Siemens RDF800KN Series User Manual

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Siemens RDF800KN.., RDF800KN/VB, RDD810KN/NF Basic documentation CE1P3174en
Smart Infrastructure 2020-02-21
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 Cooling mode
½ SDH
1
0
½ SDH
w
Y
3
0
7
6
D
0
1
T[°C]
V1
Y
½ SDC
1
0
½ SDC
w
3
0
7
6
D
0
2
T[°C]
V1
T[°C] Room temperature SDH Switching differential "Heating" (P30)
w Room temperature setpoint SDC Switching differential "Cooling" (P31)
V1 Control command "Valve" or "Compressor"
The diagrams below show the control sequence for modulating PI control.
Heating mode Cooling mode
XpH
100
0
w
Y [%]
3
0
7
6
D
0
3
T[°C]
V1
XpC
Y [%]
100
0
w
3
0
7
6
D
0
4
T[°C]
V1
T[°C] Room temperature XpH Proportional band "Heating" (P30)
w Room temperature setpoint XpC Proportional band "Cooling" (P31)
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.
On/Off control
Control sequence
On/Off output
Modulating control:
3-position
Control sequence
modulating output
Note
s
:
Setting the sequence
and the control outputs

Siemens RDF800KN Series Specifications

General

Brand	Siemens
Model	RDF800KN Series
Category	Thermostat
Language	English