Chapter 2: Planning and Project Management Chapter … 2: Planning and Project Management Figure 2.1 Sample site plan ...

Table of Contents

© 2004 BICSI® ix ITS Installation Manual, 4th edition

Figure 1.111 Breathing respirator ........................................................................................................ 1-265

Figure 1.112 Rubber gloves and apron ................................................................................................ 1-267

Figure 1.113 Communications perceptions ......................................................................................... 1-276

Chapter 2: Planning and Project Management

Figure 2.1 Sample site plan ............................................................................................................. 2-38

Figure 2.2 Sample cross-sectional diagram ...................................................................................... 2-39

Figure 2.3 Sample floor plan ............................................................................................................. 2-40

Figure 2.4 Sample room detail .......................................................................................................... 2-41

Chapter 3: Installing Supporting Structures

Figure 3.1 Typical telecommunications room layout ............................................................................ 3-7

Figure 3.2 Typical telecommunications backboard layout .................................................................... 3-8

Figure 3.3 Corner installation of plywood backboards ........................................................................ 3-10

Figure 3.4 Installation using toggle bolts in drywall construction ........................................................ 3-11

Figure 3.5 Plywood installed using toggle bolts ................................................................................. 3-12

Figure 3.6 Plan view of a typical telecommunications room with ladder rack installed on two walls ... 3-13

Figure 3.7 Vertical ladder rack .......................................................................................................... 3-14

Figure 3.8 Typical backboard layout for D-ring installation ................................................................. 3-15

Figure 3.9 Spools .............................................................................................................................. 3-16

Figure 3.10 Conduits on channel stock ............................................................................................... 3-17

Figure 3.11 Equipment rack ................................................................................................................ 3-19

Figure 3.12 Wall-mounted rack with hinge .......................................................................................... 3-21

Figure 3.13 Cable managers ............................................................................................................... 3-23

Figure 3.14 Equipment rack detail ...................................................................................................... 3-25

Figure 3.15 Electrical metallic tubing couplings .................................................................................. 3-29

Figure 3.16 Intermediate metal conduit ............................................................................................... 3-29

Figure 3.17 Intermediate metalc conduit coupling ............................................................................... 3-30

Figure 3.18 Rigid metal conduit .......................................................................................................... 3-31

Figure 3.19 Rigid metal conduit coupling............................................................................................. 3-32

Figure 3.20 Cross-section of conduit outside diameter vs. inside diameter .......................................... 3-33

Figure 3.21 Metal conduit body ........................................................................................................... 3-34

Figure 3.22 Innerduct .......................................................................................................................... 3-40

Figure 3.23 Four-inch conduit with three innerducts ............................................................................ 3-41

Figure 3.24 Tubular ladder rack ........................................................................................................... 3-42

Figure 3.25 Suspended ladder rack ..................................................................................................... 3-43

Figure 3.26 Wall bracket ..................................................................................................................... 3-44

Figure 3.27 Multilevel ladder rack ........................................................................................................ 3-45

Figure 3.28 Cable retaining posts ........................................................................................................ 3-46

Revised November 2004

Table of Contents

ITS Installation Manual, 4th edition x © 2004 BICSI®

Figure 3.29 Rod-stock cable tray ........................................................................................................ 3-46

Figure 3.30 Directional transition ......................................................................................................... 3-47

Figure 3.31 Pipe hanger ...................................................................................................................... 3-51

Figure 3.32 Screw head types ............................................................................................................ 3-54

Figure 3.33 Open top cable supports (J-hook) ..................................................................................... 3-59

Figure 3.34 Compression coupling ...................................................................................................... 3-61

Figure 3.35 Setscrew coupling ............................................................................................................ 3-62

Figure 3.36 Conduit hangers ............................................................................................................... 3-63

Chapter 4: Pulling Cable

Figure 4.1 Example of marked job floor plans with common symbols ................................................ 4-11

Figure 4.2 Area secured with safety cones and caution tape ............................................................. 4-14

Figure 4.3 Bullwheel and pulley hangers ........................................................................................... 4-15

Figure 4.4 Large reel and adjustable jack stands .............................................................................. 4-16

Figure 4.5 Cable tree ........................................................................................................................ 4-18

Figure 4.6 Vacuum blowing a ball or a bag ........................................................................................ 4-22

Figure 4.7 Vacuuming a ball .............................................................................................................. 4-23

Figure 4.8 Attaching pole rope to the cables ..................................................................................... 4-25

Figure 4.9 Minimum bending radius .................................................................................................. 4-26

Figure 4.10 Beam clamps, J-hooks, and bridge rings .......................................................................... 4-29

Figure 4.11 Telescoping pole .............................................................................................................. 4-30

Figure 4.12 Large reel and adjustable jack stands .............................................................................. 4-36

Figure 4.13 Cable tree ........................................................................................................................ 4-36

Figure 4.14 Rolling hitch knot ............................................................................................................. 4-37

Figure 4.15 A cable brake attached to the cable reel ........................................................................... 4-40

Figure 4.16 A pull rope attached to the cable lead ............................................................................... 4-41

Figure 4.17 Bullwheel ......................................................................................................................... 4-42

Figure 4.18 Vertical backbone cable support ....................................................................................... 4-43

Figure 4.19 Cable on tray from vertical pathway .................................................................................. 4-44

Figure 4.20 Backboard layout with D-rings .......................................................................................... 4-45

Figure 4.21 Wire mesh grips ............................................................................................................... 4-51

Figure 4.22 Winch in position and properly secured to a concrete slab ............................................... 4-52

Figure 4.23 A properly secured pulley ................................................................................................. 4-53

Figure 4.24 Swivel to prevent cable twisting ........................................................................................ 4-58

Figure 4.25 Four-inch conduit with three innerducts ............................................................................ 4-62

Figure 4.26 Connecting aramid yarn.................................................................................................... 4-63

Figure 4.27 Multiweave wire mesh grip with swivel pulling eye ............................................................. 4-63

Section 2: Structured Cabling System Chapter 1: Background Information

© 2004 BICSI® 1-13 ITS Installation Manual, 4th edition

Generic Structured Cabling System, continued

Other sections in this chapter provide details about local area networks (LANs),metropolitan area networks (MANs), wide area networks (WANs), and other typesof networks that involve cabling installations.

The only type of cabling installation presented in this document is an installation withina single building. OSP systems are addressed in the BICSI® Customer-OwnedOutside Plant (CO-OSP) Design Manual.

A structured cabling system includes most or all of the following components:

• Entrance facilities (EFs)

• Backbone pathways

• Backbone cabling

• Horizontal pathways

• Horizontal cabling

• Telecommunications outlets/connectors

• Equipment rooms (ERs)

• Telecommunications rooms (TRs)

• Telecommunications enclosures (TEs)

• Cross-connect facilities

• Termination hardware

• Administration (labeling and documentation)

• Multi-user telecommunications outlet assemblies (MUTOAs)

• Transition points (TPs)

• Consolidation points (CPs)

• Centralized cabling

Chapter 1: Background Information Section 2: Structured Cabling System

ITS Installation Manual, 4th edition 1-14 © 2004 BICSI®

Entrance Facility (EF)

The EF includes the cabling components needed to provide a means to connect theoutside plant facilities to building cabling. This can include the following:

• Entrance pathways

• Cables

• Connecting hardware

• Primary (electrical) protection devices

• Transition hardware

The access provider (AP) is generally responsible for the installation of regulatedfacilities, including the items listed above, to a specified point of demarcation, which isthe interface between the AP’s facility and the customer. For purposes of this manual,the ITS cabling installer is responsible for extending services from the demarcationpoint throughout the building cabling system.

In the United States, EF pathways and spaces are specified in TIA-569-B,Commercial Building Standard for Telecommunications Pathways andSpaces. In other countries, they are specified in ISO/IEC 18010, InformationTechnology—Pathways and Spaces for Customer Premises Cabling, or similarnational documents. Refer to the section on standards later in this chapter for moreinformation.

An EF is expected to provide the following:

• Point of demarcation between the APs and customer premises cabling (ifrequired).

• Primary (electrical) protection devices governed by the applicable electricalcodes.

• Space to house the transition between OSP cabling and building cabling. Thisusually involves transition from unlisted cable to listed cable. A designer shouldspecify the EF, including the pathways and spaces, and cabling and connectinghardware. Refer to Section 3: Codes, Standards, and Regulations in this chapterand National Fire Protection Association (NFPA) 70—National ElectricalCode® (NEC®) for details. Designers and cabling installers outside the UnitedStates should refer to the appropriate codes, standards, and regulations.


Chapter 1: Background Information


Section 3: Codes, Standards, and Regulations

Codes Affecting Information Transport Systems (ITS) in North America

Codes address the safety of persons, property, and the environment associated with the ITScabling installation. They include electrical codes, building codes, fire codes, environmentalcodes, and all other safety codes. When adopted by AHJs, codes have the force of law.

The National Electrical Code® (NEC®) and the Canadian Electrical Code (CE Code) arethe most widely adopted set of electrical safety requirements within North America. Inaddition, state, provincial, municipal, and local codes may add more restrictive provisions thanthe national codes and, therefore, take precedence. The order of code compliance should be infull conformance to national, state, and local codes, with the most restrictive code takingprecedence. In Mexico, the national electrical code is known as NOM-001-SEDE-1999,Instalaciones Eléctricas (Utilización). This code is revised every five years. The nextedition is expected to be published in late 2004 and will be known as NOM-001-SEDE-2004.

The National Fire Protection Association (NFPA) develops and produces codes and standardsrelating to ITS that include the NEC. The Canadian Standards Association® (CSA®) publishesthe CE Code.

National Fire Protection Association (NFPA)

The NFPA develops and produces the following fire and safety codes relating to ITS:

• NFPA 70, National Electrical Code® (NEC®), 2005

• NFPA 70E, Electrical Safety in the Workplace, 2004

• NFPA 72®, National Fire Alarm Code®, 2002

• NFPA 75, Standard for the Protection of Electronic Computer/Data ProcessingEquipment, 2003

• NFPA 76, Recommended Practice for the Fire Protection of TelecommunicationsFacilities, 2002

• NFPA 90A, Installation of Air-Conditioning and Ventilating Systems, 2002

• NFPA 101®, Life Safety Code®, 2003

• NFPA 255, Standard Method of Test of Surface Burning Characteristics of BuildingMaterials, 2000

• NFPA 262, Standard Method of Test for Flame Travel and Smoke of Wires andCables for Use in Air-Handling Spaces, 2002

• NFPA 780, Standard for the Installation of Lightning Protection Systems, 2004

• NFPA 5000®, Building Construction and Safety Code®, 2003





National Fire Protection Association (NFPA), continued

National Electrical Code® (NEC®)

The NFPA sponsors, controls, and publishes the NEC within the U.S. jurisdictional area. TheNEC is intended to protect persons and property from electrical hazards. The NEC specifiesminimum provisions necessary to safeguard persons and property from electrical hazards.

