Danfoss VLT AQUA Drive FC 202, Programming Manual

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25-43 Destaging Threshold
Range: Function:
Size
related
*
[ 0 -
100 %
] 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. 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
STAGE % =
LOW
HIGH
× 100 %
to 100%, where n
LOW
is
motor speed low limit and n
HIGH
is motor
speed high limit.
130BA367.10
3 5 0 1 Seconds
Variable speed
pump
Fixed speed
pump
Motor speed
high limit
Destaging
speed
Motor speed
low limit
Illustration 3.91 Destaging Threshold
25-44 Staging Speed [RPM]
Range: Function:
0
RPM
*
[000 -
30000
RPM] Readout of the calculated value for 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:
η
STAGE
= η
HIGH
η
STAGE %
100
where n
HIGH
is motor speed high limit and
n
STAGE100%
is the value of staging threshold.
25-45 Staging Speed [Hz]
Range: Function:
0
Hz
*
[0 -
6500
Hz] Readout of the calculated value for 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 4-14 Motor Speed High Limit [Hz] .
Staging speed is calculated with the following
formula:
STAGE = HIGH
STAGE %
100
where n
HIGH
is motor speed
high limit and n
STAGE100%
is the value of staging
threshold.
25-46 Destaging Speed [RPM]
Range: Function:
0
RPM
*
[000 -
30000
RPM] Readout of the calculated value for 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
DESTAGE %
100
where n
HIGH
is motor
speed high limit and n
DESTAGE100%
is the value
of destaging threshold.
25-47 Destaging Speed [Hz]
Range: Function:
0
Hz
*
[0 -
6500
Hz] Readout of the calculated value for 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 = HIGH
DESTAGE %
100
where n
HIGH
is motor speed high limit and
n
DESTAGE100%
is the value of destaging threshold.
Parameter Description Programming Guide
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