A little electrical question...

[Chaz]

I'm getting ready for the trip to L-ville this weekend and I was playing with my AC and generator. Seems that my 4kw gas gen does not have the s**t to pull two roof top "warts". (I guess I already knew that, but wanted to make sure)  But, "I THINK" with putting my Zantrex 4024 in auto mode it will pull from both the gen and the house batteries to make it work. (house batteries are 8-6volt golf carts. A 24volt system.)

Here's the question: The gen. I have is a noisey ol' Generac and I don't want to bother the neighbors any more than I have to. So I was wondering if a little 1kw "purring Honda gen." would do ok at recharging the batteries thru the day while we at at the show? I imagine it would take awhile (IF IT WORKS AT ALL) but it would be a whole lot less obtrusive than the Generac. Unfortunately, in the evening I will need to run the Generac so I can run both AC's.

What ya think??
      Chaz

[gumpy]

I think you're going to have some upset neighbors! 

Why do you need both airs at night?  You have several people scattered throughout the bus?

You'll have to do some calculating to see if you can make it work. I would suspect the problem you will have is that with your
4024, as you load up the generator, it will drop in frequency and / or voltage to the point that the 4024 kicks it out and goes back to inverting. Then, the generator will recover and the inverter will detect good power, and the whole process will start over.
Now, you could set the inverter to limit input amps from the generator to about 15, and then it would supplement from the batteries, but will probably then draw around 10-12 amps from your batteries. How long you can run this way will depend on the size of your battery bank and how low you're willing to let them drop.

As for the 1Kw generator recharging during the day, it's going to depend on how low your batteries are and how well that little generator maintains voltage and frequency. It will only put out about 8 amps if it can run full load at 1Kw. That's about 40 amps @ 24volts. To replace a 400 ah battery bank that's 50% down will take on the order of 15+ hours with only 40 amps input.

Pray for a cold front!

[Lin]

If there is a way you can run the 1kw generator with your 4kw generator, that may be enough to power the AC's without draining the battery bank. 

[junkman42]

Chaz, one thing that You do not want to do is parrell the output of the two generators as a out of phase disaster will  result.  Once being converted to dc either by battery charger or what ever then no problem.  My two cents,not much buying power for sure.  John

[H3Jim]

Get a bigger honda or even two or three of the small ones.  Get rid of that Generac.  The campers around a friend of mine almost got phisical with him when he used his Generac at a campground recently. We all hate the sound of a noisey generator!

[Lin]

Have you tried piping the generator exhaust above the bus?  I know that relocating the exhaust made a huge difference on my old Onan.

[Tenor]

Can you run one air on it's own line and just plug it into the small genset?  When I only had a small 30 amp system, I just wired up the second air seperatly and plugged it into it's own 20amp outlet.

FWIW!
Glenn

[JohnEd]

I have a 5KW Onan and I can't sell it for $350 and it has great compression that would indicate little use.  Your 4024 inverter is a dream come true for me and I think you have the heart of a superb system.  Don't start with bandaids now.  If you will tolerate the fuel expense of a gas generator, find an old 6.5KW Onan for cheap and add that to your system.  Then you are THERE.

I think a 5Kw will run 2 AC units....barely.  If the gen is in good shape.  What it won't do is start two at a time.  As I recall, my roof unit needed 12 amps to run but almost 30 to start.  Way back when there was a elect unit that allowed only one AC to start and held the other OFF if it tried to start its compressor at the same time.  With both running the constant load was 24 amps and the start of one with one already running was well within the limits of my 6.5 and your 5KW backed up by your 4024 should work=, at least the arithmetic.  Get rid of the Genrac and pipe the Onan to the roof.

more 2 cents....soon to be a whole nickel

John

[Chaz]

Not much chance of a cold front Gumpy.    So I guess to keep from getting tarred and feathered I better camp out in the lower 40. 
Actually, the scenerio that I had in mind was to use the gen. and batteries in the evening to run the AC's, etc. and then at "quiet time" go to just batteries and just the bedroom AC . Then in the morning, plug my shore cord (since I'm not plugged into a pole) into the 1kw Honda to try and recharge the batteries thru the day.                       But....................... it's not looking too promising.

I talked to Zantrex and............ well.................. it seems they farmed out their customer service to the "Big Sand Box" too. (Sorry, but I have a hard time with the accent and I'm not very versed in this stuff to start with. )
But anyway, he said it would take 20 hours to recharge the batteries using the Honda. He also said I can run one AC for 13 hours just on the batteries. (I have 8-6volt, 245 AH batteries) And he said I can not just plug into the Honda with the shore cord because of a bonding issue. Whether I got all that right is debatable. Given the fact I'm not much good at this and the translation thing.......who knows.

