# STC-1000 Code Functions



## acrow (10/3/14)

Howdy All,
(Firstly, I know there is a number of STC-1000 posts, but felt this - or the answers I receive may help others - for this particular query).

I need a little help on the code functions of the STC-1000.

F1 - Temperature Set Value (default 10.0C) - no problem with this as have set to 18.0C (normal beers, not lagers)

F2 - Difference Set Value (default 0.5C) - allowance temperature variation - ok with this

F3 - Compressor Delay Time (default 3 minutes) - not really sure what this does

F4 - Temperature Calibration Value ( default 0.0C) - not really sure what this does

Basically, I have set my temperature at 18.)C and the fridge turns off when temperature has reduced to 18.0C (no problem).

But which Fx is for restarting the fridge when it rises to x.xC (e.g. 19.5C).

At the moment (once fridge is at 18.0C and starts to rise) the temperature gets to 20.8C before the fridge turns back on to cool back down.

So, my main queries are;-

1) If I wanted it to turn when it gets to say 19.5C, how do I do that?

2) The F3 for the compressor - should I change the setting of 3 minutes?

3) Also, I have a digital meat probe in the fridge and is sitting on 16.0C - so when the STC-1000 gets to 18.0C, surely that is the temperature in the fridge (not 16.0C as per meat probe) - or am I 'reading' this wrong?

Thanks for any help.

Geoff


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## Ducatiboy stu (10/3/14)

Calibrate your STC in ice slurry with f4. 

Your probe may not be reading the correct temp so you will need to calibrate first


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## djar007 (10/3/14)

f3 - this is pretty important. It stops the stc from flicking your compressor on and off rapidly, which can kill it.


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## Camo6 (10/3/14)

If you want to allow it to get to 19.5 while set to 18, set F2 to 1.5 degrees. Personally I leave it around .5 degree with my sensor sandwiched between two fermentors.

I have F3 set to 10mins as I like to give the fridge a rest between compressor cycles.

Test your sensor in an ice slurry compared with a known accurate thermometer and if out adjust the difference with F4.

Leaving your sensor hanging in the fridge is gonna allow for wild fluctuations every time you open the door. Some insulate the sensor against the side of the fermentor, others suspend it in the wort and some place the sensor in a jar of water.


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## acrow (10/3/14)

ok guys that gives me some answers that will help - thanks.

I like the idea of suspending the sensor in a jar of water - I was intending to tape the sensor to the fermenter with foam insulation, but the jar of water makes so much sense.

Putting the compressor cycles to around 10 minutes seems a smart idea too.

And calibrating the it all - of course.

I have F1 set at 18.0C and have set F2 set to .5C and was expecting the fridge to turn back on at 18.5C (to cool back down to 18.0C), but it doesn't - it now goes to 21.1C before turning back on to cool (may be the calibrating comes in to this but there is a fair degree difference - so doubtful at the moment.

I have now put the sensor in some cold water and will see if the above changes.

Cheers for the help.


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## Camo6 (10/3/14)

acrow said:


> I have F1 set at 18.0C and have set F2 set to .5C and was expecting the fridge to turn back on at 18.5C (to cool back down to 18.0C), but it doesn't - it now goes to 21.1C before turning back on to cool (may be the calibrating comes in to this but there is a fair degree difference - so doubtful at the moment.


That doesn't sound right. Does the cooling light indicator come on at 18.5?

Just a note on the jar of water trick. Water won't have the same thermal properties as your wort and fermentation will raise wort temps also.


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## shmang (10/3/14)

It could be that the compressor delay is throwing you off.
When the temp reaches 18.5C (Which is the F1 value plus the F2 value) the "cool" light should start to flash if it is less than 3 minutes (or whatever F3 is set to) since the compressor was last running.
If it has been more than 3 minutes (or whatever F3 is set to) since the compressor was last running it should come straight on.


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## acrow (10/3/14)

I've taken the senor out of the water to re-try with sensor just hanging in fridge.

The temperature was on 18.0C and slowly rose.

When 18.5C was reached the cooling indicator started to flash - but fridge did not turn on.

Temperature rose to 22.3C but took a bit of time to do so - and was also thinking if the compressor is causing the delay.

At about the 10 minute mark (F3 compressor set to 10 minutes) the cool light went solid and fridge turned on.

So the compressor time set has made a difference.

