Author Topic: Just a thought on electrics and stuff  (Read 7274 times)

cody

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Just a thought on electrics and stuff
« on: February 22, 2009, 09:56:04 AM »
I was sitting here thinking, always a dangerous thing to do.  I've got a heart 458 inverter I think it's only a 1000 watt, pretty basic thing.  The inverter feeds a bank of 4 batteries, I've also got a honda 3000 watt inverter generator, my whole set up is fed thru a 30 amp power cord.  On the roof I've got 2 carrier 15K heat pumps set up on different circuits, the back one is on a completely independant circuit and heats and cools like a champ, the front one is tied into another cuicuit that has a couple of other items on it but nothing major and it cools and heats pretty marginally, there you've got a basic idea of what I've got, now what I want is to be able to cool on the road, I feel the battery bank is enough for now and the generator should handle one of the roof airs but I do seem to "run out of power" easily, I realize that what I have is a marginal set up but how can I boost the power the most cost effective way, I'm not entirely convinced the system is wired in properly either so that I get flow thru power when using shore power cause it doesn't really seem to matter,  I'm thinking a larger inverter, maybe a 2500 or a 3000 watt one, I'd rather not get a larger generator tho it is possible that I may have to.  When I bought the bus it had a huge generator with a transfer switch that was removed with the generator, the deal I worked out involved the PO keeping the generator and transfer switch.  I'd like to run one roof air on the road and I'm told that the generator I have should do that but it doesn't so I'm thinking I have to rethink the parts in between, I do know others with the same generator that run the same roof warts tho so I do know it can be done with this generator. Any ideas?

Offline buswarrior

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Re: Just a thought on electrics and stuff
« Reply #1 on: February 22, 2009, 10:17:26 AM »
I am a BIG fan of quiet generators, so you have my support to work with what you have!

I would trouble shoot that front roof air as a place to start. I'd be suspicious that it is under-performing due to its own trouble, not due to the electricity.

And a review of how these items are wired together would determine if you are getting the max out of what you have.

I run a Yamaha 3000ei feeding a Trace 4024 inverter, with a little load management, of course!
A pair of 23 year old roof airs, and an old bar fridge, with a dog's breakfast of old golf cart batteries. Somewhat underpowered for summer desert conditions, but ok for what I have done so far.

When battery charging, the auto throttle and the Trace like to fight, so I just leave the auto throttle turned off and let the Yamaha run.

happy coaching!
buswarrior
Frozen North, Greater Toronto Area
new project: 1995 MCI 102D3, Cat 3176b, Eaton Autoshift

Offline Sean

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Re: Just a thought on electrics and stuff
« Reply #2 on: February 22, 2009, 10:41:08 AM »
I'm with Buswarrior on this.  Your 3kW genny should run a single Carrier without problems.

One place to look is at the wiring to that problematic Carrier.  It's possible that there is a problem (such as too small a gauge for the run) leading to a voltage drop at the unit, which, in turn, will cause the unit to work harder and draw more current.

HTH,

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cody

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Re: Just a thought on electrics and stuff
« Reply #3 on: February 22, 2009, 10:43:57 AM »
The line going to the carrier is 12/2 romex with the kitchen on it but thats only 2 table lamps and the outlets along the counter that normally don't have much plugged into them.

Offline jjrbus

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Re: Just a thought on electrics and stuff
« Reply #4 on: February 22, 2009, 10:52:50 AM »
One of the first places to check on an underperforming AC if it has been mounted for a while is the filters. Then take the outside cover off and clean the coils!!   HTH  Jim
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Offline JohnEd

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Re: Just a thought on electrics and stuff
« Reply #5 on: February 22, 2009, 10:53:17 AM »
Cody,

Sean beat me tuit.  What he said, but here is how:  Get a analog (not digital) volt meter on the input ac lines to the "good" ac unit.  Turn it on and watch the voltage reaction/dip when it starts and runs OK.  Do the same to the front, under performing, ac unit.  You should see the voltage dip much more and stay depressed during the run cycle.  The bad wiring, if that is the case, might be a 'wire nut" splice that is loose or too light a gauge wire or other stuff.  BUT, whatever the ac source....that should stay up in the satisfactory level like the rear unit.  I agree that it is not likely that the ac unit is bad, given your symptoms, but Gosh Darn Buddy, I'd hate to see you fix you genny when the ac unit was bad after all.  I think 12 gauge wire is the min called for but I would go with 10 gauge considering that the start-up current is something like 24 amps....could be wrong and it depends on the size of your ac but the theory holds regardless.

