Manual

124
DXi User Manual
Appendix D: Setting Up a FLOW MAX System
under normal operation yet low enough to react when a main break line occurs.
Main Line Limit settings must be made at the submaster for a FLOWMAX group,
regardless of where the point of connection is. Each participating controller in the
FLOWMAX group will be held to submaster Main Line Limit settings. (Same for
Unscheduled flow.) Main Line Limit settings set at satellites in a FLOWMAX group
will be ignored.
Flow Max Limitations
Although the number of controllers in a Flow Max system is not limited, the higher
the number of participants, the less control there is to detect problems.
Assume a total of five controllers in a Flow Max group with all five controller
programs running simultaneously. Each of the five programs operating has stations
that under normal conditions use 100 Gallons Per Minute to irrigate. Each station
allows for a 10% Upper Limit Tolerance. With a 10% tolerance, a station normally
using 100 GPM would be allowed a maximum flow of 110 GPM before causing
an alarm. With five stations operating under the same conditions, Flow Max, which
sums all limits, will allow a maximum flow of 550 GPM before causing an alarm for
a station upper limit violation. This means that a broken head would require a 50
GPM measurable difference before causing an alarm, not a 10 GPM difference, which
would be the case if only one station had been operating.
Under the conditions above, normal operating flow would be 500 GPM with station
limits allowing up to 550 GPM. The main flow limit must be higher than 550 GPM.
The question is, does a main line break yield more than 550 GPM? That's where
programming and scheduling can accommodate the ability to keep the main limit
within an amount detectable by a real break.
Physical Conguration
The Hardwire Link provides the communication among all controllers of a standard
irrigation system and/or a Flow Max system. All units are connected in a series
configuration using direct burial EV-CAB-COM twin axial cable (sold separately). The
Hardwire Link provides reliable communication among the controllers at distances up
to several thousand feet.
Figure D-1: Flow Max Hardwire Configuration illustrates a typical wiring
configuration for a 3 controller system.
System configurations that include the Central Control Computer will require the
submaster controller to operate with either a wireless communication board (radio,
cellular, WiFi), a direct serial connection, or and Ethernet connection.
The following pictorial diagrams of Figures 1, 2 and 3 illustrate the wiring detail and
connections of a typical system configuration: