CommScope Drop Cable - Manual (Page 26)

Buried Installation
Underground service has become popular in many developments and subdivisions. Broadband services are
brought in by buried cable, and accessed by pedestals which are usually at the property line.
While the easiest way to run the cable is to trench or plow in a burial-grade coaxial cable to a minimum depth of
12 in (.3 m), burying cable preinstalled in conduit is a far better method. Cable-in-conduit (CIC)
offers greater physical protection against environment, abrasion, rocks, etc. than direct burial which can prolong
the life of the cable. And, should the cable ever fail, it can be replaced without digging up the yard. CIC of 1/2
in (13 mm) to 3/4 in (21 mm) is recommended. If you are directly burying cable without using conduit, you
should use an 18 in (45 cm) length of it to protect the cable 6 in (15 cm) below and 12 in (30 cm) above grade
where it emerges next to the residence.
Article 830 Considerations
Systems that use coaxial cable to carry up to 150 volts of power (as well as signal) to a NIU fall under NEC 830
regulations. Pay special attention to the buried cable depth as shown in the diagram below. Note that CIC (HDPE
conduit) doesn’t need to be buried as deeply as direct burial installations.
Although NEC 830 permits the use of metal conduit, CommScope does not recommend its use. Problems with
rust, water migration, and potential damage to the cable jacket due to cutting and scraping during installation
are possible results of using metal conduit. Frozen water will crush cable in a metal conduit, but HDPE conduit
will allow the ice to expand and save the cable.
6.1 Buried Installation
Overview