Evoqua Wallace & Tiernan SFC-SC, Руководство пользователя

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WT.050.590.002.UA.IM.0614 40
SFC ANALYZER / CONTROLLER
EVOQUA W3T109634
Single feedback Ratio Control Theory of Operation
The flow rate is recorded and the dosing capacity adjusted proportionally
to the flow rate using the flow rate sensor with linear mA output signal. On
the settings for the flow rate signal see menu "Inputs/Outputs" - "Flow Wq".
NOTE: If the measuring range end value of the flow meter is not identi-
cal with the actual maximum flow rate, a factor for adjusting the flow
rate signal should be input in the menu "Inputs/Outputs“ - "flow Wq“.
for example: Measuring range flow meter = 5000 l/h / max. flow rate =
2500 l/h => factor = 5000: 2500 = 2.0
The relationship between the flow control variable and dosing output is
determined using the internal dosing factor. This can be varied up to max.
400%.
If a positioner with feedback is used as the dosing output, it can be linear-
ized using several support points. At least two points are required (0/100
%). It possible to define 2, 3, 6 or 11 support points with definite steps. In
the menu "Dosing" - "Ym Calib. Points" the number can be defined. The
support points then have to be set in menu "Dosing" - "Ym Calib. Manual".
The controller output is calculated in this operating mode as follows:
yout = Wq x Df
Wq - Control variable 1 flow rate in %
DF - Set dosing factor in %
The figure below shows the output dosing capacity depending on the flow
rate Wq and the set dosing factor.
figure 3.4 - Dosing factor