Jim, I am ALL ABOUT getting a better gen., but I have to put it down on the list of other things i need to thro money at.  And I don't really want to by something that is just a little better. If/when I'm going to spend the money, I would like to get a 6-7kw diesel. And as you know they cost an arm and a left nugget.  I'll just to become a "loner". I really don't want to bother anyone, but it's the best i can do right now.

Tenor, That's a thought, but not sure how to go about it.

Pete (RTS Datona) gave me a call awhile ago to try and help me sort this out - and I couldn't appreciate it more!! Thanx again Pete!- and he mentioned using a small window unit with the Honda. But unfortunately, I don't have a window unit, or even a window that it would work in for that matter. 

John, That sounds like a nice enough price for the Onan. I would consider it if I weren't wanting a diesel. I just want to keep my coach to as few fuels as possible.
I agree that it will be a nice system WHEN it's done, but doing things "piece meal" makes it a little more trying. 
My AC's show a draw of about 10-11 amps each when running. That's where I think I can get the Zantrex to supplement the start up amperage and hopefully let gen. run both. But I think more likely the inverter will need a little from the batteries to keep the AC's going. (at least that is the way I understand it to work)

I hope this post makes sense for you guys who are trying to help me. My finger is typing as fast as it can as I need to make an appointment.

Thanx for all your help!!!!!!!!!!!!!!!!!!!!
   Chaz

[belfert]

If everything was 100% you might get 2 or 3 hours running an A/C if that was the only load.  You have 98 amp hours of juice at 120 volts.  At max you could draw 49 amps and probably want to draw even less so you don't toast the batteries.

[jjrbus]

 I have a trace (xantrex) Dr3624 inverter with 4 Sam's club type 6V golf cart batteries.  I have 11.5K btu roof air. In the real world this set up will run one roof air for 1 1/2 hours max. I do not see how 4 more batteries would give you 11 1/2 more hours run time on the AC !!!!!! 
Kudo's for not wanting to bother people, the world needs more like you!!!!!     Jim

[Chaz]

Yeah, I think he got his numbers mixed up somewhere. But I wrote down what he told me and that's what he told me.

Oh well, not sure what else I can do with what I got. 3 hours of AC is NOT going to make Linda happy................. not even. And as for my "four legged and furry little buddy" thru the day...... man.......I dunno. Maybe I'll have to park over by a dumpster or something.     

Chaz

[JohnEd]

Chaz,

I am in complete sympathy with you on the multi fuel tank issue.  It is the $4K problem associated with the diesel that has most of us stumped. Me for sure. Gas only has the drawback of the fuel going bad and that can be dealt with.  I start burning the old fuel in my car after spring has sprung.  When the tanks are empty i refill with fresh.  I am OK with that inconvenience.  Sure gas is less efficient.  

A better alternative is a gas rig that is converted to propane.  I have to carry propane anyway so that isn't a deal breaker.  Also, propane doesn't age and I don't have to rotate the stock.  I think you could get an old 6.5 for less than 500 but that is only a guess.  Still, I am not trying to talk you into a thing my Bro.

Really am impressed with your inverter.....you keep that locked?

[buswarrior]

Hmmm...

Is the Genereck wired for straight 120 or for 240/120?

We fixed a little 4000 watt Onan at a bus rally years ago that some "expert" had ballsed the thing, for payment, too, the dirty so and so....

Wired the proper way, all fields on line for straight 120, it would run two roof airs.

Feed the full 4000 watts into the 4024, set the 4024 for 30 amps input, feed the roof airs from the 4024, start them one after the other and see what happens.

Make sure the Genereck has lots of cooling available!

happy coaching!
buswarrior

[Chaz]

John,
A gas rig converted to propane is an interesting thought. I have a tank of propane on my bus now but just for the hot water heater. I want to go to a Webasto/proheat whatever eventually, so I can eliminate that also. (I may need a bigger diesel tank!!!!!!!! LOLOL     165 gal. may not be enough!!  )
  Yeah, I am sooooo very tempted to get an older gas job, but I really think, ultimately, that the diesel would be the best bet in the long run. And I am ok with doing without till I can come up with what I want eventually. Plus, I do have the generac to get me thru. I just need to be an "outcast" till I can figure something out.
Oh, I have 3 rabid squirrels standing guard shifts over my 4024.  lol   I think it will be a sweet setup once I get it figured out.

Hmmmmmmm........  Not sure I follow ya, Buswarrior. But I think I am set up the way you are describing. Jerry Lieber helped me set things up and I must say, he really knows his stuff. I was hoping he might jump in, but he may be out and about. (I'm going to need his expertise to connect the house and start batteries)

Thanx Guys!!!

  the "Outcast"