In the United States, most federal, state, and local municipalities have adopted the NEC inwhole or in part as their legal electrical code. Some states or localities adopt the NEC and addmore stringent requirements. Local jurisdiction determines the current version recognized anddoes not always adopt the latest edition.

The NEC (revised every three years) is used by:

• Lawyers and insurance companies to determine liability.

• Fire marshals and electrical inspectors in loss prevention and safety enforcement.

In buildings that will contain the ITS systems, NEC requirements do not necessarily addressthe adequate electrical environment for reliable and error-free operation of the installedequipment. Additional considerations beyond those necessary for safety are described inperformance standards and in the appropriate sections of this manual.

Table 1.4 lists NEC chapters, articles, and subarticles that apply to ITS.

Table 1.4National Electrical Code® chapters, articles, and subarticles that impact ITS installation

NEC Reference Title

Article 90 IntroductionSubarticle 90.2 ScopeSubarticle 90.3 Code Arrangement

Article 100 Definitions

Article 110 Requirements for Electrical InstallationsSubarticle 110.26 Spaces About Electrical EquipmentSubarticle 110.32 Work Space About EquipmentSubarticle 110.33 Entrance and Access to Work SpaceSubarticle 110.34 Work Space and Guarding

Article 210 Branch CircuitsSubarticle 210.25 Common Area Branch Circuits

Article 225 Outside Branch Circuits and FeedersSubarticle 225.14 Open-Conductor Spacings






Table 1.4, continuedNational Electrical Code® chapters, articles, and subarticles that impact ITS installation

NEC Reference Title

Article 250 Grounding and BondingSubarticle 250.32 Buildings or Structures Supplied by Feeder(s) or

Branch Circuit(s)Subarticle 250.50 Grounding Electrode SystemSubarticle 250.60 Use of Air TerminalsSubarticle 250.70 Methods of Grounding and Bonding Conductor

Connection to ElectrodesSubarticle 250.104 Bonding of Piping Systems and Exposed Structural Steel

Article 300 Wiring MethodsSubarticle 300.11 Securing and SupportingSubarticle 300.21 Spread of Fire or Products of CombustionSubarticle 300.22 Wiring in Ducts, Plenums, and Other Air-Handling

Spaces

Article 314 Outlet, Device, Pull, and Junction Boxes; Conduit Bodies;Fittings; and Handhole Enclosures

Article 324 Flat Conductor Cable: Type FCC

NOTE: The following articles from Chapter 3: Wiring Methods and Materials,primarily address pathway considerations.

Article 342 Intermediate Metal Conduit: Type IMC

Article 344 Rigid Metal Conduit: Type RMC

Article 348 Flexible Metal Conduit: Type FMC

Article 350 Liquidtight Flexible Metal Conduit: Type LFMC

Article 352 Rigid Nonmetallic Conduit: Type RNC

Article 356 Liquidtight Flexible Nonmetallic Conduit: Type LFNC

Article 358 Electrical Metallic Tubing: Type EMT

Article 360 Flexible Metallic Tubing: Type FMT

Article 362 Electrical Nonmetallic Tubing: Type ENT

Article 372 Cellular Concrete Floor Raceways






Table 1.4, continuedNational Electrical Code® chapters, articles, and subarticles that impact ITS installation

NEC Reference Title

Article 374 Cellular Metal Floor Raceways

Article 376 Metal Wireways

Article 378 Nonmetallic Wireways

Article 386 Surface Metal Raceways

Article 388 Surface Nonmetallic Raceways

Article 390 Underfloor Raceways

Article 392 Cable Trays

Article 500 Hazardous (Classified) Locations, Classes I, II, and III,Divisions 1 and 2

Article 605 Office Furnishings (Consisting of Lighting Accessories andWired Partitions)

Article 640 Audio Signal Processing, Amplification, and ReproductionEquipment

Article 645 Information Technology Equipment

Article 725 Class 1, Class 2, and Class 3 Remote-Control, Signaling, andPower-Limited Circuits

Article 760 Fire Alarm Systems

Article 770 Optical Fiber Cables and Raceways

Article 780 Closed-Loop and Programmed Power Distribution

Article 800 Communications Circuits

Article 810 Radio and Television Equipment

Article 820 Community Antenna Television and Radio Distribution Systems

Article 830 Network-Powered Broadband Communications Systems

NOTES: NEC Chapter 8: Communications Systems, stands separately and independentlyfrom other chapter and articles of the code, unless specifically referenced.Although some of the articles and subarticles listed in Table 1.4 are not referencedby chapter 8, the information in these articles and subarticles apply to all ITS.

Not all countries use the NEC but rather refer to their own wiring regulations forelectricity.





Standards Affecting Telecommunications in North America

Introduction

The purpose of a standard is to ensure a minimum level of performance. As defined in the2002 TIA Engineering Manual (3rd Edition), a standard is “a document that establishesengineering and technical requirements for processes, procedures, practices and methods thathave been decreed by authority or adopted by consensus.” Standards may be established forselection, application, and design criteria for material. Standards are established as a basis toquantify, compare, measure, or judge capacity, quantity, value, quality, performance, limits, andinteroperability.

A significant benefit of standards in the ITS industry is the aid to improved interoperability ofcomponents and systems by multiple manufacturers.

Codes often reference numerous safety standards to ensure the minimum safety requirementsof a given material or component.

In the United States, the NEC requires that the cable placed in a space defined as a plenum orother air-handling space must be listed for that purpose. This listing is given to material thatmeets a specific test standard of requirements for:

• Flammability.

• Smoke generation.

• Smoke density.

Test standards provide uniform rules for what is to be tested, how it is to be tested, and whichresults are acceptable.

American National Standards Institute/Telecommunications Industry Association/ElectronicIndustries Alliance (ANSI/TIA/EIA)

TIA and EIA are organizations that develop and submit standards to ANSI for approval andthen publish and make available to the industry. TIA and EIA publish standards for theperformance of manufacturing, installation, and electronic and telecommunications equipmentand systems. Each standard covers a specific part of building and campus cabling. Thestandards address the required cable, hardware, equipment, design, testing, and installationpractices. In addition, each standard lists related standards and other reference materials thatdeal with the same topics.

Most of the standards include sections that define important terms, acronyms, and symbols.The following are ANSI/TIA/EIA standards that pertain to cabling in commercial buildings:

• TIA TSB-140—Additional Guidelines for Field-Testing Length, Loss and Polarity ofOptical Fiber (2004)

Additional guidelines for field-testing optical fiber cabling will provide guidance on Tier 1and Tier 2 testing specifications and the use of the optical loss test set (OLTS) and theoptical time domain reflectometer (OTDR) for premise cabling.





American National Standards Institute/Telecommunications Industry Association/ElectronicIndustries Alliance (ANSI/TIA/EIA), continued

• TIA-526-7, OFSTP-7—Measurement of Optical Power Loss of Installed SinglemodeFiber Cable Plant (1998) (2002) (ANSI approval withdrawn July 2003)

The intent of this test procedure is to ensure that meaningful data describing the opticalloss performance of an installed single-mode cable plant can be obtained. It is not intendedfor component testing, nor does it define the elements of an installation that must bemeasured. The document that invokes this procedure establishes the requirements forinstallation, maintenance, repair, and conformance testing.

• TIA-526-14-A, OFSTP-14—Optical Power Loss Measurements of InstalledMultimode Fiber Cable Plan, (1998) (R2003) (ANSI approval withdrawn August 2003)

The intent of this document is to establish preferred measurement principles and practicesto ensure that meaningful data describing the optical loss performance of an installedcable plant can be obtained. It is not intended for component testing, nor does it define theelements of an installation that must be measured. Establishment of requirements forinstallation, maintenance, repair, or conformance testing is left to the specifier of this testmethod.

• ANSI/TIA/EIA-455-78-B-2002, FOTP 78—IEC 60793 Optical Fibres Part 1-40:Measurement Methods and Test Procedures—Attenuation

• ANSI/TIA/EIA-568-B.1-2001, Commercial Building Telecommunications CablingStandard—Part 1: General Requirements

This standard partially replaces ANSI/TIA/EIA-568-A, published October 1995, with theaddition of associated addenda, Telecommunications System Bulletins (TSBs), and interimstandards (ISs). This standard specifies a generic telecommunications cabling system forcommercial buildings that will support a multi-product, multi-vendor environment.

• ANSI/TIA/EIA-568-B.1-1-2001, Commercial Building Telecommunications CablingStandard—Part 1: General Requirements—Addendum 1—Minimum 4-Pair UTP and4-Pair ScTP Patch Cable Bend Radius

Addendum 1 applies to the minimum 4-pair unshielded twisted-pair (UTP) and 4-pairscreened twisted-pair (ScTP) patch cable bend radii.

• ANSI/TIA/EIA-568-B.1-2-2003, Commercial Building Telecommunications CablingStandard—Part 1: General Requirements—Addendum 2—Grounding and BondingSpecifications for Screened Balanced Twisted-Pair Horizontal Cabling

Addendum 2 specifies additional requirements for grounding (earthing) and bonding ofinstalled screened balanced horizontal cables and connecting hardware used within acommercial building environment.

• ANSI/TIA/EIA-568-B.1-3-2003, Commercial Building Telecommunications CablingStandard—Part 1: General Requirements—Addendum 3—Supportable Distancesand Channel Attenuation for Optical Fiber Applications by Fiber Type

Addendum 3 applies to the supportable distances and channel attenuation for optical fiberapplications by fiber type.



Section 5: Media

Media

Overview

Balanced twisted-pair cables are commonly used for information transport systems inbuildings. Standards ISO/IEC 11801 Ed. 2:2002 and ANSI/TIA/EIA-568-B.2 cover therequirements for use of balanced twisted-pair cables in horizontal cabling. Horizontal cablesshall consist of four balanced twisted-pairs of 24 AWG [0.51 mm (0.020 in)] thermoplasticinsulated solid conductors enclosed by a thermoplastic jacket. There are two types of cablerecognized and recommended for use in the horizontal cabling system. These cables are4-pair 100-ohm UTP or ScTP.

