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Old 01-16-2019, 05:37 PM   #1
daveinaz
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Inverter for residential fridge

The PO of our Montana replaced the stock gas/elec fridge with an electric only residential/apartment size Magic Chef unit. Since they did not travel with it, it is set up to run only on AC. He said that I could get an inverter to plug it into when towing it.

So....I'm guessing that there should be both AC and DC wiring in the compartment which means that I just need to wire an inverter into the DC and plug the fridge into the inverter when on the road? I don't need it to switch automatically, I think I should be able to just open the compartment cover, unplug it from AC and plug it into the inverter.

And hopefully the manual for the fridge tells me how many amps I need to have on the inverter.

Is it this simple, or am I missing something?

Thanks.
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Old 01-16-2019, 08:06 PM   #2
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Dave,

If you never plan to boondock and only plan to stay in parks with hookups you can get by with doing nothing. As long as everything is cold in your frig and you don't open the door while traveling you should be able to get 10-12 hours before plugging it in again.

If boondocking or really long road trips are in your future I would go with a 2000 watt inverter, a battery bank of at least 300 amp hours and wire your frig and a few other plugs to run off the inverter. Could be DIY if you have some familiarity with electric systems.
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Old 01-17-2019, 07:57 AM   #3
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If you just go from RV park to another RV park, don't worry. Your frig will be fine for lots of hours.
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Old Yesterday, 10:35 AM   #4
daveinaz
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Although it would probably be fine going from site to site just leaving the fridge closed with no power, my DW isn't comfortable with that approach so I think I'll go with the easiest method of getting power to it which is just putting a PSW 1000 watt inverter in the cap by the batteries, then run an extension cord underneath (drop the coroplast), and pop it up into the lower outside fridge panel where the fridge is plugged in. Then before we hit the road it would be a matter of opening the panel, switching the fridge to the extension cord, closing said panel, then opening front panel, turn on converter, close front panel. I know I could get an automatic inverter, but that would require significantly more wiring, plus automatic inverters constantly draw battery power.

I ordered some black child proof latches to keep the residential fridge closed when traveling with it (it's a 9.9 cf Magic Chef Vissani fridge)
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Old Yesterday, 11:19 AM   #5
Kid1956
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Dave, a PMX1000pPSW says, its 80% efficient at max load... so thats 800W..
800/120=6.6amps maxed out.. The fridge will probably draw close if not more..
Probably better with a 2000W or 2500. It will only use what it needs. But you wont be so hard on it. 2000 at 80%(normal for avg invertors) would be about 1600W or 13.3amp..

just sayin..
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Old Yesterday, 11:23 AM   #6
ChuckS
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You could purchase one of the 1000 watt inverters from WFCO...there are better ones available but this would do the job...

It needs a 120VAC source plug in and then the residential fridge is wired into the AC out on the inverter.. Inverter has an “auto sense” and when plugged intomshore power the AC is pass thru to fridge so you don’t need to worry about turning off and on..

I’d also have a separate battery for the inverter with an isolator between that batter and other batter so that it would charge from converter when shore power is applied to the rig..

https://wfcoelectronics.com/product/wf-5110r/
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Old Yesterday, 11:58 AM   #7
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Quote:
Originally Posted by ChuckS View Post
You could purchase one of the 1000 watt inverters from WFCO...there are better ones available but this would do the job...

It needs a 120VAC source plug in and then the residential fridge is wired into the AC out on the inverter.. Inverter has an “auto sense” and when plugged intomshore power the AC is pass thru to fridge so you don’t need to worry about turning off and on..

I’d also have a separate battery for the inverter with an isolator between that batter and other batter so that it would charge from converter when shore power is applied to the rig..

https://wfcoelectronics.com/product/wf-5110r/
Yes, i looked into wiring it that way, but it's a little more wiring that I want to do at this point. I suppose it's a wash -- the old pay me now or pay me later thing. More up front work now to wire it to an automatic inverter and having it be automatic vs. plugging the fridge in and turning the inverter on each time. But at this point, the *pain* of getting a AC line up to the front cap from wherever it has to come from to plug into the inverter is more work than I'm wanting to do right now.
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Old Yesterday, 12:07 PM   #8
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Dave, you'll probably want the pure sine wave version, tghey are better for motors, but there are a few.. modified sine wave that could work.. do research..
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Old Yesterday, 12:29 PM   #9
daveinaz
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Quote:
Originally Posted by Kid1956 View Post
Dave, you'll probably want the pure sine wave version, tghey are better for motors, but there are a few.. modified sine wave that could work.. do research..
Yes, I will get a PSW converter. Not sure the fridge would work well on MSW.
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Old Yesterday, 01:09 PM   #10
JABURKHOLDER
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Dave, per your original question, yes, it can be that simple.
Two recommendations...
1. Go with a 2000 watt inverter. It won’t have to work as hard.
2. Use heavy gauge wiring for you battery hook up and your extension cord to prevent high impedance and to keep everything from getting hot.
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Old Today, 10:17 AM   #11
jcurtis934
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A 1000 watt inverter will require a fuse or circuit breaker on the inverter positive battery input of approx 175 amps. The inverter can NOT be in the same compartment as the batteries since the inverter is not ignition proof and can ignite fumes from propane or hydrogen off-gassing of batteries. The front compartment is not sealed from the propane tanks and I had propane leak into that compartment when my regulator decided to leak from its guts. That fridge, I believe, has a normal compressor and should havery a label in it detailing it's max running watts. Startup current on a normal compressor can been three times the max running rate for a very brief period of time. This is one reason I installed the samsung fridge that has a digital inverter compressor and it's max draw is only 360 watts with a startup surge that is very low. Whatever inverter you go with, make sure it has a surge rating that is double it's max supply rating.
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Old Today, 12:55 PM   #12
daveinaz
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This is the first I've read about not mounting the inverter in the same compartment with the batteries. Every install I've seen so far has it close to the batteries so that there is less voltage drop associated with a longer cable run. My propane tanks are in separate compartments from the compartment under the nose. The batteries are also enclosed with a hose vent going to the outside. With my propane in different compartments and the battery boxes being vented to the outside, would you still be worried about the ignition issue?
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Old Today, 01:20 PM   #13
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Dave, our factory installed inverter is mounted in the pass through storage. They fed the DC cables through the bulkhead. The way they did it keeps the inverter in separate compartment and isolated from the batteries and propane tanks. They also have the batteries in a box vented to the outside.
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