Refrigerator 12V wire size

[Rbertalotto]

My truck camper has a 3-way refrigerator. Works fantastic on propane and 120v....but on 12v it has a hard time staying below 40 degrees.

The factory wire feeding it 12v is about 14g or 16g. Would running it directly from the battery (10' wire run length) with a #10 wire increase its performance?

[MrWizard]

you can increase the wire size, but it won't help much

12v mode is meant for holding temp, while traveling with LP off
it is not meant as a full time cooling mode while parked

the 12v heating element is not as powerful, not the same wattage as the 120v heater or lp burner

[BurbMan]

Why not just run it on propane, it's much more efficient.

[ScottG]

Lots of TC's have three ways (fridges, I mean).
I would take a voltage reading while it's running and if there's a significant voltage drop, upgrade the wiring. Any drop in voltage is a drop in heat!

[stevenal]

Why re-wire it for 12V use? I've had my three way for 17 years and can recall only using the 12V setting once while driving to refill both empty propane tanks.

[DrewE]

Agreed with the others; heavier wire will help, running on propane will help a lot more (and not consume a lot of propane). Typically the propane burner is more powerful than the 120V element, which in turn is more powerful than the 12V element.

[time2roll]

Yes I believe the #10 will have a measured improvement.
I would probably go #8 as long as I was pulling wire.
12v typically does not perform as well as 120v or propane but the poor connection is probably part of the reason.

[doughere]

Like Chris Bryant said, its really too keep food cool while driving. Using while dry camping will rapidly drain your battery.

Changing from 16ga to 10ga will decrease the voltage drop about 1V; I doubt this will make a significant difference in operation.

Regards,
Doug

[Chris_Bryant]

The 12 volt option is just to *keep* the unit cold- it isn't normally used except in transit, and after the unit is already cold.
Small models might have close to a full wattage 12 volt heater, but usually it is de-rated a bit.

[JPeyton]

Rbertalotto wrote:
It is three way....The switch on the front offers 12V / 120VAC / Gas

I just found this article:

Refrigerator: The 3-way refrigerator in most RV’s like the Oliver can run off of 12V DC, 120V AC, or propane. While running off of DC, the Oliver’s refrigerator requires a massive 15 amps of current (contrast that with the less than 2 amps required with 120V AC). To handle a 15 amp load, the refrigerator specifies 10 AWG DC wiring and maximum wire length of 20 feet.
This heavy current draw is why you should never leave a 3-way refrigerator running on DC power while stopped. The fridge can drain your trailer battery in just a matter of a few hours – and if your tow vehicle lacks a battery isolator circuit you could find that battery dead as well after a long lunch!

Located here:
http://www.technomadia.com/2008/06/rv-solar-electric-wiring-issues/

Guess I need to do some rewiring!

ok. So you're sure of your battery?

[Rbertalotto]

It is three way....The switch on the front offers 12V / 120VAC / Gas

I just found this article:

Refrigerator: The 3-way refrigerator in most RV’s like the Oliver can run off of 12V DC, 120V AC, or propane. While running off of DC, the Oliver’s refrigerator requires a massive 15 amps of current (contrast that with the less than 2 amps required with 120V AC). To handle a 15 amp load, the refrigerator specifies 10 AWG DC wiring and maximum wire length of 20 feet.
This heavy current draw is why you should never leave a 3-way refrigerator running on DC power while stopped. The fridge can drain your trailer battery in just a matter of a few hours – and if your tow vehicle lacks a battery isolator circuit you could find that battery dead as well after a long lunch!

Located here:
http://www.technomadia.com/2008/06/rv-solar-electric-wiring-issues/

Guess I need to do some rewiring!

[JPeyton]

It's likely not three way, just two. Verify that first.

12vdc is usually used only to run the control panel.