Operating Instructions

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Siemens RXB application library (KNX) RXB – Fan coil applications from FC-10, FC-11, FC-12, FC-13 CM110672en_05
Building Technologies 9BFNC20 – Four-pipe fan coil, controlled by one damper 2013-06-07
Application FNC20 includes the following functions
(refer to the description of functions CM110385 for detailed information):
Function Brief description)
Four-pipe fan coil with
damper control.
– PI control.
– Two proportional control sequences, heating and cooling.
– Control of motorized damper actuators (AC 24 V, 3-position).
Fan control.
– 1...3-speed, automatic, or
– Manual with room unit.
Temperature measurement. – Room temperature sensor or
– Return air sensor.
Room operating modes. – Comfort, Precomfort, Economy and Protection mode..
– Change of operating mode via
/Auto switch on room unit, presence detector,
window contact or central command.
Setpoint shift.
– Locally via room unit or centrally.
General functions. – Presence detector.
– Window switch.
– Master/slave operation.
– Boost heating, night cooling etc.
– Free inputs/outputs.
Room units. Available with temperature sensor, setpoint adjuster,
button for /Auto and fan speed control, and LCD display.
Compatible controllers.
FNC20 is supplied with RXB21.1/FC-10.
2 1 4 3
QAX...
R1
10385A10
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
M D1 GND D2 Y1 G Y2
CP– CP+
B1
25 26 27
RXB21.1
Q13 Q14
Y3 G Y4
Q24 Q34
28
19 21
N L N
21
L
CE– CE+
19
KNX
Y1
G
Y2
YM
3)
M
M
B
B1
T
D1
2)
D2
1 2 3
Q1
N
L
AC 230 V
N1
CE– CE+ N.C.
2)
2) Type of operation (N/O or N/C) can be selected.
3) Do not exceed the max. simultaneous load on outputs Y1...Y4: 9.5 VA (see data sheet 3873).
4) Do not connect the fans in parallel (or use cut-off relays).
Functions
Connection diagram