| Author |
Message |
Jim (Jim_in_california)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, February 27, 2005 - 11:25 pm: | |
The bus I'm considering has a single large AC unit (typical 15,000) in good shape, which isn't bad for a 34' with proper insulation. It's set up for 30a power, genset is a 4kw Onan. There's a second mount set up for an AC unit complete with wiring, right now has just a Fantastic Fan.
There's a decent Coleman AC catalog online here:
http://www.go-rv.com/coast/do/catalog/page?pagePrev=TRUE&dealerId=333&pageNum=328
We see that a Coleman Mach 15 has 15,000btu cooling, draws 71 "Locked Rotor Amps" (wazzat?) and draws 16 amps both cooling and heating.
The numbers for a standard 13,500 Coleman unit on the same page ("Roughneck" are pretty close: 67 "locked rotor amps", 15.8amps cooling, and the next page has another standard 13,500 "Mach 3+" at a fraction less.
But on that same next page, look at the "Power Saver" versions: the "Mach I Power Saver" is a 12,690btu critter drawing 44amps "locked", 9.3 amps cooling. There's also a "Mach III Power Saver" at 13,770btu, 48.3amps "locked" and 10.2 amps cooling draw.
Now here's my question: what are my odds of getting two of these "Power Savers" of either size running with first, a 30a shore power line and second, a 4kw Onan if I'm careful to turn 'em on one at a time?
If I *can* do two of those, even if it's the 12,690 units, then I can buy one now and put it in the fan's slot and see if that and the existing will live together. If not, I can pick one or the other depending on power I want to spend and then eventually upgrade the front to low-juice.
The existing front is good, but it's getting on in years... |
Jim (Jim_in_california)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, February 27, 2005 - 11:28 pm: | |
Dammit, title got screwed up by my browser...
Ian, can you change it to "AC Power drain options"? |
James Maxwell (Jmaxwell)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, February 28, 2005 - 12:31 am: | |
Jim: You can turn them on at an interval but you cannot control the cycling that may cause both to cycle on at the same time. Neither your 30 shore or 4kw Onan will start 2 15k units at the same time. Your 30 amp shore will not start the 2 power savers together but the Onan might do it, marginally. They make a smoke and mirrors device for preventing the 2 from simultaneous start but I know little about it. |
BrianMCI
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, February 28, 2005 - 12:46 am: | |
Actually with a modest bit of electrical engineering it would be possible to regulate both compressors so that at no time will both compressors start at the same moment.
Brian |
Lin
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, February 28, 2005 - 1:52 am: | |
We had a timer installed from Camping World a long time back. That can be set to cycle from one AC to the other. It gives 7 minutes to the front unit then 5 minutes to the rear. I would guess they still have them. If the timer senses that you have 50 amp service, it will run both at the same time. |
Jim (Jim_in_california)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, February 28, 2005 - 2:30 am: | |
Hmmmm.
Does anybody make a controller add-on to do that?
Here's another thought:
Say I run the 13,770 unit up front, and put something smaller at the back in the 8,000btu range?
Coleman doesn't make a really low powered unit in that size class...their "Polar Cub" 7,700 eats almost as much as the 12,690 but there's got to be other sources for an 8kw-range AC of a low-draw design...I could run one of those and the 12,690 or 13,770 maybe?
Duo-Therm has a 7,000 draining 6.6amp.
http://www.rvaddons.com/default.asp?cmd=displayproduct&CategoryID=30337&ProductID=224239&U rlID=3002808&UrlToken=ZWO2VPZ6UULBUAIS
The rest of their line isn't as efficient as the best...Colemans. They have an 11k good for 9.5amp.
So OK...who else makes something between 6,000 and 8,000btu that might be as efficient as the larger Colemans?
Failing that, what about taking over manual control of at least one of the two units, with a remote switch? |
Jim (Jim_in_california)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, February 28, 2005 - 2:33 am: | |
Lin, THANKS!!! Lemme go look for that...
Yup:
http://www.campingworld.com/browse/skus/index.cfm?deptID=&subOf=166,16&skunum=9320
$180.
Perfect. |
FAST FRED
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, February 28, 2005 - 5:39 am: | |
You can purchase a simple relay from Granger (or ?)that will only allow one unit to start at a time.
Camping stores also sell a simple controller that will cycle one compressor , then the other, leaving the fans going.
FAST FRED |
Jim (Jim_in_california)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, February 28, 2005 - 11:01 am: | |
Fast Fred: Ummm...any specifics? I've been trying to find these from your descriptions, ain't getting anywhere... |
John that newguy
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, February 28, 2005 - 5:23 pm: | |
You'll find it here: http://www.intellitec.com/products.htm
Specifically: http://www.intellitec.com/PDF/5322083100.pdf |
Jim (Jim_in_california)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, February 28, 2005 - 11:18 pm: | |
John, that looks GREAT!
How much is that puppy, ballpark?
Should work even better with a pair of 9-10am critters. |
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