Operating Instructions

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Siemens RXB (KNX) application library RXB Description of functions for FC-10, FC-11, FC-12, FC-13 CM110385en_08
Building Technologies Control sequences 2013-06-17
8.2 Fan coils with damper control
In FNC20, a single damper actuator is used for control of both heating and cooling.
8.2.1 4-pipe fan coils with damper control (FNC20)
In application FNC20, which uses a damper instead of a valve for modulating control of
the room temperature, a constant volume of water flows through the two heat
exchangers. Depending on the demand, the air flow is guided either through the
heating coil or through the cooling coil, causing a change in the resulting mixed air
temperature.
10385D52
100
TR [°C]
Y [%]
SpH SpC
YM
H C
0
N
Y Damper position
TR Room temperature
SpH Effective heating setpoint
SpC Effective cooling setpoint
H Heating sequence
N Dead band (recirculated air)
C Cooling sequence
YM Damper actuator
The heat-exchanger configuration may call for asymmetric runtimes for heating and
cooling; these can be set individually. At the mid-point where the air flow switches from
heating to cooling, the time period associated with the mechanical dead band can also
be preset.
Select Sequences.
ETSS
Professional