Sulzer ABS PC 441 - Page 34

81307063I
EN
30
Calculation functionality check routines
1. Thelevelreadingstaysonaconstantvalue-PC441hasabuilt-inleveldeviationmonitoringfeature.
2. Thelevelreadingisonaconstantlevelduetoaoverowsituation-Aspeciallydesignedoverowdetection
sensortypeMD131canbeusedtodetectthis.
3. Theactuallevelforthehighlevelalarmfromaoatcanbeentered,thislevelcanthenbeusedtocompare
with the level sensor reading. If a certain deviation from this set-point is detected a sensor failure alarm can
be raised.
Point 1 and 3 are covered in the
below settings
Point2iscoveredbyinstallingthe
MD131sensor
Calculation
Compilation of above
Whenonepumpstartsalone:
• Theactualinowvaluewhenthepumpstartsistemporarilystoredandtheindicatedinowvalue
frozen.
• Theoutowvalueisnowrampedupforacongurabletimeframe.“Startdelay”
• Thepumpcapacityiscalculatedduringacongurabletimeframe.“Calculationtime”
• Theinowindicationlockisreleased.Theinowisnowafunctionofpumpcapacity,levelandif
entered,thepumpcurve.
• Theoutowisrampeddownforacongurabletimeframeafterpumpstop.“Stopdelay”
Pump capacity calculation rules
• Thelevelmustbeover“MinLevelforCalculation”
• Thelevelmustbeunder“MaxLevelforCalculation”
• The level after calculation must be lower than when the calculation started.
Increased calculation accuracy
Toimprovethecalculationaccuracyandalarmhandling,especiallywithvaryingstartlevels,werecommend
that the pump curves are entered.
Foramoreaccurateoutowcalculation,thestationssystemcurvecanbeentered!Inthiscasethecontroller
willrecalculateandadjusttheOutowcalculationbasedonthemomentarylevel!
Presentation of the Pump Capacity calculation
ThepumpcapacityispresentedasaNominalandLastSamplevalue.
Nominal
• Thenominalvalueisre-calculatedfromvevaluestopoint1inthe“Pumpcurve”setting.Ofthese,
vevaluesarelteredbytakingo󰀨thetwomostdivergentandcalculateanaverageofthethree
remaining.
Last Sample
• Asitsounds,thelastcalculation,unltered.
Overowdetectionsensor
MD131givesanexact
indication to the controller
whenanoverowoccurs.