2-Pipe Fan Coil Unit (Rdf800Kn - Siemens RDF800KN Series Manual

On/Off control
Control sequence
On/Off output
Modulating control:
3-position
Control sequence
modulating output
Notes:
Setting the sequence
and the control outputs
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3.6.3 2-pipe fan coil unit (RDF800KN.., RDF800KN/VB only)
On 2-pipe applications, the thermostat controls a valve in heating/cooling mode
with changeover (automatically or manually), heating only, or cooling only. Factory
setting is "Cooling only" (P01 = 1).
The diagrams below show the control sequence for 2-position control.
Heating mode
Y
V1
1
w
0
½ SDH ½ SDH
T[°C] Room temperature
w Room temperature setpoint
V1 Control command "Valve" or "Compressor"
The diagrams below show the control sequence for modulating PI control.
Heating mode
Y [%]
V1
100
0
w
XpH
T[°C] Room temperature
w Room temperature setpoint
V1 Control command "Valve"
· The diagrams only show the PI thermostat's proportional action.
· For fan sequence see section 3.8.
Refer to sections 3.4, 3.6.1, and 3.7.
RDF800KN.., RDF800KN/VB, RDD810KN/NF
Cooling mode
Y
1
T[°C]
0
½ SDC
SDH
SDC
Cooling mode
Y [%]
100
T[°C]
0
XpH
XpC
Basic documentation
V1
w
T[°C]
½ SDC
Switching differential "Heating" (P30)
Switching differential "Cooling" (P31)
V1
T[°C]
w
XpC
Proportional band "Heating" (P30)
Proportional band "Cooling" (P31)
CE1P3174en
2020-02-21