Two-Pipe Fan Coils - With Valve Control - Siemens Desigo RXB Technical Manual

Selecting the control
sequence
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Siemens
Building Technologies
8.1.2

Two-pipe fan coils - With valve control

Two-pipe fan coils have only one proportional control sequence. This may be
configured for heating, cooling or changeover operation, as required. 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).
YHC
The control sequence comes into operation at the effective setpoint for heating or
cooling (see page 69).
Y [%]
Heating only
H
100
0
Y [%]
Cooling only
100
0
Y [%]
Changeover
H
(heating or
100
cooling)
0
The control sequence must be selected when the controller is engineered:
Heating only, Cooling only or Changeover.
RXB (KNX) application library
Control sequences
Q1
T
B1
YHC
TR [°C]
SpH
C
YHC
TR [°C]
SpC
Change-over
C
YHC YHC
TR [°C]
SpH SpC
FNC Description of functions for FC-10, FC-11, FC-12
Y Output signal
TR Room temperature
SpH Effective heating setpoint
SpC Effective cooling setpoint
H Heating sequence
C Cooling sequence
YHC Heating or cooling valve
B1 Return air sensor
Q1 Fan
CM110385en_05
28 Feb 2009