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Siemens
RDU340… Basic Documentation
CE1P3078en
Building Technologies
Functions
2014-11-03
4.6 Control
sequences
4.6.1 Single
duct
If the selected application is "single duct", then the controller can be used in
systems featuring:
– Heating or cooling mode (P01=0 or P01=1).
– Manual heating/cooling changeover (P01=2).
– Automatic heating/cooling changeover (P01=3).
The relevant modes can be adjusted via commissioning parameter “Control
sequence” P01, depending on the selected application.
Sequence
Parameter
P01 = 0
P01 = 1
P01 = 2
P01 = 3
Mode
Available for:
Heating mode
Cooling mode
Manually select
heating or cooling
mode
Automatic
heating/cooling
changeover via
external water
temperature
sensor or remote
switch
Single duct
ü
ü
ü
ü
In application "Single duct with el. heater", the controller operates in heating AND
cooling mode.
In single duct applications, the controller controls an actuator (valve, damper, VAV
system, etc)
– in heating/cooling mode with changeover (automatic or manual),
– heating only mode,
– or cooling only mode.
Cooling only is factory set (P01=1).
The output can be limited to a minimum and maximum value if required.
See section 4.5 "additional features".
The diagram below shows the control sequence for continuous
PI
control.
Heating only mode
Cooling only mode
Changeover
Single duct,
heating or cooling
Control sequence
modulating output