Siemens Climatix Series Basis Document page 68

HrecDampr Sequence
Function
Parameterization
Parameter
Controller
Output signal
Recovery value
Min fresh air
Start up time
Start up tmp
Startup behavior
Function
Cooling recovery function
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Basis Document Siemens Climatix Control System
Siemens
Page 68
BDCX.100820.01GB
Building Technologies
• Position Damper-Htg: For heating, the mixed air damper is deployed to the
maximum allowable recirculating position (depends on Min FreshAir), before the
subsequent heating register starts.
• Position Htg-Damper: For heating, the heating register is first deployed to full
load prior the mixed air damper control starts. The startup function for the mixed
air damper control must be disabled (StartupTime = 0 s), since otherwise the
heating register starts off directly at 100%& output.
Mixed air damper control is used for heat or cooling recovery.
The direction of control action (normal/inverse) and a minimum ration of fresh air
can be set. The plant can be started for a set period at full recirculation in depend-
ence on the outside air temperature.
Mixed damper is forced to full return air if:
– Night unoccupied (temperaturstart) heat and cool
– OSSTP/Boost
Mixed damper is forced to full fresh air if:
– Summer night cooling
– Supply fan after run
– Fire mode with running fan
Main Index > Unit > Temp control > Hrec damper
Range
0...100 [%]
0...100 [%]
0...100 [%]
0...100 [%]
0...600 [s]
–64.0...64.0 [°C]
The mixed air damper is fully opened during the startup period for outside air tem-
perature < Startup temp at startup. The controller determines the present position
after this period expires.
If heat demand exists at startup, the heating register is started in parallel, and after
successful startup, the mixed air controller for heat recovery deploys to the maxi-
mum allowable position (100% - MinFreshAir).
Cooling recovery starts, when the following conditions are met:
– Outside air temperature > room temperature + 2K
and
– Room temperature > room setpoint + 1K
Cooling recovery stops for the following cases:
– Outside air temperature <= Room temperature
or
– Room temperature >= room setpoint.
Standard application AHU
Functions
Function
Present value of the mixed air controller. Go to con-
troller settings page.
Present value for damper actuator output. Go to page
with all analog output settings.
Displays present heat recovery. For Hrec damper =
Normal, this value is always the same as the output
signal. For Hrec damper = Inverse, this value is always
the inverse of the output signal.
Minimum fresh air ratio. The controller output is limited
to 100 % - min fresh air. This ensures that some
amount of fresh air always makes it to the room.
Time for controller start behavior (100 % recircula-
tion).
Temperature limit for start behavior.
CE1P3977en_02
01.02.2010