Fridge 12V Operation

[Raz]

Originally Posted by Carol H

Recent is a relative term My 20 year old Dometic 3 way absorption fridge a model that is no longer make does use of a *tiny* bit of power when on propane.

As much as 1/2 amp to power the control board. Rather significant if you are boondocking. I bought the Dometic 2193 because, like Tom's, it uses no DC power when using propane. Raz

[Thomas G.]

Originally Posted by P. Raz

As much as 1/2 amp to power the control board. Rather significant if you are boondocking. I bought the Dometic 2193 because, like Tom's, it uses no DC power when using propane. Raz

I've gotta believe that a toggle switch placed judicially would end the power drain problem, while boondocking.

[Carol H]

Originally Posted by P. Raz

As much as 1/2 amp to power the control board. Rather significant if you are boondocking. I bought the Dometic 2193 because, like Tom's, it uses no DC power when using propane. Raz

Sorry I cant recall how much it draws but I know it cant be a lot - will have to look at it with a meter the next time I put it on. Funny enough in the first year I had the trailer - prior to getting a battery meter (so had no idea what was really happening ) and a solar panel - I did boon docked with it a fair bit. I could get by for 4 days without a problem - it never drained the battery right down to nothing, although I now know it drained it more than it should have as I only got 3 years of use from the first battery. But in addition to fridge I was only used the water pump and occasional interior lights (use head lamp for reading at night) as needed & I had wrongly assumed it was those items only draining the battery. Running the furnace for any amount of time is a much bigger drain.

Since obtaining a battery meter and a 35 watt solar & LED interior lights I only plug in every 2-3 days - it takes care of the fridge drain and everything else as well and its never taken the battery below 50%. Now that one can get a 100 watt solar panel for the same price I paid for the 35 watt a number of years ago it would be nice if Santa were to bring me a bigger panel for when camping on the wet coast & the sun forgets to show up.

HINT TO SANTA: A 60 to 80 watt would do the trick!

[Raz]

Originally Posted by Thomas G.

I've gotta believe that a toggle switch placed judicially would end the power drain problem, while boondocking.

Thermocouples produce such small voltages (<50 mV) that wire and contact resistance becomes a problem with larger units with controls in the trailer. One of the circuits found on the control board senses the thermocouple and controls the safety valve. Without a DC supply, nothing works. Raz

[Thomas G.]

Originally Posted by P. Raz

Thermocouples produce such small voltages (<50 mV) that wire and contact resistance becomes a problem with larger units with controls in the trailer. One of the circuits found on the control board senses the thermocouple and controls the safety valve. Without a DC supply, nothing works. Raz

Interesting - but it seems needlessly inefficient.

[Francesca Knowles]

Originally Posted by Thomas G.

Right. The only electricity that mine uses running on LP is what the thermocouple generates.

And mine uses none at all.

Francesca

[Thomas G.]

Originally Posted by Francesca Knowles

And mine uses none at all.

Francesca

Yours doesn't have a thermocouple?

[Francesca Knowles]

Originally Posted by Thomas G.

Yours doesn't have a thermocouple?

When operating on propane, my fridge requires neither 12v nor 110v power. It's original equipment on a trailer that as a matter of fact came from the factory with no battery installed anywhere in the system. It did come wired for 12v operation if being towed, but I've never used that feature, and disconnecting the tow from the tug had no effect on propane operation. I've since installed a battery for drycamping, but it needn't be present for the fridge to work on propane as it did for the preceding thirty years.

If that means "no thermocouple", then I guess the answer is "that's correct"!

It's not an unusual arrangement on older, true 3-way fridges.


Francesca

[Thomas G.]

Originally Posted by Francesca Knowles

When operating on propane, my fridge requires neither 12v nor 110v power. It's original equipment on a trailer that as a matter of fact came from the factory with no battery installed anywhere in the system. It did come wired for 12v operation if being towed, but I've never used that feature, and disconnecting the tow from the tug had no effect on propane operation. I've since installed a battery for drycamping, but it needn't be present for the fridge to work on propane as it did for the preceding thirty years.

If that means "no thermocouple", then I guess the answer is "that's correct"!

It's not an unusual arrangement on older, true 3-way fridges.


Francesca

Ha! gotcha!

The thermocouple creates its own electricity from the refrigerator flame.

HowStuffWorks "Thermocouple"

[Francesca Knowles]

Originally Posted by Thomas G.

Ha! gotcha!

The thermocouple creates its own electricity from the refrigerator flame.

HowStuffWorks "Thermocouple"

Gotchamewhat?

You're the one that seemed to think that the presence of a "thermocouple" would somehow prove me wrongedy-wrong-wrong about the fridge needing no external power source....

But now you're telling me that the thermocouple (if present, and whatever that may be) uses propane for energy production.

So...now can I be correct that my fridge needs nothing but propane to operate?


Francesca

[Thomas G.]

Originally Posted by Francesca Knowles

And mine uses none at all.

Francesca

Originally Posted by Francesca Knowles

my fridge needs nothing but propane to operate? Francesca

Changing the original question are we?

[Raz]

Originally Posted by Francesca Knowles

Gotchamewhat?

You're the one that seemed to think that the presence of a "thermocouple" would somehow prove me wrongedy-wrong-wrong about the fridge needing no external power source....

But now you're telling me that the thermocouple (if present, and whatever that may be) uses propane for energy production.

So...now can I be correct that my fridge needs nothing but propane to operate?


Francesca

Propane refrigerators have a thermocouple in the flame. It produces a voltage that controls a gas safety valve. If the flame goes out the voltage disappears and the valve closes stopping the gas and you live to see another day. They all have it. Raz

P.S. It's a good idea to test the system periodically. With the refrigerator running on propane shut off the gas and listen for the click.

[Francesca Knowles]

Originally Posted by P. Raz

Propane refrigerators have a thermocouple in the flame. It produces a voltage that controls a gas safety valve. If the flame goes out the voltage disappears and the valve closes stopping the gas and you live to see another day. They all have it. Raz
.

Well, thanks for the explanation, and we've now taken up a whole page talking about a point that is evidently COMPLETELY IRRELEVANT TO my original assertion that my 3-way fridge's "3-ways" are independent of each other.

But what the hey...I learned something about the way it operates when it's
OPERATING ON PROPANE ONLY

I think I'll go lie down with a wet rag on my head now...

Francesca

[Raz]

Originally Posted by Francesca Knowles

Well, thanks for the explanation, and we've now taken up a whole page talking about a point that is evidently COMPLETELY IRRELEVANT TO my original assertion that my 3-way fridge's "3-ways" are independent of each other.

But what the hey...I learned something about the way it operates when it's
OPERATING ON PROPANE ONLY

I think I'll go lie down with a wet rag on my head now...

Francesca

Better yet, go check out your safety valve.