Thanks.. looks like they are good for 10A for sure.
How about the ones that look *exactly* like the ones that came with it, and are sometimes even sold by the same seller? I have seen both the rubberized and stainless ones sold separately.
Additionally, these controllers are knockoffs, and the sensors they use are certainly the most commonly used NTC thermistor spec. The threaded sensors that Emjay linked have been used successfully by more than a few people. Whether it was dumb luck, or, more likely, a result of most manufacturers of -50C to 200C controllers using the exact same spec for thermistors- the *impossible* work, as you characterize it, has been done, and links provided.
I also highly doubt these controllers are 'batch programmed' to particular runs of sensors, and even less likely that the controller itself is tuned for the batches of all of its internal components. The actual tolerances of discrete parts are much closer than spec sheets portray, especially for a part operating within a very small region of the part's range, like the sensor we are dealing with here.
There is no need to make everything seem so difficult.
FWIW, here's a pdf datasheet for the relay.
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.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
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.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.
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.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.....
Fordzilla said: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?
HiI 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.
I think your post about sums it up.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
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.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!
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.Here is the wiring diagram for how I wired it.
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.The unit is unplugged at the moment till I work this out, but I appreciate the caution.
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.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.
I guess I could just leave the fan off entirely as well, Is it really any benefit?
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.So not worth it to run the fan? its a tightly packed kegerator....
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.I used a schematic I pulled off this forum that made sense along with the diagram that came with the unit.
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.Oh, and apart from my fan issue, it worked.
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.I couldnt, despite my searching first, find one that included a fan. If you have those links, please, post them for me.
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.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?
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).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."
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-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.
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? 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.
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