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:
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 par.25-02
is set other than
Direct on Line
[0].
[1]
At staging
Alternation of the lead pump function will take place when staging another pump.
[2]
At command
Alternation of the lead pump function will take place at an external command signal or a pre-pro-
grammed event. See par.25-51
for available options.
[3]
At staging or at 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 par.25-05
is set to
Yes
[1].
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HVAC Drive Programming Guide
3 Parameter Description
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