ITS cabling installers must be aware of the various types of media (cable) that are availablefor installation and maintenance. Each type and configuration has specific uses and definedmethods that must be employed during installation. This section focuses on horizontal media,although, backbone cable is also identified.

This document addresses various commonly used types of ITS cable. The majortelecommunications cables are:

• Balanced twisted-pair cable:

– Category 3/class C

– Category 5e/class D

– Category 6/class E

• Enhanced shielded balanced twisted-pair (STP-A) cable.

• Coaxial cable:

– Thin Ethernet IEEE 802.3

– Thick Ethernet IEEE 802.3

– Series-11 backbone, Series-6 horizontal drop, and Series-59 patch cord

– RG-62

• Optical fiber cable:

– Multimode (50/125 µm)

– Multimode (62.5/125 µm)

– Singlemode



Section 5: Media

Communications Wires and Cables and Communications Raceway Listing

The NEC categorizes communications cables and pathways for interior installations based ontheir performance when exposed to fire.

Table 1.9 summarizes Table 800.113 from the NEC.

Table 1.9Copper cable markings

Cable Marking Type

CMP Communications plenum cable

CMR Communications riser cable

CMG Communications general purpose cable

CM Communications general purpose cable

CMX Communications cable, limited use

CMUC Undercarpet communications wire and cable

Table 1.10 summarizes Table 800.154 of the NEC.

Table 1.10Copper cable substitutions

Cable Type Permitted Substitutions

CMR CMP

CMG, CM CMP, CMR

CMX CMP, CMR, CMG, CM




Section 5: Media

Communications Wires and Cables and Communications Raceway Listing, continued


Table 1.11Optical fiber cable markings

Cable Marking Type

OFNP Nonconductive optical fiber plenum cable

OFCP Conductive optical fiber plenum cable

OFNR Nonconductive optical fiber riser cable

OFCR Conductive optical fiber riser cable

OFNG Nonconductive optical fiber general-purpose cable

OFCG Conductive optical fiber general-purpose cable

OFN Nonconductive optical fiber general-purpose cable

OFC Conductive optical fiber general-purpose cable


Table 1.12Fiber cable substitutions

Cable Type Permitted Substitutions

OFNP None

OFCP OFNP

OFNR OFNP

OFCR OFNP, OFCP, OFNR

OFNG, OFN OFNP, OFNR

OFCG, OFC OFNP, OFCP, OFNR, OFCR, OFNG, OFN




Section 5: Media

Balanced Twisted-Pair Cable

Balanced twisted-pair cable has been used for many years for both voice and data cabling(see Figure 1.27). It has the following characteristics:

• Composed of pairs of wires twisted together

• Commonly available in various pair counts (2–2400 pairs)

• Normally not shielded below 600 pairs and has an overall aluminum-steel shield up to2400 pairs

• Reduces electrical interference by conductors’ twisting

• Characteristic impedance of 100 ohms at 100 MHz and 600 ohms at 16 MHz

• Recommended conductor sizes 22 AWG [0.64 mm (0.025 in)] to 24 AWG[0.51 mm (0.020 in)]

Figure 1.27Typical balanced twisted-pair cable

To improve information throughput, significant performance improvements have been made toUTP cable. In ANSI/TIA/EIA-568-B, specifications for several performance levels of UTPcable and associated connecting hardware were established as follows:

• Category 3/class C—UTP cables and associated connecting hardware with transmissioncharacteristics specified up to 16 MHz

• Category 4—UTP cables and associated connecting hardware with transmissioncharacteristics specified up to 20 MHz

• Categories 5 and 5e/class D—UTP cables and associated connecting hardware withtransmission characteristics specified up to 100 MHz

• Category 6/class E cabling up to 250 MHz

Cable jacket

Drain wire

Foil shield

Cable jacket



Section 8: Grounding, Bonding, and Protection

Grounding, Bonding and Protection

Overview

The electrical protection of ITS systems is an essential part of every installation. Propergrounding and bonding are necessary for both safety and performance. The followingmaterial from NEC® has been reprinted with permission from the National Electrical Code®

NFPA 70-2005, Copyright© 2004, National Fire Protection Association, Quincy, MA 02269:

The following definitions are from the NEC®, Article 100, Definitions:

• Ground is defined as, “A conducting connection, whether intentional or accidental,between an electrical circuit or equipment and the earth, or to some conducting body thatserves in place of the earth.”

• Bonding is defined as, “The permanent joining of metallic parts to form an electricallyconductive path that ensures electrical continuity and the capacity to conduct safely anycurrent likely to be imposed.”

Bonding conductors are not intended for carrying electrical load currents under normalconditions, but it must carry fault currents so that electrical protection (circuit breakers) wouldproperly operate.

As described earlier, another important safety application of bonding is limiting hazardouspotential differences between different systems and equipment during lightning or powerfaults. This protects against arcing between different system (or equipment) grounds andprotects personnel who may be exposed to both systems simultaneously.

Grounding System Components

The two areas of grounding that apply to commercial buildings are the:

• Grounding electrode system (also known as the earthing system).

• Equipment grounding system (also known as the electrical system’s third wire safetyground).

The grounding electrode system consists of a grounding:

• Field (earth).

• Electrode.

• Electrode conductor.

The equipment grounding system consists of:

• Equipment grounding conductor(s).

• A main bonding jumper within the electrical system’s main distribution panel.





Grounding System Components, continued

In addition to the building grounding systems, a separate grounding system fortelecommunications is defined in ANSI/J-STD-607-A. The electrical service entrance isoutside the scope of this manual and is grounded, bonded, and protected in accordance with allapplicable electrical codes. The telecommunications grounding and bonding infrastructureoriginates with a connection to the service equipment (power) ground and extends throughoutthe building. The five components comprising the telecommunications grounding system arethe:

• Bonding conductor for telecommunications (BCT).

• Telecommunications main grounding busbar (TMGB).

• Telecommunications bonding backbone (TBB).

• Telecommunications grounding busbar (TGB).

• Grounding equalizer (GE).

Additional components that may be included are:

• Lightning protector grounding system connections.

• Grounding electrodes.

• A grounding electrode conductor (GEC).

There are several types of electrical protection systems within every building. Although theITS cabling installer is not usually responsible for the other systems, it is not safe to work in abuilding without recognizing and understanding the purpose for each system. A clearunderstanding of these systems provides a basis for further training and working with othertrades when necessary.

This chapter describes the various electrical protection systems found in most of today’scommercial buildings, such as:

• Lightning protection systems.

• Grounding electrode systems.

• Electrical grounding, bonding, and protection systems.

• Electrical power protection systems.

• Surge protection devices.

• ITS grounding, bonding and electrical systems.

• ITS circuit protectors.

Safety

Primary responsibilities of the cabling installer are safeguarding personnel, property, andequipment from “foreign” electrical voltages and currents. Foreign refers to electrical voltagesor currents that are not normally carried by, or expected in, the ITS distribution systems.




References

A useful reference is the NEC® Handbook, an expanded version of the code that hasadditional explanatory comments.

NEC Chapter 8, Communications Systems, covers general requirements for grounding,bonding, and protecting low-voltage communications equipment. NEC Article 250, Groundingand Bonding covers electrical power circuits and low-voltage control and signaling systems.Even though NEC Chapter 8 is a stand-alone chapter, it refers the reader to Article 250 forspecific grounding concerns.

This manual is based on the 2005 edition of the NEC, although many local jurisdictions stillrequire adherence to earlier editions. Always consult the AHJ to determine what edition of theNEC is being used in the jurisdiction.

The Canadian Standards Association (CSA) publishes the Canadian Electrical Code® (CECode®), a CE Code® Handbook, and a number of coordinated product test standards. Theseare comparable to the NEC (based on the same system grounding and protection methods)and have many similarities, but the two codes are not identical or interchangeable.

ANSI/J-STD-607-A covers grounding and standard bonding requirements fortelecommunications applications within commercial buildings. It is available as a stand-alonedocument or along with several other telecommunication standards, including theANSI/TIA/EIA-568-B series, TIA-569-B, and ANSI/TIA/EIA-606-A documents as a set ofTelecommunications Building Wiring Standards. ANSI/J-STD-607-A does not replaceNEC requirements but provides additional standards for grounding and bonding. Note that itcovers only grounding and bonding but relies on other standards and codes for many importantprotective measures.

Electrical Exposure (ITS)

NEC Section 800.90 covers safety code requirements for protectors. Additionally, it definesthe exposed state as when a circuit is in such a position that, in case of failure of supports orinsulation, contact with another conductor may result.

The NEC requires a listed primary protector (at both ends) whenever outside plant cable maybe exposed to lightning or accidental contact with power conductors operating at more than300 V (see Figures 1.74 and 1.75).

Exposure refers to an outdoor ITS cable’s susceptibility to electrical power system faults,lightning, or other transient voltages. A cable is considered exposed if any branches orindividual circuit is exposed.

Lightning Exposure

Lightning strikes can cause severe damage to ITS systems that have not been properlyinstalled. Even with a properly installed grounding infrastructure, there are no guarantees thata direct lightning strike will not damage a system. The risk of damage is reduced when ITShas been properly bonded to the grounding infrastructure.





Lightning Exposure, continued

A Lightning Exposure Guideline is included in the NEC Section 800.90(A) Fine Print Note(FPN) No. 2. It states, “Interbuilding circuits are considered to have a lightning exposureunless one or more of the following conditions exist:

(1) Circuits in large metropolitan areas where buildings are close together and sufficientlyhigh to intercept lightning.

(2) Interbuilding cable runs of 42 m (140 ft) or less, directly buried or in underground conduit,where a continuous metallic cable shield or a continuous metallic conduit containing thecable is bonded to each building grounding electrode system.

(3) Areas having an average of five or fewer thunderstorm days per year and the earthresistivity of less than 100 ohmmeters. Such areas are found along the Pacific coast.”

If cable exposure is in question, consider it to be exposed and protect it accordingly.

There are two additional exposure factors:

• Aerial cable usually has power cables routed above it that will intercept and divert directlightning strikes. This can help but does not eliminate the need for protectors.

• Buried cable collects ground strikes within a distance determined by soil resistance(typically 1.83–6 m [6–20 ft]). High soil resistance intensifies this problem. Without theproper protection, a system could be receiving repeated ground strike surges without theevidence of damaged cable associated with an aerial strike.

Lightning is so powerful and unpredictable that the best insurance against damage is aproperly grounded and bonded system. Lightning may strike at any time with the potentialeffect of:

• A direct current surge, pulsating between 100 kHz and 2 MHz.

