Siemens RDF300 - 4.6 Control sequences

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Siemens RDF300…/RDF340.../RDF400… Basic Documentation CE1P3076en
Building Technologies 4BFunctions 28 Aug 2008
4.6 Control sequences
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)
• Heating and cooling mode (e.g. 4-pipe system) (P01=4)
The relevant modes are available and can be adjusted via commissioning
parameter “Control sequence” P01, depending on the selected application.
Sequence
T °C
T °C
T °C
T °C
T
T °C
Parameter P01 = 0 P01 = 1 P01 = 2 P01 = 3 P01 = 4
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
Heating and
cooling mode,
i.e. 4-pipe
2-pipe,
2-pipe & el. heater
   
4-pipe
  
4.6.1 2-pipe fan coil unit
In 2-pipe applications, the controller controls a valve in heating/cooling mode with
changeover (automatic or manual), heating only mode, or cooling only mode.
Cooling only is factory set (P01=1).
The diagram below shows the control sequence for on/off (2-position) control.
Heating mode Cooling mode
½ SDH
1
0
½ SDH
w
Y
3076D01
T[°C]
Y1
Y
½ SDC
1
0
½ SDC
w
3076D02
T[°C]
Y1
T[°C] Room temperature SDH Switching differential “Heating”
w Room temperature setpoint SDC Switching differential “Cooling”
Y1 Control command “Valve” or “Compressor”
On/off output
Heating or cooling
Control sequence
on/off output