Fridge issue

[Rostam]

Last year, after our last camping trip, I forgot to turn off the fridge. It was running on electric for a couple of days, while the fridge/freezer doors were left open. I went to get something from inside the trailer and noticed it.

Last week, we were preparing for our first camping trip -- It got cancelled due to rain I turned on the fridge on electric and it did not cool at all. I ran it on propane and it started to cool down (though much slower than when on electric). After some troubleshooting, I noticed that the fridge trips the circuit breaker. I studied how the fridge operates (ours is 3 way) and thought that the electric heating element might be the problem. I found the specs and it the resistance should be 52 ohms. I used a multi-meter and it measured at 38 ohms. So, I suspect the heating element is dead, and the lower resistance causes the amperage to increase and trip the breaker. I contacted Dometic and unfortunately they do not manufacture the heating element and know of no substitute.

So, unfortunately, I think I need to replace the fridge. I do not want to get an 2 or 3 way fridge as 1) they are very expensive, 2) I've heard of Dometic/Norcold fridges being defective and catching fire (apparently, there is a class action lawsuit).

I'd like to know your opinion on using a residential fridge. How can you keep the fridge doors shut when towing? Do you use a custom base to secure the fridge in place? Does a residential fridge need some form of venting? Are there any safety concerns that I should be aware of?

I know @KYAvion uses one with a converter. I appreciate info on the converter and how its hooked up.

Many thanks!

[KYAvion]

I did this in my prior Airstream. My Avion came with a brand new propane/120v fridge, but I'll do the same when this one causes me problems.

For fastening, I lag bolted through the bottom of the fridge into the subfloor of the trailer in two places. I also rigged a bracket that I attached to the upper portion of the fridge and a rib in the trailer (I had enough space above the fridge to reach back there to attach the bracket to a rib).

Now for the wiring--for my inverter and the length of the wire run from my battery to the inverter I ran 8 AWG wire with a 250 amp fuse (e.g. https://www.amazon.com/Install-Bay-ANL2 ... 3TPV2KP50e

As far as using the inverter, I only plugged my fridge into the inverter when traveling. When hooked up to shore power, I plugged the fridge into the 120v outlet. Now you could rig this so the switch was automatic, but I found it easy enough just to do it manually. If I were traveling a lot, then I'd be make it automatic. Also, for the sake of clarity, an inverter turns DC (12v) into AC (120v), whereas a converter does the opposite.

Keep in mind your fuse and minimum wire size will be dictated by your inverter and length of wire run from your batteries.

You pointed out the biggest problem with using a residential fridge--keeping the doors shut while traveling. For this, I hid some eye screws as well as I could, and then use bungees to hold the doors shut.

Anyway, once trimmed out the fridge was relatively "built in" looking. It cooled down in no time and worked great.

[KYAvion]

@Rostam BTW, when using that tag feature, be sure to wait for the drop down menu to show up after entering the "@" symbol and the first letter or two of the username you're tagging. At that point a list of usernames should pop up in a drop down menu.

[Salty]

What is the current draw on the residential fridge you used?

[Rostam]

Thanks for the info @KYAvion .

Before giving up on the fridge, I am going to do one more test. I will run it on DC and if it works fine I consider using a transformer to convert 110V AC to 12 V DC so the fridge can run on DC when we are plugged to shore power.

I am also going to search Ebay/etc for an AC heating element.

[KYAvion]

What is the current draw on the residential fridge you used?

According to this, 1.45 amps.
https://m.lowes.com/pd/Frigidaire-4-5-c ... R/50160173

[KYAvion]

Thanks for the info @KYAvion .

Before giving up on the fridge, I am going to do one more test. I will run it on DC and if it works fine I consider using a transformer to convert 110V AC to 12 V DC so the fridge can run on DC when we are plugged to shore power.

I am also going to search Ebay/etc for an AC heating element.

Since your current fridge sounds like it is wired for both AC and DC, all you need to do to force it to DC is unplug the fridge from the 110v receptacle in the wall. No need for anything extra, except of course shutting off the propane to the fridge.

[Rostam]

Thanks for the info @KYAvion .

Before giving up on the fridge, I am going to do one more test. I will run it on DC and if it works fine I consider using a transformer to convert 110V AC to 12 V DC so the fridge can run on DC when we are plugged to shore power.

I am also going to search Ebay/etc for an AC heating element.

Since your current fridge sounds like it is wired for both AC and DC, all you need to do to force it to DC is unplug the fridge from the 110v receptacle in the wall. No need for anything extra, except of course shutting off the propane to the fridge.

You are correct. Thanks!

[Rostam]

Update: I plugged in the camper to shore power and turned on the fridge on 12V. I checked a few hours later and its cooling. I put in a bottle of wine and I will check it again in a few hours

I may have dodged a bullet. If the fridge works on 12 V, I think I'm ok for now. When connected to shore power the battery gets re-charged (same thing for when towing). I can use propane at all other times (Most of our destinations have electricity so I doubt we'd be using propane much).

Thanks for your help!

[KYAvion]

Sounds good. However, I wonder what was causing your breaker to trip (or was it a gfci?)? I don't know much about these fridges, but what's different about the heating element if on 12v or 110v? I wonder if something else with the 110v might be causing the breaker to trip? Was it the breaker in the house, or the breaker at the 30 amp panel in the trailer?