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Siemens
RDG400 Basic Documentation
CE1P3182en
Building Technologies
2015-05-20
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 delivering 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 (4 °F) for heating and 1 K (2
°F) for cooling (adjustable via parameters P30 and P31).
The integral action time for modulating PI control is 5 minutes (adjustable via
parameter P35).
The temperature unit selection wizard enables to select the preferable temperature
unit display on thermostats between °C and °F under the following two situations:
1. Select application via adjusting DIP switches at the rear of thermostat.
2. Power up the thermostat after successfully connecting the line power.
Follow the steps:
1. Rotate rotary knob to select the preferable temperature unit.
2. Press the button (OK) to confirm the selection, and the thermostat goes to
normal operating page.
·
Pressing button (Esc) does not confirm the temperature unit selection.
·
If the temperature unit is not selected, °C is used by default.
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’s 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 activated.
Concurrent display of the current temperature or setpoint in °C and °F (parameter
P07) is possible.
General notes
Temperature unit
selection wizard
Note:
Display
/
Concurrent display of
°C and °F
