This recommended practice presents engineering design practices for special high-voltage protection systems intended to protect wire-line telecommunication facilities serving electric supply locations. The following topics are included in this document: a) A description of the electric supply locations environment, i.e., ground potential rise (GPR), induced voltages, lightning, and switching transients; b)A discussion of special high-voltage protection devices; c)Definitions of service types and service performance objectives for electric supply locations telecommunication services; d)Special protection theory and philosophy; e)Special protection system design guidelines; f)Personnel safety considerations; g)Grounding; h)Cables with metallic members. Other telecommunication alternatives such as radio and optica fiber systems are excluded from this recommended practice.
This recommended practice presents workable methods for the protection of wire-line telecommunication facilities serving electric supply locations. In general, special protective measures, handling procedures, and administrative procedures are necessary to provide for personnel safety, protection against damage to telecommunication facilities and terminal equipment, and reliability of service. Disturbances may arise from a number of causes,including the following: a)Ground (earth)potential rise; b)Longitudinal induction into the serving telecommunication facilities; c)Electrical contact between power and telecommunication conductors; d)Lightning surges and switching transients induced into the telecommunication system. Divided and differing opinions exist between and within the various administrations and users regarding the merits of any one protection method, voltage limits, and equipment design characteristics. This standard is not intended to supplant specific or general instructions contained in the practices of any utility, or in any agreement between a telecommunication and a power utility. Readers of this standard should evaluate all alternative procedures, methods, voltage limits, and equipment characteristics for their own use. Different administrations and users will use either peak or rms for specifying voltage levels. In the case of leased facilities, mutually agreeable methods for the design and installation of protective equipment that may be owned by either party are recommended.
Revision Standard - Superseded.
Workable methods for protecting wire-line communication circuits entering electric supply locations are presented. This document covers: the electric supply location environment; protection apparatus; service types, reliability, service performance objective classifications, and transmission considerations; protection theory and philosophy; protection configurations; installation and inspection; and safety.