Siemens RDG100T Documentation

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Siemens RDG100…/RDG110…/RDG140.../RDG160… Basic Documentation CE1P3076.en
Building Technologies Functions 28 May 2009
4.7.3 2-pipe fan coil unit
On 2-pipe applications, the thermostat controls a valve in heating / cooling mode
with changeover (automatic or manual), heating only, or cooling only. Cooling only
is factory set (P01=1).
ON/OFF control
The diagram below shows the control sequence for 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” (P30)
w Room temperature setpoint SDC Switching differential “Cooling” (P31)
Y1 Control command “Valve” or “Compressor”
Modulating control: 3-position, PWM or DC 0…10 V
The diagram below shows the control sequence for modulating PI control.
Heating mode Cooling mode
XpH
100
0
w
Y [%]
3076D03
T[°C]
Y1
XpC
Y [%]
100
0
w
3076D04
T[°C]
Y1
T[°C] Room temperature XpH Proportional band “Heating” (P30)
w Room temperature setpoint XpC Proportional band “Cooling” (P31)
Y1 Control command “Valve”
The diagrams only show the PI controller’s proportional part.
Setting the sequence and the control outputs
Refer to sections 4.5 (applications), 4.7.1 (sequences) and 4.7.2 (outputs).
Control se
quence
on/off output
Control se
quence
modulating output
Note
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Siemens RDG100T Specifications

General

Brand	Siemens
Model	RDG100T
Category	Thermostat
Language	English