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Building Technologies   Basic documentation LMV37.4...  CC1P7546en 
 12 Fan control  17.12.2018 
12.11 Standardization of speed 
 
Since the different types of fans operate at different speeds and signal handling should 
be as straightforward as possible, all speeds in the LMV37.4 are standardized between 
0% and 100%. For this reason, the VSD module uses a parameter which contains the 
Standard speed (100% speed). All absolute speeds refer to this speed. 
 
If changes to the VSD or the fan are made, speed standardization should be repeated. 
 
 
Caution! 
  If automatic speed standardization is activated, or if the standardized 
speed is changed, the settings of fuel-air ratio control must be checked! 
Any change of the standardized speed alters the assignment between the 
percentage values parameterized on the curves and the speed 
  When the parameter set (refer to ACS410 (J7352)) is restored, the 
standardized speed is restored also. 
If a data set is transferred to a new LMV37.4 via the restore process (e.g. 
during a device replacement), the standardization of the speed must be 
carried out again 
  In pneumatic fuel-air ratio control, at least one additional supervision 
threshold (parameter 667, 668 or 669) must be activated to carry out a 
speed standardization 
 
No. Parameter 
667 Minimum prepurge speed 
668 Maximum ignition speed 
669 
Minimum / maximum speed limitation in operation 
Index 0 = minimum speed 
Index 1 = maximum speed