25-47 Destaging Speed [Hz]
Range:
Function:
0.0
Hz
*
[0.0
- 0.0
Hz]
Readout of the below calculated value for
Destaging Speed. When removing a fixed speed
pump, in order 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
, and
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.
Seconds
Variable speed
pump
Motor speed
high limit
Destaging
speed
Motor speed
low limit
Fixed speed
pump
Motor speed
low limit
Destaging
speed
Motor speed
high limit
Seconds
Fixed speed
pump
Motor speed
high limit
Destaging
speed
Motor speed
low limit
Seconds
Controlled stop
command
activated
130BA368.10
3.23.4 25-5* Alternation Settings
Parameters for defining the conditions for alternation of
the variable speed pump (lead), if selected as part of the
control strategy.
25-50 Lead Pump Alternation
Option:
Function:
Lead pump alternation equalizes the use of
pumps by periodically changing the pump
that is speed controlled. This ensures that
pumps are equally used over time.
Alternation equalizes the usage of pumps by
always choosing the pump with the lowest
number of used hours to stage on next.
[0]
*
Off
No alternation of lead pump function will
take place. It is not possible to set this
parameter to options other that
Off
[0] if
is set other than
Direct on
Line
[0].
[1]
At staging
Alternation of the lead pump function will
take place when staging another pump.
25-50 Lead Pump Alternation
Option:
Function:
[2]
At
command
Alternation of the lead pump function will
take place at an external command signal or
a pre-programmed event. See
for available options.
[3]
At staging
or
command
Alternation of the variable speed (lead) pump
will take place at staging or the “At
Command” signal. (See above.)
NOTE
It is not possible to select other than
Off
[0] if
is set to
Yes
[1].
25-51 Alternation Event
Option:
Function:
This parameter is only active if the options
At
Command
[2] or
At Staging or Command
[3]
have been selected in
. If an Alternation Event is
selected, the alternation of lead pump takes
place every time the event occurs.
[0]
*
External
Alternation takes place when a signal is
applied to one of the digital inputs on the
terminal strip and this input has been
assigned to
Lead Pump Alternation
[121] in
parameter group 5-1*, Digital Inputs
.
[1]
Alternation
Time Interval
Alternation takes place every time
25-52 Alternation Time Interval
, expires.
[2]
Sleep Mode
Alternation takes place each time the lead
pump goes into sleep mode.
must be set to
Sleep Mode
[1] or an external
signal applied for this function.
[3]
Predefined
Time
Alternation takes place at a defined time of
the day. If
25-54 Alternation Predefined Time
is set, the alternation is carried out every day
at the specified time. Default time is
midnight (00:00 or 12:00AM depending on
the time format).
25-52 Alternation Time Interval
Range:
Function:
24 h
*
[1 - 999
h]
If
Alternation Time Interval
[1] option in
, is selected, the
alternation of the variable speed pump takes
place every time the Alternation Time Interval
expires (can be checked out in
25-53 Alternation Timer Value
Range:
Function:
0
*
[0 - 0 ] Readout parameter for the Alternation Time
Interval value set in
25-52 Alternation Time Interval
.
Parameter Description
VLT
®
HVAC Drive Programming Guide
MG.11.CC.02 - VLT
®
is a registered Danfoss trademark
183
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