Connect with us

Can You Look at This and Tell Me Why It Doesn't Work?

Discussion in 'General Electronics Discussion' started by sremed60, Jun 8, 2015.

Scroll to continue with content
  1. sremed60

    sremed60

    7
    0
    Jun 8, 2015
    #1 Is an adapter - 120VAC 60Hz, 12VDC 1000mA
    #2 Is a household Honeywell non-programmable thermostat. (I was told that it should work with 12 volt).
    #3 Is a Radio Shack audio fan, 12volt 300mA
    #4 Is a Radio Shack 12volt LED Indicator light.

    This is a setup I was told, (from many sources) would work for a beer fermentation chiller. The thermostat is set at 67 degrees and should kick the fan on when it gets too warm and kick it off when it drops back down to 67. Since the fan is located inside an insulated enclosure it can't be heard, so the indicator light goes on and off when the fan does just to let me know when the fan is running. If I put the thermostat in "ON" position everything works great. If I put it in "Auto" it runs when I first plug it in and shuts off when the temperature reaches the desired degree. But it won't kick back on when the temperature warms back up.

    Any help is appreciated.
     

    Attached Files:

  2. Martaine2005

    Martaine2005

    2,970
    818
    May 12, 2015
    This may sound silly but, where is the thermostat located?
    Seems to me that the thermostat is on the outside of the insulated box?

    That will only only control the temperature around the thermostat. Not inside the enclosure.
    Can you confirm this?
    Martin.

    EDIT; What thermostat is it? some require 24 volts ac.
     
    Last edited: Jun 8, 2015
  3. sremed60

    sremed60

    7
    0
    Jun 8, 2015
    It is inside the insulated box, that's why I had to hook the indicator light up. I can't hear the fan when it kicks on and off. It's a basic Honeywell RTH111B1016/A Digital Non-Programmable Thermostat for the home. It is a 24 volt ac thermostat, however I read countless comments and watched a crap load of videos on youtube from people who say that since you're only using the thermostat to turn the fan on and off then 12volts is enough. I don't know much about electronics OR thermostats so I can't vouch for how true that is. But I did a lot of research before I started this project and there seems to be a lot of people out there using these home thermometers and saying they work.

    The problem I ran into, which is why I posted this. Everything I've read says I can use this thermostat and it will work, but no one actually tells or shows how to wire it. I took my best educated guess at wiring it (as shown in the diagram). I was just wondering if anyone could look at how I have it wired and let me know if THAT is the problem, or if it's something else.

    The fan and indicator light I bought brand new at Radio Shack, (so I'm guessing they're not the issue). The ac adapter I bought at Goodwill. I made sure it was 12 v and (at least) 300mA, which is what the fan requires. The thermostat came out of my living room. It was working fine, I just replaced it with a programmable thermostat.

    So really, I'm thinking the wiring is the only thing I might have done wrong. Either that or those hundreds of people who have done this project before me and say this thermostat will work are full of crap.
     
  4. sremed60

    sremed60

    7
    0
    Jun 8, 2015
    [​IMG]
     
  5. sremed60

    sremed60

    7
    0
    Jun 8, 2015
    [​IMG]
     
  6. sremed60

    sremed60

    7
    0
    Jun 8, 2015
    [​IMG]
     
  7. sremed60

    sremed60

    7
    0
    Jun 8, 2015
    [​IMG]
     
  8. Martaine2005

    Martaine2005

    2,970
    818
    May 12, 2015
    You could try putting the fan + to G as it is now and remove the link to Y.
    Then put the + from power adapter to Y on it's own.
    Y and G linked is giving constant power to G.
    As you said, It works when switched ON but not in AUTO.
    I would try it.
    I cannot see how it can work though because a thermostat calls for heat. You don't have a heat source connected to the thermostat.
     
  9. sremed60

    sremed60

    7
    0
    Jun 8, 2015
    I'm not sure what you mean by "A thermostat calls for heat." It has a thermistor to measure air temp, and the the terminals which open or close depending on the temp and where the thermostat is set. The fermentation chiller has two sections. One is the big insulated area where the thermostat is located. It needs to stay at 67 degrees. Then there's a smaller section where you put jugs of frozen water. the fan sucks the cold air out of the smaller area into the big area. When it reaches 67 degrees the fan (hopefully shuts off). As the temp slowly creeps back up, the fan should kick on again and suck the colder air from the small area to cool it down.

    I read a lot of plans and watched a bunch of youtube videos from guys who have built these and say they work great. My problem is that I'm not that familiar with thermostats and or electronics. So I put all the pieces together the way they said, I just can't find anything that actually walks me through wiring it all together.
     
  10. Martaine2005

    Martaine2005

    2,970
    818
    May 12, 2015
    ' Calling for heat ' is when the thermostat switches on.
    You said it works except auto.
    The R and W are the switch wires.
    Put power to R and fan to W. Not sure if you still need link between RC and R but it wont hurt to leave it there.
    Give that a try.
     
  11. Arouse1973

    Arouse1973 Adam

    5,164
    1,081
    Dec 18, 2013
    Looking at the manual, there is a compressor protection circuit built in which won't switch the compressor back on for 5 minutes. I am not sure if the fan control also follows this delay. If the "Cool on" message is flashing then it is in this delay period. Also I don't think you need the Y connection, this is to control power to the cooling device and I think it is separate to the fan switch.

    Also the unit may work from 12 Volts but the rated Voltage is 24 Volts a.c so if all else fails you really should try the correct power supply.

    Adam
     
  12. BobK

    BobK

    7,682
    1,686
    Jan 5, 2010
    I hate to ask this, but do you have the thermostat set for heat or cool? If you have it set for heat, as shown in the picture, then it will come on when the temp is below the setting. I think you want it on cool.

    Bob
     
  13. Minder

    Minder

    3,018
    640
    Apr 24, 2015
    IIRC the power supply is not for the thermostat but what ever it is switching via the internal relays. Many of the modern digital Thermostats run off of the battery alone.
    All you should need is the Heat side if this is for maintaining the brew temp.
    I have a simple brew cupboard with a heater and regular thermostat.
    M.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-