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Scheduled Reset
Choose to automatically reset the flow total, and if so, Daily, Monthly or Annually.
K Factor
Enter the pulses generated by the paddlewheel per unit volume of water.
Flow Units
Select the units of measure for the water volume.
Rate Units
Select the units of measure for the flow rate time base.
Smoothing Factor
Increase the smoothing factor percentage to dampen the response to changes. For ex-
ample, with a 10% smoothing factor, the next reading shown will consist of an average
of 10% of the previous value and 90% of the current value.
Name
The name used to identify the sensor may be changed.
Type
Select the type of sensor to be connected to the digital input channel.
5.2.16
Feed Monitor
The Feed Monitor Digital Input type performs the following functions:
• Monitors a pulse signal from a pump (Iwaki PosiFlow, Tacmina Flow Checker, LMI Digital Pulse, etc)
•
Totalizes the chemical feed and calculates the current flow rate
•
Activates a Total Alarm if the feed exceeds a specified limit
• Activates a Flow verify alarm if the control output is ON and the feed monitor does not record any pulses
within a specified period of time.
Each Feed Monitor input can be linked to any type of output channel (powered relay, dry contact relay, solid state
relay, or analog 4-20 mA) to validate chemical feed from any type of pump.
Total Alarm
The W900 monitors the total feed and activates a Total Alarm if the value exceeds the Totalizer Alarm set point.
When used in conjunction with Scheduled Reset selections (Daily, Monthly, or Annually), this alarm can be used
to alert users to situations where excess chemical product is used and/or to discontinue chemical feed if the amount
exceeds the set point during the specified time period.
While a Total Alarm is active, the linked pump will be controlled based on the Total Alarm Mode setting:
Interlock
The output will be OFF while the alarm is active.
Maintain
The alarm condition has no effect on output control.
Flow Verify Alarm
The W900 monitors the status or current percent output of the channel linked to the feed monitor to determine if a
Flow Verify alarm should be activated.
The
Flow Alarm Delay
setting (MM:SS) contains the time to trigger the alarm if the output is activated and no
pulses are registered. To avoid nuisance alarms at very low flow rates, if the linked output is a solid state relay (set
with a pulse proportional or PID control mode) or an analog 4-20 mA output, the alarm will only be activated if no
input pulses are monitored while the output is set to greater than a specified Dead Band (%).
The
Flow Alarm Clear
setting is the number of pulses that must be registered to verify that pump operation is
restored and clear the Flow Verify alarm. During Flow Verify alarm conditions, the count of pulses registered will
be reset to zero if no single pulses occur during the Flow Alarm Delay time period. In this manner, random single
pulses spread over a long time period will not accumulate and result in a Flow Verify alarm being cleared before
product feed is actually restored.
If desired, a user can configure the feed monitor to attempt to reprime the pump when a Flow Verify alarm first is
activated.
The
Reprime Time
(MM:SS) specifies the amount of time that the output should be energized after the initiation of
a Flow Verify alarm. If the linked output is a solid state relay (set to a pulse proportional or PID control mode) or
an analog 4-20 mA output, the output will be set to the Max Output percent during the reprime event. If the Flow
Verify alarm is cleared during the reprime event (because the specified number of pulses was registered), the reprime
event will be immediately ended and normal control of the output channel will be restored.
While a Flow Verify alarm is active, the linked pump will be controlled based on the Flow Alarm Mode setting:
