Technische Alternative UVR 16x2 - Page 83

Cascade
83
Example 2
Automatic pump change
In large systems, a second pump is used as a backup. There is only ever one pump switched on in
the standard operating mode. The Cascade function can be used to carry out an automatic pump
change to even out the wear and tear on pumps.
Example 2: Input variables for cascade
Enable
ON
Enable generator A
ON
Enable generator B
ON
Enable generator C - H
OFF
Cascade stage 1
e.g. Function / Charging pump / Charging pump / Standard
Example 2: Parameters for cascade
Cascade stages settings
Sub-menu for setting the delay for each individual cascade stage:
All delays: 0 seconds
Generator settings
Here, the word generator refers to the pumps.
Sub-menu for setting the minimum runtimes, assigning the
generator sequence and selecting the generators for the automatic
generator change:
Minimum runtimes: both 0
Generator sequence assignment:
A: 1
B: 2
Automatic generator change: A and B: Yes
Hrs run Diff. for generator
change
Here too, the word generator refers to the pumps.
Example: 7 days
➢ Conditions for pump change:
o Every 10 minutes the controller checks whether the pump sequence should be changed.
o The change must be permitted for both 'generators' (in this case: pumps).
o If the difference in hours run is greater than the set differential the change will be carried
out if all the pumps affected by the change are either ON or OFF.
o If the difference in hours run is greater than twice the set differential, the change will be
carried out regardless of whether all the pumps are ON or OFF.
➢ As only one pump is ever switched on at a time, the pump change only occurs after twice
the set differential time, which in this example is after 14 days of pump operation.