Instruction manual

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If the conductivity is still too high, the blowdown time is recalculated and the valve is opened for
that time.
This continues until the conductivity is below the set point.
The valve closes and will not reactivate until the Interval Time has expired.
You may also change the Relay Control Mode here. If you do, you will have to reselect the Input
Assignment as well.
This section assumes that the Relay Control Mode is set to Intermittent (Proportional Blowdown
Time). Other control mode types are described in other sections of the manual.
Relay Control Mode
Click on the arrow of the pull down menu and select the way that you want to control the relay.
See Section 6.2 for details on each control mode.
Relay Input Assignment
Click on the arrow of the pull down menu to select the sensor to be used to activate this relay.
Current Reading
This is a display of the current process value as measured by the assigned sensor.
Status
This displays the current status of the relay output, either “Off” or “On”, and if on, the amount of
time it has been on. Possible status messages are Off, Off/Manual, On/Time counting
down/Sampling, Off/Time counting down/Holding, On/Time counting down/Blowdown, Off/Time
counting down/Waiting and On/Time counting down/Hand (for manual activation). The only
possible error messages are Interlock and Sensor Error. See section 8.1 for a complete description
of error messages.
Custom Name
This menu allows you to call the output another name if desired. Type the new name in the text
box.
Set Point
Type in the desired set point value. The control direction is always Force Lower.
Interval Time
Type in the desired time between samples. Too short a time will waste water and drop the
conductivity well below the set point. Too long a time will cause the conductivity to rise too high,
potentially resulting in scale or carryover.
Duration of Sample
Type in the desired sample time. This should be as short as possible while still guarantying a fresh
sample of boiler water at the electrode.
Hold Time
Type in the desired time to hold the water sample while it returns to boiler pressure.