My semi walkin 5000 btu fermentation chamber

[boredstate]

true. I think that's most likely what I'll do in the short term. thanks for all the help!

one quick question though, where should the ground go for the plug wired into the STC power if I'm ditching the outlet?

sorry. I'm dumb with electrical work and honestly probably shouldn't be attempting this myself. but hey, what's the worst that can happen, right?

 

[n240sxguy]

one quick question though, where should the ground go for the plug wired into the STC power if I'm ditching the outlet?

sorry. I'm dumb with electrical work and honestly probably shouldn't be attempting this myself. but hey, what's the worst that can happen, right?

Tie all of your grounds together, somehow. Which plug are you talking about by the way? I was talking about running a single wire from the compressor to the STC. That would eliminate a plug altogether.

Worst thing? Well, you could trip a GFCI, trip a breaker, burn up your A/C, burn down your house, or electrocute yourself. Other than that its harmless.

 

[n240sxguy]

I talked to an engineer at work today, and he's gonna let me borrow a thermal camera next week to see if I have any leaks on my fermentation chamber. Schweeeeeet!!!!!

 

[boredstate]

Which plug are you talking about by the way? I was talking about running a single wire from the compressor to the STC. That would eliminate a plug altogether.

i was talking about the male plug wired to the STC that would plug into the ranco..

so if i'd wire it direct to the compressor, how exactly should i wire the STC? would you pull the hot lead from the A/C power to wire into terminal 1 & 7 with one lead from 8 going to the compressor, and that would be the only 3 wires connected to the STC?

feeling dumb. sorry!

 

[n240sxguy]

i was talking about the male plug wired to the STC that would plug into the ranco..

so if i'd wire it direct to the compressor, how exactly should i wire the STC? would you pull the hot lead from the A/C power to wire into terminal 1 & 7 with one lead from 8 going to the compressor, and that would be the only 3 wires connected to the STC?

feeling dumb. sorry!

Ah. The plug from the STC to the ranco was fine. No problems there.

1&2 still have to have a hot and neutral to operate it. Take your hot from the ranco to 7 like you have in the diagram, but instead of having an outlet, just run the hot from the compressor to 8. The neutral and ground are already taken care of since the main A/C cord is plugged into the ranco. You'll have 4 wires plus the sensor.

I kinda see where you're coming from with this idea now. As long as the main temp controller wants it colder, the fan runs. Makes sense.

You are running into the same mental block I've had to cross before. If you aren't providing hot, neutral, and ground at the same spot, you don't think it can work. You have to baby step your way through it, even as you are wiring it, to force your mind to accept the logic that the hot, neutral, and ground can all come in at separate points. I had some baby stepping on this project too. You'll get through it. Triple check everything before you ever plug it in though!

 

[n240sxguy]

I was thinking about this a little more. I'm not sure how good it will be on the STC to be power cycled dozens of times per day. You could sell the ranco, buy another STC, and still have some money left over. Then all this wiring around the ranco stuff would be history. All this came about because I was thinking of how to switch my fan over to the different ways other people are doing it. i.e. always on, on with cooling like yours, or timed after compressor shutdown like mine. I just thought of another one. I could combine my way and your way. It would run as long as the controller was calling for cooling plus a set time after that. I may end up doing that one. Though, it kinda does that now anyway. It runs, eventually freezes, thaws for 6 min, and starts back up. The fan timer is set to 8 min, so it never gets the chance to cycle off til it reaches temp. Anyway. I vote sell ranco. Or wire everything off one junction box so you can power both controllers at the same time.

 

[boredstate]

ok. so the plug's hot & neutral in 1 & 2. plug's hot in 7, compressor's hot in 8... plus sensor wires. ground from plug going nowhere. this is making sense now and is what you were trying to get across initially. got it. finally. ha!

i guess as long as the stc resets back to the original cool set point & delay time after losing power, it wouldn't be a big deal since the box fans are keeping the air moving anyways and the air temp isn't super cold. it's not like i'm not trying to get down in the 30's or anything. just trying to keep the ambient temp as close to 50 as possible...

