Please note: All interim revisions for this edition available at time of your purchase will be included.

Protectors for Coaxial Communications Circuits

UL 497C

1 Scope

1.1 These requirements cover protectors for use on coaxial cable circuits to be used in accordance with the applicable requirements of the National Electrical Code, NFPA 70.

1.2 As covered by these requirements, a coaxial cable circuit protector consists of single or multiple air gap arresters, gas tube arresters, or solid-state arresters, with or without fuses or other current-limiting devices. A circuit protector is intended to protect equipment, wiring, and personnel at the subscriber premises against the effects of excessive potentials and currents on the coaxial line caused by lightning, contacts with power conductors, power induction, or rises in ground potential.

1.3 This standard does not cover the following:

a) Lightning protective devices for the protection of secondary distribution wiring systems and equipment.

b) Antenna discharge units for radio and television receiving appliances.

c) Lightning conductor and air terminals for connection of lightning rods for building protection.

d) Protectors for fire alarm signaling circuits that are covered by the Standard for Protectors for Data Communications and Fire-Alarm Circuits, UL 497B.

e) Equipment covered by the Standard for Secondary Protectors for Communications Circuits, UL 497A.

f) Equipment covered by the Standard for Transient Voltage Surge Suppressors, UL 1449.

g) Equipment covered by the Standard for Protectors for Paired-Conductor Communications Circuits, UL 497.