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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
8.3
Fan coils with an electric heating coil
This function will be implemented later.
8.4
Fan coils with an electric reheater
In addition to controlling heating and/or cooling valves, some applications also provide
an output for the control of an electric heating coil. This is then operated as a
reheater
,
i.e. it only comes into operation when the heating valve is fully open.
•
With
motorized
actuators, the electric reheater is only enabled when the heating
valve is fully open.
•
In the case of
thermal
actuators, the electric reheater is not enabled until the thermal
actuator has been operated at maximum flow (100%) for at least 2 minutes.
•
The switching differential is fixed at 1.0 K.
8.4.1
4-pipe fan-coils with electric reheater
T
B1
YC
YH
Q1
D3
YR
10
3
85S
07
Y Output
signal
TR Room
temperature
SpC Effective
cooling
setpoint
SpH
Effective heating setpoint
H Heating
sequence
C Cooling
sequence
YH Heating
valve
YC Cooling
valve
YR Electric
reheater
D3 Safety
thermostat
B1
Return air sensor
Q1 Fan
1-step
Modulating
OFF
YR
ON
0%
Y
100%
YC
YH
TR [°C]
YR
H
1 K
SpH
SpC
10
38
5
D
54
YC
YH
0%
TR [°C]
YR, Y
100%
H
SpH
SpC
YR
10
38
5D
55
Notes