The level control is based on two modes.
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Emptying mode
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Filling mode
The level control mode follows this sequence of operation:
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The “PmpLevelComparator” compares the actual level (“ActLevel”) with the set start levels (“StartLevel” [1...8]). Based on which the comparator decides the demand - “NoOfPumpDemand”. This demand goes as an input information to the “PmpLevelDistributor”.
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The “PmpLevelDistributor” then starts the required pumps. In case the pumps are driven by VFD, the distributor also gives the speed reference to each pump. The information of which pump to start in the sequence is given to the distributor by “PmpSequenceGen”.
Time diagram: Emptying mode
Time diagram: Filling mode
