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PUMP CONTROL
8. PUMP CONTROL
Pump control can be enabled (automatic control) or disabled (off; manual control).
See SETUP section for further details on how to enable or disable pump control.
LCD backlight color indicates the pump control status:
• green - automatic control or in View menu mode
• light green - for manual control or in Edit menu mode
On the LCD screen, the pump status is displayed as below:
manual control is set, no dosing
ready to dose, dosing
Startup Delay (Automatic Control Only)
When Startup Delay option is enabled, the meter is in Control Off mode for the set time; and the LCD
backlight color is light green. The delay countdown will start upon powering the controller. At the end
of the timing the LCD backlight turns green and the control mode is automatic (Auto).
8.1. AUTOMATIC CONTROL TYPES
There are two automatic control types: On/Off (constant) control and proportional control.
On/Off Control
With On/Off control type for pH enabled in SETUP, the algorithm uses only "set point" and "hysteresis",
both with user-selectable values. See SETUP section for further details.
High control mode: When the process pH drifts upward and it reaches a High set point, this triggers
the reagent pump to come on and add a solution to decrease the pH (an acid). The pump will remain
on until the pH has decreased to the Set point value minus the hysteresis value set. Then the pump
will shut off.
Low Control mode: Conversely, with Low control mode, the process pH drifts down until it reaches a
Low set point. This triggers the pump to come on and add a solution to increase the pH (a base). The
pump will remain on until the pH has increased to the Set point value plus the hysteresis value set.
Then the pump will shut off.
The typical pool application uses a High control point and the addition of a acid reagent.
The
BL101
presents a similar behavior with hypochlorite dosing.
The typical pool application uses a Low control point and the addition of hypochlorite solution to
increase the ORP value.
