Keezer A419 control problem, help please

[Cookiedds]

I just finished building a 7 tap/keg chest keezer and all is well and dandy except for the temperature. I have a Johnson Controls A419 temperature control and initaially set the SP to 55 degrees with a dif of 1, anti short cycle set at 12 minutes. the temp fluctuates pretty radically with the low in the low 30s and high up around 56. What am I doing wrong? It doesnt seem to matter where I put the probe or even if I put it in an insulator.

 

[motobrewer]

set the anti-short cycle to 1 or 2

 

[samc]

What are your other settings at?
Is the freezer filled with kegs of beer?
Not sure it would have anything to do with short cycle delay.

 

[motobrewer]

if the short cycle delay is keeping the keezer on for 12 minutes, that will certainly drop the temp well below 55. that explains why it only goes up to 56.

 

[samc]

The short cycle delay keeps the freezer off for 12 minutes before allowing the compressor to restart.

At least that's the way I understand it to work. It only goes to 56F because he set the SP to 55 with a 1 degree differential.

 

[motobrewer]

well, yeah you're probably right, unless it was wired to the normally-closed contacts.

 

[Cookiedds]

It's filled with 7 empty kegs, a full 20 pound CO2 tank and all the hoses & fittings.

 

[chefkdub]

Try putting the probe in a glass of water. That seems to work for me.

 

[samc]

It's filled with 7 empty kegs, a full 20 pound CO2 tank and all the hoses & fittings.

Fill one keg with water and tape probe with some foam insulation over it to the keg. Then test.

 

[SweetSounds]

I would also install a small muffin fan to circulate the air in the keezer. Without circulation the temperature will always vary in different places in the keezer.

This fan should always be on.

 

[Naked_Eskimo]

What is a muffin fan?!

 

[SweetSounds]

A small 4" or so computer fan. Like you would find in a computer power supply.
Your local computer store or radio shack will have them. Radio Shack has 120 volt fans too, if you don't want to have to use a wall wart to power a 12v one.

 

[tlael]

If the temp swings so wildly, I doubt the actual freezer or controller is at fault.

My guess would be that the probe is getting direct cooling and shutting the whole rig down before the inside air temp actually is down to the desired range.
The glass of water trick is a good way to prevent the probe from being flash cooled.

Those probes are surprisingly accurate and responsive. I think the controller samples temperature every 15 seconds or so.

 

[pretzelb]

I would also install a small muffin fan to circulate the air in the keezer. Without circulation the temperature will always vary in different places in the keezer.

This fan should always be on.

I am having the same issue (we now have 3 threads on the same topic) and I was considering a fan. But this doesn't make sense to me. If the probe stays put, and the top stays closed, why would it matter if the air circulates?

The probe should keep monitoring the exact same area which should then grow warmer / colder as things change. If the controller turns on and starts to cool then it should turn off when it hits the target. In my case I set it for 45 but I commonly see 38.

I am willing to try a fan but I just don't see how that will change the fact that the controller seems to keep cooling when it should be stopping.

 

[pretzelb]

Try putting the probe in a glass of water. That seems to work for me.

Isn't it a bad idea to put moisture in the keezer? I've seen people buy dehumidifier chemicals and devices in keezers to avoid moisture buildup.

 

[SweetSounds]

I am having the same issue (we now have 3 threads on the same topic) and I was considering a fan. But this doesn't make sense to me. If the probe stays put, and the top stays closed, why would it matter if the air circulates?

The probe should keep monitoring the exact same area which should then grow warmer / colder as things change. If the controller turns on and starts to cool then it should turn off when it hits the target. In my case I set it for 45 but I commonly see 38.

I am willing to try a fan but I just don't see how that will change the fact that the controller seems to keep cooling when it should be stopping.

YMMV, but I use fans in all 3 of my coolers for this reason. Circulating the air mainly keeps the temperature uniform. I would assume that this is why every commercial cooler or walk-in I have ever seen all have fans.

 

[MrFugglz]

I have a slightly different problem, I have a converted Sanyo 4912m and am using the Johnson Controls 419 (model # - A419ABG-3C) with the probe suspended in ice pack gel affixed to the top of the refrigerator. I have a 4" blower fan circulating the air into the tap tower. Here are my settings of my 419:

SP - 42
diF - 5
ASd- 12
OFS - 0
SF - 0

My problem is that the temperature will never get below 50 degrees. I have not tried removing it from the ice pack gel, that is my next step...

However, I left the thermostat unit plugged in, but plugged in the refrigerator into the wall so I could get a read out of the temp on the display. The refrigerator is set to max and got down to 32 overnight. I plugged the refrigerator back into the thermostat unit, it was back to 50 by the morning. Any thoughts?

 

[Hermit]

Sit down with a home brew and wait for the unit to kick on. Record the temp. Record how long the unit runs and what the temp is when the unit shuts off. Does the temp continue to go down once the unit shuts off? The compressor SHOULD kick off when the display shows it has dropped the differential. If the compressor continues to run as the temp drops then the unit is not shutting off at the right temperature. Either a bad setting or a bad control.

 

[SweetSounds]

Do you have ice on the evap coils? When mine iced up it would be a steady 50 degrees no matter how long the compressor ran.

 

[MrFugglz]

I do indeed have ice on the evap coils in the back... Thanks for the tip, I'll deice when I get home tonight. Did you come up with a long term solution for keeping the ice off?

 

[SweetSounds]

I do indeed have ice on the evap coils in the back... Thanks for the tip, I'll deice when I get home tonight. Did you come up with a long term solution for keeping the ice off?

Yea - I mounted a fan inside so it blows over the coils all the time. When the compressor turns off, the moving air de-frosts the coils because it's still above freezing.