 

[boredstate]

hmm. i posted the above before seeing you last post.. i can use the ranco somewhere else in my setup, like controlling my spare fridge or mash temp even.. another stc is $18, not too hard to swing. i ferment in conicals and also in sankes. sankes fit in the fridge, conicals do not, hence the spare bathroom as my ferm chamber and additional means necessary to control their temps.

i was trying to find a way that the stc would be always on and kick the compressor on & off as needed with the ranco controlling the a/c power.. problem i was seeing is that at times when the ranco killed the a/c unit, the stc could still be trying to kick the compressor on. that's what lead me to come up with that last diagram where the ranco controlled both the stc and a/c power.

so ideally i think, at least in my situation, i need 2 controllers that are always on with the a/c main power always on so the fan runs constantly. the only thing really being cut on & off is the compressor. the a/c thermostat would be bypassed, and a 1st controller reads actual ferment temp and kicks the compressor on & off as needed. a 2nd controller reads a/c coil temp and kills the compressor as it reaches freezing, regardless of what the 1st controller wants, but waits at least 3 minutes until it kicks it back on if the 1st controller is still calling for it, all the while the a/c fan is still running moving air across the coils defrosting in the most efficient way possible.. my brain is taking its sweet ass time trying to figure that solution out (besides the obvious $299 drop on a coolbot), and the last diagram i posted was the closest i could manage to get thus far.

 

[n240sxguy]

You're on the right track. As far as the STC trying to turn the compressor on when the ranco has it off, that's exactly what it will do. That's no problem. The second controller is just a permissive start. It doesn't matter if its contacts stay closed because there's no power there til the first controller sends it to it.

 

[boredstate]

So after all this, I go to my brew buddy's house to watch the LSU game and hands me this:

 

[n240sxguy]

Well then.

 

[fermentednonsense]

Nice!

 

[n240sxguy]

As soon as my centennial blonde-ish slows down fermentation I'm gonna give the cold crash another shot. I'm gonna hopefully check the chamber with the thermal imaging camera tomorrow to see if/where I have any leaks. I'll see how low it will go.

 

[n240sxguy]

I did find two places with the thermal camera that need a little more insulation around the door. I lowered the temp from 62 to 35 last night two see what it would do. It went from 62 to 51 in about 2.5 hours. This morning, 7-8 hours later, it had only dropped to 47. I'll see what it's at when I get home, which will be 12 hours since the last reading.

 

[n240sxguy]

When I got home it was down to 45. Soon thereafter it got to 44, and is sitting right there with the A/C running every second that the controller will let it. The fan is on a 10 minute timer, and it never has a chance to shut off.

 

[n240sxguy]

So, 16 hours later, it has dropped a whopping 1 degree. It is down to 43, and apparently that's where it's gonna stay. Next step is install some computer fans. I bought four 120mm fans on newegg for $12.99.

 

[n240sxguy]

12 hours later and it is bouncing between 43 and 44. I taped over the hole I drilled in the bottom to drain to see if the water slinger will help it get any colder.

 

[pickles]

Did you end up getting it any cooler?

 

[n240sxguy]

Not a damn bit! 44 is as low as it would go. I'm gonna put a few computer fans in there and give it another shot soon.

 

[pickles]

I've got a similar build going as we speak. Do you think it's necessary to have the delay relay keep the fan going for a bit or not?

 

[n240sxguy]

Probably not. Either leave it running all the time, or use computer fans.

 

[n240sxguy]

Update:
I had a little mold grow in my chamber because I cooled it down, and let it come back up too quickly. Also, as the weather has cooled off, the A/C compressor would turn off leaving just the fan running. The fan would actually heat the inside of the chamber up to the high 70's. Yesterday I pulled the A/C out and bypassed the factory temperature switch so it will run when the controller tells it to without interference from the factory switch. I have to clean the mold out, and get the insulation I removed put back in. On my next batch I'm gonna either run the A/C fan 24/7, or finally get a power supply for the computer fans I bought. I also learned not to increase the temperature too fast. That's where my condensation came from. It basically sat there for a day and a half or more just sweating. Having a fan running that whole time may have minimized it. Either way, I'm not gonna raise the temp more than a couple degrees a day from now on. That way the A/C will have a chance to kick on and remove the moisture.

 

[bleme]

If you cover the insulation with something non-porous, like FRP, it would help with mold. Even contact paper would do in a pinch.

 

[n240sxguy]

The mold was only on the shelf, not the insulation. I need to cover that shelf with something or paint it like someone recommended before.

 

[bleme]

I covered my shelf with contact paper.
So far, so good.

 

[n240sxguy]

Like the stuff you put on cabinet shelves?

 

[bleme]

Yup. Covered both sides and wrapped around the edges. Lots of overlap because the stuff sticks to itself better than anything else.

 

[n240sxguy]

Ok. Cool