Stc-1000 wiring

Thanks.. looks like they are good for 10A for sure.

 

How long do you expect the compressor to go on for??? Cooling to 60F in most climates, I would think several minutes at a time. I think there is usually a big surge at start-up of the compressor, then when it's running it's only pulling a few hundred watts for your modern freezer.

 

Hi

Oddly enough, I've actually been in the sort of places that "knock off" this sort of stuff. The way they do it is pretty simple. They all get a specific batch of parts from a single source. Each of them build up the parts and sell them. That way they don't have to worry about complicated things like getting the right this or that. It also lets them buy thermistors in large enough batches to get them made right.

Bob

 

Anyone know if the STC-1000 will push enough amps to start up a Holiday 7cu chest freezer set up in my garage?

Here are some specs from the back of the freezer:
Voltage: 115v~60Hz
Amps:1.70A
Startup Amps: 12A

 

It should have no issues with that load. The running load is minimal and even the starting load is below the relay rating. I'm using it on a GE 7 cu ft chest freezer I am guessing has similar specs and it is working fine.

 

About what I figured. The relay spec looks like it is 277VAC and 15A. The different ratings printed on the relay itself are just test certifications for common load limits for US and EU certs. The max power rating seems like it is just the max power for its 277VAC test cert. From what I remember, V is mostly limited by contact arcing issues, and A is mostly limited by contact fusing issues.

Looking at the cycles/ops data shows the effects of working at the upper current limit. It decreases the life by 1/2 going from 7 to 10A (100k vs 50k). Going to 15A would be much less life, since the cycles vs. amps plot isn't likely to be a straight line. Depending on your usage, a 15A load may or may not be an issue. A guess for the typical ops for a keezer is ~10k/yr, but they are only ~5A.

 

I think you are giving them too much credit, and complicating things again. I doubt anyone goes to the trouble of verifying the (out of) tolerance for each batch of discrete components, and then adjusts things to create a matched component set. I think a more plausible scenario is they build up the controller from whatever batches of parts they have; calibrate the meter to a known resistance; then toss in one of sensors from whatever batch.

Thermistors of all specs are commonly available enough that they don't need to 'get them made right', they just need to decide how much accuracy they want to pay for. The price difference can't be much either, since even stateside high quality ones can be had for $0.10 in bulk.

These controllers are not lab test gear that have to read a host of sensors and a wide range of temps. They can be optimized to be forgiving for the limited usage range. As Emjay's results show, any replacement sensor of the same spec will work for the range of temps of the controller. He didn't even need to use the calibration setting, but it is there if needed. Probably a case of "that may work in real life, but it will never work in theory".

I think a big reason they chose thermistors is because of the relatively flat response curve that can be created for the typical temp range. That, and cost. Thermistors are arguably the best sensor choice for this range of temps- less calibration, less required meter sensitivity, easy to linearize, ease of manufacture, ... the list goes on.

 

Additionally, the peak in-rush/startup current probably occurs for a short enough time, long enough after the relay closes, and isn't a factor for relay opening, so that it isn't even relevant to the relay function or life expectancy. The startup current is more for circuit breaker limits.

 

I put together and tested my temp controller tonight, using Revvy's diagram from the first page of this thread. Thanks Revvy! It works wonderfully.

Funny story, I used Home Depot's in-store pickup on their web site to try and save some time. It took 20 minutes for the 3 employees to figure out how to ring out my order. Also, the extension cord they picked was not the one I had ordered. Easy enough, I just swapped it for the right one in store. Tonight, after I wired everything up, I realize one of my outlets is BROWN, not BLACK. Ugh! I don't feel like tearing this thing apart, so it's going to stay as my reminder never to use Home Depot in-store pickup again!

 

I'll offer up a comment on your build. The wide slot of the receptacles is defined by code as neutral. Correct me if wrong, but it appears you have hot connected to that side of your receptacles. Any single pole switches internal to appliances connected to the receptacles will be switching neutral instead of hot. While this configuration will work, it is not the best situation and can be unsafe depending on the design of the appliances.

 

If you are unsure or if you are cautious, this.

 

This is a great tool. They cost like 3 dollars and you are bound to find some improperly wired outlets around the house.

 

I did not know there was a right way or wrong way to wire up an outlet. I will tear it apart and check it out. Thanks for keeping an eye out!

What is the name of that tool?

 

Home circuit tester? Head over to Lowes or Home Depot and go to the electrical tools aisle. You should be able to find it. It comes in 2 flavors. For a few bucks more you can get one with a button to test GFCI sockets.

