Low Ambient Heater on fridge

[skid_o]

I just found out our fridge has a Low Ambient Heater on it.
The weather was getting colder out and we where deciding whether to take the trailer out again.
While the trailer is sitting by our place I have a battery tender on it, I did not disconnect the battery.
After a few days I noticed that the battery was not up to full charge. We had a few cool nights.
I placed an amp meter in the main circuit and found out I had a steady 1.8 amp draw which is enough to drain the battery after a while.
Everything in the trailer was turned off. After much hunting and testing I found out that even if the fridge is turned off this Low Ambient Heater is still drawing power.
The only way to stop the draw it is to pull the small 3 amp fuse that is by the fridge circuit outside or disconnect the battery.
This Low Ambient Heater kit supplies DC voltage to the heater any time the ambient temperature is low enough. Extended storage during cold weather will drain the batteries.

[60sumtin]

Thanks. Was not aware of such an option. Is this heater supposed to keep the fridge contents from freezing during cold weather?

[skid_o]

I am not sure what is does. I think you may be correct.
It was an option I did know i got. I think a lot of the newer models have this option already installed and you may not know it.

[keymastr]

I think it is part of the cold weather operation kit from Norcold. I know mine has it just not sure what all it includes.

[Rickeoni]

By looking at the retrofit kit, you might be able to add a switch to turn it off.

Norcold Cold Weather Kit 634913 (cooling unit heater) - The Norcold Guy

[egwilly]

Thanks for the discovery!

I was wondering what all the blue covered wires attached to the coils were for

Since we are located in southern climates, don't think I'll have to worry about it too much.

[60sumtin]

From what I can gather absorption fridges found in RVs don't operate properly in cold weather similar to conventional Acs, refrigerators, and freezers. Conventional refrigeration need temps above 50F for them to operate properly. Many AC units that typically sit outside have temp sensors built in that will prevent them from operating if outside ambient air temps drops below 50F.

From what I've gathered absorption units found in RVs need to be 'warm' as well: The refrigerant in a propane/electric refrigerator is a mixture of distilled water, ammonia, sodium carbonate and hydrogen gas, all at 200 psi pressure. When the temperature drops below 20 degrees this liquid can turn to a gel and may permanently plug the coils of the refrigeration system. (From RV.NET)

Good to know if planning to do some winter camping and thanks to skid_o for bringing this to our attention.

[brulaz]

Originally Posted by skid_o

...
While the trailer is sitting by our place I have a battery tender on it, I did not disconnect the battery.
After a few days I noticed that the battery was not up to full charge. We had a few cool nights.
I placed an amp meter in the main circuit and found out I had a steady 1.8 amp draw which is enough to drain the battery after a while.
Everything in the trailer was turned off. After much hunting and testing I found out that even if the fridge is turned off this Low Ambient Heater is still drawing power.
The only way to stop the draw it is to pull the small 3 amp fuse that is by the fridge circuit outside or disconnect the battery.
...

Thanks for this info.
Odd that it's not connected through the frig switch.
I take it you do not use your battery disconnect switch when in storage?

And AFAIK, 60sumtin's explanation is correct. Absorption frigs can freeze up. Know of one guy who routinely runs a light bulb into the back of his when it gets too cold. This kit is a better option.

[skid_o]

Our trailer sits right beside our house. In the winter I use the battery disconnect.
This was fall time and we were maybe going to take it out before the snow starts to fly. The ORV factory says they asked the fridge manufacture about using the fridge switch and they got told them it draws to much for the fridge circuit.

[keymastr]

I wonder if the battery switch needs to be turned on for while when coming out of cold weather storage to get the coolant flowing again. Anyone know how long that might take? I typically plug the trailer in and get the fridge started the day before we leave but in cold weather I might have to wait a few hours to turn on the fridge. Something to think about anyway. Cooking the coolant when it is in it's gel state would be too easy to do.

[1bigmess]

Did your testing reveal if turning the fridge off at the switch on the front of the fridge will disable the heating?

[brulaz]

Next time I'm at the trailer I'm going to have to physically look for this.
Right now I don't think our frig has one.

Just collected all my solar logs while in storage. The parasitic loads+battery self-discharge seem to decline with temperature.

This device is temperature controlled and should increase parasitic loads as temperature drops. Self discharge should decrease as I observed.

Something new the factory has started adding to the trailers?

[skid_o]

Originally Posted by 1bigmess

Did your testing reveal if turning the fridge off at the switch on the front of the fridge will disable the heating?

That is how i found out about the draw on the battery. Everything in the trailer was turned off. I then went and started pulling individual fuses to find out which circuit was drawing the power. In my trailer number 8 circuit feeds the fridge, bathroom fan and the range fan. Then after disconnecting both fans and pulling the wires off the terminals on the fridge. I found out the Low Ambient Heater is fed directly. Also phoning ORV and asking for the wiring drawing the ones they sent were close but not correct. I talked to someone and he mentioned they get a few calls about this issue in the fall time. While hunting for the problem it also gave me a opportunity to clean out the debris from around the convertor and get rid of all the excess black tape around all the wiring behind the convertor.

[1bigmess]

Time to install a switch then. Thanks.