2-Stage Heating Or Cooling - Siemens RDG100 Basic Documentation

2-stage heating
or cooling
Heating mode
Cooling mode
ON/OFF control
Heating mode (P01=0)
Y
SDH SDH
1
w
0
w
D
Changeover (P01=2 or P01= 3)
Changeover
Y
SDH SDH SDC
1
SDC
w
0
w w
D D
Siemens
Building Technologies
4.7.8

2-stage heating or cooling

On 2-stage applications, the thermostat controls 2 valves or compressors in
heating or cooling mode or changeover (automatic or manual).
"Cooling only" is factory-set (P01=1).
In heating mode, the 1st stage is activated if the acquired temperature is below the
setpoint.
The 2nd stage is activated if the acquired room temperature drops below "setpoint"
minus "setpoint differential".
In cooling mode, the 1st stage is activated if the acquired temperature is above the
setpoint.
The 2nd stage is activated if the acquired room temperature rises above "setpoint"
plus "setpoint differential".
The diagrams below show the control sequence for 2-position control.
TR [°C]
TR [°C]
RDG100, RDG100T, RDG110, RDG140, RDG160
Functions
Cooling mode P01=1)
Y
SDC SDC
1
w
0
w
D
T[°C] Room temperature
w Room temperature setpoint
YHC1 Control command "Stage 1"
YHC2 Control command "Stage 2"
SDH Switching differential "Heating" (P30)
SDC Switching differential "Cooling" (P31)
X Dead zone (P33)
dz
w Setpoint differential (P34)
D
Basic Documentation
TR [°C]
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CE1P3181en
14 Dec 2011