Johnson Controls A419 Settings

You have two options:
Set the set point to 40 with the jumper in the "cut out" position. No matter what differential you use, the compressor will stop running once it cools down to 40. Then the temp will rise and the compressor will kick in once it warms up to 40+(differential) to start cooling again and bring it back down to 40.

The other option would be to set the setpoint at 40+(differential) and have the jumper set to cut in. In this case, for example lets say your differential is 5, the set point would be 45, so the compressor would start running when the temp rises to 45, and it would stop running when it cools by 5 degrees to 40.

I've installed several of these controls in commercial refrigerators & make tables and always use the "cut out @ set point" option.

Sittofalcon and Junkster... After reading about 20 different threads to figure out whether to cut in or cut out, the two of you gave me my answer in a minute. Thank you both.

I'm set to cut-out @ set point.

I have a Johnson A419 controller and I'm wondering if anyone has used it in heating mode? My fermentation chamber (upright freezer) is in a non insulated garage in Maine. The current temp inside it is around 40*F (unplugged). I have a Brewers Edge space heater to help me bring the chamber up to ale fermentation temps.

I'm curious why I have to "jumper" the controller to "heating mode"? If my settings are telling the appliance to cut in or cut out based on a temperature set point then why does it matter if I have a cooling appliance or a heating appliance plugged into the controller and what mode the controller is set to?

Am I looking at this right?

CGJesse said:

I have a Johnson A419 controller and I'm wondering if anyone has used it in heating mode? My fermentation chamber (upright freezer) is in a non insulated garage in Maine. The current temp inside it is around 40*F (unplugged). I have a Brewers Edge space heater to help me bring the chamber up to ale fermentation temps.



I'm curious why I have to "jumper" the controller to "heating mode"? If my settings are telling the appliance to cut in or cut out based on a temperature set point then why does it matter if I have a cooling appliance or a heating appliance plugged into the controller and what mode the controller is set to?



Am I looking at this right?

Click to expand...

Jesse,

I'm no expert as I always have to refer to the instructions each time I change from heating to cooling modes.

Heating cut-in: jumper 1 installed, jumper 2 removed for cut-in (circuit energized at cut-in). Say you want to maintain 68 degree fermentation temp in a cold ambient environment. I set the set-point to 67 with a differential of 1. When the temp drops below 68 the heater engages and runs until the temp hits 69 then shuts off. Temp oscillates between 67 and change and 69 maintaining a mean temp of ~68.

Cooling cut-in (default setting): both jumpers removed (circuit energized at cut-in but at a temp below ambient). If I want to maintain my keezer at a beer serving temp of 42 degrees I set the set point to 43. At 43 the condenser energizes and cools until my 1 degree differential of 41+. This maintains a mean temp at ~42 degrees. Technically I don't maintain this close a tolerance on cooling as I set the ASd cycle delay to 10 minutes.

Hope this helps.

It does help, thanks. At least I know I'm using it correctly in heat mode. I'm pretty much running it the same way. Main difference is I have it jumpered to cut out at set point instead of cut in. I don't know the benefit of either way. A matter of preference I presume.

Still confused on the importance of the mode selection. Why does the controller need to know if it's using a heating source or a cooling source? All it's doing is telling the appliance to turn on or off based on the settings, right? Would a heating element work if the controller was still in "cooling mode"? The directions don't say much besides it determines whether the display shows a snowflake or flame. Sorry... I'm electrically ignorant among other things.

I'm just trying to see if it's necessary to open up the controller and change modes or if I can just leave it in one mode and plug in my freezer or heater as necessary.

CGJesse said:

It does help, thanks. At least I know I'm using it correctly in heat mode. I'm pretty much running it the same way. Main difference is I have it jumpered to cut out at set point instead of cut in. I don't know the benefit of either way. A matter of preference I presume.

Still confused on the importance of the mode selection. Why does the controller need to know if it's using a heating source or a cooling source? All it's doing is telling the appliance to turn on or off based on the settings, right? Would a heating element work if the controller was still in "cooling mode"? The directions don't say much besides it determines whether the display shows a snowflake or flame. Sorry... I'm electrically ignorant among other things.

I'm just trying to see if it's necessary to open up the controller and change modes or if I can just leave it in one mode and plug in my freezer or heater as necessary.

Click to expand...

So, say you have it set to "cooling" by accident but you have it hooked up to a space heater or something, with the SP at 60F with a differential of 1F. So, what will happen is it will kick on the space heater when the probe reads 61F. Now the obvious problem is it will NEVER get down to 60F so it will just turn that space heater on and keep going.

Lightbulb! That's the kickstart my brain needed. Makes perfect sense. Thanks.

I am getting this thermostat in the mail today and plan on hooking it up. Need Help!

This will be for my fermentation chamber in my 7 cubic foot Criterion chest freezer. My plan of action is to basically plug and play this thing with no problems and using the controller probe to stick up against the fermenter while using a separate digital thermometer probe dangling in the air to monitor ambient air temp in the freezer. I will also be using a fan inside to circulate the air. (This is the best method from what I can understand reading through this thread as well as others).

My questions are:

1.Does the above method work best for you guys/gals too. According to cwi it's best for fermentation.

2. What "mode" is this thing defaulted at out of the box from the factory? Cooling/Cut-in mode, Cooling/cutout mode, Heating/Cut-in mode or Heating/Cutout mode. I feel like I'm going cross eyed stupid trying to understand the PDF instructions I found online here.

3. I typically do ales that like to ferment in the mid to upper 60's. What should my recommended temp settings be for this thing(say for example I want to ferment at 65 degrees)? Set point, differential, and Offset (which btw what the hell is offset used for?)

I'm trying to avoid large temperature swings of course while maintaining that designated set point temp. Just loookin for a little advice. Thanks.