• 10 million V or greater.

• An average 40,000 amperes that can peak as high as 270,000 amperes.

• Temperatures in excess of 27 760 ºC (50,000 ºF).

Grounding and earthing systems must be designed and installed in such a way that they cansafely carry the unwanted voltages to the earth.

Electrical Exposure (Building Structure)

NFPA 780, Standard for the Installation of Lightning Protection Systems, covers lightningprotection systems for buildings and defines the exposed state as anything above ground andoutside a “zone of protection” (an area under or nearly under a lightning protection system).This does not include communications cable. A zone of protection is shown in Figure 1.74.

These lightning protection systems intercept and ground lightning strikes to the building. Theyare generally recognized by the metal spikes on top of the building.





Lightning Protection System, continued• If the ITS ground relies on the electrical service grounding electrode system, the more

common grounding practices will apply. ITS grounding practices will be discussed later inthe chapter.

• NEC Section 800.53 and NFPA 780 require that, where practicable, a separation of atleast 1.8 m (6 ft) should be maintained between communications wires and cables onbuildings and lightning conductors. This separation will help prevent hazardous voltagesfrom being induced or coupled over to the ITS cables during a lightning strike. Thisseparation requirement does not apply to buildings that use building steel as the lightningdown conductor.

Electrical Power Systems

An electrical power system provides the electrical infrastructure necessary to distributeelectricity throughout the building. All the appliances, lighting circuits, and equipment are fedthrough the network of branch circuits. The heart of the electrical power system is its beingreferenced or grounded to the earth. In most ITS grounding systems, the ground reference isestablished by bonding the bonding conductor for ITS to the electrical service ground at theelectrical service equipment (see Figure 1.77).

Figure 1.77Typical (small) electrical power system

Groundconductor

Overcurrentprotection

Detail

Detail

Metal water pipeFooting ground

Main electricalservice panel

Buildingstructuralsteel

Branchcircuitbondedconduit

Grounding electrode system

Receptacle





Electrical Bonding and Grounding

Throughout NEC Article 250, electrical bonding and grounding are described as metallicpanels and raceways that are bonded to an equipment grounding conductor and are thenbonded to the grounded electrical service neutral at the service equipment. An equipmentgrounding conductor shall be routed with the power and neutral conductors.

Electrical systems and metallic apparatus are bonded and grounded to limit hazardous voltagesdue to:

• Electrical power faults.

• Lightning.

• Other electrical transients.

This facilitates overcurrent protection operation in the case of electrical power faults thatwould otherwise place hazardous voltages at dangerous points. Inadvertent shorting of thepower conductor to the equipment ground, or to other bonded metal or conductors, will causea circuit breaker (overcurrent protection) to operate and disconnect power.

These systems are not usually the responsibility of the cabling installer, but they should berecognized and understood, since most sites have power protection designed specifically forITS equipment.

Electrical Power Protection

Electrical power protection is covered throughout NEC Chapter 2, Wiring and Protection,which includes electrical bonding and grounding requirements. The following are required forcomplete electrical protection:

• Surge arresters—Divert surge current coming in on utility power conductors.

• Service disconnecting means—Main service breaker provides a method for overall powershutdown based on emergency or maintenance.

• Overcurrent protection—Circuit breakers open individual power circuits, if the currentreaches a predetermined unsafe level.

NOTE: Other components that improve the overall quality of electrical power include powerline conditioners, UPSs, and power backup systems.

These systems are not usually the responsibility of the cabling installer, but should berecognized and understood, since most sites have power protection designed specifically forITS equipment.

Grounding Electrode System

As defined in NEC Article 100, Definitions, a grounding electrode is a device that establishesan electrical connection to earth.

A grounding electrode system is a network of electrically connected ground electrodes used toachieve an improved low resistance to the earth and, in many cases, to aid equalization ofpotentials around a building.





Grounding Electrode System, continued

All ground electrodes can be divided into two groups:

• Underground piping systems, metal building framework, well casings, steel pilings, andother underground metal structures installed for purposes other than grounding.

• Electrodes specifically designed for grounding purposes (i.e., driven and buried groundrod, ground rod system, buried ground rings and grids, metal plates, chemically enhancedground rods and systems).

A properly functioning ground is essential to electrical protection because it:

• Conducts any excess electrical energy to the earth without causing hazardous arcing,heating, or explosion during lightning.

• Establishes a common potential reference.

NEC Section 250.58 requires a common grounding electrode system for different electricalsystems within a building. Where two or more electrodes are effectively bonded together, theyshall be considered as a single grounding electrode system.

NEC Section 250.94 requires an intersystem bonding connection accessible at the electricalservice equipment. This connection is a prime choice for establishing an ITS ground. (SeeUsing the Electrical Service Ground in this section.)

In a distribution system of 600 V or less, the objective is to achieve the lowest possiblegrounding electrode resistance. This applies to the ITS installation, since the electricalgrounding electrodes are usually shared by the ITS grounding infrastructure. The use ofcontinuous metallic underground water pipes, as well as metal structural frames of buildings,typically provides excellent ground resistance not exceeding 3 ohms.

When a single electrode is installed, NEC 250.56 states that “a single electrode consisting of arod, pipe, or plate that does not have a resistance to ground of 25 ohms or less shall beaugmented by one additional electrode of any of the types specified by 250.52(A)(2) through(A)(7). Where multiple rod, pipe, or plate electrodes are installed to meet the requirements ofthis section, they shall not be less than 1.8 m (6 ft) apart.”

When a single electrode fails to meet the 25 ohm requirement, the NEC requires that a singleadditional electrode be installed. NEC does not require the installation to be retested or to meetthe 25 ohm requirement. The reason is that the installation is no longer a single electrode but isnow defined as a system. NEC 250.58 states, “Two or more grounding electrodes that areeffectively bonded together shall be considered as a single grounding electrode system in thissense.”

NEC Article 250 does not offer a requirement for the maximum resistance to the earth whena grounding electrode system is installed. It is commonly assumed in error that the groundingelectrode system will have a resistance to ground of 25 ohms or less. (See IEEE 1100,Recommended Practice for Powering and Grounding Electronic Equipment.)

Many smaller installations have two ground rods driven into the earth, 1.8 m (6 ft) apart and,therefore, have met the requirements of a system. Since most local authorities do not requirethe actual resistance values of systems to be verified, equipment and personnel may be placedin jeopardy.





Grounding Electrode System, continued

On the flip side, installers should keep in mind that NEC’s primary focus is the safety ofpeople and property (buildings), and that thus its requirements do not specifically address theprotection of today’s sensitive electronics.

If the grounding requirements set forth by the equipment manufacturer are not met, thewarranty may not be honored. Electronics often requires grounding connections to the earth ofless than 10 ohms, with some as little as 1 ohm. Understanding how to install and test agrounding electrode system is a crucial task for a cabling installer.

Installing a Grounding Electrode

The resistance of the grounding electrode system should be as low as possible (25 ohms orless) and measured annually with an earth megger.

NOTE: 25 ohms or less ground is an NEC safety requirement and has nothing to do withsystem performance. Some system performance requirements can only be met byless than a 1 ohm impedance to ground.

The NEC® Handbook, Section 250.52, provides a few examples for the installation of agrounding electrode or electrode system. The installation of a telecommunications groundingelectrode is allowed if:

• There is no electrical service ground (e.g., a telephone and its cable protectors areinstalled in a barn that has no electrical service).

• Additional grounding is needed (NEC 250.54, 62, 64, and 118). If so, the installedelectrode must be bonded to the existing ground electrode system.

According to NEC 800.100(B)(2)(2), buildings or structures without a grounding means (noelectrical service, such as a barn or possibly a warehouse) may have an electrode installed forthe purpose of bonding the ITS circuit protectors to the earth. This rod may be sized not lessthan 12.7 mm (0.5 in) diameter and only 1.5 m (5 ft) long. A rod of this size is not allowed forany other purpose than bonding an ITS protector terminal.

The cabling installer should avoid using 1.5 m (5 ft) electrodes. After a 1.5 m (5 ft) rod hasbeen installed, it could be assumed that it was driven 2.4 m (8 ft) into the earth. An electricianinstalling a new service may attempt using a smaller rod as a means of grounding. This wouldnot be a safe installation, since NEC Article 250 requirements would not be met.

BICSI does not recommend that 1.5 m (5 ft) rods be used. Instead, an electrode sized inaccordance with NEC 250.52(A)(5), should be installed. This will provide for a safeinstallation and for any future electrical system additions.

BICSI recommends a:

• Minimum 2.4 m (8 ft) by 16 mm (5/8 in) copper-clad ground rod.

• 6 AWG [4.1 mm (0.16 in)] solid grounding conductor.

NOTE: If the connection to the grounding conductor is made below grade, use anexothermic weld. Exothermic weld is discussed in detail later in this chapter.





Installing a Grounding Electrode, continued

Other alternative electrodes include ground rings and plates. The ground ring electrodeconsists of:

• A non-insulated conductor that is buried in the shape of a ring according to NEC250.52(A)(4).

• Conductors that are buried at a minimum depth of 762 mm (30 in).

• A minimum of 6 m (20 ft) in length.

• A minimum of 2 AWG [6.5 mm (0.26 in)].

The plate electrode consists of:

• Iron or steel plates that are minimum 6.3 mm (0.25 in) thick.

• Nonferrous metal plates that are minimum 1.6 mm (0.063 in) thick.

• Exposed surface area of at least 0.186 m2 (2 ft2).

The following conditions must be strictly observed:

• Any installed grounding electrode must be at least 1.83 m (6 ft) away from other existingelectrodes.

• Electrodes or down conductors that are part of a lightning protection system are notallowed for use as an electrode for this purpose.

• Regardless of what alternative is selected for installing a ground rod, all other electricalsystem grounds, structural building steel, and metallic piping systems must be bondedtogether. This is required of the electrical service and is usually already accomplished, butit should be verified.

• Gas pipes, steam pipes, or hot water pipes are not allowed as a grounding electrode, butstill require bonding to other electrodes.

Physical Protection

The electrode should be installed so that the top of the electrode is at or below ground level. Ifthe top of the electrode is above ground level, the electrode, GEC, and their bond should beprotected from damage, as per NEC Section 250.10. If the protection consists of a metallicconduit or raceway, both ends must be bonded to the grounding conductor or the sameterminal or electrode to which the grounding conductor is connected, as per NEC Section800.100(A)(6). The bonding of the conductor to both ends of the metallic conduit or racewaywill provide equalization between the conductor and the metallic pathway. If not properlybonded together, an inductive choke may be created, which, in the event of a fault, couldhinder the flow of current.

