6 | Maintenance Instructions TOPAX DX | BA-40100-0-V04
Chapter 8: Controller
The following formulas can be used for calculation:
Xp ~ 0,83 · ΔX / Δt · Tu
Tn ~ 3,3 · Tu
Variable
Description
Yh
setting range e.g. valve fully up or 100% of the metering pump
delivery
Xmax
maximum value of the controller variable at 100% metering rate
to
Start of Y
ΔX / Δt
gradient
Tg
compensation time (s)
Tu
lag time (s)
Vmax
maximum increase rate of the measured variable
Vmax
Xmax / Tg = ΔX / Δt
WARNING!
The following values are only approximate and indi-
cative ones.
In order to meter chlorine gas, you need accounting for the speed
of the chlorine gas valve. The value of Xp is computed for a drive
speed from 0% through 100% in 60 seconds. A slower operation
would show the same trend as a bigger proportional range Xp. In
order to adjust this, the Xp value must be first reduced at slower
operation and vice versa.
The following formula can be used:
Xp(new) = Xp · 60 sek /Ty
Ty = manipulation time of Y
As we are dealing here with approximate values, a certain im-
provement of the controlled variable can sometimes be obtained
by changing the Xp value after certain time. If the regulation
should react too slowly or on the contrary too fast, smaller Xp and
smaller Tn would result into a faster automatic controller action
and in a larger Xp and/or Tn slower-acting settings.
t
Yh
(open) 100%
(closed) 0%
t
0
Fig. 8.1.: Opening of the valve or metering rate of the pump.
Here below, a diagram shows for the controlled variable X over
the time t:
t
X
X
t
0
max
t
X
Tu
Fig. 8..: X = actual value e.g. free chlorine or pH)
The control parameters can be automatically entered in the
TOPAX DX in the respective items of “Auto setup” menu.
8.4 Controller parameters
For free chlorine, pH, bonded chlorine and conductivity inputs the
following controller settings may be programmed:
Controller
Xp -value
Tn-value
Tv-value
Proportional controller (P) 1 - 500 %
-
Proportional integral
automatic controller (PI)
1 - 500 %
1 - 00 min
Proportional differential
automatic controller (PD)
1 - 500 %
1 - 100 s
Proportional integral
differential automatic
controller (PID)
1 - 500 %
1 - 00 min
1 - 100 s
The following control parameters are set by the manufacturer
before shipment:
Controller
Xp
Tn
Tv
Free chlorine controller
35 %
15 min
OFF
pH controller
Xp: 10 %
OFF
OFF
Bonded chlorine controller (Only for
codes 40100003 and 40100005)
Xp: 10 %
OFF
OFF
Conductivity controller (Only for
codes 40100004 and 40100005)
Xp: 10 %
OFF
OFF
8.5 Control direction
The control direction can be set for each controller. In order to
calculate it you need:
• value UP
(Arrow shows up)
• value DOWN
(Arrow shows down)
• -side regulation
(only free chlorine and pH value)
8.6 Metering of the base load
A basic load dosage can be configured outside of the range of
control. This dosage takes place even if the PID automatic con-
troller output is 0%. If a basic load is configured, this value is
represented in blue on the display screen in the y-display. The
y-display of the automatic regulation is represented in green. In
the status display, this condition is marked by a “+” after the
y-display. It should be noted that this basic load is always effec-
tive and independent of the regulation of a certain percentage of
the control elements, although the automatic controller does not
request any dosage. The basic load is separately adjustable for
each input to a maximum of 0% of the control range.
8.7 Manual operation mode
Automatic controllers feature the possibility of a manual opera-
tion mode. If an automatic controller is hand-operated, then a
large “M” behind the “Y” will appears in the status display and
the y-display on screen will be “blue”. In addition the hand-oper-
ated is indicated in the lower line. In the menu of the manual set-
tings the controller output can be adjusted to any value between
0 % and 100 % and saved directly.
WARNING!
The manual operation does not reset automatically.
