Siemens RDG100T Basic Documentation

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Siemens RDG100, RDG100T, RDG110, RDG140, RDG160 Basic Documentation CE1P3181en
Building Technologies Functions 14 Dec 2011
4.9 Fan control
Different fan output signals are available depending on the thermostat type:
Control output
Product no.
On/off
1- / 3-speed fan
Modulating fan
DC 0…10 V
RDG100, RDG100T, RDG100T/H Q1,Q2,Q3 (3)
RDG110 Q1,Q2,Q3 (3)
RDG140 Q1,Q2,Q3 (3)
RDG160 Y50 (1)
( ) Number of outputs
Only one fan output at a time is on, either Q1, Q2 or Q3.
The fan operates in automatic mode or at the selected speed with manual mode.
In automatic mode, the fan speed depends on the setpoint and the current room
temperature. When the room temperature reaches the setpoint, the control valve
closes and the fan switches off or stays at fan speed 1
SW 7.2and higher: Parameter P15 (factory setting 0 = fan speed OFF in dead zone)
SW < 7.2 : Parameter P60 (factory setting 0 = fan speed 1 in dead zone)
The individual switching points for ON of each fan stage can be adjusted via control
parameters P55…P57. The fan speed switch off point is 20% below the switch on
point. The diagrams below show fan speed control for modulating PI control.
w Room temperature setpoint
Q Fan speed
Y
H
Control demand “Heating”
Y
C
Control demand “Cooling”
XpH Proportional band “Heating”
XpC Proportional band “Cooling”
X
dz
Dead zone
w
XpH
Y
C
[%]
Q
Q3
Q2
Q1
Y
H
[%]
0
0
XpC
100
100
x
dz
The diagram only shows the PI controller’s proportional part.
On applications with 2-position control:
1) The switching point for low fan speed (Q1) is synchronized to the heating /
cooling output. Parameter “Switching point fan speed low” P57 is not relevant.
2) The maximum switching range of the fan (XpH
Fan
/ XpC
Fan
) is defined by the
switching differential (SDH/SDC) via a look-up table.
T[°C] Room temperature
w Room temperature setpoint
Q Fan speed
Y Control command “Valve”
SDH Switching differential “Heating”
SDC Switching differential “Cooling”
X
dz
Dead zone
XpH
Fan
Switching range for fan “Heating”
Cool
T[°C]
w
XpH
Fan
Q
Q3
Q2
Q1
T[°C]
Y
1
0
w
XpC
Fan
x
dz
SDC
SDH
XpC
Fan
Switching range for fan “Cooling”
SDH/SDC [K] 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 >4.5
XpH
Fan
/XpC
Fan
[K] 2 3 4 5 6 7 8 9 10
Overview of fan
outputs
3-speed fan control
with modulating
heating / cooling
control
Note:
3-speed fan control
with on/off heating /
cooling control
Look-up table with
on/off control

Siemens RDG100T Specifications

General

Brand	Siemens
Model	RDG100T
Category	Thermostat
Language	English