Hacking the Haier BC112G for BrewPi

Hi all,

This question is for the electrical engineering types, and the makers/hackers.

I have a Haier BC112G wine fridge that I'm converting to a ferm chamber for a BrewPi setup. I think I've found a way to hack the fridge without hot-wiring it the way they did in fall-line's thread. I want the light and temp display to work, and really just replace their controller with mine.

If you follow the traces on the board, the large relay in the center opens and closes the common wire to run the compressor. The relay is operated with DC 12V and has 4 points. Across the left two points of the relay is a diode and then a transistor.

From tracing the mains power through the board, I'm 99% certain this is the relay that operates the compressor. My plan here is to remove the relay entirely, and insert my own relay across the two points that it was switching, leaving the rest of the board completely untouched.

I know it's hard to make a judgement without seeing the board in front of you, but do you agree with my logic that I should be able to simply remove this relay and wire in my own?

 

Is there an evaporator and/or condenser fan that's running off the smaller relay - and that wants to be sync'd up with the compressor?

Cheers!

 

I traced the wires this evening and the second, smaller relay is running the fluorescent light inside. Keep in mind that this is a wine cooler and not a fridge so it doesn't have a blower to move any cold air around and also has no defrost or anything like that. I'm gonna give this a whirl maybe over the weekend

 

For those who may be following this thread, my approach of desoldering the large relay from the board and attaching my own worked perfectly! I can now switch the compressor on and off using BrewPi

 

[ame="https://vimeo.com/149322767"]https://vimeo.com/149322767[/ame]

 

That is awesome.

 

Used this description and an external 110V relay connected to cooling output of my STC-1000+

 

Awesome! Glad to hear it worked out for you.