Siemens RDG100KN Basic Documentation page 74

3-speed fan control
with modulating
heating/cooling control
(PWM, 3-pos or
DC 0...10 V)
Heating/cooling
Q3
1- or 3-speed fan
Q2
Q1
Off
Note
3-speed/ECM fan
control with On/Off
heating/cooling control
Heating/cooling
Q3
1- or 3-speed fan
Q2
Q1
ECM fan
74 / 132
Siemens
Building Technologies
The individual switching points for ON of each fan stage can be adjusted via
control 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.
Y
The diagram only shows the PI control's proportional part.
On applications with On/Off control:
1) The switching point for low fan speed is synchronized to the heating/cooling
output. P57 (switching point fan speed low) is not relevant.
2) The maximum switching range of the fan (XpH
switching differential (SDH/SDC) via a look-up table.
Y
RDG100KN, RDG160KN, RDG165KN Basic Documentation
w Room temperature setpoint
Q Fan speed
Y Control demand "Heating"
H
Y Control demand "Cooling"
C
XpH Proportional band "Heating" (P30)
XpC Proportional band "Cooling" (P31)
X Dead zone (P33)
dz
Fan speed switching point high (P55)
Fan speed switching point med (P56)
Fan speed switching point low (P57)
/XpC ) is defined by the
Fan Fan
T [°C] Room temperature
w Room temperature setpoint
Q Fan speed
Y Control command "Valve"
SDH Switching differential "Heating" (P30)
SDC Switching differential "Cooling" (P31)
Xdz Dead zone (P33)
XpH Switching range for fan "Heating" (Table)
Fan
XpC Switching range for fan "Cooling" (Table)
Fan
Fan 3-speed switching point high (P55)
Fan 3-speed switching point med (P56)
Fan_max Max. ECM fan speed (P55)
Fan_min Min. ECM fan speed (P56)
CE1P3191en
2018-07-03