Siemens RDF300 - Page 16

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Siemens RDF300…/RDF340.../RDF400… Basic Documentation CE1P3076en
Building Technologies 4BFunctions 28 Aug 2008
The diagram below shows the control sequence for on/off (2-position) control.
Heating mode
(automatic changeover=heating or heating only)
Cooling mode
(man. /auto. changeover=cooling or cooling only)
Y
½ SDH
1
0
½ SDH
w
3076D06
T[°C]
Y1
½ SDH
½ SDH
YE
w
D
Y
½ SDC
1
0
½ SDC
w
3076D05
T[°C]
Y1
½ SDH
½ SDH
YE
x
dz
Heating mode with manual changeover
(P01=2)
(manual changeover=heating)
T[°C] Room temperature
W Room temperature setpoint
Y1 Control command “Valve” or “Compressor”
YE Control command “electrical heater”
SDH Switching differential “Heating”
SDC Switching differential “Cooling”
X
dz
Dead zone
½ SDH
1
0
½ SDH
w
Y
3076D07
T[°C]
YE
w
D
Setpoint differential
The diagram below shows the control sequence for continuous PI control.
Heating mode
(automatic changeover=heating or heating only)
Cooling mode
(man. /auto. changeover=cooling or cooling only)
Y [%]
100
0
w
3076D09
T[°C]
Y1
XpH
YE
w
D
XpH
Y [%]
100
0
w
3076D08
T[°C]
Y1
XpH
YE
x
dz
XpC
Heating mode with manual changeover
(P01=2)
(manual changeover=heating)
T[°C] Room temperature
W Room temperature setpoint
Y1 Control command “Valve”
YE Control command “electrical heater”
XpH Proportional band “Heating”
XpC Proportional band “Cooling”
X
dz
Dead zone
XpH
100
0
w
Y [%]
3076D10
T[°C]
YE
w
D
Setpoint differential
Note: The diagrams only show the PI controller's proportional part.
Control sequence
on/off output
Control sequence
modulating output