Alternation Settings - Danfoss VLT FC 102 Programming Manual

Programming Guide | VLT® HVAC Drive FC 102
Readout of the calculated value for destaging speed. When removing a fixed-speed pump to prevent an overshoot 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 calculation is based on parameter 25-43 Destaging Threshold and parameter 4-14 Motor Speed High Limit
[Hz].
The staging speed is calculated with the following formula:
where n
Motor speed
high limit
Destaging
speed
Motor speed
low limit
Controlled stop
command
activated
Motor speed
high limit
Fixed-speed
pump
Destaging
speed
Motor speed
low limit
Motor speed
high limit
Destaging
speed
Motor speed
low limit
Figure 110: Destaging Speed

25-5* Alternation Settings

6.25.5
The parameters in this group are for defining the conditions for alternation of the variable-speed pump if alternation is selected as
control strategy.
25-50 Lead Pump Alternation
Default value: [0] Off
Setup: All setups
Data type: Uint8
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.
Option Name
[0]* Off
[1] At staging
564 | © 2024.10
is motor speed high limit, and n
HIGH
Variable-speed
pump
Seconds
Seconds
Fixed-speed
pump
Seconds
is the value of the destaging threshold.
DESTAGE100%
Parameter type:
Conversion index:
Change during operation:
NOTICE
Description
No alternation of lead-pump function takes place. If parameter
25-02 Motor Start is set to other than [0] Direct on line, it is not
possible to set this parameter to options other than [0] Off.
Alternation of the lead-pump function takes place when staging
another pump.
Parameter Descriptions
Option
–
True
AU430028034214en-001901 / 130R0310