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Siemens
Room Unit for Boiler Control
CE1U2283en
Building Technologies
Description of room unit settings
2015-09-16
To be able to use the control variant "Weather compensation with room influence",
the following conditions must be satisfied:
·
An
outside sensor
must be connected to boiler control
·
Room influence
must
be enabled to act on the relevant heating circuits
·
There may be
no thermostatic radiator valves
in the reference room (If such
valves are present, they must be set to their fully open position).
During quick setback, the heating circuit pump is deactivated.
·
Function with room sensor:
When using the room sensor, the function keeps the heating switched off until
the room temperature has dropped to the level of the reduced setpoint or the
frost level.
When the room temperature has fallen to the reduced level or the frost level, the
heating circuit pump will be activated and the mixing valve will be released.
·
Function without room sensor:
Quick setback switches the heating off for a certain period of time, depending on
the outside temperature and the building time constant.
Duration of quick setback when Comfort setpoint minus Reduced setpoint = 2 °C
(e.g. Comfort setpoint = 20 °C and Reduced setpoint =18 °C)
Outside temperature
composite:
Building time constant:
0
2
5
10
15
20
50
15 °C
0
3.1
7.7
15.3
23
30.6
76.6
10 °C
0
1.3
3.3
6.7
10
13.4
33.5
5 °C
0
0.9
2.1
4.3
6.4
8.6
21.5
0 °C
0
0.6
1.6
3.2
4.7
6.3
15.8
-5 °C
0
0.5
1.3
2.5
3.8
5.0
12.5
-10 °C
0
0.4
1.0
2.1
3.1
4.1
10.3
-15 °C
0
0.4
0.9
1.8
2.6
3.5
8.8
-20 °C
0
0.3
0.8
1.5
2.3
3.1
7.7
Duration of quick setback in hours
·
T Quick setback is possible with or without a room sensor
It is used for room temperature limitation. This function prevent rooms from getting
overheated.
The switching differential for 2-position control will be changed.
– – . –
Switching differential is inactive
– The pump always remains activated
Decrease: Switching differential will become smaller
– The pumps are switched on and off more often
– The room temperature varies within a narrower band
Increase: Switching differential will become greater
– The pumps are switched on and off less often
– The room temperature varies within a wider band
Quick setback (QSETB)
Example
Room temperature
maximum limitation
(SDR)
