Inverter for a Small Fridge

When my main fridge died, for about 2 weeks, I purchased a small electric fridge and put it in the closet that was designed for the Washer/Dryer. In my Landmark, that closet is right inside the door to the rig. Anyway, I would like to hook up an inverter to it so that in the rare case I am off grid for a night (normally at a walmart) or while driving, the fridge will stay on. My thought would be to put it as close to the batteries as possible (I remember something about the shorter the connection between the inverter and the batteries the better) and then run the cord from the fridge to it. I would like it after the cut-off switch so when I shut down the batteries the inverter will be shut down as well. I figure I can deal with a modified sinewave inverter. Oh, I am going to have 2 Size 31 AGM Deep Cycle batteries. I know that 6 volt Golf Cart batteries would give me more capacity, but like I said, I am off the grid for just a night every so often so I don't think I would need the capacity that a 6 volt set up would give me.

So, what recommendations do you have for me? Am I close to being on track with my thoughts or am I far away from reality.

Hi Ronn,

The block wiring diagram on p 11 of the Residential Refrigerator Guide might be of help.

danemayer said:

Hi Ronn,

The block wiring diagram on p 11 of the Residential Refrigerator Guide might be of help.

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Damm that's complicated. I guess if I kept it "simple" and did a direct connect from the fridge to the inverter and the inverter to the battery that would mean the fridge would always be running off the inverter and never off shore power. Am I correct?

Greengas said:

Damm that's complicated. I guess if I kept it "simple" and did a direct connect from the fridge to the inverter and the inverter to the battery that would mean the fridge would always be running off the inverter and never off shore power. Am I correct?

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Yes.

When on shore power, the Power Converter would probably have enough output to keep the batteries charged even though running the refrigerator.

Or you could just unplug it from the inverter and plug it into a regular outlet.

You may want to put a high value fuse or circuit breaker in between the battery and inverter to protect the battery if something were to malfunction on the inverter. A 1000 watt inverter powering a 22 cu ft refrigerator can draw a bit over 80 amps from the battery when the compressor starts. So 100 amp fuse or breaker would be good. For a smaller refrigerator, maybe a smaller fuse would be ok.

Now, as far as putting thevinverter on the outbound side of the cutoff to ensure when I shut down the batteries there is no draw from the inverter, am I on track with that thinking? I was also thinking about installing a separate cutoff for the inverter which would prevent me from cutting into existing wires. And the fuse you were referring to would be on the outbound side of the cutoff or between the cutoff and the battery?

Greengas said:

Now, as far as putting thevinverter on the outbound side of the cutoff to ensure when I shut down the batteries there is no draw from the inverter, am I on track with that thinking? I was also thinking about installing a separate cutoff for the inverter which would prevent me from cutting into existing wires. And the fuse you were referring to would be on the outbound side of the cutoff or between the cutoff and the battery?

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It's good to have a cutoff for everything. Also good to have a separate cutoff for the inverter so you can isolate the inverter if there's ever a problem. Fuse location just needs to be somewhere between inverter and battery. I don't think it matters which side of the cutoff switch.

So, if I have this right, it is battery to fuse to cutoff to inverter to fridge. Right?

Greengas said:

So, if I have this right, it is battery to fuse to cutoff to inverter to fridge. Right?

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Sounds good.