MANUALPC-2010 CHAPTER IV - OPERATION Page 27
8.2 - OPERATIONS SUBMENU
The Operations Submenu allows the operator to access and
change operating conditions during normal operation.
8.2.1 - Audio Alarms
This option is used to disconnect the audio alarm (buzzer) and
remote alarm in case of out-of-range or other alarm conditions.
All visual alarms, such as flashing on the screen, still remain
operative.
8.2.2 - Bypass Line
T
he bypass line is a recommended feature for sensor
installation on large recirculation lines, i.e. over 2 inches in
diameter. It is included with all PC5000 and PC7000
controllers.
A Safety Flow Switch is used to prevent operation when there
is insufficient water flow in the bypass line. This can occur
particularly when the bypass line is shut down for
maintenance.
The standard flow switch provided with the CHEMTROL® PC
is a rotary flowmeter with a paddle wheel. The shutoff is set at
1 gpm (about 4 l/m).
The Bypass Line Protection option should always be set to
YES, indicating that the alarm is active and will cause the
interruption of all feed events.
If the flow switch is defective or temporarily disabled, the
bypass alarm can be overridden by setting the Bypass option
to NO. This override should be used with extreme caution:
WARNING: Feeding chemicals when there is no water
running in the bypass line may cause dangerous chemical
reactions.
8.2.3 - Langelier Saturation Index
T
he Langelier Saturation Index is used for monitoring the
development of corrosive or scaling tendencies in water. The
Saturation Index SI is calculated from the formula:
SI = pH + TF + AF + CF - 12.1
where:
pH = pH sensor reading or keyboard input,
TF = Temperature factor calculated from sensor input or
keyboard input,
AF = Alkalinity factor from data table,
CF = Calcium Hardness factor from data table.
The microprocessor inside the controller calculates the factors
TF, AF and CF directly from the raw data input for temperature
(degrees), alkalinity (ppm) and hardness (ppm). The operator
therefore does not have to resort complicated conversion
tables.
Submenu 8.2
S
ubmenu 8.2.3
Submenu 8.2.3.5
Langelier Limits
The standard limits for the Langelier Index show "OK"
between 0 and +0.3, "CORR" if below 0, and "SCALE" above
+0.3. If an alarm condition develops, the Display Screen alerts
it with flashing characters.
The above values are the generally accepted limits for water
saturation. Some experts however, recommend different
values, such as -0.3 and +0.3 instead. The limits can therefore
be changed by in Submenu 8.2.3. 5.
Audio Alarms YES
Bypass Line YES
Saturation Index OK
Print Reports
Reset
Battery
Probe Monitor YES
Alkalinity (ppm) 150
pH 7.5
Temperature 80
Limits
Langelier Index 0.23
Scaling above + 0.3
Corrosive below - 0.0
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