User Manual

Siemens Building Technologies Application :74 RWD68/74 - 02.2001
HVAC Products RWD68 3
The main display shows ,
a) Whether Q1 is On or Off ( = off, = on )
b) Y1 output in Volts dc. (0..10V = 0..100% range)
c) Whether day or night set point is selected. (
¤ = day, b = night)
d) X1 value ( room temperature) in ° C.
Other displays are available by pressing the + button, and the various
displays are listed below in sequence from the main display.
On entering any of the four set point displays, the setpoint on display can be
adjusted by pushing the enter/save button, increase value by pressing the
+ button or decrease the value by pressing the – button, and when the
required value is reached, press the enter/save button to save the new
value.
The alternative displays return to the main display after 20 seconds duration.
Press
buttons
Action Current display Selected display Selected display comments
Push + button
Q1 Y1 ¤ X1 Y1 SP – c ¤ 28.0c Y1 - cooling day set point.
Push + button Y1 SP – c ¤ 28.0c Q1 SP – c ¤ 32.0c Q1 – cooling day set point.
Push + button Q1 SP – c ¤ 32.0c Y1 SP – c b 32.0c Y1 – cooling night set point.
Push + button Y1 SP – c b 32.0c Q1 SP – c b 36.0c Q1 – cooling night set point.
Push + button Q1 SP – c b 36.0c X1 18.0c X1 - main temperature sensor reading
Push + button X1 18.0c X2 19.0c X2 – outside air temperature sensor reading
Push + button X2 19.0c Y1 5.0 Y1 – cooling analogue output value in Vdc to one decimal point
Push + button Y1 5.0 Q1 OFF Q1 – cooling digital output, display on or off.
Push + button Q1 OFF COMP 74 Control sequence diagram and application number display.
Push + button COMP 74 Q1 Y1 ¤ X1 Back to main display
Values shown are either default values or nominated for information only
Main Display