Siemens RDG20 KN Series Basic Documentation page 85

Modulating control:
3-position, PWM or
DC 0...10 V
Note
Note
A6V11545892_en--_c
The diagrams below show the control sequence for modulating PI control.
Heating mode (P001 = 0)
Changeover (P001 = 2 or P001 = 3,
P254 = 0)
T[° C] Room temperature
w Room temperature setpoint
YHC1 Control command "Stage 1"
YHC2 Control command "Stage 2"
The diagrams only show the PI thermostat's proportional part.
For setting sequence and control outputs, see Application overview [➙ 42],
Sequence overview (setting via P001) [➙ 75] and Control outputs [➙ 99].
●
For applications with different signals, On/Off (1
heating/cooling P-band modulating (P050, P052), a small switching differential
SDH / SDC (P051, P053) is suggested to start 1
/ cooling demand is requested.
●
Set the heating flow limitation function with parameter P256 (RDG26..KN)
when using a PICV in this application. See Additional functions [➙ 47].
Functions
Control sequences
Cooling mode (P001 = 1)
Changeover (P001 = 2 or P001 = 3,
P254 = 1) (swap function)
XpH Proportional band "Heating"
(P050)
XpC Proportional band "Cooling"
(P052)
w Setpoint differential (P056)
D
st
stage) and DC (2
st sequence as soon as heating
4
nd
stage),
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