IEEE 487-2015 pdf free download – IEEE Standard for the Electrical Protection of Communications Facilities Serving Electric Supply Locations—General Considerations.
3. Definitions, acronyms, and abbreviations
3.1 Definitions
For the purposes of this document, the following terms and definitions apply. The IEEE Standards
Dictionary Online should be consulted for terms not defined in this clause.
carbon block surge protective device (carbon block SPD): An assembly of two or three carbon blocks and air gaps designed to a specific breakdown voltage. These devices are normally connected to telecommunications circuits to provide overvoltage protection and a current path to ground during such overvoltage.
NOTE—The manufacturing of carbon blocks has been largely discontinued. 6
conductive (resistive) coupling: See: coupling.
coupling: The mode of propagation of disturbing energy from a power system to a telecommunications system. There are three forms of coupling between the two systems: magnetic (inductive) coupling, electric (capacitive) coupling, and conductive (resistive) coupling. In addition, coupling by electromagnetic radiation exists and is associated with propagation of radiation fields, e.g., radio frequency interference,electromagnetic pulse (EMP), and corona.
demarcation point: The point of interconnection between the telecommunications facilities of a provider of wire-line telecommunications service and the subscriber’s terminal equipment, protective apparatus,cables, or wiring.
drainage unit or drainage reactor: A center-tapped inductive device designed to relieve conductor-to-conductor and conductor-to-ground voltage stress by draining extraneous currents to ground. These units are also designed to serve the purpose of a mutual drainage reactor (MDR), forcing near-simultaneous surge protective device (SPD)-gap operation.
electric (capacitive) coupling: See: coupling.
clech-ic supply location: Any building, separate space, or site in which elecinc supply equipment is located that may be subjected to the effects of ground potential rise IOPRI from power system fault currents. Ihis definition includes generation. translor,naiton, conversion, switching. and delivery facilities.
gas discharge tab (Gl)l): A discharge gap between two or more electmde% hermetically sealed in a ceramic or glass envelope.
ground poteatlal rIse (GPR): The electrical potential that a gtound electrode (01 grounding systeitsb ny attain relative to a distant grounding point.
NOTE I—Under norsniil eundu ions, the grounded electrical ajuipiri operates at ia zero ground potential. In other words, the potential of a grounded neutral eonductnr is scarfs identical to the potential of rensite earth lAiring a ground fails, the portion of fault current that is eotsiucted b ai electric tupply le.,ation grounding god into the eatiti i,ausc’s the rise of the grid potenial with n.sçect to remote earth.
NOTE 2—See IEEE Stat 367 for the method of calculating (irK.’
high’-dleleetrk table: Cable that provides a higher voltage insulation between conductors, tw!cen conductors and shield, and between shield and earth than standard igcntnl usel outside plant cables.
NOTE—See IEEE Stat 7tt9 additional silorirution.
high-voltage dlsco.nect jack: A device used to disconnect esble pairs for testing purposes Used to help safeguaivl personnel from remote ground potentials.
high-v nltags’ cnsironntrnt (lIVE): A location requiring caution becattse it may expenence a ground potential rise (GPR) from power line fault currents anttor lightning strike energy.
hlgh-soltage l.terfaer (HVl): Proti.’ctise apparatus that provides elect.rtal isolation of wire-line telecommunications conductive paths.
high-voltage isolating relay: A device that provides for the repeating of dc onoff signals while maintaining longitudinal isolation. I ligh-soltage isolating iday may be used in conjttnction with isolation transformers or may be used as stand-alone devices for dc tnppmg or & telernetenng.
horn gap: An aix-gap metal electrode device, consisting of a straight vertical, round electrode and an angularly shaped. round electrode. For a telecommunications pair, there exist one common grounded. central, straight. vertical electrode and two angular electrodes, one for each side of the pair The g,aps are tisually adjustable Horn gaps ate used usually outdoors on open-wile lines exposed to high-voltage power transmission lines and in conjunction with isolation or drainage translbrmers They are also frequently used alone out along the open-wire pair. They provide protection against both lightning and power contacts.
Insulating trasslormer: Set isolation I insulating) transloriner,
isolation (l.sulatiiig) tra.slormrr: A transtormer that provides longitudinal tcoinmon.model isolation of the telecorunrunications facility. These transformers can be desigiic’d for use in a combined isolation- drainage transformer configuration anti also can be designed for a low longiiudinal.to-mesallic conversion
isolation tramsformer with high-voltage isolating relay: An assembly that provides protection Iör standard telephone service and consists banically of an isolation transformer and a high-voltage isolating relay. The transformer provides a path for voice and ringing frequencies while the relay provides a nicans for repeating dc signals around the transformer. A locally supplied battery or dc power supply is required for operation of the telephone and telay.IEEE 487 pdf download.