Hunter Industries FLOW-SYNC HFS Owners Manual Page: 19

Mainline Pressure Fluctuation
Some water sources may have varying pressure
depending upon the demand for water upstream
of the point of connection. During times of heavy
demand, system pressure through the mainline
may drop.
This is why the flow limit percentage and delay
periods (set in the controller) are important,
as false alarms lead to a lack of confidence in
the system.
Additionally, excess air in irrigation piping causes
the Flow-Sync impeller to spin freely during
station startup, which may cause temporarily
high readings. This problem may be reduced by
installing check valves in the system, and by
setting the alarm delay values to prevent
premature alarms.