2-Pipe Fan Coil Unit - Siemens RDG200KN Basic Documentation

4.7.3 2-pipe fan coil unit

On/Off control
Control sequence
On/Off control output
Modulating control:
3-position, PWM or
DC 0...10 V
Control sequence
modulating output
Note
Note
A6V11545892_en--_a
In 2-pipe applications, the thermostat controls a valve in heating/cooling mode with
changeover (automatically or manually), heating only, or cooling only (factory
setting, P001 = 1).
The diagrams below show the control sequence for On/Off control.
Heating mode
T[°C] Room temperature
w Room temperature setpoint
YHC Control command "Valve"
The diagrams below show the control sequence for modulating PI control.
Heating mode
T[°C] Room temperature
w Room temperature setpoint
YHC Control command "Valve"
The diagrams only show the PI thermostat's proportional part.
For setting sequence and control outputs, see Application overview [➙ 37],
Sequence overview (setting via P001) [➙ 56] and Control outputs [➙ 78].
Parameter P256 (RDG260KN) sets the heating flow limitation when using a PICV.
See Additional functions [➙ 42].
Functions
Control sequences
Cooling mode
SDH Switching differential "Heating"
(P051)
SDC Switching differential "Cooling"
(P053)
Cooling mode
XpH Proportional band "Heating"
(P050)
XpC Proportional band "Cooling"
(P052)
4
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