genset can be insulated and mufflers added.
I think your wife is right on this one. Keeping it simple should be
the camper's credo. |
TWO DOGS (63.156.216.17)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 11, 2004 - 9:29 am: | |
(or) sell me the propane genset |
Gary Stadler (Boogiethecat) (68.7.217.217)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 11, 2004 - 9:39 am: | |
If you had the room and really want two gensets (why not? It's "your" way...) I'd propane-ize the second one and not carry gasoline.
The two cannot be "tied" together electrically though, so you'd have to create either a separate system for one of em, or a relay mess to transfer power here and there when needed.
As far as the Atwood water heater though, since you'll have propane for the genset, I'd sell it and put in a propane water heater. I use a cheepo atwood propane one with a 6 gallon tank- it's fine. It heats up LOTS faster than an electric one and can keep up with as many or as long a shower as anyone wants to take. An electric doesn't have the capacity to create that much heat.
Cheers
Gary |
John that newguy (199.232.240.57)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 11, 2004 - 10:07 am: | |
The only problem with propane, (aside from price, availability,
and hazards) are the routes you are forced to take around tunnels
and some bridges. It'd be nice not to have to hide the gas from
the "law" (I'll likely be hiding -my- small bottles inside a bay)
As an all electric setup, I'd be using it (very rarely) for stove top
cooking (backup), rarely for hot water (backup), some for
refrigeration (travel backup) and very, very rarely for heat (backup).
If I had to run a genset on propane, I'd need a full-blown tank to
hold the gas.
But hey... If you don't plan to travel through tunnels or into "hazmat"
restricted areas and don't mind carrying yet another fuel, go for it.
There's no "right or wrong". "Do it your way" is the criteria. |
Rodger in WA (64.70.24.56)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 11, 2004 - 11:37 am: | |
I agree with wife for several reasons. Here are some.
2 gensets is a lousy idea. Consumes too much space, the noise of two gensets, and 2 over complicates the electrical system. Each unit requiring different fuels, neither diesel makes it even worse.
Hauling gasoline in portable cans is a major PIA. Been there, done that, hated it. Sold the gasser and installed a diesel. Never regretted it.
3KW is inadequate for an all electric coach, even without air cond. 7KW is minimally adequate.
JMO |
Gary Stadler (Boogiethecat) (68.7.217.217)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 11, 2004 - 12:12 pm: | |
John, I'd be interested in the "problem" of carrying propane thru tunnels, "sensitive places" etc. As far as I know, as long as it's a "built in" tank, there's no problem. It's only loose tanks they don't like... I may be totally wrong here, and would be interested in anyone piping up who can reference the actual laws & rules ...
I never give it a thought. And for instance, I went over the Hoover Dam recently where they inspected the bus like crazy. They didn't give a rats butt about the 110 gallons of propane....
Experience: I had a 4kw genset and it was totally inadaquate for 2 A/C's. Now I have a 7kw and it's totally fine.
And yes, I have a 110 gallon tank on my "mostly propane" bus. It does a week in hot desert with 2 A/C's running fulltime, just fine, with fuel to spare. I wouldn't recommend less than 50 gallon tank though, if you're doing it with everything propane...
Last, the wife's comment... "if he has enough space for two gensets, why not install only one and make his wife a bigger closet for her clothes?" |
John that newguy (199.232.240.212)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 11, 2004 - 12:41 pm: | |
Yes Gary. You are totally wrong here.
I would rather suggest you learn about hazmat, than simply copy
and paste the "proof" you need.
The fines are stiff, for going through a hazmat restricted area with
a tank of propane aboard. I've done it; others have done it, but
we've all been fortunate enough to not have been caught.
I would suggest a 6.5 or 7.5 genset of any type fuel, for anyone
wishing to "dry camp" for any amount of time. Running the 110v
air conditioners is a plus while driving through hot climates as well.
