Page 6 of 18 APHITEMPCON001-11-04
Heating+CoolingSequence controlwithZeroEnergyBand
This kind of control requiresZeroEnergyBand (Z-Band). Z-Band ispre-set. For control purpose,
the zeroenergy band is centered on theuser set point (SP), so its valuedefines the effective
heating (HSP) & cooling (CSP) set points. The cooling set point (CSP) will be positionedon
the right side of Z-Band& the heating set point (HSP) on the left side of Z-Band. Z-Band can be
set as 1.5°C or 3.0°C. Any changeof set point will causebothheatingand cooling set points to
change in parallel. Either output1 or output2 can be used for cooling or heating control. The
control logic is seen inDiagram2 and 3.
Diagram2: Heating +CoolingSequenceControl.
Z-Band
Output 2
Cooling
50%
ValveOpen
100%
Temperature Increase
ValveClose
0%
SP
Output 1
Heating
Diff
HSP
CSP
