Danfoss VLT HVAC Series Programming Manual page 269

VLT ® HVAC Drive Programming Guide
3.23.5 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:
[0] * OFF
[1] At staging
[2] At command
[3] At staging or at command
NOTE!
It is not possible to select other than
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.
No alternation of lead pump function will take place. It is not possible to set this parameter to options
Off Motor Start
other that [0] if par.25-02
Alternation of the lead pump function will take place when staging another pump.
Alternation of the lead pump function will take place at an external command signal or a pre-pro-
Alternation Event
grammed event. See par.25-51
Alternation of the variable speed (lead) pump will take place at staging or the "At Command" signal.
(See above.)
Off Fixed Lead Pump
[0] if par.25-05
MG.11.C6.22 - VLT ® is a registered Danfoss trademark
3 Parameter Description
Direct on Line
is set other than [0].
for available options.
Yes
is set to [1].
3
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