I would prefer to think that "the wife" is more concerned with all
the associated problems and headaches "the husband" will have to
endure maintaining all that equipment, rather than some assumed
self-serving purpose of the statement.
My hey..... it's just -my- opinion. |
Adame (129.82.228.252)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 11, 2004 - 1:40 pm: | |
I think you have a very smart wife. Nuff said. |
Jim Ashworth (Jimnh) (172.131.79.85)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 11, 2004 - 5:42 pm: | |
Gary- One of the tunnels through Baltimore is NO propane-period. Not portable, not fixed, probably not in a Bernz-O-Matic tank.
Second place is the George Washington bridge in NYC. Upper deck only restriction.
The Chesapeake Bay Bridge/Tunnel is another that you must shut off the propane.
You can probably tell I go from NH to FL on the East coast, huh?
In the West, there are fewer tunnels/bridges to worry about, but it can be a PITA in the East half of the country.
Jim |
Niles (24.73.65.124)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 11, 2004 - 6:01 pm: | |
I was not allowed on chesapeake tunnel w/ ANY propane - and no tunnels in and out of manhattan , but did cros the GW - can't remember but I think it was top deck - enclosed ferries require shut off at main tank valve and they externally mark its location w/ tape - Niles |
Abajaba (12.217.192.62)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 11, 2004 - 9:23 pm: | |
One could use both generators in parallel but there are some power wasting steps that would be required to do it. And more weight. Output of Generators would need to be dropped down to battery levels and put through a charger to a battery bank. Then after the battery bank the power is fed into a large inverter that actually makes the AC power that you are using. When you don't need too much power, run off the battery. Then when the power is increasing one of the generators can be started to keep the power into the system up. When the load increases to the highest level then the second generator can be started.
If both generators are the same type of fuel then you only have to carry one type of fuel. If two different fuels then go with the least expensive.
If you have one type of fuel then you could alternate between which generator you used to power the coach.
While traveling down the road the battery could be charged off of the main engine.
Just an idea. Not necassarily a good one.
Abajaba |
DrivingMissLazy (66.168.175.51)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 12, 2004 - 9:09 am: | |
I have to say that this is one of the oddest installations that I have ever seen discussed. The idea of the bus being diesel, one genset gasoline and one genset propane kinda blows my mind LOL.
Do not even think about paralleling the outputs of the the gensets. Special governors and special voltage regulators required and they are not available for these units. You could use one genset to feed one buss, and the other to feed a second buss, but it would be an electricians nightmare to accommodate all the potential configurations.
I have been working with gensets for half a century and in no way shape or form would I attempt to install a configuration like that, but maybe I am just chicken. Lots of potential for hazardous conditions exist. Be very very careful if you do this.
Richard |
Abajaba (12.217.192.62)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 12, 2004 - 10:58 pm: | |
It would be a major pain in the keester if one had multiple fuels. I just made that one of the options. And the way that I was suggesting up above was to take the output of the gen set, rectify it to D.C. to charge the battery bank and then have an inverter to actually make the A.C. power. As I stated it would mean some power wasting steps in the middle. BUT, with D.C. feeding the battery from the gen set one could isolate the two gen sets with two BIG diodes. Then it wouldn't matter that the frequency or voltage of the two sets didn't match PERFECTLY. After all, there is no such thing as perfect.
If I were to try and do something like this it would be with two alternators putting out some BIG D.C. current being driven by motors that run on the same fuel as the main engine of the bus. That way one doesn't have to worry about the step of taking A.C. power, transform it down and then rectify and regulate it.
This is just some strange thought process of mine but if it were done right, then the motor driving the alternator would be about right for normal power loads and one motor could run about 85 percent throttle and not be in the wasteful power range they normally run in.At the same time the other motor would be shut down to only start up when the first motor hit 100 percent throttle or more and stayed there for some period of time.
Of course Honda and some of the other generator companies have beat me to this idea with some of their generators that actually run with the capability of paralleling them. |
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