STC 1000

[woodwormm]

I just wanted to break the Electronics, Hardware & Software Section's cherry for STC 1000 threads...

this poor section is going to be like the proverbial sausage down a hall way once all the STC 1000 threads have a go.... :super:

Love the new AHB!

 

[TheCarbinator]

So if I have a problem with my STC 1000, do I post here or do I start a new thread?

 

[woodwormm]

post it here and wait for all the nay-sayers to say "did you search" .... hehe I like the cut of ur jib Carbinator

 

[raven19]

I would anticipate Dane will be *maybe* moving some of the bigger topics (such as STC threads) to these new areas given some time.

 

[TheCarbinator]

All jokes aside, I do have a problem with my new STC 1000 though.

It keeps over cooling and kicks in the heating function (I have a heat pad stuck to the inside of the chesty).

Yes I do have the probe in a two litre bucket of water.

No I haven't searched for another thread due to it not working since the upgrade.

I had it set at 18c with 1 degree tolerance and then I changed the tolerance to 0.3c and it is still doing it.

The compressor delay is set to 10 mins.

I have taped the probe to the side of the fermenter tonight with a piece of insulation over it so I will see how that goes.

My theory is that the freezer is so efficient that the ice on the inside walls continues to cool after the compressor has been switched off.

I am thinking of installing a fan so that the ice will not form so much and the temp will be more even.

Opinions???

 

[woodwormm]

I find chesty's always overshoot worse than fridges so you may be on the money with the ice on the walls... a fan may help the situation. on the upside though your 23L ish fermenter volume is not going to change as much/quickly as your 2L bucket so i dont think your fermenter is fluctuating quite as much as you may be worrying about... how's the beer taste?

 

[stux]

Your chesty is cooling flatout, cooling the cavity and then turning off. But then the fermenter keeps on cooling as the ambient is colder than it. Then it gets too cold and the heater kicks in. But the heater has to warm the chesty before it has an effect, once it warms the cavity it over warms it and then your fermenter needs cooling and the cycle continues

You need to break the cycle, and you can do this by applying direct heat to your fermenter with a heat belt, and then reading the fermenter's actual wort temperature with a thermowell.

Your chesty will probably still overcool, but at least the heater won't have to fight it anymore and you should get into an equilibrium.

 

[verysupple]

Yeah, I agree with Stux. I have my probe actually in my wort but it over shoots on the lower temp. I agree and think it's because the 20 - 25 L of wort takes so much longer to change temp than the air temp inside the fridge (yeah, i use a fridge not freezer). So once the wort is at, say 18C, the air temp is way lower.

Anyhoos, I found that after the vigorous primary, where there is enough heat being produced to keep wort temp within +/- 0.3C, if I raise the temp setting +0.3C it stays about right (i.e. if I want 18C I set it to 18.3C) and the over-shoot on the cool side cancels out.

 

[carniebrew]

I had it set at 18c with 1 degree tolerance and then I changed the tolerance to 0.3c and it is still doing it.

The compressor delay is set to 10 mins.

Shouldn't it be the other way around? IIRC, the tolerance means how far below your set temp it has to drop before it turns the heat on (or vice versa). So if you set your stc to 18, with a 1 degree tolerance, and it gets to 19 degrees, it'll turn your freezer on (after the 10 min delay you've built in). As soon as it hits 18, it turns it off, and won't turn the heat on unless your temp continues to drop and reaches 17. So putting it to a 0.3 degree tolerance will actually turn the heat on when it drops to 17.7....i.e. more often.

I agree with everyone saying your freezer is so cold it's continuing to drop the temp of your wort for a long time after it reaches the desired temp. But maybe you need to increase the tolerance temp to say 2 degrees, and decrease your compressor delay (maybe 2 mins?). The only problem with that is it won't start cooling until your 2 litres of water reaches 2 degrees over your desired temp...but that may not be too bad, given the temp of 2 litres will raise much more quickly than 20 litres + of wort.

It's early and i'm a bit foggy from a head cold but I think that's right?

