Siemens RDG100 Basic Documentation page 22

Parameter P51
OFF
OFF
10...50 C (50...122 F)
10...50 C (50...122 F)
Application
2-pipe
2-pipe and electric heater
2-pipe and radiator
4-pipe
4-pipe and electric heater
2-stage
Note
Supply air temperature
limitation (RDG160T..)
Note
Dewpoint monitoring
22/81
Siemens
Building Technologies
The table below shows the relation between parameter, temperature source and
temperature display:
External temp. sensor Source for display of room
available temperature
No Built-in sensor
Yes External temp. sensor
No Built-in sensor
Yes Built-in sensor
The floor temperature limitation function influences the outputs listed in the table
below:
Output Y1 Output Y2
H/C valve
H/C valve Electric heater
H/C valve Radiator
Heating valve Cooling valve
Heating valve Cooling valve
st nd
1 H/C 2 H/C
*)
If P13 = ON electric heater in cooling mode
Either floor temperature sensor or external room temperature sensor can be used.
This function increases the comfort in the room by keeping the supply air temperature
of the fan coil unit between the selected minimum and maximum temperature limits.
If the supply air temperature exceeds a limit, the thermostat reduces the
corresponding valve position until the supply air temperature is back in the limits.
In case the air flow is too low (especially with DC 0...10 V fans), this prevents cold air
from dumping into the room/warm air from bubbling straight up instead of circulating.
To enable this function, the multifunctional input, to which the supply air sensor is
connected, needs to be set to "Supply air sensor" (e.g. P38=9). Then the parameters
for the limits are visible (P63: minimum supply air temperature, P64: maximum supply
air temperature).
This function is only active in Comfort mode and can only be used with DC 0...10 V
actuators.
For applications with electric heater and radiator, this function is available only on the
cooling valve (in cooling mode).
Dewpoint monitoring is essential to prevent condensation on the chilled ceiling
(cooling with fan disabled, parameter P52). It helps avoid associated damage to the
building.
A dewpoint sensor with a potential-free contact is connected to multifunctional input
X1, X2 or D1. If there is condensation, the cooling valve is fully closed until no more
condensation is detected, and the cooling output is disabled temporarily.
The condensation symbol
The input must be commissioned accordingly (P38, P40, P42).
See section 4.10.
RDG100.., RDG110.., RDG160T.. Basic Documentation
Functions
Output control according to
Built-in sensor
External temp. sensor
Built-in sensor
Built-in sensor + limit by
external sensor
Floor temp. limit function has influence on
output
Heat. mode
Output Y3 (P01=0/2/3)
Y1
Y2
Y2
Y1
Electric heater Y3
Y1, Y2
is displayed during temporary override.
Floor temp. limit
function
Not active
Not active
Not active
Active
Cool. mode Heat. and cool.
(P01=1/2/3) mode (P01=4)
N/A
*)
Y2
Y2
N/A Y1
N/A Y3
N/A
Remark
Only electric heater
Only radiator
Only electric heater
CE1P3181en
2015-07-29