AC/DC compressor refrigerator vers just DC

[Steveva]

Need to and want to replace our Dometic RM 8500 3-way as parts are very difficult to find. Thinking of using an Isotherm Cruise 130 as it will easily fit. The big issue is the width needs to be under 20.875 wide. We have been using our van at sites with electric hook-ups only as our current battery capacity is low and I've noticed the compressor refrigerators are specified as DC and some as AC/DC. If we are plugged in or traveling the DC fridge is going to work using the battery. What is the purpose of the AC/DC fridge? After replacing the fridge we will replace and upgrade the battery, the charging, the inverter and add solar. Current battery is a size 24 lead acid. We have a 2011 Pleasure Way Excel on the Ford E350 with the V10.
Thanks Steve

[booster]

Originally Posted by Steveva

Need to and want to replace our Dometic RM 8500 3-way as parts are very difficult to find. Thinking of using an Isotherm Cruise 130 as it will easily fit. The big issue is the width needs to be under 20.875 wide. We have been using our van at sites with electric hook-ups only as our current battery capacity is low and I've noticed the compressor refrigerators are specified as DC and some as AC/DC. If we are plugged in or traveling the DC fridge is going to work using the battery. What is the purpose of the AC/DC fridge? After replacing the fridge we will replace and upgrade the battery, the charging, the inverter and add solar. Current battery is a size 24 lead acid. We have a 2011 Pleasure Way Excel on the Ford E350 with the V10.
Thanks Steve

IMO, the AC part of the frig in an RV is not ever needed. When on shore power you have the battery charger to provide the little bit of power required for the frig running on DC, when you are driving the alternator is generating DC power, solar is DC power. All you lose in a tiny bit of charging of battery speed while on shore power, which to almost everyone will not even be noticed.


The said our Isotherm is AC/DC because that was all we could find when we needed to replace or failed 10 year old Isotherm. The AC cord is not even plugged in.

[Chuck711]

Just replaced my 2 way with a 12 Volt Compressor Fridge ( Norcold )

My 370 Watt Solar keeps the Fridge running 24/7 without being plugged in

Freezer temps to 17 degrees ( Lower if you want )

[GeorgeRa]

I wired AC/DC fridge into my camper van from the get go and use it often before and after trips. I can simply disconnect all DC and have AC from shore power connection feeding fridge only, everything else is off. From my past experience I tend to disconnect DC power in my RVs or boats if not in use.

Is this feature necessary, absolutely not, but it is convenient to have fridge running so we don’t have to rush with packing or unpacking without worrying about safety with DC on.

This is an example of your needs driving your design reasonably easily realized with your own DIY.

[N147JK]

I asked the manufacturer of my fridge (Nova Kool) about this. They responded saying the AC capability is there for people who want to use the fridge in places where AC power is available but 12V DC power is not. For example, in most homes or garages.

[Steveva]

Thanks for the information. It is as what I was thinking, just wanted to confirm or see if there may be something else I was missing. Ordered a Dometic CRX 110 from West Marine. Shipped to the local store and if there is any issues I can return. Steve

[W9TR]

All the small RV compressor refrigerators use a Danfoss heremetically sealed compressor. This is a DC only compressor. So RV AC/DC compressor refrigerators use an AC to DC converter to operate on AC.

On some refrigerators this converter is optional and on others it is standard. There are good reasons to have AC capability but if you don’t need it then don’t pay extra for it.

[Rocinante]

Originally Posted by W9TR

All the small RV compressor refrigerators use a Danfoss heremetically sealed compressor. This is a DC only compressor. So RV AC/DC compressor refrigerators use an AC to DC converter to operate on AC.

On some refrigerators this converter is optional and on others it is standard. There are good reasons to have AC capability but if you don’t need it then don’t pay extra for it.

...and that's why we unplugged the AC cord from the compressor fridge in our van. Now it runs only on DC, even when plugged into shore power, running the inverter, or running the generator. The fridge's power consumption is more efficient that way.

[TomF]

A few years ago, I went the AC,DC route with a Norcold. The first time I turned it on, the DC voltage climbed, and hit 100V before I turned it off. The dealer freaked out when he plugged it in to test it. The second unit lasted 1 year before it died. A 50 cent component on the motherboard fried, but the unit had been discontinued by Norcold, so no parts available. I went back to the Dometic three way.

[Steveva]

Got very busy over the summer. Just finished the installation and the refrigerator works fine in the drive way. Have a 3 inch opening above the refrigerator going to try to install a drawer.

[MsNomer]

My Engel fridge and freezer (separate units) are AC/DC and I use the feature whenever the van is in the driveway—particularly valuable in summer heat. Run down the house batteries to ~50-70%SOC as we approach home. Plug in the van—fridge and freezer switch automatically to AC. This takes the load off the batteries and allows them to maintain their SOC til we leave again. Driveway is shaded, so minimal solar, and I unplug the AC charger.