3 way frig. vs. 2 way

[cwdtmmrs]

TDF, I grounded my 2 cooling fans directly to the camper frame inside the refrigerator compartment. I pulled the 12v + from the existing circuit at the fridge to an on/off switch. Both fans only draw about 1/4 amp total when running. Nothing to worry about.

cwd

 

[TDFuego]

Thanks again CWD, this should work perfectly.

tdf

 

[cwdtmmrs]

TDF, Please post your results when you have the new alternator and fans installed.

cwd

 

[TDFuego]

CWD; Have been traveling for three weeks (without camper), busy with other things and wanted to give update such as it is.

Have new alternator (140amp), installed and have put a 1.5v computer fan in upper vent of fridge compartment, wired up as you suggested. All appears to be working great. Only problem I've not been able to check things out properly. Hoping to get away for a night or so in next few weeks for shakedown cruise. Being retired is great, but where does the time go? Will post again after decent "road" test.

Your posts have been very helpful, thanks--- TDF

 

[ntsqd]

Put in an Isotherm 2-way after the continuously dismal/unpredictable performance of the supplied Dometic 3-way that eventually just failed to do anything while on the Mojave Road last Spring. At it's best 40° below ambient was a dream, 30° or less was more like it.

In mild ambient temps we've unintentionally frozen stuff in the Isotherm as we're still figuring out how to set it. My wife just came in from cleaning out the truck from our last trip and told me I'd made a good choice in fridges, Whatever the interior is made from wiped clean effortlessly.
I have witnessed a 3.4A draw while running during overcast daylight hours on the TriMetric monitor. Do not recall what the solar was producing prior to the fridge kicking on. I don't tend to be obsessive about stuff like that. I periodically cycle the options on the monitor to see how things are working, but I have to be rigorous at work - I'm not going to do so on a trip.

As a bonus I've removed the noisy venting fans & thermostats from the rear of the fridge compartment because they're no longer needed. Can barely hear the cooling fan (40mm box fan) on the coils running and have not ever heard the compressor itself running.

We seldom stay in one place two nights in a row, so our 100w panel really only is about keeping the camper batteries up while it sits between trips. I'm working towards doubling the panel wattage so that if we do stay more than one night in the same place the solar has a better chance of keeping up.

 

[cwdtmmrs]

I just got back from a 5 day trip to the Sierras in a class B motorhome with a Dometic 3 way fridge and it worked beyond my expectations. Ambient temps were low to mid 80's day and high 40's night. The freezer was amazing. Froze our limits of fish rock solid in less than 2 hours. Adult beverages were frosty as well. Couldn't ask for better.

cwd

 

[TDFuego]

CWD: If you are still monitoring, The shakedown cruise failed. Best advice I have now (this from auto electrical fellow) is to change out the 10/2 wires from alternator to 6/2. I may do this after my shoulder surgery heals, or, I might just throw in towel... Oh, the fan hook up works like a charm.

Thanks for all your help

TDF

 

[cwdtmmrs]

TDF, that's a little sad, but 10/2 wires just won't carry enough current. If you are going to run new wires anyway, go with the biggest wires that will fit. I left my #10 wires in place and added #4 wires as well. The #10 wires have an Anderson connector so I can plug in a small generator, battery charger or a portable solar charger if I ever need one (which I haven't).

cwd

 

[Vic Harder]

TDF, that's a little sad, but 10/2 wires just won't carry enough current.
cwd

+1 I went with 2 AWG welding cable. Works like a charm to pull those AH down into the camper batteries.

 

[TDFuego]

To CWD, Vic and others who might be watching this very old post.

With COVID time available, and finally healed from various medical issues, I strung a #4 stranded wire from truck battery to an Anderson terminal in the bed, passing through a 100 amp breaker mounted on the truck firewall. I strung another #4 wire from Anderson terminal into house battery and Blue Sea Relay model 7610. I discarded the original #10 wire and connector. I do use a small cooling fan that CWD uses as well.

ALL WORKS WELL. I know now that the problem all along was the #10 original wire was just too small to let the 12v refigerator function. This is what Vic and others told me three years ago! Originally, I took Fourwheel advice and used #10 because that is what they used when installing the RM2193.

I Just returned from a camping trip in 90 degree weather and refrigerator temperature held at 40 degrees (and more) below ambient, and house battery kept at full charge with six hours time each way on freeway and mountain back roads. After five years I've got a refigerator that works well in all three modes!

Many, many thanks to Vic, CWD and others who commented on this post.

TDF

 

[arg]

Could those with a 3-way propane fridges comment on whether or not the flame is left on while moving? Safe or absolutely do not do. If the flame is off, I would assume that is during a drive to a new location, and in that situation, is there sufficient insulation to keep ice frozen during, say a 4 or 6 or 12 hour flame off time period. I ask these questions because solar does look very practical, but I get ambient temperatures, cloud cover, etc. are important factors. Thanks in advance for responses.

 

[Casa Escarlata Robles Too]

Here is my use of my 3 way.
Before the trip I start the fridge on 120v at home.

I have a frozen gallon of water plus a half gallon.
They go in first.The food kept in the 3 way is frozen to start with.

All is loaded and when leaving change over to propane.
I keep it on propane usually wile driving.

In camp it's always on propane and the contents stay frozen.

The frozen water jugs help to keep the temp at or below freezing.
I have seen temps in the fridge as low as 28*

Our day to day cold items are kept in a 45L Truckfridge brand of cooler which runs all the time.
This uses very little power and the solar keeps up without any problem.

We have used this method for our cold storage items since we have had the camper.

We are more or less vegetarian maybe some salmon and chicken but that keeps well frozen.
This has worked very well for us.Our trips a lot of time are 3/4 weeks out.

We have taken two long trips to Alaska with ferry time
and the frozen items in the 3 way with the frozen water jugs has worked well.

The Truckfridge will run on our 100a battery for about 5 days without being charged.
This is our method ,I would like to hear others also.
Frank

 

[ckent323]

arg,

We have a Norcold N300x 2.7 cu ft 3-way in the camper. We cool it with 120 v before loading for departure. We leave the propane cooling on while driving. It typically does not blow out. However, sometimes with strong crosswinds it does blow out.

We use an Acuright wireless thermometer with readout unit in the truck cab and remote refrigerator and freezer sensors in the Norcold. When we notice the temp warming up we know the pilot has been blown out and I go restart it.

https://www.amazon.com/AcuRite-Refrigerator-Thermometer-Temperature-Customizable/dp/B004QJVU78/ref=sr_1_5?dchild=1&keywords=rv+fridge+thermometer&qid=1596309398&sr=8-5

If we need to run on 12 v it will hold temp if it is already cold, except in over 90 or so degree weather, but it takes forever to cool down so we use 120 V or propane to cool it down.

We also have a Dometic CFX-35 in the truck cab behind the center console (truck is a 1993 Dodge Clubcab aka extended cab). It works great and cools quickly. We keep cold drinks, snacks and similar in it since our trips often involve long distance drives. It is small enough that when empty I can remove it and use it elsewhere but 90% of the time it stays in the truck cab.

 

[DanoT]

I mostly do winter camping in ski area parking lots where propane fridge works great, sips propane, and no aftermarket fans needed.

Except when it gets really cold. -18*C/0*F the fridge stops working. The solution is a 100w light bulb in the back of the fridge if you have 120v shore power OR block off the lower fridge vent (never the upper). This will create enough warmth for the fridge to turn on and start working. Just remember to remove the cardboard or whatever covering the lower vent once the outdoor temperature moderates a bit.