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Author Topic: rv fridge 110v power from inverter?  (Read 6150 times)

deavthevanman

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rv fridge 110v power from inverter?
« on: January 29, 2010, 10:01:48 AM »
Im sure this has been talked about before on here but i couldnt find it.

can you run a rv fridge on in 120v mode with a inverter? and how big of one would i need? how long should i expect it to last? i have 2 10 w solar panels not installed yet. running off 1 deep cycle marine batt.

ive heard that the heating elements in rv fridges pull around 400-1000 watts but theres a big difference there. any closer numbers?
thanks
82 pace arrow v "bunk beds" 29' fully loaded. p30 chevy chassis. 454 v8 and th400 trans.

John From Detroit

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Re: rv fridge 110v power from inverter?
« Reply #1 on: January 29, 2010, 10:17:00 AM »
Short answer: YES.. The fridge takes aroudn 350-450 watts depending on the make and model when it's running, run cycle can be well over 50% so a single pair of U-2200's can run it 2-4 hours.  That's the problem.. Run time.

I have done this when on the road.  I have mine set so I can toggle between shore/generator only or Shore/Generator/Inverter.   Makes it easy to test.
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Lou Schneider

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Re: rv fridge 110v power from inverter?
« Reply #2 on: January 29, 2010, 11:15:11 AM »
It's not really practical to run an absorption refrigerator from the batteries.   Absorption refrigerators work by using heat (from a flame or an electrical heating element) to provide the power to run the cooling unit.    This is much less efficient than using a motor driven compressor to do the same thing.

An absorption refrigerator uses heating elements that draw between 350 to 600 watts, depending on the size of the refrigerator, or about 10 times as much power as a conventional compressor driven refrigerator uses.

Two 10 watt solar panels making their full rated power produce 20 watts.   If your refrigerator uses 400 watts, that's 20 times as much power as your solar panels produce under ideal conditions.

To put it another way, an absorption refrigerator will use an hour's worth of solar power in 3 minutes.

Running it from the inverter while you're going down the road and the vehicle's alternator is charging the batteries may work, but you'll be increasing the load on the vehicle alternator by a significant amount to supply the extra power that the refrigerator is drawing from the batteries.   Make sure it's up to the task of doing that while also producing enough power to run the rest of the vehicle.

Gary RV Roamer

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Re: rv fridge 110v power from inverter?
« Reply #3 on: January 29, 2010, 11:27:47 AM »
It's quite common for people to run a fridge via inverter while driving and the engine alternator can keep the batteries up, but less so when parked. You need an adequate battery bank for the wattage and even 400 watts is a lot at 12-13dcv.   My Norcold is actually 450 watts, so I would be pulling about 36 amps from the batteries. On a moderately warm day, the fridge runs most of the time, so that pretty much continuous at temps much above 70 degrees.

A new residential type fridge with a low energy compressor is actually more efficient if you wnt to run in this fashion. Wattage is similar but the duty cycle less.
Gary
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Just Lou

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Re: rv fridge 110v power from inverter?
« Reply #4 on: January 29, 2010, 11:51:10 AM »
I ran an absorption refer on an inverter in my old class-C (while on the road) for a couple of years without a problem.  I used propane when boondocked or AC when available, but was never able to keep the burner lit on the road, thus the inverter solution.

I also currently run a portable freezer on inverter.  It is, of course, the compressor type unit.

I often run my refrigerator on inverter while driving to conserve propane, but I also have a 160 amp alternator.
'97 Bounder 34V (F53 w/tag), '99 Honda Accord EX

deavthevanman

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Re: rv fridge 110v power from inverter?
« Reply #5 on: January 29, 2010, 12:25:04 PM »
is it safe to run my generator while driving down the road? so i could use my fridge and ac unit?
82 pace arrow v "bunk beds" 29' fully loaded. p30 chevy chassis. 454 v8 and th400 trans.

Marsha/CA

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Re: rv fridge 110v power from inverter?
« Reply #6 on: January 29, 2010, 01:00:36 PM »
Yes, on running the generator while traveling down the road.  Lots of us do it, for either air conditioners or heat. 

The newer model refrigerators have 2 way cooling:  AC or propane.  Many of us run our refrigerators on propane while on the road.   Then the refrigerator switches over to AC when connected to shore power.

Marsha~
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Ned

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Re: rv fridge 110v power from inverter?
« Reply #7 on: January 29, 2010, 01:13:05 PM »
is it safe to run my generator while driving down the road? so i could use my fridge and ac unit?

Certainly.  It's quite common.
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