Broadband Applications & Construction Manual - Public - CommScope

8.1 Attaching to the NIU per NEC 830
Attaching to the NIU
Attaching to the NIU - The 8 Foot Rule
NEC Article 830 covers the installation of cable from the tap to the connection of the NIU. NEC 830-rated
cables supply the voltage that powers the NIU. The NIU then distributes the various signals coming in over the
drop (CATV, internet, telephone service, etc.) onto the preferred cable and connections that branch from the NIU
throughout the residence. These interior cables (NEC 820 coax, NEC 800 twisted pair, NEC 770 fiber optic)
carry very low, if any, voltage.
Pages 5.1 (aerial drop installation) and 6.1 (buried drop installation) discuss the distances required for a safe installation
of NEC 830 cable and service to the residence.
The 8 Foot Rule
NEC 830 requires that powered broadband cables that are attached to a building within 8 feet (2.5 meters) of
the finished grade must be protected by molding or conduit. If you are using CIC, this requirement is
easily met by extending the conduit from the ground to the entry point.
If you are using direct burial cable without
conduit, you must run the cable in conduit
starting 18 in (45 cm) below finished
grade and finishing in contact with the
NIU enclosure.
With an aerial installation, the cable
should be placed in conduit with a J-joint
at the top to prevent water from getting
into the NIU, and then run to the top of
the NIU enclosure.