Use Johnson Controls A419 on 4912 Kegerator?

[RoaringBrewer]

Ok, so I bought a Johnson Controls (JC) A419 temp controller (single stage) for a chest freezer I have, for lagering. Well, I am not into too much lagering right now, so the freezer and controller are not in use.

I am however getting back into brewing ales and I have some on tap now, as well as a commercial sixtel. The problem is my Sanyo 4912 kegerator doesn't do very well at holding an accurate temp. I like it around 40F, and if I want to warm my beer up to 45-50F, depending what it is, I will just let it sit out a little while before consuming.

So, anyway, if I put the kegerator at 5 of 6 setting, I get 44F constant. If I set it at 5.25 or 5.5 of 6 setting, I get 30-32F, aka nearly freezing my beer twice now. There is no middle ground - aka the 40F I am looking for.

Is there a problem with using my JC A419 to run the fridge? Set the controller at the 40F I am looking for, set the fridge at 5.5 or even full 6 setting (which would cool 2 kegs to 30F apparently), and let the controller turn the fridge off at 40F, and back on when it rises above? I don't see why it would be a problem, but maybe I am missing something b/c ppl normally just use these on freezers.

I guess I am wondering if the fridge compressor will run constantly on the fridge until it hits 40, or will the fridge still keep its defrost cycles and sometimes turn off the compressor on its own so it doesn't get overworked. Obviously on a freezer, with controller set to 40F, the compressor will run constantly until temp is hit b/c the freezer wants to cool until below 0F. But for my fridge that only wants to cool to 30F or so anyway on its highest setting, I'm not sure if it will run constant or not? Any problem with cycling on the fridge compressor? I set the anti-short cycle setting on the 419 to 5 mins.

Anyone? I'm trying it now, so if I am going to hurt it, I will go unplug it, set it to 5, and just deal with the 44F being the temp I use as standard.

 

[RoaringBrewer]

Also - if it is OK, what should I set my "dif" setting at. I set it to 1F to keep it as close to 40 as I can get it. As I understand it, this will determine when the controller cycles on and off? If I set the temp setting to 40, dif to 5, it won't turn back on until 45F after turning off? With it set at 1, it will turn off at 40, back on at 41, as long as its not within the anti-short cycle timeframe? Or am I misunderstanding this?

 

[BrewNinja1]

Sounds like everything your thinking/doing is fine. A dif of 1 is fine (like you said, you have the short cycle delay set). People use them on freezers because a freezer is usually cheaper and you get more room in it. Good luck!

 

[RoaringBrewer]

Sounds like everything your thinking/doing is fine. A dif of 1 is fine (like you said, you have the short cycle delay set). People use them on freezers because a freezer is usually cheaper and you get more room in it. Good luck!

Well thats one vote of confidence. Thanks for the reply!

Anyone else have thoughts or first hand experience?

I checked on it today and it was sitting at 39F on the temp guage on the JC controller. I had it programmed to 40F, but guessing it can get to 39F without switching off due to the 1F dif...

I turned it up 2 degrees then, and it automatically turned off, so I guess its working!

 

[BrewNinja1]

Setting it at 40 with 1* diff means it will swing from 39 to 41. So its all good on that part.

 

[RoaringBrewer]

Setting it at 40 with 1* diff means it will swing from 39 to 41. So its all good on that part.

This is what I have done and everytime I check on it, its sitting at 39-40F - nice!

I did turn the anti-short cycle delay up to 10 or 12 minutes too. I doubt it will rise from 39F to 41F in 12 mins anyway, so it should stay off, more than on once I reach the 39F, and if I keep from opening the door.

 

[RoaringBrewer]

Ok, so I think I got this thing finally figured out. I put the temp probe in a beer bottle full of water. Stops the temp swings in the controller when I open the door and is more accurate reading of the actual beer temp.

Turns out air temp in there is about 3F-4F or so higher than the liquid temp. This is how I almost froze the brew before, when I set it at 39F with a 1 dif the first day using air temp. It read air temp accurate and go down to 38F with the dif, but liquid temp was closer to 34F, aka borderline freeze.

Now, I set the temp according to the liquid and set it to 40F with 1 degree dif, the beer stays where I want it at 40F, even though the thermometer in there reading the air temp says 43-44.

I've checked it several times today and appears the controller is off more than on, which I assume is good for the fridge and my electrical bill... and oh yeah, the beer!