Running LP/AC fridge on inverter while traveling?

[Bullitt6283]

I usually run the fridge on propane while traveling. I don't think this is extraordinarily risky, but there is a risk.

So, in my usual mode of overthinking everything, I am wondering if I can run the fridge in AC mode with the 1000 watt inverter while driving. It would require a minor bit of rewiring the rat's nest behind the power center. The AC heating element of the fridge pulls about 300 watts. This would equate to about 25 amps on the DC side of the inverter, so the loads look OK since this is a Class C and the alternator should be able to keep up.

The inverter has a transfer switch in it, so if I am hooked to shore power or running the generator the fridge would run on AC power directly.

Am I missing something?
.

[Mustang65]

Originally Posted by Bullitt6283

I usually run the fridge on propane while traveling. I don't think this is extraordinarily risky, but there is a risk.

So, in my usual mode of overthinking everything, I am wondering if I can run the fridge in AC mode with the 1000 watt inverter while driving. It would require a minor bit of rewiring the rat's nest behind the power center. The AC heating element of the fridge pulls about 300 watts. This would equate to about 25 amps on the DC side of the inverter, so the loads look OK since this is a Class C and the alternator should be able to keep up.

The inverter has a transfer switch in it, so if I am hooked to shore power or running the generator the fridge would run on AC power directly.

Am I missing something?
.

I guess my first question would be what is the wire gauge of the cable between the Inverter and the battery. Granted it will not be a constant 25 amps, but no clue as to how long the cable would have to carry that load.

Don
My Registry

RVing with SOLAR

[RPR]

Alternator output varies with engine rpm. At idle say 680 rpm about 50 amps. Depends what all you have on as to what draw you have. Lights, vehicle ac fan, radio, draw of inverter etc. I would be concerned with low voltage to frig. Low voltage and frig may try and draw more amps to keep watts up.

[Bullitt6283]

Originally Posted by Mustang65

I guess my first question would be what is the wire gauge of the cable between the Inverter and the battery. Granted it will not be a constant 25 amps, but no clue as to how long the cable would have to carry that load.

The wires feeding 12 volts from the house battery to the inverter are #6 and we're talking about maybe 25 feet..
.

[Bullitt6283]

Originally Posted by RPR

Alternator output varies with engine rpm. At idle say 680 rpm about 50 amps. Depends what all you have on as to what draw you have. Lights, vehicle ac fan, radio, draw of inverter etc. I would be concerned with low voltage to frig. Low voltage and frig may try and draw more amps to keep watts up.

Understood.

If the alternator cannot keep the batteries up and the DC voltage to the inverter falls off, the inverter will trip off and show a 'low voltage' alarm.
.

[RPR]

Do you have the house size frig or the smaller one. Little research and found some owners had to go with a bigger inverter with the house size frig.

[Bullitt6283]

Originally Posted by RPR

Do you have the house size frig or the smaller one. Little research and found some owners had to go with a bigger inverter with the house size frig.

I have the 8 cubic foot Norcold fridge typically used in recreational vehicles. The documentation and nameplate show 300 watt consumption at 120 volts AC.
.

[mcole9]

Hi Ron,
I have done exactly what you are thinking about. I have a 2017 Redhawk 26X1 with a 1000watt inverter under the bed. What I did was run an extra line from the inverter to the fridge. It works great when the engine is going and you moving along the highway. No propane safety concerns. When the engine is off it is very hard on the house battery.

I replaced the stock battery with 2 AGM batteries. One in the stock location and one under the bed. There is lots of room there and no space is taken in the storage lockers. An added bonus is all the major wiring is under the bed.

I have the situation where I have a 2 hour ferry ride to get from Vancouver Island to the mainland (both USA and Canada). Running the fridge on the AGM batteries works, but it is very hard on these batteries. As a result I'm in the process of switching the 2nd house battery out and replacing it with a more powerful lithium battery.

Have fun with this project!!

Marty

[ALJO]

Inverter should be as close to the battery. From the inverter run #14 wire and install a two way switch so the fridge can run on normal and inverter. While traveling I run my fridge on the inverter and the usual 12 volt circuit for control (no propane).

[Bullitt6283]

Originally Posted by mcole9

...... What I did was run an extra line from the inverter to the fridge. .....

Hello Marty,
I got the wiring harness diagrams from Jayco for my model. It looks like the existing fridge 120AC cable runs directly to the area under the bed where the inverter and other electrical stuff is. I have to put eyeballs on it to be sure, but it looks like this part of the change might be very easy.
I'm looking at putting a pair of 300 amp-hr 6 volt AGMs in the compartment next to where my single 12 volt battery is now. I just need to reinforce the compartment floor. I don't have any room under the bed for much to be added.
.

[Bullitt6283]

Originally Posted by ALJO

Inverter should be as close to the battery. From the inverter run #14 wire and install a two way switch so the fridge can run on normal and inverter. While traveling I run my fridge on the inverter and the usual 12 volt circuit for control (no propane).

Good idea about the 2-way switch. My inverter has a built-in transfer switch so guess it does the same thing.
.