Danfoss VLT AQUA Drive FC 200 Programming Manual page 179

Parameter Description
Figure 3.76
NOTICE!
If the setpoint is reached after staging before the variable-
speed pump reaches its minimum speed, the system will
enter the closed-loop state as soon as the feedback
pressure crosses the setpoint.
25-43 De-staging Threshold
Range: Function:
Size [ 0 - When removing a fixed-speed pump, to prevent
related 100 an undershoot of pressure, the variable-speed
*
%] pump ramps up to a higher speed. When the
variable-speed pump reaches the "De-staging
Speed," the fixed-speed pump is de-staged. The
De-staging 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 De-staging threshold is the
ratio of 4-11 Motor Speed Low Limit [RPM] or
4-12 Motor Speed Low Limit [Hz], to the
4-13 Motor Speed High Limit [RPM] or 4-14 Motor
Speed High Limit [Hz], expressed in percent.
De-staging Threshold must range from
LOW
STAGE % =
HIGH
is Motor Speed Low Limit and n
Speed High Limit.
Figure 3.77
®
VLT AQUA Drive Programming Guide
to 100%, where n
× 100 %
LOW
is Motor
HIGH
®
MG20O622 - VLT is a registered Danfoss trademark
NOTICE!
If the setpoint is reached after staging before the variable-
speed pump reaches its maximum speed, the system will
enter the closed-loop state as soon as the feedback
pressure crosses the setpoint.
25-44 Staging Speed [RPM]
Range: Function:
0 [000 - Readout of the calculated value below for
RPM 0 RPM] Staging Speed. When adding a fixed-speed
*
pump, 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. Staging Speed calculation is based
on 25-42 Staging Threshold, and 4-13 Motor
Speed High Limit [RPM].
Staging Speed is calculated with the following
formula:
STAGE = HIGH
where n is Motor Speed High Limit and
HIGH
n is the value of Staging Threshold.
STAGE100%
25-45 Staging Speed [Hz]
Range: Function:
0 [0 - Readout of the calculated value below for Staging
Hz 0 Hz] Speed. When adding a fixed-speed pump, 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.
Staging Speed calculation is based on
25-42 Staging Threshold, and 4-14 Motor Speed High
Limit [Hz].
Staging Speed is calculated with the following
formula:
STAGE %
STAGE = HIGH
100
High Limit and n
Threshold.
STAGE %
100
where n is Motor Speed
HIGH
is the value of Staging
STAGE100%
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