STC 1000 "Ebay" Temperature Controller Build

[troy2000]

I just ordered another STC-1000 from Ebay, for an old fridge I plan to bottle-condition my brews in. I brew in the town where I work, when my time off is too short to make it home. Summer's coming up, and I don't want to run the AC in my motor home 24/7 just to condition my beer... I'm going to stick the fridge outside in the shade, and set it at 70*.

It cost me $19.98 (the controller; the fridge was free), with free expedited shipping. This is the evening of May 4th, and they promise delivery by May 8th. Hard to beat that... could I have maybe shaved another buck or two, had I kept looking and been willing to take a longer delivery time? Maybe. But this is the middle of the desert, and the days are already hitting melt-down temps. I want that fridge up and running as soon as possible, because I have a session beer bottle-conditioning already and a saison ready to bottle.

And by the way: the STC-1000 on my converted mini-fridge fermenter seems to be going south on me. I can still set the temp, but I can't get into the functions that control compressor delay, temperature differential, or calibration. Which is OK so far, because those are all set where I want them anyway. But it makes me wonder if it's on its way to quitting completely....

Does anyone have any idea how long these gadgets typically last?

 

[troy2000]

...And by the way: the STC-1000 on my converted mini-fridge fermenter seems to be going south on me. I can still set the temp, but I can't get into the functions that control compressor delay, temperature differential, or calibration. Which is OK so far, because those are all set where I want them anyway. But it makes me wonder if it's on its way to quitting completely....

Does anyone have any idea how long these gadgets typically last?

Never mind; I just realized what I was doing wrong. I wasn't letting go of the S button before trying to arrow up or down through the four functions.

 

[Reef]

If anyone is looking to pick one up, a seller on Amazon has them for $1.99 right now, shipping is $10, but that still puts them at about $12 a piece. Just ordered 3 for myself http://www.amazon.com/gp/product/B008KVCPH2/?tag=skimlinks_replacement-20

 

[day_trippr]

"100% positive over the past 12 months. (4 total ratings)"

Impressive seller cred...

Cheers!

 

[mgr_stl]

Quick electrical question that will show my lack of knowledge regarding anything electricity-related...

I dissected some old computer power cords to get the wires for my stc 1000 setup. Are all wires the same on the inside or are certain colors different? For example, is the grounding wire different or can any wires be used for any part of the wiring process?

 

[ReddHead]

[quote mgr_stl;6148]Quick electrical question that will show my lack of knowledge regarding anything electricity-related...

I dissected some old computer power cords to get the wires for my stc 1000 setup. Are all wires the same on the inside or are certain colors different? For example, is the grounding wire different or can any wires be used for any part of the wiring process?[/quote]

They will all be the same gauge and number of strands but for the sake of consistency green should be ground, white neutral and black hot.

 

[mgr_stl]

Awesome, thanks! In the video I watched, a guy also had red wires. Are those typically used for a specific purpose?

 

[Matterpro]

+1 for what ReddHead said.

Color is there for convenience so that you remember what is hot, neutral and ground. Organization is key, since mixing those can do bad things. Red is just a color. The US uses the standard of white/green/black, but they don't have special properties.

There's a whole rainbow of wiring colors outside of the standard white/black/green (used for power), and they can represent whatever the wire tech wanted (just pull out the radio deck in your car sometime and look at the mess of wires).

Wire gauge is the real difference inside. Inside all wires (for this purpose) are either stranded or solid wire, of different sizes... the smaller the gauge, the larger the wire thickness and likewise the larger amount of amps that wire can handle. Most uses of for this controller require 12 gauge 15amp rated wire.

If you used old computer POWER cables you're golden. Those are spec'd for 15 amps, and color coded to help you keep things organized!

If you're not 100% confident in your wiring, call an electrician. They're cheaper than hospitals or burning your house down.

 

[mgr_stl]

Is there a way to tell the gauge/amp rating of a wire by looking at its cross-section? From what I can estimate, I'd say they're are about 20 copper wires inside each colored wire bundle (if that makes any sense). Also, on the original computer cord it says SVT 3-18. Not sure if that means anything. Thanks.

 

[orangehero]

It's 3 wires, 18 gauge. The diameter (cross section) is the gauge.

 

[JuanMoore]

It's 3 wires, 18 gauge.

This. Which IMO is a bit too small for wiring up an stc-1000.

 

[mgr_stl]

So would you recommend a typical reasonably heavy duty orange power cord instead?

 

[Matterpro]

To run power through it to a fridge/freezer you should really have 12 gauge wire. Frys, home depot, lowes carries them in spools. But I usually buy 12-3 (12gauge-3wire) romex in the 25' coil at home depot for just under $30 and it lasts me several projects. And if you need to run a new outlet or lightswitch in your house, hey, you have it on hand!

That orange power chord might work for you though, if it's big enough. Check the ends and see if it says that it's 15 or 20 amp rated.

 

[mgr_stl]

Ok, you guys talked me into delaying my wiring so I can be sure everything will be safe. Now I just need to find the best deal on wires. My initial searches have found lots of bulk sales, but nothing in the range I'm thinking of (ten feet). Can you buy wires by the foot at home depot/lowes/menards?

 

[jbaysurfer]

To run power through it to a fridge/freezer you should really have 12 gauge wire. Frys, home depot, lowes carries them in spools. But I usually buy 12-3 (12gauge-3wire) romex in the 25' coil at home depot for just under $30 and it lasts me several projects. And if you need to run a new outlet or lightswitch in your house, hey, you have it on hand!

That orange power chord might work for you though, if it's big enough. Check the ends and see if it says that it's 15 or 20 amp rated.

I'm no electrician, but I have done a fair amount of wiring....all my fridge cords are 14Gauge I think?

