Heating and cooling
In 4-pipe applications, the thermostat controls 2 valves in heating and cooling mode, heating/cooling mode by manual selection. Heating and cooling mode (P02 = 5) is factory-set.
4-pipe application with manual changeover
The heating or cooling output can be released via mode button if P02 is set to Manual (P02 = 4).
On/Off control
The diagrams below show the control sequence for On/Off control.
Heating and cooling mode (P02 = 5) | |
|
Heating mode with manual selection (P02 = 4) | Cooling mode with manual selection (P02 =4) |
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|
YH | Control command "Valve" (heating) |
YC | Control command "Valve" (cooling) |
SDH | Hysteresis "Heating" (P43) |
SDC | Hysteresis "Cooling" (P44) |
T[°C] | Room temperature |
w | Room temperature setpoint |
Xdz | Zero energy zone (P41) |
Modulating control:
3-position or DC 0...10 V
The diagrams below show the control sequence of modulating PI control.
Heating and cooling mode (P02 = 5) | |
|
Heating mode with manual selection (P02 = 4) | Cooling mode with manual selection (P02 = 4) |
|
|
YH | Control command "Valve" (heating) |
YC | Control command "Valve" (cooling) |
XpH | Proportional band "Heating" (P43) |
XpC | Proportional band "Cooling" (P44) |
T[°C] | Room temperature |
w | Room temperature setpoint |
Xdz | Zero energy zone (P41) |
Note
The diagrams only show the PI thermostat’s proportional part.
For setting sequence and control outputs, see Sequence overview (setting via P02) and Control outputs.