Motor Help!

Discussion in 'The Projects Forum' started by onebigfellah, Nov 27, 2012.

  1. onebigfellah

    Thread Starter New Member

    Apr 3, 2012
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    Hi everyone.

    I am trying to build a temperature & humidity controlled chamber...in order to remove humidity I need to modify the fan speed (decrease it) on the air conditioner because the room is small (57 ft²) and the A/C is way oversized (18 kBtu). The approximate CFM for a room this size should be around 50.

    I purchased a 230VAC 0.5hp 1ph variable frequency drive to accomplish this.

    My problem is this, which legs should I put it on for an asynchronous motor?

    Please see attached photo of the motor's label for schematic.

    It is my belief that the "Red", "Yellow" & "White" wires would be connected to the three different blower speeds (Hi, Med, Lo)...There is also an "Auto" mode for the fan circulating air in the room.
     
  2. crutschow

    Expert

    Mar 14, 2008
    13,003
    3,232
    If you lower the fan speed on the air conditioner the coils may frost and clog the airflow through the evaporator. Have you considered that?

    Why not just cycle the air conditioner on and off?
     
  3. onebigfellah

    Thread Starter New Member

    Apr 3, 2012
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    There is a controller that monitors the Evaproator coil for freezing. The unit is already cycling on and off every 5 minutes and it cannot go any lower because there is some sort of internal timer on it.

    So, any idea as to which terminals would be the correct ones?
     
  4. crutschow

    Expert

    Mar 14, 2008
    13,003
    3,232
    So where do those motor wires go now?

    I assume the new variable frequency drive has a two wire output?
     
  5. Dodgydave

    Distinguished Member

    Jun 22, 2012
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  6. onebigfellah

    Thread Starter New Member

    Apr 3, 2012
    9
    0
    Last edited: Nov 28, 2012
  7. thedoc8

    New Member

    Nov 28, 2012
    3
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    Before you distroy your compressor, why not just run a dehumidifier and set your ac to what you want.
     
  8. #12

    Expert

    Nov 30, 2010
    16,278
    6,791
    PS, the timer is to keep you from trying to re-start the compressor before the Freon pressures equalize. If you do, the compressor will not start and it will allow high current until the internal overheat safety pops. (Compressors don't like that.)
     
  9. onebigfellah

    Thread Starter New Member

    Apr 3, 2012
    9
    0
    Thanks for everyone's concern about this project; I have worked with compressors and A/C units for a long time in a previous life.

    I am going to unplug all of the wires and try them one by one to figure out what each one does.

    I'll keep you posted.

    A dehumidifier would be a great idea if I had the space in the room and the power...
     
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