Braeburn 3220 - About Your Thermostat; Thermostat Features

Installer Guide 4
Wiring Terminations for model 3220
Terminal Function Description
  Rc Input 24VoltACCoolingTransformer
    (DualTransformerSystemsOnly)
  Rh Input PowerConnection(24VoltACHeating  
    TransformerorMillivoltPowerSource)
G Output FanControl
W1/E/W3 Output (W1)1stStageConventionalHeat,
   (E)EmergencyHeat,    
(W3)3rdStageAuxiliaryHeat
  W2 Output 2ndStageConventionalHeat  
O/B/V3 Output (O)CoolActiveReversingValve   
    (B)HeatActiveReversingValve
    (V3)ZoneValvePowerClose
  Y1 Output 1stStageCompressor
  Y2 Output 2ndStageCompressor
  L Input SystemMalfunctionIndicator
C Input 24VoltACTransformerCommon
  S1
  S2
Connecting Your Wires (continued)
3
Input OptionalRemoteSensor(indoororoutdoor)