 

[raouliii]

....... But I usually buy 12-3 (12gauge-3wire) romex.....

Romex should not be used for power cords. It's not rated or designed for that application. In addition, the stc1000 terminals can't create the required torque for good, solid core wire, connections. Stranded wires should be used.

 

[LLBrewer]

I haven't read through this entire thread but it seems to me that the stc-1000 plus a couple of 20A solid state relays, a low voltage DC power supply, box, and an outlet and you would have a pretty beefy temp control system for under $50. Oh I would get a short extension cord to handle the wiring from the wall to the outlet box.

 

[mgr_stl]

So I finished up my stc 1000 setup today and the whole process was more challenging than this electrical newbie expected. The main sources of my frustration stemmed from difficulty cutting the enclosure and using 12 gauge solid wiring (am now thinking I should've gone stranded). It is not enjoyable trying to maneuver this wire...so rigid! Plus, trying to use one of those plastic connectors to connect four twelve gauge solid wires is no fun. Wires kept on popping out at various points in the process. Perhaps I needed XXL plastic twisty connectors. I'm just hoping everything stays together. I've got it hung on the wall, so I'm feeling better since I shouldn't have to move it again in the foreseeable future. Probably would have been better off buying a more user ready setup, but I certainly have learned a lot the last couple days.

 

[alien]

Right now the STC-1000 on Amazon is $16.25 in my area - the lowest ever price, as far as I know, and eligible for free shipping.

 

[tCad]

Ordered one this weekend plus all parts. Sometime this week will be putting it all together.

While I wait I want to design the enclosure. Anyone have the mounting dimensions for it, as well as for a duplex plug ( the mounting hole on the one I ordered is a single rectangle, not two individual round outlets)

I'm planning on using a laser cutter and some acrylic to make a nice box. Similar to this, though maybe in black.
http://7hillsmake.files.wordpress.com/2012/03/box.jpg

 

[Smellyglove]

http://www.tradeger.co.za/pdf/stc1000_operating_manual.pdf

Remember to look at "mounting size".

 

[mgr_stl]

When you guys cold crash using your stc 1000, how do you go about it? I dry hopped Monday evening, and am trying to figure out how long it will take for the beer to cool.

How many days into the dry hop do you usually crank down the temp? What temp do you set it at?

 

[raouliii]

I do it in 2C/3F degree steps, twice a day, to get down to crash temperature of about 3degC/38degF. It takes about 5 days for ales.

There is a blurb in Chris White's book, YEAST, that mentions that crashing too quickly can promote the release of certain undesirable compounds from the yeast.

 

[mgr_stl]

Good info, thanks. So how many days after dry hopping do you start your cool down process?

 

[Puddlethumper]

To run power through it to a fridge/freezer you should really have 12 gauge wire. Frys, home depot, lowes carries them in spools. But I usually buy 12-3 (12gauge-3wire) romex in the 25' coil at home depot for just under $30 and it lasts me several projects. And if you need to run a new outlet or lightswitch in your house, hey, you have it on hand!

That orange power chord might work for you though, if it's big enough. Check the ends and see if it says that it's 15 or 20 amp rated.

Gotta jump in here and disagree. There has been some pretty crappy advice given in this thread and the above is a great example of a "little knowledge is a dangerous thing".

Just for the record, 14 ga. stranded copper wire is perfectly suitable for use with these units. 14 ga. is rated at 15 amps. 12 ga. is rated at 20 amps. Unless you are running 50'+ leads a 14 ga. stranded wire lead will work just fine. (You might look at the cord coming from your freezer -- it is 14 ga.)

And +1 to the earlier post that suggested use of stranded wire only. Do not use Romex or other solid core wire (as in house wiring) for this project. It is best to cut and strip the ends. Heat them with a soldering iron and "tin" the leads with rosin core solder before inserting them into the STC-1000 unit's connectors. This step will create an excellent, professional quality connection that will not overheat or work loose. If you don't own a soldering iron and aren't familiar with the technique of "tinning" the leads you may be able to make it work, but probably shouldn't be attempting this project. As stated earlier, an electrician may be expensive, but he/she will always be cheaper than a house fire or a trip to the hospital.

Just a couple cents' worth from an old-school communications tech.

Cheers!

 

[sdgenxr]

And +1 to the earlier post that suggested use of stranded wire only. Do not use Romex or other solid core wire (as in house wiring) for this project.

I couldn't agree more. Do not use solid wire when connecting your temperature controller. The connectors cannot adequately clamp down on solid wire and you run the risk of the wire pulling out or much worse.

 

[TastyAdventure]

Is there a way to connect the STC directly to my fridge without using outlets?

 

[raouliii]

Is there a way to connect the STC directly to my fridge without using outlets?

Yes. A schematic or VERY clear photos of the existing wiring is necessary.

 

[Matterpro]

+1 to what raouliii said. Every fridge thermostat is wired differently, so toss up some pics.

I have these units rewired as the "new" thermostats in both my fermentation fridge and keezer setup. So the power always stays on, and this thing only fires on the compressor as needed, exactly how the original thermostat did. And the fridge/freezer still uses it's original cord right into the wall.

Basically you need to locate the original thermostat in the fridge, usually attached to a dial that you can adjust for temp control inside the fridge. Behind the fascia that covers that dial you'll find a set of components. And make sure you're doing this with the fridge UNPLUGGED! Sometimes the thermostat is the same component as the dial, sometimes it's connected but separate. Youtube "replacing a fridge thermostat" for reference. Because that's basically what you're doing.

All of the power, ground and neutral wires needed to power the STC and to control the compressor should be at or near the thermostat. Again, should be. All fridges are different.

 

[TastyAdventure]

Thanks guys. Here's a pic of my fridge schematic. Sorry, that's a stain near the middle...