BWT Bewazon VULW 45 - P;PID Controller, Analogue Output (Optional)

EN
23
8.5 P/PID controller, analogue output
(optional)
Ozone device: Ready/operation
If the “Prop. controller” operating mode is released for “Set ozone
level” on the “Ozone device: extended settings” screen, this operating
mode can be selected. For actual controller operation, the controller
parameters must be set beforehand on the “Ozone device: proport.
controller” screen.
Next screen: Proport. controller
Ozone device: Proport. controller
During operation with the prop. controller, the ozone device delivers
an ozone output that is in direct proportion to the external 4 to 20 mA
measurement signal that is supplied via the analogue input module.
Signal source unit: Physical unit of the signal, e.g. m
3
/h
Min. signal: 4 mA =: Measurement signal that corresponds to the 4 mA
signalling current, e.g. 0 m
3
/h
Max. signal: 20 mA =: Measurement signal that corresponds to the
20 mA signalling current, e.g. 140 m
3
/h
Proportional factor: Factor for determining the ozone level,
ozonelevel≈proportionalfactor*measuredvalue
Example1:Dosageofozoneintoawaterow:Proportionalfactor=0.10
Measured value = 28 m
3
/h
The controller calculates: 0.10 * 28 = 2.8 – the ozone level is the rounded
value, i.e. ozone level = 3.
Example 2: Ozone generation is to be controlled so that bound chlorine
is eliminated as needed. An online measurement device
constantly measures bound chlorine. The measured value
is output as a 4 to 20 mA signal for the measurement range
of 0.0 to 2.0 mg/l. At a concentration of 0.2 mg/l of bound
chlorine, the unit is to be operated with level 10 in order to
reliably eliminate the bound chlorine:
proportional factor = ozone
level
/ measured value
= 10 / 0.2 mg/l = 50
Note: Automatic level switching is preceded by a hysteresis corres-
ponding to 0.5 steps, so that the unit does not switch back and
forth constantly when the measurement signal leads to an ozone
output around the limits for switching between two ozone levels.
Ozone device: Ready/operation
If the “PID controller” operating mode is released for “Set ozone level” on
the “Ozone device: extended settings” screen, this operating mode can
be selected. For actual controller operation, the controller parameters
must be set beforehand on the “Ozone device: PID controller” screen.
Next screen: PID controller