Earth Resistance

Generally, earth resistance is the resistance of soil to the passage of electrical current. Theearth is a relatively poor conductor of electricity compared to normal conductors (e.g., copperwire). However, if the path for current is large enough, the resistance can be quite low andearth can be a good conductor.





Earth Resistance, continued

Earth resistivity is far from a constant, and has a predictable value ranging generally from 500to 200,000 ohm-cm. Some factors that can affect the resistance value of the surrounding earthinclude:

• Moisture content of the soil.

• Quantity of electrolytes (a conducting medium that allows the flow of current).

• Type of electrolytes.

• Adjacent conductors.

• Temperature.

• Electrode depth.

• Electrode diameter.

• Electrode(s) spacing distance.

Earth Resistance Tester or Earth Megger

Formulas used for computing the earth resistivity are complicated, and the earth resistivity isneither uniform nor constant; therefore, a simple and direct method of measuring the earthresistance is needed. The instrument used is an earth megger tester.

The earth megger tester is a self-contained portable instrument that is reliable and easy to use.It can measure the resistance of the earth alone or the resistance of an installed electrodesystem and its surrounding earth.

An earth resistance tester is known as an earth megger but should not be confused with anelectrician’s megohmmeter (commonly called a megger). The electrician’s megger is used totest the insulation of power conductors and cannot be used to measure the earth resistivity.

An earth electrode system that provides a low ground resistance is not easy to obtain.However, with experience, a cabling installer can learn to set up a reliable system and checkthe resistance value with reasonable accuracy.

The principles and methods of earth resistance testing apply to systems that require lowresistance ground connections and include:

• Lightning arrester installations.

• Power generating stations.

• Electrical distribution systems.

• Industrial plants.

• ITS installations.

Several companies manufacture earth megger instruments for the testing of earth resistance.These instruments incorporate:

• A voltage source.

• An ohmmeter.

• Switches to change the meter’s resistance range.

• Small test rods or electrodes.




Improving Earth Resistance, continued

Hollow rods are similar to a hollow drainage pipe that has small holes drilled along its length toallow water to leach into the surrounding soil. These rods are usually 64 mm (2.5 in) wide andare available in varying lengths. The rod is filled with electrolyte-enhancing chemicals andburied either vertically or horizontally in the soil. Most hollow rods require that one end remainaccessible for future replenishment of chemicals. These rods offer a greater area of treatmentdue to their ability to leach more chemicals into the surrounding earth.

NOTE: These chemicals may be corrosive and may cause the ground rods to have ashortened life span when compared to that of a standard ground rod.

Chemically treated rods are often used:

• Where the location does not allow vertical placement of a driven ground rod.

• Where the soil resistivity is extremely high.

• In conjunction with standard ground rods to form a grounding network.

Soil Treatment

Chemical treatment of the soil improves earth-electrode resistance when longer rods cannotbe driven into the soil because of rock beds. A soil that has been chemically treated provides amore uniform ground through seasonal changes. Some of the disadvantages are:

• Chemicals concentrated around electrodes may cause corrosion and shorten the life of aninstalled electrode system.

• Chemicals leach through the soil and dissipate. Scheduled replenishment may be requiredevery few years or as often as every three months. Dissipation is dependent on weather,rainfall, and, even, sprinkler systems.

• Some areas of the country prohibit the use of chemical treatment due to the possiblecontamination of the water table and the local drinking water.

An alternative to chemical treatment is the use of a noncorrosive, but conductive, compoundbetween the electrode and the soil. A hole in the soil is created around the electrode; bags ofthe granular compound are premixed with water to create a cement-like mortar, which is thenpoured into the hole. It is covered with topsoil. When water is not readily available, someproducts may be installed in a dry powder form. Dry installations will not provide themaximum ground resistance reduction until moisture leaches into the soil and cures thecompound. Unlike chemical treatment, this is considered a permanent treatment, since thecompound will not leach away when exposed to moisture. Premixing is recommendedbecause it ensures a consistent installation and can be readily tested after the curing time. Dryinstallations may take months to reach their full conductive potential.




Telecommunications Bonding and Grounding

Telecommunications bonding and grounding are dedicated specifically for ITS.Telecommunications grounding and bonding are designed and installed to help ensure theproper performance of ITS equipment and cables. Previously in this chapter, NEC and NFPA780 were mentioned as the sources of requirements for grounding and bonding from a safetycode standpoint.

There are several situations where these minimal safety codes can be interpreted andimplemented differently. Some may not be as suitable as others for sensitive equipmentreliability and performance.

Manufacturers and designers use a wide range of different solutions to adapt to:

• Site variations.

• Prewired buildings.

• Manufacturer interpretations.

• Multivendor applications.

• Equipment design.

• Sensitive high-speed electronics.

• Multiple electrical service feeds.

Most situations cannot rely solely on the safety grounding methods. Instead, ITS systemsrequire dedicated and precise grounding and bonding.

Telecommunications bonding and grounding are used to:

• Minimize electrical surge effects and hazards.

• Augment electrical bonding.

• Lower the system ground reference impedance.

NOTE: This does not replace the requirements for electrical power grounding butsupplements them with the additional bonding that generally followstelecommunications pathways between EFs, ERs, TEs, and TRs.

Telecommunications Bonding Principles

Most buildings have low overall impedance (many are designed as part of a lightningprotection system to safely conduct lightning strikes to earth). However, significantdifferences in ground potential can exist throughout a building. Additional bonding conductorsare an effective way to improve marginal situations; especially in buildings that lack an overallbonded steel structure.

If continuous structural steel exists along the same path, there may be little actualimprovement. Even here, a certain assurance is gained by having specific bonding conductorsthat can be verified and inspected.





Telecommunications Grounding Practices

Overview

Establishing a suitable telecommunications ground is critical in properly grounded ITSequipment. A telecommunications ground is always required and is typically found in:

• Telecommunications EF for sites with exposed cable.

• ERs.

• TEs.

• TRs.

Grounding Choices

Direct attachment to the closest point in the building’s electrical service grounding electrodesystem is preferred because ITS cabling and power cabling must be effectively equalized.

Select the nearest accessible location on:

• The building ground electrode system.

• An accessible electrical service ground.

If no electrical service exists, use either:

• Driven ground rod (described under Installing a Grounding Electrode in this section); or

• Another grounding electrode system installed for the purpose.

Using the Electrical Service Ground

A direct electrical service ground is one of the best points for grounding ITS systems (seeFigure 1.87). In a new construction, an electrical contractor must provide accessible means.NEC 250.94 requires an intersystem bonding connection accessible at the electrical serviceequipment, such as:

• Exposed nonflexible metallic raceways

• Exposed grounding electrode conductor

WARNING: This conductor is critical to the safety of the electrical power system. Donot move, modify, or disconnect the conductor without the directparticipation of the personnel responsible for that system.

• Approved means for the external connection of a copper or other corrosion-resistantbonding or grounding conductor to the grounded raceway or equipment

NOTE: Ensure the grounding electrode system is properly installed. Verify the details withthe electrical contractor, or have the system tested by a licensed electrician.





Using the Electrical Service Ground, continued

Figure 1.87Typical telecommunications ground to an exposed raceway

Community Antenna Television (CATV)

Bond the established ground to the outer conductive shield of a CATV coaxial cable in thesame manner as other ITS cables to help limit potential differences between these systemsand other metallic systems (NEC 820.93).

Water Pipes

Historically, the first choice for a grounding electrode had been a metallic cold water pipeconnected to a utility water distribution system. This is no longer common. Nonmetallic pipe isincreasingly used, and electrical systems should not rely on plumbing systems. The NEC doesnot allow a water pipe to be the sole electrode for establishing a ground. It requires that waterpipes be bonded to another electrode type to ensure a ground is still present in case the waterpipe’s continuity is interrupted.

For a similar reason, caution must be exercised when water pipe is used as an intersystembonding conductor. An intersystem bonding conductor might use a cold water pipe to extend aground potential from one end of a building to another, where the cabling installer uses abonding clamp for attachment. If a plumber were to disconnect the pipes in the middle duringa failure or for maintenance, the bond would be lost. NEC 250.50 and 250.104 cover suchusage; however, avoid this practice and use a minimum 6 AWG [4.1 mm (0.16 in)] copperbonding conductor.

Electrical service panel





Bonding Connections, continued

Exothermic welding is shown in Figure 1.90 (see NEC 250.8).

Figure 1.90Exothermic welding

The exothermic weld process uses a special mold and heat-resistant material to bond metallicconductors together (see Figure 1.91). A variety of molds meet the requirements of:

• Conductor size and shape.

• Ground rod material (based on the diameter, treated or untreated).

• Application—busbar, pipe, rebar, building steel.

• Configuration—tee, tap, inline splice or connector.

The exothermic weld process is commonly applied:

• Within the ground electrode system.

• To parts of a grounding system that are subject to corrosion or that must reliably carryhigh currents.

• In direct-buried applications.

• To locations requiring minimal maintenance.





Bonding Connections, continued

Figure 1.91Exothermic welding mold

Follow the steps below to complete an exothermic weld.

Step Completing an Exothermic Weld

1 Determine which type of connection is needed.

2 Obtain the proper mold for conductors to be bonded.

3 Follow the safety procedures and wear leather gloves and safety glasses.

4 Open the mold and place the metal conductors into the mold, following themanufacturer’s instructions.

5 Close the mold around the conductors to be bonded.

6 Place the steel disk in the base of the crucible.

NOTE: The disk keeps the weld metal in the crucible until the disk melts and theweld metal flows down into the weld cavity.

7 Fill the crucible with the weld metal.

NOTE: Each canister of weld metal is sized for a specific size mold. Match the sizenumber on the canister to the number required on the mold.

Complete mold assembly

Starter material

Rear halfof mold

Weld metal Steel disk

Weld cavity

Metal conductors




Bonding Conductors

Bonding conductors shall be copper. To avoid unintentional ground connections, bondingconductors within buildings may be insulated. Insulated conductors must be listed for theapplication (e.g., plenum, riser). This can be a problem in some installations. Largerconductors are not readily available with plenum rated insulation. The cabling installer hasthree options when going through a plenum:

• Use plenum rated conductors (when available)

• Use noninsulated conductors

Installing a nonplenum rated conductor in a metallic conduit will significantly add to the laborand cost and require additional bonding of the bonding conductor at each end of the conduit.

