Johnson a19 temp controller

[sauerj67]

Good morining
Has anyone atempted to recalibrate a Johnson A19 analog temp controller. I have one that is 15 degrees off(have it set on 50 and the frig is holding at 35). Also, is there any danger drilling a hole thru the side of a refigerator, I have a freezer on top kenmore that is pretty new. And, once I get the probe in the refrigerator, is it best to just let it dangle in the air or attach it to the wall or wall of the fermentor? Any help would be greatly appreciated.
Thanks
Jason

 

[Teaman]

Where is the fridge located? And where is the probe now?
Is the fridge turning on and off?
If the temp controller is at 50 and the fridge is at 35 then that would mean that the controller isn't controlling anything because the temp in the fridge would have to exceed 50 before the controller would kick in. You can't warm the fridge up with the controller, you can only cool it down.
I have two of these controllers and they are nearly dead on temp.

 

[sauerj67]

Well it was cycling on and off, but I just thought of something. I put the probe in a frig that was already cold and I set the dial to 50 and turned the frig controls all the way up. Oh man, I may be a DA!!! If I did all of that and the frig was already bellow 50 then the controller was not controlling anything the frig was. Correct?
The probe was on a shelf. Is there a better place to put it?

 

[Donner]

first off, it doesn't sound like it's the calibration.

Do you know if you have the controller set to heat or cool? If you have it set to cool then it should allow the fridge to come on when it senses that your fridge is above 50. If you have it set to heat then it thinks it needs to come on to raise the temp up to 50. It will cycle like normal since it's doing what a fridge does and is just staying on.

There are two tests i'd suggest. First, run the controller down to 30ish degrees and see if it turns the power to the fridge off. If it does then you know that it is set wrong since it will sense that the temp is colder than the desired temp and it wont need to run.

The other thing you could do is run the controller up to 65 (or higher since you don't know how far off it might be) and see if that does anything. If it does then you might have one that is reading the temps wrong

Also, the other thing to check might be your differential. If you have it set too far apart then you might be within your range. Most brewers keep theirs in the 2-4 range.

 

[Teaman]

Right. I have never used mine with a fridge, just two chest freezers. I set the freezer on coldest setting and have the probe running in and duct taped to the side with the actual probe just hanging in the air about mid height of the compartment.

Is your fridge plugged into the controller and the controller plugged into the wall?
If so then the fridge compressor shouldn't come on until the temp comes up to what the controller is set to.

 

[Teaman]

.

Good morining
Has anyone atempted to recalibrate a Johnson A19 analog temp controller. I have one that is 15 degrees off(have it set on 50 and the frig is holding at 35). Also, is there any danger drilling a hole thru the side of a refigerator, I have a freezer on top kenmore that is pretty new. And, once I get the probe in the refrigerator, is it best to just let it dangle in the air or attach it to the wall or wall of the fermentor? Any help would be greatly appreciated.
Thanks
Jason

 

[sauerj67]

Ya it is plugged into the controller but since the temp of the frig was already low then was the refrigerator thermostat keeping it colder since I had it set as cold as it would go

 

[Teaman]

Well if the fridge is plugged into the controller plug which is plugged into the wall then the fridge themostat is bypassed. Do you have the probe from the controller inside the fridge??
Is the fridge in your house or outside?

 

[Donner]

does the analog controller have the ability to be set to heat like the digital one does? It's not a menu option, or anything, you physically have to open up the unit and change the circuit around.

If the analog unit can get low enough, dial it down below the fridge temp and see if it turn the fridge off.

If the unit is working right, it should cut the power to the fridge once it reaches the programed temp. It sounds like the unit is behaving opposite of how it should. Instead of cutting power to the unit when it reaches the right temp, it thinks it needs to keep the power on to maintain the temp below the setting. (Almost like it thinks it needs to turn a heater on to raise the temp up to the programed level).

 

[Teaman]

I've got two of these and I don't see any way to change them over from heat to cold or adjust anything. It's a simple box with a dial on it and both of mine work great. I have noticed though since summer has left and my house is now around 65-68F all the time that I can't ferment in my chest freezer up around 70F. Obviously the controller can't warm the freezer up to a 70F temp because it's not designed to do that and the ambient temp in the house is cooler than 70F. So if his fridge is in the garage in Colorado it'll never get to 50F. Can't figure out what's up with his situation????

 

[Donner]

the digital ones can be opened up and you reconfigure the pins to switch it. Instead of coming on to lower the temp it is changed to turn on to raise the temp. So if you unplug the fridge and plug it into a heater then it would turn on when the temp gets too low and turn off when the temp reaches the right level.

This manual does indicate that things like differential might be adjustable, but i'm not sure about the turn on/turn off change.

 

[Donner]

actually, this may be a better one.

 

[sauerj67]

The frig was in my house. I am just going to have to try it again and this time pay more attention to what I am doing.
Thanks guys

 

[LKHA]

I don't open my digital one up unless i want to lock it to switch from cooling to heat just scroll in the set up and change the c1/h1 setting that easy