Destaging Threshold; Staging Speed; Destaging Speed - Danfoss VLT CDS 303 Operating Instructions Manual

Parameter Descriptions

25-43 Destaging Threshold

Range: Function:
50% [0 – When removing a fixed speed compressor, in
*
100%] order to prevent an undershoot of pressure, the
variable speed compressor ramps up to a higher
speed. When the variable speed compressor
reaches the "Destaging Speed" the fixed speed
compressor is destaged. The Destaging
Threshold is used to calculate the speed of the
variable speed compressor when the destaging
of the fixed speed compressor 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
η
LOW
η = × 100 %
STAGE % η
HIGH
to 100%, where n
and n is Motor Speed High Limit.
HIGH
Figure 6.34 Destaging Threshold
25-44 Staging Speed [RPM]
Option: Function:
0 N/A Readout of the below calculated value for Staging
Speed. When adding a fixed speed compressor, in
order to prevent an overshoot of pressure, the
variable speed compressor ramps down to a lower
speed. When the variable speed compressor reaches
the "Staging Speed" the fixed speed compressor 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 100
where n is Motor Speed High Limit and n
HIGH
is the value of Staging Threshold.
25-45 Staging Speed [Hz]
Option: Function:
0 N/A Readout of the below calculated value for Staging
Speed When adding a fixed speed compressor, in
order to prevent an overshoot of pressure, the
variable speed compressor ramps down to a lower
MG34M422
Operating Instructions
is Motor Speed Low Limit
LOW
STAGE100%
Danfoss A/S © Rev. 2013-07-03 All rights reserved.
25-45 Staging Speed [Hz]
Option: Function:
speed. When the variable speed compressor reaches
the "Staging Speed" the fixed speed compressor 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:
η
STAGE % where n
η = η
STAGE HIGH 100
Limit and n is the value of Staging Threshold.
STAGE100%
25-46 Destaging Speed [RPM]
Option: Function:
0 N/A Readout of the below calculated value for Destaging
Speed. When removing a fixed speed compressor, in
order to prevent an undershoot of pressure, the
variable speed compressor ramps up to a higher
speed. When the variable speed compressor reaches
the "Destaging Speed" the fixed speed compressor is
destaged. Destaging Speed is calculated based on
parameter 25-43 De-staging Threshold and
parameter 4-13 Motor Speed High Limit [RPM].
Destaging Speed is calculated with the following
formula:
η
DESTAGE % where n
η = η
DESTAGE HIGH 100
Limit and n
DESTAGE100%
Threshold.
25-47 Destaging Speed [Hz]
Option: Function:
Readout of the below calculated value for Destaging
Speed. When removing a fixed speed compressor, in
order to prevent an undershoot of pressure, the
variable speed compressor ramps up to a higher speed.
When the variable speed compressor reaches the
"Destaging Speed" the fixed speed compressor is
destaged. Destaging Speed is calculated based on
parameter 25-43 De-staging Threshold and
parameter 4-14 Motor Speed High Limit [Hz]
Destaging Speed is calculated with the following
formula:
η
DESTAGE %
η = η
DESTAGE HIGH
100
where n is Motor Speed High Limit and n
HIGH
is the value of Destaging Threshold.
is Motor Speed High
HIGH
is Motor Speed High
HIGH
is the value of Destaging
DESTAGE100%
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