Bonding conductors shall be green or marked with a distinctive green color. Noninsulatedconductors shall have green phasing tape wrapped around the conductor at each end, and anytime they enter or exit a wall or pathway. Label at the point of termination, so the label can beeasily read.

Bonding conductors must be routed with minimum bends or changes in direction. Highervoltages have difficulty making sharp turns and may become a hazardous arc leaving theconductor where tight turns are encountered. Maintain a minimum bend radius of eight timesthe bonding conductor’s diameter to ensure proper performance during a fault.

NEC 800.100(A)(3) requires at least a 14 AWG [1.6 mm (0.063 in)] stranded or solidinsulated conductor for connecting the ITS protectors and associated metallic cable sheaths tothe selected ground. Other NEC ground requirements generally indicate a 6 AWG [4.1 mm(0.16 in)] minimum. A 6 AWG [4.1 mm (0.16 in)] stranded conductor should be used becausethis accommodates different code requirements and allows future changes.

In most applications, the bond type selected depends on the application and the fault currentcarrying capacity needed, but a minimum 6 AWG [4.1 mm (0.16 in)] copper conductor isgenerally used throughout typical commercial buildings. According to ANSI/J-STD-607-A,consideration should be given to sizing conductors as large as 3/0 AWG [14.73 mm (0.580 in)].

Some bonding conductors must be guarded against physical damage. The preferred physicalprotection is nonmetallic. If metallic conduit is used, the bonding conductor must be bonded tothe conduit at both ends to ensure the metallic conduit will not act as an inductive chokepreventing current to flow during a fault. The bonding at each end equalizes possible potentialdifferences between the conduit and the conductor inside it.

Inspection

Ground systems require scheduled maintenance. They should be checked for tight connectionsannually. Critical ITS systems should be tested annually to ensure low resistant connectionsthroughout the system and to the earth.





Inspection, continued

Visual inspection can usually reveal problems, such as:

• Loose connections.

• Corrosion.

• Physical damage.

• System modifications.

During any service work, the ITS cabling installer should visually inspect bonding connections.The cabling installer should always ensure that a ground system has been installed properly,since approximately 90 percent of all grounding troubles are the result of loose connections.




Large Systems, continued

Grounding Equalizer (GE)

In larger, multistory buildings that have multiple TRs on each floor, the potentials between TRsneed to be equalized. When applicable, a GE conductor is installed between TGBs tointerconnect all the TRs on the same floor. The GE is not required for every floor, but isinstalled on every third floor and the top floor.

The GE shall be sized following the TBB sizing requirements.

NOTE: The GE was formally known as the telecommunications bonding backboneinterconnecting bonding conductor (TBBIBC).

Equipment Rooms (ERs)

Each ER shall have at least one busbar. If the entrance facility is in the ER, then the TMGBwill meet this requirement. If the ER and the EF are separate, then the ER will require its ownTGB.

Telecommunications Rooms (TRs)

Each TR shall have at least one TGB.

In a TR, suitable ground options include:

• Building structural steel.

• An electrical receptacle box or approved conduit connection.

• A combination of the above that is accessible.

• An already established telecommunications ground.

Multiple TGBs within the same space shall be bonded together with a conductor the same sizeas the TBB or with splice bars.

Backbone Cable Protection

Cables inside a building are generally considered not exposed, but there are situations that callfor protective measures. The following guidelines should be applied:

• Electrical power cabling should not be routed directly alongside ITS cable. Electricalcabling is usually in conduit, providing additional shielding (see NEC Section 800.133 forseparation and exceptions).

• Telecommunications cable should be routed near the middle of the building. Surroundingthe cable with structural building steel or a lightning protection system provides shieldingand usually diverts transient currents.

• Lightning protection system should be installed.

• Other exposed cables that enter the building must be protected and grounded.

• Some form of bonding conductor should be installed along each backbone cable pathway.

In high-rise buildings and low-wide buildings (particularly, if located in an area with highlightning activity or high soil resistivity), protective measures are vital. The same may be truefor buildings that are close to an electrical substation or heavy industrial facilities.





Coupled Bonding Conductor (CBC)

A CBC is a bonding conductor that provides equalization like a TBB. A CBC provides adifferent form of protection through electromagnetic coupling (close proximity) with the ITScable (see Figure 1.92). The CBC is considered part of an installed ITS cabling system andnot part of a grounding and bonding infrastructure. Some PBX equipment manufacturersspecify a CBC between their equipment and exposed circuit protectors.

There are two basic forms of CBC:

• Cable shield

• Separate copper conductor tie, wrapped at regular intervals to an unshielded cable

Typically, the CBC is specified as 10 AWG [2.6 mm (0.10 in)]. It is recommended that a CBCbe sized as a 6 AWG [4.1 mm (0.16 in)] to avoid confusion when installing bonding conductorsin the bonding and grounding systems. To work properly, the CBC installed for a PBX must beconnected directly to the protector ground and to the PBX ground.

When EMI is a concern for unshielded cables running between TRs, the cable may be co-routed with a CBC. The CBC acts as an antenna for EMI, thus protecting the unshieldedcables.

While a TBB co-routed with unshielded ITS cables may act as a CBC, it is considered part ofthe grounding and bonding system and not the cabling system. To the contrary, a CBC mayrun between TRs, but it is part of the cabling system and not the grounding and bondingsystem. A cable’s shield is a form of CBC, but it is never considered a TBB since it is notdesigned to carry the required currents that may be imposed during a fault. The shield may bedisconnected during maintenance. This would leave the remote busbar ungrounded if it hadbeen incorrectly used as a CBC.

Unshielded Backbone Cable

For unshielded backbone cable, a CBC or a co-routed bonding conductor (TBB) should beinstalled.

A TBB is required for installations of shielded intrabuilding backbone cable.

Shielded Cabling Systems

Some indoor cabling systems rely on shielding as an integral factor in their signal transmissionperformance, most notably, those with coaxial, STP wire, or ScTP. The term shielded in thissection is used to describe coaxial, STP, and ScTP cabling systems. Each of these shieldedcabling systems requires the use of shielded patch cord assemblies in order to maintain theshield integrity to the customer premises equipment at each end of the system.




Telecommunications Circuit Protectors

Overview

NEC Article 800.90 covers telecommunications circuit protection, a primary responsibility ofthe ITS distribution designer. The basic functions of protectors are:

• Arresting surges or overvoltages (diverting them to ground) that come from exposedcircuit pairs.

• Protecting against sustained hazardous currents that may be imposed.

Section 800.90(B) requires that the primary protector be located as close as practicable to thepoint at which the cable enters the building. Therefore, in installations requiring a primaryprotector, the OSP cable may not be permitted to extend 15 m (50 ft) into the building, if it ispracticable to place the primary protector closer than 15 m (50 ft) to the entrance point.

Based on UL standards, there are three types of telecommunications circuit protectors:

• Primary protectors as qualified by UL 497, Standard for Protectors for Paired-Conductor Communications Circuits—These are intended for application on exposedcircuits according to NEC requirements. These must be installed as near as possible to thepoint at which the exposed cables enter the building, and the grounding conductor mustsafely carry lightning and power fault currents.

• Secondary protectors as qualified by UL 497A, Standard for Secondary Protectors forCommunications Circuits—These are not required by the NEC but are typically used foradditional protection behind primary protectors. In addition to voltage protection, this typemust protect against sneak current. Sneak current can be caused by:

– Power faults that are too low in voltage to operate primary protectors.

– Station equipment that will draw excess current and overheat station wire.

– Induction from power lines.

• Data and fire alarm protectors as qualified by UL 497B, Standard for Protectors forData Communication and Fire Alarm Circuits—These modules are more sensitive witha lower fault threshold because they do not have to allow for the 90 V associated with atelephone’s ring voltage. Though not required by the NEC, these modules must performprimary protection against lightning transients. They do not have the ability to protectagainst power faults. These should be used according to the manufacturers’ guidelines.

There can be some overlap in function with the available products. The ITS equipmentmanufacturers should be consulted for specific applications; however, the following rulesgenerally apply:

– A primary protector is required where a circuit is exposed to electrical power faultsand lightning. Other protector types are not qualified for protection under theseconditions.

– Where a circuit is exposed to lightning surges, a primary protector or a data/alarmprotector is required as dictated by equipment manufacturers.





Overview, continued– Where sneak currents are hazardous, a secondary protector or primary protector with

secondary protection is required (as directed by equipment manufacturers). The basicsecondary protector function (sneak current protection) can be included bymanufacturers in some primary protectors.

– ITS equipment manufacturers may include additional protection functions, sometimescalled enhanced protection, for specific applications.

– European rules regarding circuit protectors include the Italian ElectrotechnicalCommittee (CEI) rule classified as 64-8, Electric Plants with Nominal Voltage NotExceeding 1000 V in ac and 1500 V in dc, acknowledged by the InternationalElectrotechnical Commission (IEC) 60364-1, Electrical Installations of Buildings,Part 1: Fundamental Principles, Assessment of General Characteristics,Definitions, which gives the fundamental principles an electrical plant has to have forits correct planning and execution, according to the standards of safety andfunctionality. CEI rule 81-1, Protection of Structures Against Lightning,acknowledged by the European Rule IEC 61024-1, Protection of Structures AgainstLightning, Part 1: General Principles, gives the methods of planning, realization,and control of the systems of lightning surge protection.




Primary Protector Terminal Installation Practices

Overview

Suggested cabling installation practices:

• Primary protectors must be installed immediately adjacent to the exposed cable’s point ofentry. The associated grounding conductor must be routed, as straight as possible, directlyto the closest approved ground.

• A noncorrosive atmosphere is required for long-term reliability.

• Adequate lighting is important for personnel safety at protector locations.

• When a protector is installed in a metal box, bond the box with an approved groundingconductor directly to the protector ground.

• Ensure that there are no obstructions around or in front of protectors, and that protectorlocations will not be used for temporary storage.

WARNING: Do not locate primary protectors near any hazardous or easily ignitablematerial. See NEC 800.90(C).

An exception to the minimum 6 AWG [4.1 mm (0.16 in)] bonding conductor are smaller EFs.UL 497 requires the protection unit to determine the minimum-size conductor based on theanticipated current flow from the number of conductor pairs and the distance of the protectorterminal from the ground source. The following conductor sizes are based on the assumptionthat the protector terminals will be located up to 6 m (20 ft) away from the electrodes. Unitsthat are designed for:

• One and two pairs of protection require a minimum 12 AWG [2.1 mm (0.083 in)].

