Siemens RDG400 - Manual (Page 8)

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Siemens RDG100…/RDG110…/RDG140.../RDG160… Basic Documentation CE1P3182en
Building Technologies Functions 28 May 2009
4 Functions
4.1 Temperature control
Setting of the control parameters (P01 etc., mentioned throughout the document) is
described in section 4.12.
The thermostat acquires the room temperature via built-in sensor, external room
temperature sensor (QAA32), or external return air temperature sensor (QAH11.1),
and maintains the setpoint by issuing actuator control commands to heating and/or
cooling equipment. The following control outputs are available:
• Modulating PI / P control with DC 0 … 10 V control output
• Modulating PI / P control with 3-position control output
• Modulating PI / P control with PWM output
• On/off control (2-position)
The switching differential or proportional band is 2 K for heating and 1 K for cooling
(adjustable via parameters P30 and P31).
The integral action time for continuous PI control is 5 minutes (adjustable via
parameter P35).
The display shows the acquired room temperature or the Comfort setpoint, selecta-
ble via parameter P06. The factory setting displays the current room temperature.
Use parameter P04 to display the room temperature or setpoint in °F rather than
°C as needed.
If the thermostat is used in a system with manual heating/cooling changeover
(P01=2), the heating and cooling symbols on the display show the terminal
unit status. Thus, the symbols are displayed even when the thermostat operates in
the neutral zone. For all other cases, the heating and cooling
symbols are
displayed when the heating or cooling output is energized.
Concurrent display of the current temperature or setpoint in °C and in °F
(parameter P07) is possible.
General note
Display
/
Concurrent display of
°C and °F