16 / 87
Siemens
RDG400KN,RGD405KN Basic documentation
CE1P3192en
Building Technologies
2017-02-17
Selection P07 = 7: CO
2
symbols
The CO
2
concentration is shown on the second line with "+++, ++-, +--". This
parameter can be useful when a VOC sensor is installed.
GOOD
: Current CO
2
concentration is below the CO
2
setpoint
OKAY
: Current CO
2
concentration is within the CO
2
Xp
(proportional band)
POOR
: Current CO
2
concentration is above the CO2
se Xp (proportional band)
When the thermostat is programmed with a CO
2
display (ppm or symbols) and no
values are available (no sensor on U1 or no value on KNX), or when the value
received is below 100 ppm, the thermostat displays "---"
IAQ control using a VOC sensor
The VOC sensor can only be connected to the local analog input U1.
Since the thermostat does not distinguish between CO
2
or VOC sensor, the IAQ
function and the thermostat’s behavior are the same as for applications with a CO
2
sensor.
For this application, we suggest to keep the default values of setpoint [P19] and
proportional band [P20]. Later, based on the occupant’s feeling, these parameters
can be readjusted for optimum room comfort.
3.2 Operating
modes
The thermostat's operating mode can be influenced in different ways (see below).
Specific heating and cooling setpoints are assigned to each operating mode.
The thermostat sends the effective room operating mode on the bus.
The following operating modes are available:
In Auto Timer mode, the room operating mode is commanded via bus.
Auto Timer mode is replaced by Comfort mode when no time schedule via bus is
present.
In Comfort mode, the thermostat maintains the Comfort setpoint. This setpoint can
be defined via P8, P9 and P10.
It can be locally adjusted via the rotary knob or the bus.
The thermostat switches to Comfort mode when the presence detector (local or via
KNX) is active (room occupied).*)
The setpoints (less heating and cooling than in Comfort mode) can be defined via
P11 and P12.
The thermostat switches to Economy mode when ...
– the operating mode button is pressed (only possible if P02 = 2),
– Economy is sent via bus,
KNX
R
Room operating mode:
State
Auto Timer
Comfort
Economy
KNX presence detector
(RDG405KN)