Siemens RDG400 - Manual (Page 19)

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Siemens RDG100, RDG100T, RDG110, RDG140, RDG160 Basic Documentation CE1P3182en
Building Technologies Functions 28 May 2009
4.7.4 Single duct
In single duct applications, the controller controls an actuator (valve, damper, VAV
system, etc)
– in heating/cooling mode with changeover (automatic or manual),
– heating only mode,
– or cooling only mode.
Cooling only is factory set (P01=1).
The output signal for the air flow can be limited to a minimum and maximum value
if required (see section 4.6 "additional features").
Modulating control 3-position, PWM or DC 0 … 10 V
The diagram below shows the control sequence for continuous PI control.
Heating only (P01 = 0) Cooling only (P01 = 1)
max
mi
n
XpH
Y10
0%
100%
TR [°C] W
H
Vmin
Vmax
max
mi
n
Y10
0%
100%
TR [°C]
XpC
W
C
Vmin
Vmax
Changeover (P01 = 2, 3)
max
mi
n
Changeover
XpH
Y10
0%
100%
TR [°C]
XpC
W
C H
Vmin
Vmax
T[°C] Room temperature XpH Proportional band “Heating”
w Room temperature setpoint XpC Proportional band “Cooling”
Y10 Control command “Valve” Vmin Min. limitation for output
Vmax Max. limitation for output
The diagrams show the PI controller’s proportional part only.
Setting the sequence and the control outputs
Refer to sections 4.5 (applications), 4.7.1 (sequences) and 4.7.3 (outputs).
Single duct,
heating or cooling
Note