Walchem WebMaster ONE Instruction Manual page 113

Prebleed Conductivity (only appears if Prebleed is Conductivity Based)
Type the conductivity set point for the prebleed into the text box. This should be less than the
normal bleed set point.
Prebleed Time Limit (only appears if Prebleed is Conductivity Based)
A time limit may be imposed on the conductivity based prebleed. If a system problem such as a
faulty conductivity sensor or bleed valve prevents the prebleed conductivity from being
achievable, the time limit will trigger the biocide add to occur.
Prebleed Time (only appears if Prebleed is Time Based)
Type the desired prebleed time (in minutes) in the text box.
Dispersant Addition
If you want to feed another chemical, such as a dispersant, penetrant or surfactant prior to the
biocide addition, click on the radio button and select the method desired.
Select Not Used if no dispersant addition is desired.
Select Before Biocide to activate the dispersant relay for fixed amount of time prior to
each biocide addition.
Select After Biocide to activate the dispersant relay for fixed amount of time after each
biocide addition.
Assign Dispersant Relay
Click the arrow of the pull down menu to select the relay that will be used to feed the dispersant.
Mutual Interlocks
Click the check boxes to select or de-select the relays and analog output control outputs that you
want to be prevented from turning ON if this output relay is already ON. If you do not need any
other output to shut off when this relay turns on, UNCHECK all boxes. The selection is mutually
exclusive, meaning that if Relay 2 has Relay 4 interlocked, then R2 won't turn on if R4 is already
on, and R4 won't turn on if R2 is already on. This feature should be used with caution since it can
potentially delay a chemical addition for a long time.
Output Mode
Click on the radio buttons to manually control the relay. The normal selection will be Auto, where
the controller uses the various set points to open and close the relay. You can force the relay closed
regardless of the set points by selecting Hand, or force the relay open regardless of the set points
by selecting Off.
If you select Off, the relay will not activate again until either Hand or Auto is selected (or if power
is cycled)! If you select Hand, the relay will activate until either Auto or Off is selected, or until
the Hand Time Limit (programmed in the next menu) expires or until the controller power is
cycled.
The Off mode is handy to prevent the relay from activating while you are changing set points. The
Hand mode is handy to be able to test the pump or valve, wiring, etc without needing to change set
points.
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