 

"Outlet tester" should find it.

 

Hi

I realize that for some reason you have a need to attack any post I make anywhere on the Forum, no matter what the topic. Why - who knows.

I've bought millions of thermistors and used them in temperature control applications. They do indeed vary far more than you believe. An RTD or a Thermocouple depends on basic physics to do what it does. A thermistor is a mix of a number of compounds, each of which impacts the temperature characteristics. There is no practical way to make them "same every time". Instead what happens is a selection process. Some get sorted into bin #1, some into bin #2 and so on until many dozens / hundreds of bins are considered. If you do it right, what you get is the contents of a specific bin. You do your numbers to make that bin work.

I realize you don't like that idea, but it's the compromise you accept with a thermistor based device.

Bob

 

Got mine at Harbor Fright ( ). Works fine. Dirt cheap.

 

I think your post about sums it up.
Your advice only seems to vary between explaining how impossibly complicated a task is that only someone with your talents could possibly do it successfully, or completely incorrect advice.

If you recall, it isn't only me who corrects your posts.

Even RTDs and thermocouples cannot be made 'the same every time' and have to be binned and calibrated, so I am not sure what your point is. Thermistors are available with various curves and tolerances. They are commonly linearized- either in software, or with a simple circuit and a few discrete components.

The way you make it sound, you shouldn't even bother looking for a 10k Ohm resistor because, in case you didn't know, the basic physics involved make it virtually impossible to accurately build even one, much less 2 that are within 5k of each other.

I realize you don't like the idea that things are this simple, but ceramic bead thermistors are very precise, accurate, and even preferred in these temp ranges.

Again, this sums up your posts in this thread: "it may work in practice, but it will never work in theory".

 

Hi all,
I was hoping you could help me with wiring a fan into this setup. I have a 110 fan that I wired in with one black lead from the main power cord, and the other side came off of the same wire that goes from terminal 8 to the outlet. When I plugged it in, all the main functions work fine, but the fan comes on when the compressor switches off. even if I turn the unit off at the power switch, the fan runs. I guess that is fine, but I'd kinda rather the fan run while the unit is cooling and already noisy. Im assuming its a simple wire switch, I just dont know which one.

Thanks!

 

Can you post your wiring diagram yousudsymf?

 

It would be wise to unplug the whole thing until you figure out what is going on. Something is wired wrong, and it could be serious.

I would suggest rethinking your fan approach. For most applications, having the fan run only when the compressor is running provides almost no benefit. Running a small fan continuously is a much better solution. A small computer case fan (12V) powered by a cell phone charger (5-12V) is the most common method.

RE:wiring issue- You haven't provided enough information to know for certain, but the most likely scenario is that you are cooking your compressor motor by completing the fan circuit through it.

 

The unit is unplugged at the moment till I work this out, but I appreciate the caution. If its better to leave it always on, I guess I could wire it as an always on outlet then? Id rather not have to wire up a whole nother outlet and then plug a cell charger/fan combo into it, and I already have the 110 fan.

Here is the wiring diagram for how I wired it.

http://www.homebrewtalk.com/attachment.php?attachmentid=77201&stc=1&d=1348674672

I guess I could just leave the fan off entirely as well, Is it really any benefit?

Thanks for the help!

 

Usually the fan is of benefit in a chest freezer. Ok I see the problem, your fan is wired incorrectly. The black wire shown on your fan actually needs to connect to the red wire that goes to pin 2 (neutral). What's happening is the fan is drawing current through whatever is plugged into the cooling outlet when the cooling contact is open. (If the fan has a black wire and a white wire, the black wire should actually go to the wire coming out of pin 8, and the white wire should go to the wire connected to pin 2.)

 

ok, that makes sense. I figured it might just be a switched wire, just wasnt sure which one to switch. No color coding on the fan wires btw. Thanks! So not worth it to run the fan? its a tightly packed kegerator....

 

Sounds good! It sounds like many people are saying the fan does help but usually a small computer fan is used and it is let run all the time, rather than switching it on just when in cool.

 

If you don't understand electricity, use an approved schematic that does what you want. There are several schematics that do exactly what you are wanting, along with many posts questioning why they don't run the fan full time. There are schematics for that as well.

DIY doesn't mean you have to do everything yourself. It isn't like you built the fan, outlet, controller, etc.

