The ARP Refrigerator Protection Device Saved Me !

[powercat_ras]

I recently learned that RV Absorbtion Refrigerators without a "cold weather" option must not be operated when outside temperature is below freezing (32 F).

Solution in the outside of the refrigerator can freeze, preventing the refrigerator from cooling and worse, causing the refrigerator boiler to overheat and cause corrosion and overpressure conditions that worst case can cause catastrophic failure and a fire to be initiated behind the refrigerator.

Before I learned all of this I started up my Norcold in December and was using my RV. Had taken steps to make sure water and holding tanks were kept above freezing. Did NOT know about the refrigerator not working when it is below freezing outside.

I don't know how far below freezing the refrigerator stops working, but at some point mine did. It was well below zero F when I noticed the refrigerator had stopped working !

I have the ARP Control Refrigerator Protection Device on my Norcold. IT SAVED ME ! When my refrigerator solution froze, causing the boiler to begin to overheat , it detected the boiler beginning to overheat and shut down the heat source before it overheated to the level that causes damage, keeping my refrigerator from being destroyed !

LOVE MY ARP REFRIGERATOR CONTROL ! ! ! Check it out on ARPRV.COM



FYI, the "cold weather" option consists of putting plumbing style heat tape around the parts of the tubing behind the refrigerator where the solution can freeze in the lower back part of the refrigerator

[Old-Biscuit]

A 60W light bulb in lower section via access panel works also

Been in -19*F temps and fridge still kept on cooling...

The ARP device is a good temp sensing unit and controller. It does what it is designed to do..sense overheating and shut down fridge heat source.

[johnhicks]

Please cite your source of info. I just looked through Dometic and Norcold and didn't find that statement.

[Raybo]

Me to ARP TAKES WORRYING OUT OF USING AN LEVELING YOUR UNIT

[powercat_ras]

Originally Posted by johnhicks

Please cite your source of info. I just looked through Dometic and Norcold and didn't find that statement.

My Norcold is the N822 Model. It's owners manual has a section on page 13 titled "Effects of Freezing Temperatures on Refrigerator Operation".

Exceprts from this section:

A gas absorbtion refrigerator is not designed to operate in freezing temperatures. If the refrigerator is not equipped for low temperature operation, and if the refrigerator is exposed to temperatures of 32 F or lower for an extended period of time, the refrigerator operation may be disrupted.

Disrupted operation of the refrigerator due to operation in temperatures of 32 F or lower are not covered by the Norcold limited warranty.

[Old-Biscuit]

Originally Posted by johnhicks

Please cite your source of info. I just looked through Dometic and Norcold and didn't find that statement.

Several Dometic Fridges come with a 'LAT' Switch
Low Ambient Temperature Switch
Turn it ON when ambient air temps rare less then 50*F


Basically turns food compartment light ON causing cooling unit to cycle more frequently due to the 'heat load' in food compartment.
This keeps freezer section frozen (low ambient temps food compartment doesn't warm up as much therefore less cooling cycles and freezer section can warm up)
Frequent cooling cycles also keeps the cooling unit from freezing up in low ambient temps

[EnduroRdr]

Interesting!
So before I dig into this, quick question.
Is there risk of freezing when “not” using refrigerator?
As in busting or splitting tubing? Or is this just a blockage concern during operation?

Well I guess that 2 quick questions, inquiring minds want to know!

[johnhicks]

OK I found info in the Dometic service manual.

The manual states that the low ambient function should be switched on below 50F (indoors and outdoors) to keep unit cycling and not let the freezer temp rise. This is the same situation as a residential refrigerator used in an unheated garage; the thermostat senses the temp to be low due low ambient temp and doesn't run the compressor therefore letting the freezer heat up to the ambient temp.

The second statement is that the low ambient setting "will keep the cooling unit from freezing up in low outdoor temperatures. (20 to 0 F)"
I guess they're referring to the boiling point of ammonia at -28F.

Note that we're talking about the entire refrigerator being at the low ambient temperature, not being in ordinary everyday use in a heated camper with the cooling cycling many times.

[Old-Biscuit]

Originally Posted by johnhicks

OK I found info in the Dometic service manual.

The manual states that the low ambient function should be switched on below 50F (indoors and outdoors) to keep unit cycling and not let the freezer temp rise. This is the same situation as a residential refrigerator used in an unheated garage; the thermostat senses the temp to be low due low ambient temp and doesn't run the compressor therefore letting the freezer heat up to the ambient temp.

The second statement is that the low ambient setting "will keep the cooling unit from freezing up in low outdoor temperatures. (20 to 0 F)"
I guess they're referring to the boiling point of ammonia at -28F.

Note that we're talking about the entire refrigerator being at the low ambient temperature, not being in ordinary everyday use in a heated camper with the cooling cycling many times.

Actually talking about the outside air temps and the backside of cooling unit being exposed to those low ambient air temps

Food compartment where the thermistor is located will remain cold and thermostat which senses the thermistor will not turn on electric or propane heat source for a cooling cycle......in mean time freezer temps get warmer and warmer until frozen food thaws.
By the time food compartment temps rise enough to cause a 'cooling cycle' the frozen food is no longer frozen
Plus coolant may not heat/vaporize/condense because it has now freezing due to lack of heat cycles


The 'LAT' makes food compartment warmer via the 10W Lamp causing more frequent cooling cycles which keeps the coolant flowing in cooling unit

Outside air temps

[johnhicks]

I read a bit from a Norcold tech stating that what happens is that the heat source is so small that in really old weather it can't power the process, thus preventing cooling. Not that it freezes solid, plugs up etc.

So going by that it couldn't overheat the tube simply because there's not enough heat applied to the tube.

I also get that it's a long-term cold problem rather than a dip to low temps and back up the next morning.

Fortunately this is a problem I don't need to pay much attention to LOL.

I do, however have an ARP. I don't believe it's ever triggered.

[Old-Biscuit]

Originally Posted by johnhicks

I read a bit from a Norcold tech stating that what happens is that the heat source is so small that in really old weather it can't power the process, thus preventing cooling. Not that it freezes solid, plugs up etc.

So going by that it couldn't overheat the tube simply because there's not enough heat applied to the tube.

I also get that it's a long-term cold problem rather than a dip to low temps and back up the next morning.

Fortunately this is a problem I don't need to pay much attention to LOL.

I do, however have an ARP. I don't believe it's ever triggered.

NO.....
Tube can be overheated/stressed/fatigued because the TUBE is absorbing the heat vs the coolant because the coolant is not flowing

The coolant flowing thru the tubes is only thing that keeps the tubes from being overheated.