Refrigerator 12V wire size

[Rbertalotto]

My truck camper has a 3-way refrigerator. Works fantastic on propane and 120v....but on 12v it has a hard time staying below 40 degrees.

The factory wire feeding it 12v is about 14g or 16g. Would running it directly from the battery (10' wire run length) with a #10 wire increase its performance?

[Rbertalotto]

Hey Red, when you invite me over for dinner, I'll bring my own food.....:B

[red31]

I did not suggest that 40F was the min for proper food handling, I suggest your reference to bacteria starting to grow at 41 IS bogus, my fridge is proof.



http://classes.midlandstech.edu/carterp/courses/bio225/chap06/Microbial%20Growth%20ss1.htm

[tenbear]

Measure the voltage at the battery and also at the refrig when the 12v heater is on. You will then know what the voltage drop is and have a better idea what you can gain.

[Rbertalotto]

I owned a restaurant for a number of years. Had to keep thermometers in the refrigerators. Heath inspector comes in and it is over 40 degrees F. they shut you down and throw out all the food......

Do a search on Google

"restaurant refrigerator temperature"

[red31]

sorry, 40F does not magically stop bacteria growth

[Rbertalotto]

A refrigerator must be below 40 degrees F to comply with health standards. Bacteria starts to grow at 41 degrees F.

[kellertx5er]

Rbertalotto wrote:
My truck camper has a 3-way refrigerator. Works fantastic on propane and 120v....but on 12v it has a hard time staying below 40 degrees.

How cold do you need it to be?

[Chris_Bryant]

One thing to look at is if the refrigerator runs off the TC battery, make certain the charging line is good, otherwise you can arrive at a destination, only to find the camper battery drained.

The Dometic 4 and 5 cubic foot units use around 1000 btu/hr of LP- LP has ~21,000 btu per pound, so you can gauge use accordingly- the pound per day is pretty spot on.

[RinconVTR]

I use 12v all the time while traveling, but its always "pre-cooled" before we depart.

And mine only runs on 12v when the truck is running, it will not run off the battery with the truck off, even if I force it, it beeps in error.

So when its set to auto, when I turn off the truck the fridge switches to LP. Plug into shore power, and it runs on 120v.

The most manual interference I have done, is forcing it to run on 12v only when we depart, so it doesn't kick to LP. This is typically only gas and food stops, with little to nothing in the freezer. Everything is plenty cold at our destination.

Finally, you can run a 14AWG wire pulling 15amps @ 12v over a 10' run per spec. So whatever the problem is, a larger wire will not help unless the current wire is getting hot to the touch. Warm is not abnormal.

[DrewE]

Rbertalotto wrote:
Thanks for all the help on this. I guess I'll just leave it alone and use propane. I was trying to conserve propane on long drive. I typically can drive 12-16 hours at a stretch. If the 12V would keep the frozen food frozen, this would be better than using propane.

You can probably run it on propane for a couple of weeks or more without emptying your propane tank(s). A typical RV fridge might burn about a pound of propane a day, very roughly speaking.

[2oldman]

Rbertalotto wrote:
I was trying to conserve propane on long drive.

They use surprisingly little propane, but if I had 12v I'd use it.

[pianotuna]

Hi,

My fridge works *great* on 12 volt, but ONLY if I'm plugged into shore power. It draws a whopping 34 amps when doing so.

I tend to run my fridge on 120 volt via my inverter when trundling down the road.

[Rbertalotto]

Why would the mfr wire it too small?

Seems like EVERYTHING having to do with wiring in this Palomino Bronco is wrong, sub-standard, a mess, or haphazard!

I can't believe how much wiring I've fixed. In some areas, black is negative and in others white is negative! And then there is a smattering of red and green just to make it interesting!

Thanks for all the help on this. I guess I'll just leave it alone and use propane. I was trying to conserve propane on long drive. I typically can drive 12-16 hours at a stretch. If the 12V would keep the frozen food frozen, this would be better than using propane.

[2oldman]

Why would the mfr wire it too small?