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Aerial installation/messenger (figure-8) cable – CommScope Drop Cable User Manual

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Aerial Installation/Messenger (Figure-8) Cable

For best efficiency and lowest cost, aerial installation is generally preferred. However, local or subdivision codes

sometimes require that utilities be installed underground. There are times the customer may want the cables hidden

for aesthetic reasons. In these cases, see Section 6 for instructions on buried installations.

A typical installation is shown below. A continuous length of cable runs from the tap to the attachment point and

continues to the grounding point, called a ground/bond block. A second cable continues from the ground block

through the point of entry to a termination point within the structure.

Article 830 Considerations

Some systems use coaxial or UTP cable to carry power as well as signal to the NIU

(Network Interface Unit - sometimes called a NID/Network Interface Device). When

installing powered coax cable (carrying up to150 volts), pay special attention to the

cable-to-earth distance as shown in the diagram below.

NEC 830 also requires that cable attached to the building within 8 ft (2.5 m) of grade

must be placed within conduit, raceway or some other approved cable guard.

NIUs and Ground Blocks

NEC 830 installations will terminate at an NIU. Most NIUs have built-in connections that must be grounded at the

meter or other approved point. See Section 8/Attaching to the NIU per NEC 830.

tech tip:

when pulling

and hanging

cable, avoid

twisting,

scraping,

stepping on

or crushing it

5.1 Aerial Installation

Overview