Another Fermentation Chiller Wiring Questions Thread...

I'm in the process of building a mother of fermentation chiller, but have little experience as an electrition.

I looking at getting a 12VDC fan and the RiteTemp 8099 thermostat. Now as far as a wall wort, I'm going to need a 12VDC, correct?

The thing I'm having trouble with is understanding if these will be compatable. It is my understanding that all you are doing with the thermostat is creating a relay for the ground wire of the fan. When the temp rises above its set point, the stat connects the relay points and the circuit is complete, thus allowing the fan to run. Correct me if I'm wrong.

The thermostat runs on two AA batteries at 24VAC. I know that this does not supply power to the fan at all, but wouldn't the ENTIRE circuit need to be DC for it to be complete?

Will these components work together at all?

My other idea was that I have a very small fan that plugs into the wall that I could hook up to a fan switch, set on low, and have continuous circulation of air, and adjust the ice quantity to keep the temp at a certain level.

What do you think? I need to hear from someone that has actually done this or knows more about electric troubleshooting.

Thanks!

 

Yes, you need a 12vdc wallwort.

The relay works pretty much how you said, except the relay contact will make and break the hot side (+) of the circuit, not the ground.

The thermostat runs on 24vac, the batteries are there so if you lose power you wont lose your settings.

As far as one being 24Vac and the other being 12Vdc, not a problem. Relays isolate voltages, so you can have it controled by one voltage (in this case 24vac) and have the contact make and break an completely different voltage (in this case the 12vdc).

hope this helps.

 

Um...what? That makes no sense.

 

^ Great input, but I cleared that up for him already. Thanks!

 

THANK YOU!

Now for another question. Since I already have a small fan, 120VAC/12W, and spliced the thermostat onto the ground wire, would this work effectively too? Basically it is a 4" fan that plugs into a normal outlet. I thought that since I already had this fan I might be able to use it. What do you think?>

Thank you (x10) again for your help!

 

You're welcome, glad I can help.


The relays on a thermostat are designed to control a circuit board and other low voltage, low power relays, contactors, etc. I'm almost positive they can't handle 120Vac at 12W.

Also, when you say "ground" what exactly are you referring too? In an AC circuit there is the hot (black wire), neutral (white wire) and ground (green or bare wire). The ground is NOT a current carrying conductor so it shouldn't be switched. Only the neutral, or more preferably the hot.

 

my simple minded electricity knowledge pool isn't that deep. I am only familiar with basic, ground and hot wires. I will just get a comp fan and wire it up! Thanks again for the help!

 

You might want to brush up a little...you know, before you kill yourself.