Run fridge on 12v only?

[KYAirstream]

My older all electric fridge is tripping the breaker when plugged into 110v. The moment the fridge is plugged in the breaker trips. If left unplugged it runs fine on 12v. Any problem leaving the fridge running on 12v while the trailer is plugged into shore power?

[jdalrymple]

No problem. Don't forget propane, unless it is a three-way model. Have you looked into the breaker problem? The AC starts with a regular styled plugin behind the refer. Unplug the and reset the breaker. If it still trips, the problem is not the refer.

[KYAirstream]

Glad to hear running on the 12v is not an issue. All electric fridge, so no propane. As long as the fridge is unplugged there is no problem with the breaker, so it seems it is something with the fridge AC. I don't need it since I have shore power and can run the 12v off the converter, so I don't really see the point of the fridge on 110v anyway????

[Pahaska]

The 12v operation on the 3-way models just tries to hold the internal temperature. It is not intended as a primary way to run the refrigerator, just a way to hold temperature while on the road.

Make sure that the 12v mode for your all-electric model can actually cool the box and is not just a sustaining mode like on 3-ways. It takes an awful lot of 12v amps to fully drive the refrigerator.

My refrigerator uses 325 watts of 120v AC power according to the manual. Ohms law says amperes are equal to watts divided by volts (325/12). That calculates to 27+ amperes of 12v to get the same cooling as AC mode. That is half of my converter rating and will run batteries flat in no time.

[KYAirstream]

Since I am plugged into shore power I don't guess running the batteries flat is much of a concern? As long as my converter can handle the amps, I guess I should be fine?

Originally Posted by Pahaska

My refrigerator uses 325 watts of 120v AC power according to the manual. Ohms law says amperes are equal to watts divided by volts (325/12). That calculates to 27+ amperes of 12v to get the same cooling as AC mode. That is half of my converter rating and will run batteries flat in no time.

[DKB_SATX]

Originally Posted by KYAirstream

Since I am plugged into shore power I don't guess running the batteries flat is much of a concern? As long as my converter can handle the amps, I guess I should be fine?

Provided you're not running enough other 12V stuff to exceed the converter capacity. 12V lights and fans will eat into the capacity, and you could get to a point where you're using both converter and battery output and eventually run down the battery, but as long as you're on shore power and the converter is still happy you can just turn off a few things.

[RickDavis]

We have all been assuming this fridge cools by making heat like a normal RV fridge.
Since you say it is 110 / 12 volt only this could possibly be a compressor type fridge.
There may be a nameplate telling you the wattage or current draw. If not it would be good to measure it.

The typical 3 way RV unit only uses 12 volts for maintenance cooling as the current draw is so high

[KYAirstream]

Appreciate the replies. I'll look into the amps to see what's needed.