• Three to six pairs of protection require a minimum 10 AWG [2.6 mm (0.10 in)].

• Greater than six pairs of protection requires a minimum 6 AWG [4.1 mm (0.16 in)].

NOTE: The NEC allows the conductor to be as small as 14 AWG [1.6 mm (0.063 in)]. It issafer to use the AWG sizes of 12, 10, and 6 as outlined above when installingprotection terminals.





Protector Technology

Primary Protectors

Many different components are used by manufacturers to implement protection functions. Thefollowing components are typical of primary protectors.

Carbon Blocks

These are the original protectors. An air gap between carbon elements is set to arc at about300 V to 1000 V and conducts surge current to a grounding conductor. When the surgecurrent finally drops low enough, the arc stops and the protector resumes its normal isolationof ground.

A fail-safe function causes carbon blocks to short permanently to ground when an extendedhot surge or permanent fault current overheats them. They are typically installed as pairs andare the lowest cost option; however, carbon blocks tend to wear out quickly under extremeconditions and can cause leakage and noise in voice circuits.

Gas Tubes

These are improved arresters that operate the same as carbon blocks, arcing over a gap to agrounding conductor. They have a wider gap because of special gas and therefore a higherreliability. They have tighter tolerances on arc breakdown voltage and are typically set to arcat a lower voltage, providing better protection than carbon blocks.

Another type of gas tube, the dual-gap, provides a common arc chamber that grounds bothwires of a pair together and minimizes metallic surges that would otherwise occur fromindividual arrester operation.

Solid State

This is the newest type of arrester. It relies on high-power semiconductor technology. Thoughmore expensive than either carbon block or gas tube, the cost is recovered over the extendedlife of the protector. They are fast acting and well balanced and do not deteriorate with agebelow a rated maximum surge current.

Fuses and Fuse Links

The NEC 800.90(A)(1) and (2) identify the two types of primary protectors as fused andfuseless. In case of extended overcurrent situations, the exposed side must fuse open withoutdamaging the ground conductor or indoor circuit. The fused type accomplishes this with anintegral line fuse (see Figure 1.99). The fuseless type must be installed with fine-gauge fusewire (a fuse link) on the exposed line side (provided by the manufacturer). Both types willoperate the same way when installed.



© 2004 BICSI® 2-iii ITS Installation Manual, 4th edition

Figures

Figure 2.1 Sample site plan ............................................................................................................. 2-38

Figure 2.2 Sample cross-sectional diagram ...................................................................................... 2-39

Figure 2.3 Sample floor plan ............................................................................................................. 2-40

Figure 2.4 Sample room detail .......................................................................................................... 2-41



ITS Installation Manual, 4th edition 2-iv © 2004 BICSI®



Metallic Conduit and Tubing, continued

Placement of Conduit in Pathways

Pathway Preparation

It is important to determine the entire route of a backbone pathway prior to installingthe supporting hangers, all-threaded-rod (ATR), or other support mechanisms. Theentire route should be planned ahead of time to ensure that the conduit can beinstalled without unforeseen obstacles. This is especially true when having topenetrate fire- or smoke-rated walls and floors. If the penetration cannot beestablished, then all the work done to install the support hardware may have to berepeated at another location.

Always make penetrations through fire- or smoke-rated walls and floors prior toinstalling the hangers, clamps, and trapezes. Once the conduit is installed, firestop thepenetrations using approved methods (see Chapter 5: Firestopping).

Support Requirements

The support requirements from the part of NEC Chapter 3: Wiring Methods andMaterials, referring to conduit shall be followed. Where out-of-the-ordinary heavyloads or abuse is anticipated, cabling installers may choose to add extra supports toassure joints remain secure. EMT, IMC, and RMC shall not be supported by theceiling grid nor by the ceiling support wires. Separate support shall be provided. Thisis particularly important when the ceiling is fire rated, as any extra load couldcompromise the rating.

All exposed raceways are to be run as near parallel or perpendicular to walls andceilings as the cabling installer can achieve.

Do not use raceways as support for equipment. Provide separate support, unlessotherwise permitted by the NEC.

Install the complete raceway before installing the cables. Be sure joints are tight andthe raceway is securely terminated and held firmly in place.

Cutting and Threading Conduit

A roll-type cutter should not be used on EMT. Using a hacksaw or band saw willpermit reaming EMT without flaring the ends. Be sure to make a square cut. It is bestto ream EMT with a tool that is designed for that purpose. This will make fittingsinstall easier and better. If other tools are used (e.g., pliers), special care must betaken not to flare the ends.

Be sure to measure the exact length of conduit needed. If it is too short, good threadengagement cannot be made with IMC and RMC, or setscrews and rings ofcompression fittings will not engage with EMT.

Use a standard 19 mm (0.75 in) per foot sharp taper die to cut full, clean, threads. Aworn die or poor threading practices can result in ragged and torn threads.





Adjust the threading dies and use a factory-threaded piece to set the die. Lock thedies so they are firmly held in the head by tightening the screws or locking collar. Aproper thread will usually be one thread short of flush with the thread gauge. This iswithin permitted tolerances.

IMC and RMC can be cut with a saw or roller cutter. It is very important to make astraight cut and to start the die on the pipe squarely. Wheel-and-roll cutters must berevolved completely around the pipe, typically tightening the handle about one-quarterturn each time it is rotated.

Ream interior edges after cutting and before threading. One of the most importantsteps for good threading is to use cutting oil freely. Apply it for the first time right afterthe die has taken hold. Keep the conduit well lubricated throughout the entirethreading process.

It is a good practice to thread one thread short to prevent butting of conduit in acoupling and allow the coupling to cover all of the threads on the conduit whenwrenched tightly.

After the die is backed off, clean the chips and lubricant from the thread.

Joint Makeup

Always read and follow packaging instructions for any fittings. Use fittingsspecifically for the raceway type and size being installed. This information is generallyfound on the container. Expansion fittings are seldom needed for steel conduit installedin buildings. Expansion joints for the raceway shall be evaluated if large temperatureextremes are expected, or building expansion joints are in the pathway.

The need for square cut ends where threadless fittings are used has been discussed.These ends are to be cleaned and assembled flush against the fittings end stop.Threadless fittings for IMC or RMC should not be used unless the conduitmanufacturer specifically recommends that application. This is due to the fact thatthreadless fittings do not give gas-tight and oil-tight seals.

All threaded joints have to be made up wrench tight. Engage at least five full threads,but be careful not to overtighten.

EMT is joined by setscrew or compression fittings. There are a variety of designs,and there is no one method of tightening that applies to all. It is important not toovertorque or overtighten screws while assuring they are firmly secured. Most poorjoints result from the lack of attention to workmanship and failure to set the screws orcompression glands.

For good joints and terminations, it is important to measure the length of conduitneeded and select the right elbows.




The same anchoring mechanisms can be used to secure the clamps and cross bracesas used to hang the conduits from the building structure.

NEC Chapter 3 dictates conduit securing and supporting requirements. Articles800.3(C), 800.3(D), 800.24, 800.110, 800.133(D) and 800.154(A) also provide usefulinformation in regards to properly installing backbone pathways.

Stub-Up/Stub-Out Conduits

The terms stub-up and stub-out imply that a section of conduit is used for providing apathway in a vertical and then horizontal direction from a point of termination. Whilesimilar in many ways, they are significantly different from a cabling installationperspective.

Stub-Up Cabling Installation

Stub-ups are usually single sections of small diameter (not less than 21 mm [3/4 tradesize]) metallic conduit. They originate at a single- or double-gang box installed indrywall or paneling. The stub-up continues vertically through the wall cavity, where itpenetrates the wall cap and stubs up into the ceiling area. It terminates at that pointand is usually equipped with a conduit bushing. Sometimes the stub-up is equippedwith a 90-degree bend that is turned back into the room, especially when installed infire- or smoke-rated walls.

Stub-Out Cabling Installation

Stub-outs are usually short runs of small diameter metallic conduit. They originate at asingle- or double-gang box installed in drywall or paneling. The stub-out continuesvertically through the wall cavity, where it penetrates the wall cap and continues intothe ceiling area. In a typical cabling installation, the conduit continues out of the roomarea and into an adjacent hallway. The conduit may terminate as it exits the wall ofthe hallway or may continue to another type of supporting structure (e.g., a cable trayor ladder rack). It terminates at that point and is usually equipped with a conduitbushing and sometimes a pull string.

NOTE: Conduit sizes larger than 32 mm (1.25 in) ID are not generally employed inthis type of cabling installation because the knockouts on standardreceptacle boxes do not accept box adapters for larger conduits.





Plenum- and nonplenum-rated innerducts are available in a variety of colors. Althoughusually purchased with a pull rope preinstalled inside for attaching the fiber cable to bepulled, innerducts are available without pull ropes (see Figure 3.22). The pathway of afiber cable must be free of sharp bends and turns. Normally, innerducts are placedinside conduit, through sleeves, or in cable trays. Care should be taken to ensure thatthe properly fire-rated innerduct is being installed.

Figure 3.22Innerduct

NOTE: All cables installed in innerduct must have the proper sheath rating for thearea in which they are installed. Material installed in a plenum area must beplenum rated. Do not install nonrated cable in plenum innerduct.

If the requirement is to place innerducts within a conduit, determine the size andnumber of innerducts permitted. Innerducts and conduit are both sized by their OD. Inthe past, innerducts were sized by their ID, but this practice is falling out of favor inthe industry.



Installing Grounding Infrastructure

Overview

Grounding and bonding of an ITS cabling project is a significant part of a cablinginstaller’s job. It assists in protecting people and equipment from electrical hazardsand provides improved performance in many copper-based systems.

Proper grounding and bonding provides protection from overvoltages or accidentalconnection to foreign electrical voltages or currents. This can range from lightningprotection systems to simple grounding of ITS cable sheaths. Refer to Chapter 1,Section 8: Grounding, Bonding, and Protection, for more in-depth information.

The NEC is written primarily for equipment and personal safety. Manufacturers mayrequire additional grounding and bonding. Always review the manufacturer’sspecifications for equipment grounding and bonding. When a conflict exists between acode and a manufacturer’s specification, request an interpretation from the localgoverning agency or a variance.

The building may be grounded at different points depending on its size, age, andlocation. Smaller buildings are typically grounded at the ac service meter base. Aground conductor is installed from the power neutral bus in the meter base to a man-made electrode (typically a driven ground rod). Larger buildings will be grounded atthe main distribution panel (MDP) in the building. A grounding electrode conductor isinstalled from the equipment grounding bus in the MDP to a man-made electrodecalled the grounding electrode system. The different derived electrodes are describedin detail in NEC 250.50 and 250.52.

