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First Company VFD Air HAndler Wiring

meatball
meatball Member Posts: 5
in THE MAIN WALL
installed, have the RC (blue wire from tstat) going to R on the unit. AC works.

Have RH (red wire from tstat) that is hanging out there (no connection)

Wiring diagram is weak.



I can make heat or ac work individually but not via the tstat switch.



Anyone have an idea how to make this work?

Comments

  • pipe4zen
    pipe4zen Member Posts: 108
    switching relay

    Try a SPNO swich relay. RH-C to coil side dry contact side to your heating control.
  • Techman
    Techman Member Posts: 2,144
    edited October 2011
    Wiring

    The power for the  24v control wiring goes from the hot side of the xformer TO the "R" terminal in the AHU ,then from "R" terminal it goes TO the t'stat "RC" terminal, then from the t'stat "Y" terminal the power goes BACK to the AHU "Y" terminal and on to the AC. Then, IF, the heat has it's own 24vac xformer then the hot side of the heat xformer goes TO the t'stat "RH" terminal (NO jumper between RC -RH) and then BACK to the heat thru the t'stat "W" terminal. OR ,depending, a relay at the heat xformer can control the heat thru the relays contacts. And then back @ the t'stat put IN  a jumper from "RC" to "RH" then the( AHU 24v power) power goes thru the "W" terminal to the (heat )relay coil. Or a few other ways.

    What is the heat source?
This discussion has been closed.

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