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Siemens
Standard application AHU
CE1P3977en_02
Building Technologies
Functions
01.02.2010
Main Index > Global functions > Su/Wi calculation
Parameter
Range
Function
State
– Winter
– Summer
Status of Summer/Winter changeover:
– Winter operation is enabled.
– Summer operation is enabled.
Su/Wi input
– Winter
– Summer
Status of input on hardware side for changeover.
Go to page with all digital input settings. For exam-
ple, you can change the input’s direction of control
there.
– Winter operation enabled: Signal 0.
– Summer operation enabled: Signal 1.
Outs air tmp damped
Damped outside air temperature.
Summer date / time
*.* *:*
Set date and time for changeover to summer op-
eration.
Example:
23:30 01.Apr ---> Changeover on April 1 at 11:30
pm.
– Asterisks only (*.* *:*): Changeover date is not
relevant; changeover occurs based on tempera-
ture.
– Permissible time entries:
*:* ---> 00:00
*:20 ---> 00:20
10:* ---> 10:00.
– Date entry:
Allowed: 15.May
Not allowed by month: Odd / Even.
Winter date / time
*.* *:*
Set date and time for changeover to winter opera-
tion.
Example:
10:40:00 PM 01.Oct ---> Changeover on October
1 at 10:40 pm.
Note: See summer date / time
Time constant
0…36000 [h]
Time constant to calculate dampened (determined
over this period) outside air temperature. Set this
value for the short period to 0 to reset the damp-
ened or assume present outside air temperature.
Outs air tmp summer
-64...64 [°C]
Changes over to summer operation when the
damped outside air temperature is greater than this
value.
Outs air tmp winter
-64...64 [°C]
Changes over to winter operation when the
damped outside air temperature is less than this
value.
Parameter
Basis Document Siemens Climatix Control System
BDCX.100820.01GB
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