Types Of Pipe Networks; Looping Communication Wire; Combining Wire Paths At The Interface - Rain Bird IC System Design Manual

5. Although not required, an optional shielding wire can also be utilized to improve the grounding
of the system. If used, the shielding wire should be a 10 AWG (6 mm
connects to each of the grounding rods or plates in the system. The purpose of the shielding wire
is to provide shielding for the MAXI wire path by attracting surges to the shielding wire. The
addition of a shielding wire does not change or reduce the requirement of achieving 50 ohms or
less resistance at each ICSD grounding point without the shielding wire connected. Rain Bird
believes the decision to use a shielding wire on a project should be based on the localized
conditions at the project and is not specific to a control system type or manufacturer type. A
course would have a shielding wire regardless of control system, or it does not. It should be the
decision of the irrigation designer.
NOTE: If a shielding wire is used, the ground rods or plates should be tested independently, prior
to connecting the shielding wire to the rods or plates. This will ensure that the rods or plates
provide a good earth ground at the ICSD. A measurement with the shield connected does not give
a true reading of the individual/local ground location at the ICSD and will give a reading that is
considerably lower than the actual grounding at that location.

Types of Pipe Networks

The IC System works equally well with "herringbone" or "sub-loop lateral" pipe network designs. Rain Bird
looks to the irrigation designer to select the best pipe network layout for the irrigation system design and
then apply the IC System wire path on that layout. Each type of pipe network design offers different
advantages depending upon the location and size of the irrigation system. There is no preference for the
IC System wire path.

Looping Communication Wire

The IC System communication wire must NOT be looped. Dead ends are required to maintain system
diagnostic capabilities. While the system will function with looped communication wire, troubleshooting
will be more difficult, so looping is not recommended.

Combining Wire Paths at the Interface

While a single IC wire path can handle 750 ICMs when sized according to the design guide table, there are
times when it may make sense to bring separate "wire paths" (with fewer ICMs) directly back to the
interface. When combining two or more distinct wire paths into a single output terminal at the ICI+, it is
not necessary to calculate the total length of all the wire paths combined when calculating Trunk wire
size. Each distinct path is viewed separately as a Trunk and not a Branch. Therefore, size each of the Trunk
wire paths separately, considering the number of ICMs and length of that path to calculate the wire size.
NOTE: The combined number of ICMs on a single terminal output still cannot exceed 750 ICMs.
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) bare copper wire that
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IC System Design Guide, v2.4