Technical Instructions
RDU20U, RDU50U and RDU50.2U Room Temperature Controllers
Document Number 155-735
with LCD for Heating and Cooling Systems
November 1, 2006
Page 6
Siemens Industry, Inc.
Setting and
Operating Elements
Figure 10.
1
Display of the room or return air
temperature, setpoints, and control
parameters
2
Symbol used when displaying the
current room temperature
3
Normal operation
Energy Saving mode
4
Cooling valve open
Heating valve open
5
Buttons for adjusting the setpoints and
the control parameters
6
Slider switch for manual heat-off-cool
setting (RDU50.2U only)
Setting the Control
Parameters
A number of control parameters can be set to optimize the control performance. These
parameters can also be set during operation without opening the unit. A 24 Vac supply
to the controller is required to enable parameter adjustment.
The parameters can be changed as follows:
1. Press buttons "+" and "
–" simultaneously for a minimum of three seconds and a
maximum of five seconds. Release the buttons and then press button "+" again for
approximately three seconds until the display shows “P01“.
2. Select the required parameter by repeatedly pressing buttons "+" or "
–".
3. Press buttons "+" and "
–" simultaneously. The current value of the selected
parameter appears, which can be changed by repeatedly pressing either button.
4. Press buttons "+" and "
–" simultaneously again, or five seconds after the last press
of a button, to store the new value and display the parameter.
5. Repeat steps 2 through 4 to display and change additional parameters.
6. Wait ten seconds after the last display or setting. All changes will be stored and the
controller returns to normal operation.
