Danfoss VLT AQUA Drive FC 202 Programming Manual page 215

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
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
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 3.91 Destaging Threshold
25-44 Staging Speed [RPM]
Range: Function:
0 [000 - Readout of the calculated value for staging
RPM 30000 speed. When adding a fixed speed pump to
*
RPM] 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:
η
STAGE %
η = η
STAGE HIGH
where n
HIGH
n is the value of staging threshold.
STAGE100%
MG20OB02
Programming Guide
to 100%, where n is
× 100 %
LOW
is motor
HIGH
Variable speed
pump
5 Seconds
100
is motor speed high limit and
Danfoss A/S © 05/2018 All rights reserved.
25-45 Staging Speed [Hz]
Range: Function:
0 [0 - Readout of the calculated value for staging
Hz 6500 speed. When adding a fixed speed pump to
*
Hz] 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
threshold.
25-46 Destaging Speed [RPM]
Range: Function:
0 [000 - Readout of the calculated value for destaging
RPM 30000 speed. When removing a fixed speed pump to
*
RPM] 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
of destaging threshold.
25-47 Destaging Speed [Hz]
Range: Function:
0 [0 - Readout of the calculated value for destaging
Hz 6500 speed. When removing a fixed speed pump to
*
Hz] 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
100
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
STAGE100%
where n is motor
DESTAGE %
HIGH
100
is the value
DESTAGE100%
213
3 3