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SECTION 4
Pr.55 Pump Maintenance Dropout
(D=0)
The removal of one pump for maintenance can necessitate a great deal of
readjustment to ensure correct control. Pr.55 removes this need by allowing one
pump to be removed without affecting the control levels. Pumps are re-assigned
downwards so that the highest level is not used, therefore, normal control levels are
maintained for lower level setting.
Enter 0
1
2
3
4
5
NOTE:
-
All pumps in
Drop out pump 1
Drop out pump 2
Drop out pump 3
Drop out pump 4
Drop out pump 5
a.
The system assumes that the lower numbered pumps turn on first.
b.
CAUTION - A PUMP NOT INCLUDED IN AN ALTERNATING
SEQUENCE BUT PROGRAMMED INTO THE FIXED PART OF
THE SEQUENCE WILL BE SUBSTITUTED INTO THE ALTERNATING SEQUENCE TO REPLACE A PUMP DROPPED OUT.
c.
This feature should not be used if the relays are being used for a
mixture of pump control and alarm functions.
Pr.56 Pump Run-on Interval
(D=0.00)
When submersible pumps are used, it may be necessary to pump down occasionally to
clear the sludge from the bottom of the well. This feature is controlled by Pr.56 and
Pr.57. Once in every interval defined by Pr.56, the pump will run-on for the time
period defined by Pr.57.
Enter the time interval in hours between each run-on cycle.
Pr.57 Pump Run-on Time
(D=0)
Enter the pump running time in seconds. Maximum 120 seconds.
Only one run-on cycle occurs per interval as set by Pr.56.
NOTE:
a.
Caution is required when choosing a value for pump run-on time,
as extended pump run-on can lead to cavitation, causing air locks or
pump damage.
b.
As overflow can occur, do not use pump run-on for pump up
operation, set Pr.56 and Pr.57 to zero.
c.
Care should be taken if pump sequence and pump run-on are defined
together, as pump run-on will be assigned to the last pump to turn off,
which could be any of those in the sequence.
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Ref: PANEL MANUAL LMPIM-2
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