14
Meaning of parameters
P1:
This parameter allows to select the measurement type, pH or redox (mV).
When setting P1=0 (pH reading with two decimal), please note that the two decimal places are visible only
for pH values below 10, because the display can show up to three digits. However, generally the precision of
pH measurements with one decimal is sufficient in most applications.
P2:
This parameter allows to configure the working mode of level contact:
0 = NO (normally open, standard configuration)
1 = NC (normally closed, fail-safe mode)
P3:
This parameter allows to store the status of the ON/OFF button at the system shutdown:
0 = at start-up the pump is always enabled
1 = at start-up the pump restores its status at shutdown
P4:
This parameter allows to set the pump working mode:
0 = OFF
the pump is always off, independently from measured value: this option allows to monitor the
measurement without intervening, for example during the plant start-up
1 = ON
the pump is always on, independently from measured value: this option is used to manually force
the dosage, for example during the plant start-up or maintenance
2 = ON/OFF acid
this option is typically used for acidification; the pump activates when the measurement
exceeds the “working thr½ hysteresis” level, and deactivates when the measurement falls below the
“working threshold – ½ hysteresis” value
3 = Proportional acid
the pump is definitely active when the measurement is greater than the “working
thr ½ hysteresis” level, and definitely off when measurement is lower than the “working threshold
– ½ hysteresis” value, while for measurements between these limits, the operating time of the pump is
proportional to the distance of measurement from the limits. The time base is fixed (90 seconds) and
operation follows the trend shown in the table below:
Measurement = pH ; Working threshold = 7.20 pH ; Hysteresis = 0.40 pH
Measure
<= 7.00
7.10
7.20
7.30
>= 7.40
% dosage
0%
25%
50%
75%
100%
Pump ON
never
23 seconds
45 seconds
67 seconds
always
Pump OFF
always
67 seconds
45 seconds
23 seconds
never
4 = ON/OFF chlorine
this option is typically used for chloration or alkalinization; the pump activates when
the measurement is lower than the “working threshold – ½ hysteresis” value, and deactivates when the
measurement exceeds the “working thr ½ hysteresis” level.
5 = Proportional chlorine
the pump is definitely active when the measurement is lower than the “working
threshold – ½ hysteresis” value, and definitely off when measurement is greater than the “working threshold
+ ½ hysteresis” level, while for measurements between these limits, the operating time of the pump is
proportional to the distance of measurement from the limits. The time base is fixed (90 seconds) and
operation follows the trend shown in the table below:
Measurement = Redox ; Working threshold = 680 mV ; Hysteresis = 20 mV
Measure
<= 670
675
680
685
>= 690
% dosage
100%
75%
50%
25%
0%
Pump ON
always
67 seconds
45 seconds
23 seconds
never
Pump OFF
never
23 seconds
45 seconds
67 seconds
always
P5:
This parameter allows to set the working threshold used when the pump operates in automatic control.
P6:
This parameter represents the intervention hysteresis around the working threshold; in the case of ON/OFF
controls it can be set between zero and 2.00 pH (or between zero and 200 mV), while in the case of
proportional controls the hysteresis must have a value between 0.20 and 1.00 pH(or between 20 and 100mV).
P7:
At the device start-up, some electrodes require a stabilization (or polarization) time, during which the
measurement is not reliable. This parameter allows to set a delay at start-up (in minutes), during which the
pump is off and the display alternates between the measurement and the “PAU” message. Typically, in the
case of pH electrode a delay of 1 minute is sufficient, while in the case of redox electrode it is recommended
to set a delay of at least 20 min. Sometime this standby time is also useful to compensate for hydraulic delays
that can occur at the plant start-up. Once the set time has elapsed, the pump begins to operate normally.
P8:
This parameter allows to set a time limit within which the measure must return to the working threshold value
(P5), otherwise an alarm is generated. A time between 0 (feature disabled) and 600 min. (10 hours) can be
set. The alarm time count begins when the system detects a measurement out of range, and automatically
resets when the measure returns within the threshold value. If the measurement remains outside this
threshold longer than the set time, an alarm is generated and the display alternates between the measurement
and the “ALL” message. When the alarm is active, the dosage is disabled and normal operation is resumed
when the alarm is reset by pressing the ON/OFF button, by turning the pump off and on again, or
automatically when measurement returns to an acceptable value. This condition may occur due to an
insufficient dosage, such as not to allow the achievement of the threshold value.