Danfoss VLT FC 100 Series Programming Manual page 215

®
VLT HVAC Drive Programming Guide
25-42 Staging Threshold
Range:
*
90% [0 – 100%]
25-43 Destaging Threshold
Range:
*
50% [0 – 100%]
Function:
When adding a fixed speed pump, in order to prevent an overshoot of pressure, the variable speed pump ramps
down to a lower speed. When the variable speed pump reaches the "Staging Speed" the fixed speed pump is
staged on. The Staging Threshold is used to calculate the speed of the variable speed pump when the "cut-in
point" of the fixed speed pump occurs. The calculation of the Staging Threshold is the ratio of
Limit Motor Speed High Limit
, par. 4-11 or 4-12, to the
η
Staging Threshold must range from
to 100%, where n is Motor Speed Low Limit and n
LOW
Function:
When removing a fixed speed pump, in order to prevent an undershoot of pressure, the variable speed pump
ramps up to a higher speed. When the variable speed pump reaches the "Destaging Speed" the fixed speed pump
is destaged. The Destaging Threshold is used to calculate the speed of the variable speed pump when the de-
staging of the fixed speed pump occurs. The calculation of the Destaging Threshold is the ratio of
Low Limit Motor Speed High Limit
, par. 4-11 or 4-12, to the
Destaging Threshold must range from
Speed Low Limit and n is Motor Speed High Limit.
HIGH
MG.11.C5.02 - VLT ® is a registered Danfoss trademark
, par. 4-13 or 4-14, expressed in percent.
η
LOW
% = × 100 %
STAGE
η
HIGH
is Motor Speed High Limit.
HIGH
, par. 4-13 or 4-14, expressed in percent.
η
LOW
η = × 100 %
STAGE
%
η
HIGH
3. Parameter Description
Motor Speed Low
Motor Speed
to 100%, where n is Motor
LOW
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