 

[QldKev]

Shouldn't it be the other way around? IIRC, the tolerance means how far below your set temp it has to drop before it turns the heat on (or vice versa). So if you set your stc to 18, with a 1 degree tolerance, and it gets to 19 degrees, it'll turn your freezer on (after the 10 min delay you've built in). As soon as it hits 18, it turns it off, and won't turn the heat on unless your temp continues to drop and reaches 17. So putting it to a 0.3 degree tolerance will actually turn the heat on when it drops to 17.7....i.e. more often.

I agree with everyone saying your freezer is so cold it's continuing to drop the temp of your wort for a long time after it reaches the desired temp. But maybe you need to increase the tolerance temp to say 2 degrees, and decrease your compressor delay (maybe 2 mins?). The only problem with that is it won't start cooling until your 2 litres of water reaches 2 degrees over your desired temp...but that may not be too bad, given the temp of 2 litres will raise much more quickly than 20 litres + of wort.

It's early and i'm a bit foggy from a head cold but I think that's right?

You don't want to measure the wall of the kegerator, or little bottles of water. As carniebrew mentioned, the temp swing are different from your wort. You want to control the temp of your wort, so measure the temp of your wort. Stick the probe to the side and insulate it. With the bigger thermal mass of the wort you will find all the overshoot and other issue will go away. Set the Hy to a low number, and compressor delay to a couple of minutes.

 

[Spiesy]

get a thermowell and probe, mate - measure what's actually going on within your wort. Cheap as chips on BeerBelly.

 

[Maheel]

get a thermowell and probe, mate - measure what's actually going on within your wort. Cheap as chips on BeerBelly.

plenty throw the stc probe into the fermenter

or you could make a thermo well out of a bit of plastic tube to cover the probe and wire and drop it in.

 

[slash22000]

It keeps over cooling and kicks in the heating function (I have a heat pad stuck to the inside of the chesty).

This happens to me as well with my chest freezer. No matter what I do, freezer will always cool more than I want. Since I can't "fix" it I decided to use some Logic© to work around it.

I figured out that, no matter what, the absolute minimum it would end up cooling is about -0.8ºC from where it started. Doesn't matter what settings I use on the STC-1000 or the freezer itself, absolute minimum it's going to chill is about -0.8ºC.

So what I did was set it to a temperature to take into account the 0.8ºC swing. if I'm making an ale (18ºC ideal fermentation temp) I set the "target temperature" to 18.3ºC and the difference to 0.3ºC with minimum compressor delay. Thus, it turns on the cooling on at 18.6ºC (I figure it's better to be slightly warmer than slightly too cool) and cools it down to 17.8ºC in about 20 seconds flat. Not ideal, but I can live with +/- 0.5ºC from the ideal environment.

If I'm chilling more than a few degrees at a time (e.g. when crash chilling from 18ºC to -1ºC), I make sure to set it maybe 1 or 2 degrees higher than the temperature I want so it doesn't barrel past at 100% compressor and end up at absolute zero or something. Then when it's down to the "almost" perfect temp I'll set it to the temp I want (keeping in mind the 0.8ºC swing again).

No idea if that helps you at all, but hey, that's my story and I'm sticking to it.

 

[TheCarbinator]

Thanks for all your help guys.

I am working on a thermowell for the fermenter (along with the many other things I am working on).

The probe taped to the side of the fermenter will have to do for this brew.

Is a fan in the chesty worthwhile or is it just a waste of time?

 

[jaypes]

Insulate your probe on the side of your fermentor with some foam or the like

 

[TheCarbinator]

Read the 5th post Jaypes.

 

[jaypes]

sorry i cant count, or read posts with more than 4 lines

 

[philmud]

I have a possibly stupid question. I am about to grab an STC-1000 from ebay, and I'm wondering if there's any difference between the units. I notice some are Aussie based, but I assume they are the same unit as the ones from Honkers and China - Some are also branded Elitech and some are generic - any difference? Did anyone find their seller so great they'd recommend or should I just hit "Buy it Now"?

 

[bowhunterslodge]

http://www.ebay.com/itm/All-purpose-Temperature-Controller-STC-1000-Whit-sensor-/320628773067?ssPageName=ADME:L:OC:AU:3160

I ORDERED TWO FROM THIS FELLA A DAY AGO,SEE HOW I GO,SAYS POSTED ALREADY..

 

[philmud]

That's the one I was looking at actually! I think I'll probably just give them a go too