HTH,

John
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cody

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Re: Just a thought on electrics and stuff
« Reply #6 on: February 22, 2009, 11:02:49 AM »
I had hoped that 12/2 romex would be heavy enough, it's what our house is wired with, maybe it isn't

Offline Dreamscape

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Re: Just a thought on electrics and stuff
« Reply #7 on: February 22, 2009, 11:10:01 AM »
Cody, I have 12/2 for all three of our A/C's, and have had no problems. They are probably older than dirt too. I'd take off the shroud after you have done your sparky thing and check it out, might be just dirty.

~Paul~
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Offline Sean

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Re: Just a thought on electrics and stuff
« Reply #8 on: February 22, 2009, 11:22:10 AM »
The additional items on the circuit might be part of the problem, if they are wired "ahead" of the AC.  Each device represents a splice in the circuit, which can present additional voltage drop.

Rather than speculate, you should go measure it with the unit running.

FWIW, the AC manufacturer mandates a dedicated circuit for the unit.  I would not stray from this requirement.

-Sean
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Offline Sam 4106

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Re: Just a thought on electrics and stuff
« Reply #9 on: February 22, 2009, 11:34:02 AM »
Hi Cody,
You say your bedroom heat pump works well and your living room heat pump is marginal. Is it possible that the noticable difference is because the bedroom is much smaller than the living room and there are more windows in the living room? Have you compared the output temperature of both units? That would give you an indication of whether one is truely working better. I am not discounting what others have suggested, just adding more things to check.
Good luck, Sam 4106
1976 MCI-8TA with 8V92 DDEC II and Allison HT740

cody

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Re: Just a thought on electrics and stuff
« Reply #10 on: February 22, 2009, 11:57:39 AM »
I'm going to add a dedicated circuit to the front unit, the back unit already has that, the filters and coils are clean thats the first thing I checked on them, it's easy to tell the difference in output between the two the front one doesn't throw air that even feels very cool wheen it comes out of the unit or as warm when the heat cycle is used.  One concern is that the back one will kick in and cool but the front one will work on the fan setting but when you put it on low cool it trips and kicks out so it's a probably voltage problem.  One think I'm going to do is wire the front one to a plug and plug it directly into the generator bypassing the inverter, fusebox and everything in between, that should tell me a lot too.  I tested the front one in the past on household power and it kicks in and cools but not as well as the back one, I'm really thinking that the inverter is just too small for it. and I'm doubting that the pass thru feature of the inverter is working properly, I'll have to pick up a tester.

Offline JimG

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Re: Just a thought on electrics and stuff
« Reply #11 on: February 22, 2009, 07:56:22 PM »
Cody.

The EU3000i generator can handle the 13,500 AC. Although it doesn't sound like much more, the 15K is in a larger category. I made the mistake of "bigger is is better" when I put a Carrier 15K in my popup camper. My EU3000i tries to run it but now I know better. I love the quietness of this generator.

I Googled the following info:

Honda EU3000is Generator
3000 Watt Honda Inverter Generators
Super Quiet! 49-58dB!
Efficient! 20 Hour Runtime at 1/2 load
Electric Start with Recoil Back Up
Inverter Equipped - AC/DC Use
Runs RV and Camper Air conditioners up to 13,500btu

Hope it helps, Jim G. - 1979 RTS-II
Jim & Linda Gochnauer Plain City, Ohio
1979 RTS-II 40'X96"

cody

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Re: Just a thought on electrics and stuff
« Reply #12 on: February 23, 2009, 05:20:56 AM »
Jim, the little honda starts the rear a/c but i know it's pretty much at it's limits, once the rear a/c is started and running then I normally can fire up the other circuits too like the refrigerator and lights.  I do have an older model Onan 5K rv generator I could put in if needed but I'd rather not if i didn't have to, the honda is just so incredibly quiet I like that.  because of how loud the blowers are on the carriers, what we try to do is run the back a/c when we're in the front and run the front a/c when we're in the back.

Offline Van

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Re: Just a thought on electrics and stuff
« Reply #13 on: February 23, 2009, 05:38:36 AM »
Hi,I have an older CCK5kw(1976) also that runs fine also but have some wiring ?'s.Seems I have no power to the coil and have to use a jumper wire to get power to it,also have to jump the solenoid to activate the starter(start button inactive) ,once that is done it provides plenty of ac/dc.What I have been unable to locate online is the wiring schematic for the panel ,does anyone have a link or a copy?Have tried the onan site ,but it does not seem to go back that far for the CCK 5.5Kw ??? Thanks
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cody

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Re: Just a thought on electrics and stuff
« Reply #14 on: February 23, 2009, 05:45:31 AM »
Van, I'm thinking NCBob would probably have the answer for that one, if I'm not mistaken he's an onan guru, rumor has it that he had one of the first onan equipted dinosaurs in rockstone township lol.

 

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