Fan Operation - Siemens RDB160BN Basic Documentation

5 Control outputs

Fan operation

5.2 Fan operation
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3-speed fan control with On/Off heating / cooling control
In applications with 2-position control, the switching point for the fan speeds
can be defined via control parameters P26, P27 and P28.
Valve on
Valve Off
3 speed fan
Speed 3
Speed 2
Speed 1
100% 60%
P28 P27
Selection of fan output
Different fan output signals are available based on the setting:
Product On/Off
1-/2-/3-speed
fan
RDB160BN DO1, DO2, DO3
The type of fan output (DC 0...10 V, 1-, 2- or 3-speed) can be selected via local
HMI using parameters P77 and P30 or via BACnet objects.
● P77 is used to select the fan type (1-, 2- or 3-speed fan or DC fan).
● P30 is used to select the number of fan speeds.
Fan operation for heating / cooling mode, or disabled
The thermostat can be used on universal applications such as chilled / heated
ceilings and radiator.
Fan operation can be limited to active for cooling only or heating only, or even
to disabled via control parameter P25 ('Fan control in auto mode').
The manual fan operation is locked with parameter P66.
● If P66 is set to 0, the fan is disabled in auto mode as per parameter P25.
The user can still manually set the speed.
● If P66 is set to 1, the fan is disabled in auto mode as per parameter P25.
The user cannot manually set the fan speed. Fan operation is locked.
X P05
DZ
2K
T T
P29
5%
w
20%
P26
Modulating fan
DC 0...10 V
AO2
P29
5%
20% 60% 100%
P26 P27 P28
Control type
selected via
P77, P30
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Room T
Room T