Broadband Applications & Construction Manual - Public - CommScope

NEC Articles 820 and 830
NEC articles 820 and 830 both deal with broadband coaxial cable. Traditional coax networks carry a low-voltage
radio frequency (RF) signal. The voltage is so low that it is not considered dangerous. NEC article 820 is written
with fire safety, not voltage, in mind.
However, with the advent of multiple services available over coax systems, the need for powered coax or UTP has
risen. Some of these newer services require that a network interface unit (NIU) be installed at the subscriber’s residence
with the NIU being powered via the cable. Generally, if there is a NIU involved, the cable will have to be
rated for NEC 830.
Basically, higher voltage NEC 830 cables need to be installed to provide greater protection
for people than NEC 820 cables. Refer to the charts in Section 4.1/Aerial Installation or 5.1/Buried Installation
for specific distances.
Look for the cable rating on the jacket. The cable ratings are:
Plenum-rated cables, designed for use in plenums, ducts
and air handling spaces, carry the strictest NEC rating.
Riser-rated cables are used in vertical shafts that penetrate
more than one floor.
General purpose-rated cables may be used in locations
other than plenums or risers.
Residential-rated cables are for use in one, two and multifamily
dwellings and in raceways.
Buried cables are for use underground alone or in conduit.
This rating only concerns NEC 830 applications.
Appendix 13.3
NEC and Other Ratings