You are running an amount of current (as a guess, ~double the fan's current, at ~half the wall voltage), through your compressor. Most likely it is too little current and voltage to turn the compressor motor, so it is just heating it up.

I have an old garden hose sprayer that I could have used to serve beer with, but it didn't prevent me from buying a SS faucet. A computer case fan can be had for the price of a plastic picnic/cobra faucet, or less (free) if you have an old computer sitting around. If you don't have an old cell phone charger in a drawer somewhere, DIY may not be your bag. Hording kind of comes with the territory, otherwise it is usually cheaper to buy prebuilt.

Whatever the wattage is of the 110V fan you are using will go directly into your kegerator as heat. As an example, if the fan is 40W, you will approximately double the run time of a typical kegerator, plus paying to run the fan as well. So, the actual kegerator electricity usage will be tripled compared to no fan. A typical computer fan is 3W at 12V, and ~half that using a 5V cell phone charger to power it.

The outlet for the fan doesn't have to be part of the controller box. You can plug the cell phone charger directly into a wall outlet, although I don't understand why you feel wiring up a $0.79 outlet into your controller box is such a chore.

Fans are very helpful for virtually all places where post boil beer resides. Depending on what type of kegerator you have, there are different places where the fan works best.

 

All quotes CWI

"If you don't understand electricity, use an approved schematic that does what you want. There are several schematics that do exactly what you are wanting, along with many posts questioning why they don't run the fan full time. There are schematics for that as well."

I used a schematic I pulled off this forum that made sense along with the diagram that came with the unit. Oh, and apart from my fan issue, it worked. I couldnt, despite my searching first, find one that included a fan. If you have those links, please, post them for me.



"DIY doesn't mean you have to do everything yourself. It isn't like you built the fan, outlet, controller, etc."

I'm not even sure why you included this. It's totally irrelevant.



"I have an old garden hose sprayer that I could have used to serve beer with, but it didn't prevent me from buying a SS faucet. A computer case fan can be had for the price of a plastic picnic/cobra faucet, or less (free) if you have an old computer sitting around. If you don't have an old cell phone charger in a drawer somewhere, DIY may not be your bag. Hording kind of comes with the territory, otherwise it is usually cheaper to buy prebuilt."

Perhaps you misunderstood. I wired in a 110 computer fan to the circuit. One similar to those found in computer cases. Did you think I stuck a box fan in a 4 c.f. kegerator? I in fact do have an old computer fan and cell charger sitting around, Its what I made my stir plate out of. Myself...


" although I don't understand why you feel wiring up a $0.79 outlet into your controller box is such a chore."

A chore, not really. But I'd still rather not if I didnt have to. Plus I'm using a rather small project box and there isnt room for a second outlet. And where did price come in as an issue?!



"Fans are very helpful for virtually all places where post boil beer resides. Depending on what type of kegerator you have, there are different places where the fan works best."

Perhaps the best attempt at being helpful and useful you've managed yet. It's your standard mini fridge modified to fit two 5 gal cornies with a tower in the top. co2 tank external. Oh yeah, I did all that myself too.... So where is the best place for the fan in this setup?

Don't be such a condescending prick CWI. Just because I dont know everything doesn't mean I don't know anything. Look how simple the answer was from Porcupine 73 and how nicely he delivered it. Whereas you, didn't really help, just spouted off and made assumptions.

 

One nice feature might be able to be able to switch the fan off manually though. Some people I've seen say that if they open their kegerator with the fan on then it blows all the cool air out quickly. But that might be more for chest freezer operations than uprights. Your box fan idea makes me think of trimming down the blades on an old ceiling fan to mount under the lid.

 

If you got that as a verified schematic off the forum, you obviously copied/redrew it incorrectly. Anyone with basic electrical knowledge would have immediately seen it was incorrect, and told the person who posted it to take it off.

Really? You were completing the fan circuit through the compressor. If you had left it plugged in as-built, it could have fried your compressor (and fan), and in a worst case scenario caught it on fire.

So, the schematic you pulled off the forum was just used as a basis for you to add your own fan circuit too? That explains your posted schematic (which should be replaced or pulled off immediately, lest someone gets a hold of it). Had you asked for a link to a schematic prior to deciding to play engineer yourself, or at least posted your homebrewed schematic for vetting prior to actually using it, that would have been a much better approach.

Well, considering I mentioned using a computer fan, and only got the response that "I already have a 110V fan", coupled with your demonstrated wiring aptitude, and that there was never any mention of the size/type of your appliance; I had a pretty funny picture of your setup in my head, and went with that.