But as the sensor is hanging in there, a temp difference varies greatly I suppose.

But if the sensor is insulated against the fermenter, may be the temp changes are much more slower (getting past the compressor 10 minute set) and therefore should work more like it should hopefully.

Once I test this I shall report back (gotta find some insulation foam).


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## Mardoo (10/3/14)

If you'd like to test further one thing you could do is to try a basic thermowell, like the one from Beerbelly. You can actually learn a lot from working out how to make your temperature controller sing, so to speak. There are a lot of things about temperature change dynamics of fermentations that we can learn. I'm just starting to work it out. Fascinating.


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## acrow (12/3/14)

ok, got some foam, put probe against fermenter and all taped on. 

Temp result are now consistent 18.0 - 18.5C and STC-1000 working great as it should compared to my temp variations above.

Have looked at the Beerbelly thermowell and seems a handy idea, as I can see using the foam/taping on fermenter will become annoying to me (although easy to do) and it leaving sticky from the tape on the fermenter over time.

One thing with the Therowell it says on the site it is 'welded shut and polished' - this could lead to nasties in the 'welded' end? or is it smoothed off?


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## gsouth82 (12/3/14)

acrow said:


> I can see using the foam/taping on fermenter will become annoying to me (although easy to do) and it leaving sticky from the tape on the fermenter over time.


I use electrical tape. Works a treat and doesn't leave any stickiness behind.
I just tape the sensor to the fermenter then tape a thick sponge over it.


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## acrow (5/4/14)

I have had the STC1000 going for about 3 weeks now but noticed this morning that the temperature showed 17.8C.

I have the following settings (and rechecked them also).

F1 = 18.0C
F2 = 0.5C
F3 = 10 minutes
F4 = 0.0C

With the temp set at 18C but display is showing 17.8C, does it mean the fridge is getting cooler than over the past 3 weeks (it has been working properly since set-up e.g.: hits 18.5C, fridge turns on and cools 18.0C and fridge turns off).

I held probe to increase tempt to 18.5C to test this morning also and ok (fridge turns on and off at 18C). The LED cool light is also lit.

Is there a 'tip' on what I should to stop temp going below 18.0C (doh! and just as I typed this sentence I have remember others saying to use a heat mat/belt or light inside fridge).

What would be best? as it only needs say 0.2C increase (I have a belt but could that be too warm?)

Thanks.


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## Yob (5/4/14)

Your F2 is the overshoot tolerance, I set mine to 0.3, meaning I get a Max of +|- 0.3 of the F1. Before the controller will turn on heat or the fridge


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## mb-squared (5/4/14)

you'll get some thermal "inertia" (for lack of a better term), which will cause you to undershoot. If you are undershooting by .2C, I'd say you're more than fine and not to worry about it. If you see that you're undershooting by more than .5C, and you have your probe positioned properly (i.e. not dangling in air), then you might need to plug in a heat source too. I personally have not found this necessary in my setups (chest freezers).


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## acrow (5/4/14)

ok, no worries fellas - thanks.
I was going to bottle the brew today after 3 weeks of fermenting.
And do another brew today also - so will keep an eye on the temp.


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## gap (5/4/14)

With the setting you have ,F2 = 0.5C , and set point 18 C your fridge will turn off at 17.5C not 18C.
F2 = 0.5C is a + or - factor ie 17.5C and 18.5C


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## acrow (5/4/14)

I see what you are saying, but it turns on at 18.5C to cool back down to 18.0C and turns off.

I have never noticed the temp display showing anything below 18.0C until this morning.


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## Camo6 (5/4/14)

It'll always turn off devices at your set temp ie 18*C. The .5*C is the allowance before it turns on your heating or cooling device. You'll always get some swing either side depending on ambient temps (and other factors) so I wouldn't stress. I unplug my heater pad throughout the warmer months and only need it when it starts getting cold.


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## 431neb (5/4/14)

I have 3 STCs running 24/7 and I have to admit that when I got the first one, I spent 5 minutes looking at all the functions and gave up. To-date I have never done anything to them except set the desired temperature. I laminated the instructions and stuck them to the fridge but they remain unread.

One runs a ghetto "glycol chiller" (read font cooler), one runs a keezer and one runs a fermenting fridge. There's a few spare units now so I'm gonna have to try out some of the recipes in Sous Vide thread and maybe start recirculating my mash . Endless fun.


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