25-46 Destaging Speed [RPM]
Option:
Function:
25-43 Destaging Threshold
and
Destaging Speed is calculated with the following
formula:
ηDESTAGE = ηHIGH
ηDESTAGE%
100
where n
HIGH
is Motor
Speed High Limit and n
DESTAGE100%
is the value of
Destaging 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
25-43 Destaging
Threshold
and
4-14 Motor Speed High Limit [Hz]
Destaging Speed is calculated with the following
formula:
ηDESTAGE = ηHIGH
ηDESTAGE%
100
where n
HIGH
is Motor Speed High Limit and n
DESTAGE100%
is the value of Destaging Threshold.
Illustration 3.67
3.19.6 25-8* Status
Readout parameters informing about the operating status
of the pack controller and the compressors controlled.
25-80 Pack Status
Option:
Function:
Read out of the status of the Pack Controller.
Disabled
Pack Controller is disabled (
25-00 Pack
Controller
).
Emergency
All compressors have been stopped by means
of a Coast/Coast inverse or an External Interlock
command applied to the frequency converter.
25-80 Pack Status
Option:
Function:
Off
All compressors have been stopped by means
of a Stop command applied to the frequency
converter.
In Open Loop
has been set for
[0]
Open Loop
. All fixed speed compressors are
stopped. The variable speed compressor will
continue to run.
Frozen
Staging/destaging of compressors has been
locked and reference locked.
Jogging
All fixed speed compressors are stopped. When
stopped, the variable speed compressor will run
at jog speed.
Running
A Start command is applied to the frequency
converter and the Pack controller is controlling
the compressors.
Running FSBW The frequency converter is tripped off and the
Pack Controller is controlling the fixed speed
compressors based on
Staging
The Pack Controller is staging fixed speed
compressors.
Destaging
The Pack Controller is destaging fixed speed
compressors.
Lead Not Set
No compressor available to be assigned as
variable speed compressor.
25-81 Compressor Status
Option:
Function:
Compressor Status shows the status for the
number of compressors selected in
. It is a readout of
the status for each of the compressors
showing a string, which consists of
compressor number and the current status of
the compressor.
Example: Readout is with the abbreviation like
“1:D 2:O” This means that compressor 1 is
running and speed controlled by the
frequency converter and compressor 2 is
stopped.
[X] Disabled
The compressor is interlocked either via
25-90 Compressor Interlock
, or signal on a
digital input programmed for Compressor
(number on compressor) Interlock in
Digital
Inputs
, parameter group 5-1*. Can only refer to
fixed speed compressors.
[O] Off
Stopped by the cascade controller (but not
interlocked).
[D] Running on
Frequency
Converter
Variable speed compressor, regardless if
connected directly or controlled via relay in
the frequency converter.
[R] Running on
Mains
Running on mains. Fixed speed compressor
running.
Parameter Description
VLT
®
Refrigeration Drive Programming Guide
MG16H102 - VLT
®
is a registered Danfoss trademark
155
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