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Siemens
RXB (KNX) application library
FNC Description of functions for FC-10, FC-11, FC-12
CM110385en_05
Building Technologies
Control sequences
28 Feb 2009
8 Control
sequences
8.1
Fan coils with valve control
8.1.1
Four-pipe fan coils - With valve control
The applications for 4-pipe fan coils each have a proportional heating and proportional
cooling sequence. The controllers operate with a PI algorithm optimized for thermal or
motorized valve actuators. (For simplicity, the diagrams below only show the P-control
action).
T
B1
YC
YH
Q1
10
38
5S
01
The control sequences come into operation at the effective setpoints for heating and
cooling (see page 69).
Y [%]
SpH
SpC
TR [°C]
H
C
YH
YC
100
0
10
3
85D
08
Y Output
signal
TR Room
temperature
SpH
Effective heating setpoint
SpC Effective
cooling
setpoint
H Heating
sequence
C Cooling
sequence
YH Heating
valve
YC
Cooling valve
B1
Return air sensor
Q1 Fan
Different applications support different valve actuators, and these do not all require the
same number of outputs on the controller. The tool displays the actuators suitable for
the selected application. Selection occurs at the engineering stage (see page 85).
Actuator type