Wireing an Aprilaire 700 to Waterfurnace 5

Discussion in 'General Discussions' started by Sherwoodator, Mar 5, 2015.

  1. Sherwoodator

    Sherwoodator New Member

    I just bought an Aprilaire 700 from Amazon and awaiting its arrival but decided to get ahead and see how to wire this thing. Upon looking at the schematics of my Waterfurnace 5, its not as black and white as a fossil fueled furnace. Anybody know how to wire this thing up the way Aprilaire wants me too? I see the R and C connections for power but the other 3 connections to either the stat or furnace has got me scratching my head. I have the communicating t-stat too. I really want to avoid the fees to get my dealer to come out if I can. I'm an electrician by trade but not too educated on controls. I have included the schematics from my Waterfurnace 5 and the Aprilaire 700. Thanks in advance.
    Capture.PNG 20150305_142816.jpg
     
  2. urthbuoy

    urthbuoy Well-Known Member Industry Professional Forum Leader

    Typically your thermostat has the humidity reading that dictates whether or not to run the humidifier. So you would need to wire it from the thermostat as per their instructions.
     
  3. Sherwoodator

    Sherwoodator New Member

    Unfortunately, the thermostat that came with the system does not support the humidifier option per the instruction guide.
     
  4. urthbuoy

    urthbuoy Well-Known Member Industry Professional Forum Leader

    Is there a humidistat that then comes with the humidifier? That generally can be considered a SPST type device (you said you were an electrician). So you just wire it inline with the 24V to the humidifier. That 24V can come off the R/C on the unit if you so want it to. Many units have a 24V device connection (for solenoids or such).
     
  5. Sherwoodator

    Sherwoodator New Member

    There is a humidistat. It should have shown up on the pictures I provided. Upon looking further, I noticed on another schematic for the humidistat that I just need to wire up to the "C" common and "G" for the blower and then of course the 24v power. Now, I just need to find the "G" that turns on when the blower turns on. Although I will probably not be able to use the feature of the humidifier turning on the blower when it calls for humidity. Been metering all the "G"s in there and none turn on with the fan. I also metered the accessory ports with no luck. I can run power to these things all day long but I dont know how to run controls for them.
     
  6. urthbuoy

    urthbuoy Well-Known Member Industry Professional Forum Leader

    Yes, I admit I looked at the diagram after I replied. And I'm noting all the additional input/outputs. I don't know that humidistat. But the simplest operation is humidity only supplied when required (humidistat reading) and when heat pump on (the 24V). So that is just a 2-wire connection - the humidistat just operating as a dry switch. You should be able to get it running with that, and then go from there.

    The other settings look to make sure it is only in heating, fan on, etc...
     
  7. Sherwoodator

    Sherwoodator New Member

    I agree. I just need to find the heat pump/fan 24 volts and I'll be fine. Thanks for the help.
     
  8. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    G should be hot every time the fan runs.
     
  9. Sherwoodator

    Sherwoodator New Member

    I'm not sure if the "G" that I am metering is an input or not but it does not register 24 v at all. Schematics does not explain that one. The "F" next to it is connected to the fan, per the schematics, and it does have 24 v when fan is running. Those mentioned are blade terminals if that matters at all. After a couple of hours reading all the installation instruction manual, I noticed I also have a set of NO/NC dry set of contacts. Unfortunately with dry contacts, it does not provide the 24 v signal the humidifier needs. I figured I could use the NO contact and provide my own 24v either from the board or externally to provide the 24v signal to the humidifier that the fan is running and just utilize the NO contact as my switch.
     
  10. urthbuoy

    urthbuoy Well-Known Member Industry Professional Forum Leader

    Wiring between the C and G should get you what you want.
     
  11. Oseanesy

    Oseanesy New Member

    You said you have the communicating stat so why not skip the humidistat and use the humidity control on your thermostat instead? Wire humidifier to the access relay on the abc board, power relay from the R terminal, and set dip switch sw2 -4 and sw2-5 to cycle with comm t-stat hum cmd. If you have an od sensor installed your hum set pt will automatically adjust with outdoor temps.
     
  12. Sherwoodator

    Sherwoodator New Member

    I looked into that also as that is what I read in the install manual. Unfortunately, the communicating t-stat that I have does not support the humidifier option. I am going to upgrade to the touchscreen t-stat and monitoring system with the Intellistart this summer and when they come out, I'll see if they can integrate everything together. Thanks a lot for the help.
     

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