Programming an STC-1000

[bendog15]

Just got done wiring my chest freezer with an STC-1000 (complete in a project box, (thankyou homebrew talk forum). I'm not gifted electronically and need a little help programming this. I want 19 degrees Celsius for a fermentation chamber. I set the F1 at 19 degrees and F2 at .05 correction, that's as far as I got.
Problem is, after the freezer kicks off (at 18.9C) the temp still keeps dropping. All the way down to 14.5 C. I live in Hawaii, no need for a heater on this system. How do I program the STC-1000 so the temp doesn't drop so low?

 

[RM-MN]

Are you measuring the temperature of a container of liquid or just air temp?

 

[disney7]

RM-MN's question was a good one. If the sensor is in free air, you will see some quickly changing readings.

For fermenting, you want to insulate the probe and tape it against the side of the fermentation vessel. Most people use some bubble wrap, fold it up a few times, and tape it to the fermenter with the probe between the fermenter and the bubble wrap.

Chest freezers have a lot of thermal momentum compared to a refrigerator. So, you are going to see more overshoot than you would with a fridge. I would suggest adding a fan to circulate the air in the freezer. That will help quite a bit to even the temps out.

What is your hysteresis band set to? (It's the third settings you didn't mention).

 

[bendog15]

Are you measuring the temperature of a container of liquid or just air temp?

RM-MN I've got the sensor taped to a carboy in the chest freezer, with a piece of insulation taped over it.

 

[bendog15]

Disney7,
The fan is a good idea. I may look into putting a small one in there.
Also I haven't looked into the 3rd setting yet. I assume it is just set to default setting. I will check that out today.

 

[smagic14]

Set the 3rd for 10 (10 minutes) so it wont activate all the time this is for how often it can activate so it wont activate more than once in 10 minutes. .. the 4th is for correction if the probe reads wrong

Once the temperature stabilizes then you wont have this huge swing of temperature the first time you set it up trying to cool the whole carboy takes a long time... once it is to that temp it wont be as hard and wont take much and the swing in temp will be minimal


Hope this helps

 

[BigFloyd]

Once the temperature stabilizes then you wont have this huge swing of temperature the first time you set it up trying to cool the whole carboy takes a long time... once it is to that temp it wont be as hard and wont take much and the swing in temp will be minimal

This is quite true, especially if the fermenter bucket/carboy is a bit warmer than the set temp. Don't worry. After a while it will reach equilibrium and the overshoot will go away.

One thing you can do to help with this in the future is to chill the wort a few degrees cooler than your initial target ferment temp before pitching yeast. That's a good brew practice anyway.

+1 on taping it to the fermenter and insulating over it. You've got it set up right.