Danfoss VLT AQUA Drive FC 202 Programming Manual page 216

Parameter Description
Motor speed
high limit
Destaging
speed
Motor speed
low limit
3 3
Motor speed
high limit
Destaging
speed
Motor speed
low limit
Motor speed
high limit
Destaging
speed
Motor speed
low limit
Illustration 3.92 Destaging Speed
25-49 Staging Principle
Select the staging principle for the staging of fixed speed pumps
(direct online mode). To configure the frequency converter to
return to closed-loop operation immediately after a pump was
staged or destaged, select [1] Rapid Staging. Use [1] Rapid Staging
in systems with rapid demand changes.
Option:
[0]
*
[1]
3.22.4 25-5* Alternation Settings
Parameters for defining the conditions for alternation of
the variable speed pump (lead), if selected as control
strategy.
25-50 Lead Pump Alternation
Option:
[0] Off
214
VLT
Variable speed
pump
Controlled stop Seconds
command
activated
Fixed speed
pump
Seconds
Fixed speed
pump
Seconds
Function:
Normal
Rapid Staging
Function:
NOTICE
If parameter 25-05 Fixed Lead Pump is set
to [1] Yes, it is only possible to select [0]
Off.
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 selecting the pump
with the lowest number of hours run to stage
on next.
No alternation of lead pump function takes
place. It is not possible to set this parameter to
options other than [0] Off if
parameter 25-02 Motor Start is set other than [0]
Direct on Line.
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®
AQUA Drive FC 202
25-50 Lead Pump Alternation
Option:
[1] At staging
[2] At
command
[3] At staging
or
command
25-51 Alternation Event
Option:
[0] External
*
[1] Alternation
Time
Interval
[2] Sleep Mode Alternation takes place each time the lead
[3] Predefined
Time
25-52 Alternation Time Interval
Range:
24 [1 -
h 999 h]
*
Function:
Alternation of the lead pump function takes
place when staging another pump.
Alternation of the lead pump function takes
place at an external command signal or a pre-
programmed event. See
parameter 25-51 Alternation Event for available
options.
Alternation of the variable speed (lead) pump
takes place at staging or according to [2] At
command.
Function:
This parameter is only active if the options [2]
At Command or [3] At Staging or Command
have been selected in parameter 25-50 Lead
Pump Alternation. If an alternation event is
selected, the alternation of lead pump takes
place every time the event occurs.
Alternation takes place when a signal is
applied to 1 of the digital inputs on the
terminal strip and this input has been assigned
to [121] Lead Pump Alternation in parameter
group 5-1*, Digital Inputs.
Alternation takes place every time
parameter 25-52 Alternation Time Interval
expires.
pump goes into sleep mode. Set
parameter 20-23 Setpoint 3 to [1] Sleep Mode or
apply an external signal for this function.
Alternation takes place at a defined time of the
day. If parameter 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).
Function:
If selecting [1] Alternation Time Interval in
parameter 25-51 Alternation Event, the alternation
of the variable speed pump takes place every
time the alternation time interval expires (can be
checked in parameter 25-53 Alternation Timer
Value). The timer pauses when the frequency
converter is not running.
MG20OB02