Danfoss VLT AQUA Drive FC 202 Programming Manual page 181

Parameter Description
25-43 Destaging Threshold
Range: Function:
Size [ 0 - When removing a fixed speed pump to
related 100 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 destaging
of the fixed speed pump occurs. The
calculation of the destaging threshold is the
ratio of parameter 4-11 Motor Speed Low Limit
[RPM] or parameter 4-12 Motor Speed Low Limit
[Hz], to the parameter 4-13 Motor Speed High
Limit [RPM] or parameter 4-14 Motor Speed
High Limit [Hz], expressed in percent.
Destaging threshold must range from
LOW
STAGE % =
HIGH
is motor speed low limit and n
Speed High Limit.
Motor speed
high limit
Destaging
speed
Fixed speed
pump
Motor speed
low limit
0 1 3
Illustration 3.83 Destaging Threshold
NOTICE
If the setpoint is reached after staging before the
variable speed pump reaches its maximum speed, the
system will enter the state closed loop as soon as the
feedback pressure is crossing the setpoint.
25-44 Staging Speed [RPM]
Range: Function:
0 [000 - Readout of the below calculated value 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 parameter 25-42 Staging Threshold, and
parameter 4-13 Motor Speed High Limit [RPM].
Staging speed is calculated with the following
formula:
STAGE %
STAGE = HIGH
where n is motor speed high limit and
HIGH
n is the value of staging threshold.
STAGE100%
MG20O702
Programming Guide
to 100%, where n
× 100%
LOW
is Motor
HIGH
Variable speed
pump
5 Seconds
100
Danfoss A/S © Rev. 2014-01-21 All rights reserved.
25-45 Staging Speed [Hz]
Range: Function:
0 [0 - Readout of the below calculated value 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
parameter 25-42 Staging Threshold, and
parameter 4-14 Motor Speed High Limit [Hz].
Staging speed is calculated with the following
formula:
STAGE %
STAGE = HIGH
100
high limit and n
STAGE100%
threshold.
25-46 Destaging Speed [RPM]
Range: Function:
0 [000 - Readout of the below calculated value for
RPM 0 RPM] destaging speed. When removing a fixed speed
*
pump 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. Destaging speed is calculated based
on parameter 25-43 Destaging Threshold, and
parameter 4-13 Motor Speed High Limit [RPM].
Destaging speed is calculated with the
following formula:
DESTAGE = HIGH
speed high limit and n
destaging threshold.
25-47 Destaging Speed [Hz]
Range: Function:
0 [0 - Readout of the below calculated value for
Hz 0 Hz] destaging speed. When removing a fixed speed
*
pump 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. Destaging speed is calculated based on
parameter 25-43 Destaging Threshold, and
parameter 4-14 Motor Speed High Limit [Hz].
Destaging speed is calculated with the following
formula:
DESTAGE %
DESTAGE = HIGH
where n is motor speed high limit and
HIGH
n is the value of destaging threshold.
DESTAGE100%
where n is motor speed
HIGH
is the value of staging
DESTAGE %
where n is motor
HIGH
100
is the value of
DESTAGE100%
100
179
3 3