Fridge DC power Requirements
 

Our 2001 260TFB has a three way fridge.
Is is necessary to have the fridge connected to a battery to run properly?

I ask because our previous trailer (a 2005) had a 110/ propane fridge that required a battery be attached to it to run when on propane ( according to the manual even if the battery was "dead"). I think this was because the unit had a microprocessor to control the propane.

My thinking is that this 2001 which has the stock/ original fridge does not need the battery while on propane. It is from pre- computer times.

Can someone confirm this?

I can only talk about the fridge in my trailer, a 2007 model. It has to have DC power to the control panel to run, on any of the cooling power sources (AC, DC and Propane). If yours does not use electrical power to turn on, I suppose it's possible it would not need the battery. However, I'm having trouble figuring out how it would be controlled this way. My guess is, it needs some kind of electrical power.

- Jack

I'm playing the "just supposing" here Jack, I don't think anything made in the last 40;years or so works this way, "but"...

A purely mechanical ammonia fridge could work by using a typical bi-metal spring thermostat controlling a simple mechanical gas valve. This would require a pilot light of course.

Just throwing it out there as a thought experiment. I doubt any ammonia systems have been made this way since the early 70's or so.

I think your "thought experiment" is a good one, Knotty. So, it could be turned on using a simple ON/OFF gas valve too.

My guess though, as you implied, is that it's electrically controlled. Sometimes I'm really grateful for progress!

- Jack

If your fridge has a manual push button pilot light on the control panel there is probably no electric control module requiring 12 volt power. The flame stays lit all the time, whereas the electrically controlled units have an igniter to light the flame as needed.

But Rich, what about when it operates on electricity? Wouldn't there be some kind of electrical temperature control then? (The thermostat). I can't imagine there'd be a different one for propane cooling.

And, if the flame stays lit all the time, wouldn't the refrigerator get TOO cold?

I'm not being argumentative - just trying to understand how such a device could work.

- Jack

Our 1705T had the push button spark lighter for the flame and it stayed on all the time. I think the height of the flame was the only thing that regulated it. The 12volt and 110 volt modes probably were electrically controlled in some manner.

I think when Jack said "the flame stays on", he was referring to the pilot light. When the thermostat says "It's getting warm in here", the pilot ignites the burner section and starts the cooling cycle. How's that sound?
Tree

I'm not really sure WHAT I'm talking about here. :o :o

In my trailer, the propane flame is very small for the refrigerator. I've actually never seen it (although now that I think of it I've never taken the panel off to look for it while it's operating). I just know the "burner section", seems to be very small.

Still, SOMETHING controls the internal temperature in the refrigerator. It COULD be a bi-metal strip like Knotty suggested that somehow opens and closes a valve, but that seems pretty crude. I really think it's electrical, and that implies a likely DC power source. This gets back to Bravada's original question - "Does it need to be connected to a battery to operate?" I still think the answer is "yes".

- Jack

I can buy LP gas refrigerators at Lehman's Hardware in Kidron, OH that do not require electric. Amish and off griders buy them. They are thermostatically controlled. They aren't far from where the Hi-Lo factory was.
https://www.lehmans.com/product/diam...refrigerators/

If it doesn't have a push button to light the burner it is most likely module controlled. If you remove the lower out side cover you can probably see the module.

My fridge is a Dometic, Americana, RM 2453.

Reading the manual online it doesn't need D.C. power to run on LP.

Will verify with my own test by pulling the breakers/ fuses and running it.

That's pretty cool Rich-thanks for the link!

Bravado,

I'm sorry to report that page 7 of my RM2453 manual says "This refrigerator model require a continuous 12 volt DC supply to maintain the automatic energy system." It is one of the few circuits that is always live in my Hi-Lo. You are going to need 12 volts in order to get your fridge to work.

George
WB4IPB

Thanks for catching that. I'll go back and reread it. Don't want to push incorrect info.

Rich, I bow to your superior knowledge on this subject. *bows* *bows* I'll have to learn how those things work. I would not have guessed it was practical.

- Jack

Bows not required. Maybe a bow-wow is more in order. :D

Woof! :o :o

- Jack

Results.

Disconnected the battery from the trailer. Disconnected the shore power. Propane on.

Fridge started and ran on propane.

Went back and re read that manual I was referring to it was for the Canadian market. Never bothered to look for one specific for the US market.

Have owned our HiLo since 2001
 

Still learning operational information as the situations present themselves.