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Siemens  Standard application AHU  CE1P3977en_02 
Building Technologies  Functions  01.02.2010 
Parameter  Range  Function 
Disable high speed  -64.0…64.0 [°C] 
 
Stages greater than 1 (setpoint stage 1) are blocked (as with 
manual operation) if the outside air temperature < Disable High-
Speed. All possible stages are enabled for outside air tempera-
ture > Disable HighSpeed + 1K. In Winter (at low outside air 
temperature) the function prevents too great a volume of air from 
discharging requiring heating, saving energy in this manner. 
Disable fan comp   
 
–  None 
 
 
 
 
 
–  St4age 1 
 
 
 
 
 
 
–  St4age1+Stage
2 
Limit to compensated step up (step up switching): 
–  No limit. For active stage 1 can be switched to stage 2, for 
active stage 2 to stage 3. For analog controlled variable speed 
drives (Fan control mode <> Direct or DirectVar), can be 
stepped up per curve (see Fan compensation) for active 
stage1 setpoint and stage2 setpoint. 
–  Compensation blocked for active stage 1(Stage1 setpoint). 
Can be switched to stage 3 for active stage 2. 
For analog controlled variable speed drives (Fan control mode 
<> Direct or DirectVar), can be stepped up per curve (see Fan 
compensation) for active stage2 setpoint. 
–  Compensation blocked for active stage 1 and active stage 2. 
For analog controlled variable speed drive the active stage 3 
can be compensated to MaxForce. 
Summer comp  -100….100%    Present value for summer compensation. Go to parameter page 
for summer compensation. 
Winter comp  -100….100%    Present value for winter compensation. Go to parameter page for 
winter compensation. 
Op hours settings    Go to parameter page for fan maintenance messages. 
 
 
5.4.2  General Operating Modes 
 
The following relationship apply among the values for the parameters fan control 
mode, TSP steps, fan step freq conv and fan steps type.  
Fan control mode = Direct/DirectVar 
  DO1  DO2  DO3 
Off  0  0  0 
Stage1  1  0  0 
Stage2  0  1  0 
Stage3  0  0  1 
DOs each for supply fan and  exhaust fan (if 
selected) 
 
Fan control mode <> Direct/DirectVar, Fan steps freq conv = 1 
  DO1 
Off  0 
Stage1  1 
Stage2  1 
Stage3  1 
 
DO1 each for supply fan and exhaust fan (if 
selected) 
 
Fan control mode <> Direct/DirectVar, Fan steps freq conv > 1 
  DO1  DO2  DO3 
Off  0  0  0 
Stage1  1  0  0 
Stage2  1  1  0 
DOs each for supply fan and  exhaust fan (if 
selected)
 
Fan steps type = 
Separated 
Fan steps type = 
Separated (Forts.) 
Basis Document Siemens Climatix Control System
BDCX.100820.01GB
Page 52