I can provide links to several people with various household fans, up to dual 12" diameter ones, inside their kegerators.

Again, the only information you provided was that you would 'rather not' wire up a "whole nother" outlet if possible, and already bitched about not wanting to buy a $2 case fan because you already had a 110V one (with no size/type communicated yet).

Had you given sufficient information, I still would have recommended using a 12V fan just for safety reasons- no live 110V wires inside the chamber to possibly kill you. You don't even need to put an outlet on the controller box, just plugging it in the wall will work, provided your house wasn't a DIY project, too.

If I thought you understood how to communicate the minimum details needed to provide any advice, much less take heed of any that I take the time to provide, I might have been inclined. Just take a look at the fan discourse-

Me: Use an always on 12V case fan and cell phone charger.
You: But I already have a 110V fan (no type).
Me: Computer fans are cheap, even free.
You: I don't want to bother with a 'whole nother' outlet. (no reason given)
Me: running the fan all the time provides the most benefits
You: I could just leave the fan off. Is there any benefit?
Porc:A fan is of benefit in a chest freezers.
You: So, it's not worth it to run a fan in a kegerator? (No description/type)

I didn't even include your first post which essentially amounted to "I have some black wires, and I wired some of them together, and now it no work. Oh, and, it makes some noise that I no like."

Porc was essentially repeating what I posted in my initial and subsequent posts. Had you asked the same question 3 more times now that he answered your question twice (at least), even he might have gotten a bit frustrated.

I provided the most crucial advice, which was to unplug the device as soon as possible. The only assumption I got wrong was the size of your fan. My initial diagnosis was correct even though it was based off assumptions from the limited information you (continually) provided. I only got short after it became apparent you don't read thoroughly, don't provide enough information, assume others should intuit your situation, and don't heed advice well.

The information you are now seeking really isn't related to this thread. Try looking for threads about fans.

 

Yup, you're a prick.

 

Here is another DIY success story brought to you by yousudsymf:

http://www.homebrewtalk.com/f35/oster-5-0-side-holes-careful-325759/#post4050362

At least you are consistent- act first, ask questions later.

 

Hey, cwi, we understand you are a dick. Go be a dick somewhere else.

 

Thanks to everyone who contributed photos, diagrams and details to this thread. I finished my temperature controller box last night and I now have my first keg carbing in my keezer. Next project: make my first lager.

 

A couple pics of my STC-1000 build. So many great ideas on this site! I know I have seen neater wiring but mine works.

 

Just wondering if it is necessary to use such expensive outlets vs cheaper ones that have similar shape. For example I see a bunch of people using http://www.homedepot.com/buy/levito...utlet---white-r62-16252-0ws.html#.UPYJuaHjl4U so would this be acceptable instead http://www.homedepot.com/h_d1/N-5yc...oreId=10051&superSkuId=202887008#.UPYLEqHjl4U ? Thanks in advance for any advice you all may have.

 

I hardwired mine right into the freezer. I think that it's cleaner and more convenient.

 

Definitely went with the cheaper outlets to save about $10 a controller, especially when you buy the 10 pack. Needed 2 and a friend wanted one so much more cost effective. Thanks for the awesome wiring diagrams, super easy to follow and completed two boxes in less than 2 hours.

 

So....I wired up one of these today, and the heating side works as expected, but I get no power for cooling. I have checked and re-checked the wiring for that path, even going so far as to completely rewire the entire path from the incoming power cord all the way through the controller and to that outlet, but still it doesn't work. My wife has moved my outlet tester and multimeter somewhere I can't find it and she's out shopping. Otherwise, I'd be able to tell you more details about where power is getting. However, the wiring on these things is pretty straightforward so I have to think that at least there is power getting to the "cooling" relay.

When the heating side turns on, there is an audible click from the relay, but I don't really get the same click for cooling, leading me to believe perhaps I have a faulty relay in my controller. Anyone else run into issues like this?

 

Are you waiting for the compressor delay? Is the cooling light flashing? In case you didn't know, the cooling side has a compressor delay feature, which prevents the relay from switching if it's been on recently. This is to protect the compressor from short cycling. It activates when the unit is first plugged in also.

Edit: If the cooling light is blinking, it means that it's in compressor delay status. The factory setting for the compressor delay is 3 min IIRC, but you can change it under menu item F3. I suggest maxing it out at 10 min.

 

Ah, I didn't know that. How long is the delay?