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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 choos-
ing 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. 25-03, Motor Start
, 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-programmed event.
See
par. 25-51, Alternation Event
, for available options.
[3]
At Staging or at Com-
mand
Alternation of the variable speed (lead) pump will take place at staging or the “At Command” signal. (See above.)
NB!
It is not possible to select other than
Off
[0] if
par. 25-05, Fixed Lead Pump
, is set to
Yes
[1].
VLT
®
HVAC Drive Programming Guide
3. Parameter Description
MG.11.C5.02 - VLT
®
is a registered Danfoss trademark
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