Fridge Wiring Help (Any Electrical Engineers Out There?)

The key thing is the value and reaction temperature range of the thermistor. Try calling the manufacturer and asking for a part number, or a replacement.

 

While this is NOT as good as a fusible link, it is infinitely better than nothing.
Keep the fuses on the POSITIVE cable. While technically it could be either, CONVENTION has it that the fuses all go on the positive side. This convention protects you from ending up with home-brewed circuits made by backyard mechanics that have SOME circuits protected on negative side, and others protected on positive side. Mixing them is dangerous, since the positive line from the circuit protected on negative could short with the negative line from the circuit protected on positive. Further, since battery powered devices are typically negative-to-chassis, having any length of unprotected positive circuit in the whole system could be dangerous.

 

I would highly recommend that you contact the manufacturer or search ebay or something, and obtain the correct part.

 

Manufacturer is a no go unfortunately. I can buy the part I need from them for about $78 but they have a $500 minimum order rule. And they say they can't offer me any kind of tech support because I bought the unit second hand. Super butts.

 

What is the manufacturer and part number?

 

Here's the link to the manufacturer's info page.

http://csafeglobal.com/products-acutemp-ax56l/

The maker of the fridge is Acutemp. I guess they are owned or something by a larger company called CSafe.

The part number listed in the manual is 100956

 

You need to determine if the black box is a thermal switch or a thermal sensor. A switch will be normally closed until it reaches a certain temperature and then it opens, disconnecting power. A sensor will return a certain voltage to the mother board to determine the actual temperature.

 

I'd pretty much have to have one to test to determine that. Or talk to someone who could measure the resistance while the unit was running. It's a great thought though! I'm hoping it's a sensor. I bought that Blue Sea one from a few posts ago. Gonna try it out maybe. It was only $15.

 

Updates! Here's pics of the harness I've created.



Initial testing is going well. I plugged in the unit with AC power and the batteries achieved full charge it about 1 hour. I then unplugged the fridge and let it run on "cool" mode til they were dead. It maintained 4*C for 33 hours. Room temperature varied between mid 80s to mid 70s, maybe mid 60s at night. I then plugged in AC power and the batteries recharged completely in about 9 hours while still maintaining 4*C.

I'm currently testing "freeze" mode on AC power. Once it reaches temp I will unplug it and see if it runs properly on battery power. It draws a bit more current on freeze setting, I believe. After that I want to try testing it on DC. I'm thinking of hooking it up to a jump box and seeing if the fridge will run and charge the batteries on DC power.

A question about fuses. I have a 5A fuse in each battery positive. The unit is supposed to draw around 4.5A max. Should I replace each fuse with a 3A so I have 6A total? If I have 10A total as it sits could that be too much margin?

 

did you try contacting the company?

 

yea, I had to make a $500 minimum order. I built my own harness with stuff I had around for like $17!

*EDIT* And lots of help from the community!

 

Given the way those batteries are wired, it looks like either one can run the whole thing, so I think you need 5A on each.