Johnson A419 Question

[wesasmith]

Hey HBT,

I have a question about my Johnson A419.
Yesterday i brewed a double ipa (10 gallon), 18.5 Platos, and cooled it to 69 degrees via my heat exchanger.

I set my temp controller to 68deg F.
the controller is set up as follows,
SP - 68
dif - 1
ASd - 0
ofs - 0
sf - 0

when i checked in on the beer 12 hours later the Johnson read 54 degrees.
my question is are my settings off? the temp only needed to drop one degree but 15 instead. FYI i have the probe taped to the outside of the carboy,
i know that a heat source would solve this problem, but i want to know if there is anything change on my settings that would help first,
thanks

 

[processhead]

There are three control terminals on the controller. Which two did you connect your wires to?

Also, there are mode jumpers on P4 to select heating and cooling mode.
How are yours positioned?

http://cgproducts.johnsoncontrols.com/met_pdf/125188.pdf

 

[wesasmith]

when i purchased the controller, i plugged the freezer plug into the controller female outlet, i can open it up and check.

 

[Yooper]

What's the ambient temperature?

 

[wesasmith]

What's the ambient temperature?

ambient inside of the keezer is in the mid fifties, outside of the fridge, is about 60-65.

 

[Yooper]

ambient inside of the keezer is in the mid fifties, outside of the fridge, is about 60-65.

Did it get cooler than 60 degrees last night? I mean, it will never be warmer inside than ambient, without a heating device. And if it got colder, the freezer will "hold" cold temperatures very well, as it was designed to do.

 

[processhead]

You can do a quick function test of the controller to verify it is wired and configured to cool.

Lower the SP to 40 degrees and see if the freezer compressor kicks on.