Vega VEGAMET 861 - Pump station with pump control function

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11 Applications and functions
VEGAMET 861 • 4 … 20 mA/HART
58866-EN-200401
To display the percentage level correctly, select under "Measurement
loop - Linearization curve" the entry "Horiz. cylindrical tank".
To display the volume in litres, you have to enter "Volume" as the unit
in litres under "Measurement loop - Scaling". The allocation is then
carried out, in this example 100 % ≙ 10000 litres and 0 % ≙ 0 litres.
Percent is selected as reference value for the relays. The mode of
relay1issettooverllprotection,relay2mustbeactivatedandgets
modedryrunprotection.Toensurethatthepumpswitchesoincase
of failure, the reaction in case of failure should be set to switching
status OFF. The switching points are set as follows:
•
Relay 1:Switch-opoint90%,switch-onpoint85%
•
Relay 2: Switch-opoint5%,switch-onpoint10%
Information:
Theswitch-onandswitch-opointoftherelaysmustnotbesettothe
same switching point because this would cause a continuous switch-
ingonandowhenthisthresholdisreached.Toavoidthiseectalso
withuctuatingproductsurfaces,itisagoodideatosetadierence
(hysteresis) of 5 % between the switching points.
11.2 Pump station with pump control function
The waste water from households and industry, together with surface
water, is fed to the sewage treatment plant via an extensive network
ofsewers.Ifthenaturalgradientisnotsucient,variouspumping
stationsarerequiredtocompensateforthedierencesinheight.The
level measurement in the inlet shaft serves for the economic control
of the pumps. The intelligent control of up to four pumps can be easily
adjusted by the controller.
Linearisation
Scaling
Relay
Application description