Local code information is obtained from the local government agency charged withthe responsibility for code enforcement. Some local government agencies may nothave adopted a code. In this situation, state government agencies may be chargedwith implementing code restrictions or enforcing the NEC. Remember that the AHJ isthe only entity that can interpret the code and make exceptions or interpretations tothe code. Do not rely on code information from other contractors or people who claimto know the local restrictions. They may not be entirely familiar with the localrequirements.

Other things to consider when planning for bonding and grounding are:

• Multiple TRs on each floor of the building.

• Multiple vendors’ products to be installed.

• Special electronics equipment.

To determine the effectiveness of a ground wire, measure the resistance between theground source and a reference ground that is isolated from the other ground system.The closer the cabling installer can get to one ohm (preferably less), the better thesystem.



Overview, continued

Building entrance protectors and metallic cable shields shall be connected to theground system to protect circuits from lightning and power faults. Only buildingentrance protectors installed on customer-owned physical plant should be groundedand bonded by cabling technicians employed by the customer. Physical plant installedby the local regulated telephone company, cable television company, or other regulatedentity can only be maintained, modified, or otherwise changed by their employees.Work by technicians other than regulated company employees may result in serviceoutages or billing rendered to the customer for unauthorized tampering with regulatedcompany facilities.

Avoid splicing a grounding or bonding conductor. Grounding and bonding conductorsshould be installed in the shortest, straightest route between the equipment beinggrounded and bonded and the points being connected. If the cabling installer mustsplice a grounding or bonding conductor, use an irreversible compression connector oran exothermic weld.

Local Code Requirements

Always review the local code requirements before proceeding. This includesinformation on the current code and any exceptions to the code adopted by the AHJ.Most of the code requirements for the job should be included in the cabling designer’sdocuments. The cabling installer should never take this information for granted,because the ITS contractor is fully responsible for all work done on the project.

If no code has been adopted locally, consult with the state fire marshal’s office todetermine which state agency is responsible for that geographical area and whichcodes are in effect. Do not depend on other cabling installers, contractors, orcompany personnel in making these determinations.

Standards and Codes

Except when local codes are in conflict, follow the national codes and standards.Familiarize yourself with the NEC and ANSI J-STD-607-A. Ensure that all workperformed complies with these standards. Determine whether manufacturers haverequirements that exceed the NEC, ANSI J-STD-607-A, or local code requirements.If a conflict exists, obtain an interpretation from the AHJ. Typically, the morerestrictive code or standard prevails.

Ground Source

Refer to architectural blueprints that contain electrical drawings, if available, todetermine what has been provided and installed by the electrical contractor. Refer tothe electrical riser diagram and the electrical engineer’s notes that accompany it todetermine what grounding electrode system has been designed and installed. Consultwith the electrical contractor on the job to inquire whether they followed the design orwhether changes have been made since the drawings were issued.


Chapter 5: Firestopping


Firestopping

Introduction

This chapter describes firestopping regulations, testing, materials and methods, andguidelines for selecting a firestopping system. It primarily addresses the United Statesand Canada. Other countries should consult their local authorities for similar practices.

Worldwide, fire kills thousands of people, injures hundreds of thousands more, anddestroys billions of dollars in property each year. In commercial and residentialbuildings, more deaths, injuries, and property damage result from smoke and toxicgases than from the fire itself.

Building codes establish strict requirements and regulations designed to safeguard lifeand property from fire hazards. In the United States, information transport systems(ITS) distribution designers and contractors must adhere to federal, state, and localcodes for new construction and renovation projects. These codes are based onaccepted fire protection principles.

The most common fire protection principle is compartmentation—construction of fire-resistant barriers to contain a fire to the area where it starts. Fire-resistant means thata material or structure can withstand fire and the passage of flame, smoke, or gasesfor a known period of time. Fire-resistant barriers can be floors, floor/ceiling or roof/ceiling assemblies, and walls. These barriers include other components (e.g., firedoors, penetration seals, and fire dampers) that help maintain the fire resistance of thefloor, ceiling, roof, and wall assemblies.

Penetrations in fire barriers used or made by an ITS cabling installer to place cablemust be properly sealed or firestopped. Firestopping is the process of installing listedfire-rated materials into penetrations of fire-rated barriers to reestablish the fire-resistance rating of the barrier. A penetration that is left open or improperly sealedmay allow lethal flames, toxic gases, and smoke to travel throughout a building anddamage areas that otherwise would not be exposed to a fire.

Generally, construction drawings and specifications indicate:

• Locations that must be firestopped.

• The required performance of firestopping systems.

• Acceptable manufacturers.

For cabling installations, it is usually up to the cabling installer to determine appropriatefirestopping means and methods that maintain code compliance. This requiresknowledge of local fire protection codes and the various manufacturers’ systems, theirfire ratings, and how to properly install them. The cabling installer plays a critical rolein protecting people and structures from the devastation of fire.

Chapter 5: Firestopping


Protection Codes and Ratings

Overview

Whether the cabling contractor is installing cable in a new building or as part of arenovation project, the cabling installer must know where firestopping is required andhow to choose suitable materials. Government code regulations mandate locations thatmust be firestopped. These regulations require the use of tested and certified firestopproducts. This section describes the codes and testing criteria for firestoppingsystems.

National Electrical Code® (NEC®)

The NEC not only requires that listed cables be installed in all commercial buildings, butrequires installations in hollow spaces, vertical shafts, and ventilation or air handlingducts shall be made so that the possible spread of fire or products of combustion is notsubstantially increased. Openings around penetrations through fire resistant-rated walls,partitions, floors, or ceilings shall be firestopped using approved methods to maintain thefire resistance rating.

Building Codes

The governments of most countries regulate the construction industry through buildingcodes. These codes are intended to ensure the safety of building occupants byproviding minimum standards for design, construction, materials, building use, location,and maintenance. Building codes include strict requirements for protecting occupantsfrom fire, smoke, super-heated gasses, and toxic fumes.

The first set of international, unified building codes was adopted in September 1999 atthe Codes Forum Joint Annual Conference. The International Code Council (ICC)sponsored the conference. However, until the international building codes are globallyaccepted, firestopping systems must meet the requirements of existing local codes.

Throughout the United States, federal, state, and local government agencies haveregulations that apply to building construction. Some states have a uniform statewidebuilding code. In other states, counties and municipalities are responsible for adoptingcodes.

Three private organizations have developed model codes. Most government agenciesadopt part or all of one of the following model codes:

• The Building Officials and Code Administrators International (BOCA), whichpublishes the National Building Code

• International Conference of Building Officials (ICBO), which publishes theUniform Building Code

• Southern Building Code Congress International (SBCCI), which publishes theStandard Building Code

The three codifying agencies have since consolidated into the ICC.


Section 1: Copper Cable Chapter 7: Splicing Cable


Overview, continued

Single connectors:

• Are not to be used in a category compliant installation.

• Are available in designs capable of terminating two or three conductors.

• Can be filled or nonfilled.

• Accept different gauge wires.

• Require no special tools.

• Require minimum setup time.

• Are not recommended for splices of 200 pairs or more.

NOTE: Where the NEC applies, only the listed cable can be used within a buildingstructure, except for an entrance cable that is terminated or transitionedwithin 15 m (50 ft) from its point of entrance (2005 NEC Article 800.113,Exception Number 2). Fine Print Note Number 2 to Exception Number 2implies that the cable may not extend to the full 15 m (50 ft), if theinstallation requires a primary protector and it is practicable to place theprimary protector closer than the 15 m (50 ft) to the entrance point.Listed copper cables are identified by markings on the outer sheath such asCM (general use), CMR (riser rated), and CMP (plenum rated).


Chapter 7: Splicing Cable Section 1: Copper Cable


Overview, continued

Planning is critical to the splicing operation. Several items must be considered, such ascable placement, support structure for the splice, and selection of the type of closure.Generally, the designer who prepares the drawings, and many times ensures the partsare ordered, does the planning. The splicing operation can be done with one of thetwo commonly used types of equipment, MS2 or Type 710. Both have insulationdisplacement contacts (IDCs).

The cabling installer must position the cable, rig the support structure, and ensure thatthe proper materials are used—such as the right splicing modules and closure (e.g.,too many cable conductors spliced in a closure without adequate splice banks maystress the wires). Reentry and churning (repetitive activity) access to conductorswithout proper planning can lead to deterioration of the cables at the weakest point—the splice.

Three major types of splice closures are typically used in both copper and fibersplicing (see Figure 7.3).

NOTE: Although all three closures are the same (i.e., the round drum container), itis the endplates, ordered separately, that make the difference.

• Straight—Connecting cables straight through in a line-by-line (generally the samepair count) manner

• Branch—Three or more cables entering a splice case from any direction in whichcable pairs or optic counts move from one sheath to another

• Butt—Two or more cables that enter a splice case from the same direction

Figure 7.3Example of splice closures

600 Pair 600 Pair

300 Pair600 Pair

300 Pair

600 Pair

600 Pair

Straight

Branch

Butt

Chapter 10: Retrofit Installations


Retrofit Installations

Overview

An information transport system (ITS) retrofit involves the replacement oraugmentation of an existing installation. Performing a retrofit or extensive systemupgrade will always be far more complicated and labor intensive than a new ITSinstallation in unoccupied spaces.

Planning the Cutover

Planning for a retrofit installation involves a multitude of tasks. All of these tasks mustbe completed before any cable is removed or installed. When all of these planningtasks are completed, a comprehensive plan will have been developed and the ITSinstallation team fully prepared to proceed with the project.

Determined by the scope and design of the cabling installation, each retrofit willrequire the ITS cabling installer to address a unique set of circumstances. Someretrofits may involve a simple expansion of a telephone system or a data network.Other retrofits may involve voice and data systems, security and fire alarm systems,and upgrades to the backbone or horizontal cabling infrastructure.

Good communications with the customer are essential when determining what part, ifany, of the existing cable plant will be reused. Obtain as much information as possiblefrom the customer and verify that the information is accurate. If the existingdocumentation is questionable or does not exist, it may be necessary to trace anddocument the current system. If the customer wants to utilize portions of the presentcables and equipment, the existing components will have to conform to the newrequirements. In addition, the cabling installer must test the existing cable plant toverify the level of service it can support. In many cases, system upgrades require anew cabling configuration that prevents the use of the current infrastructure.

Existing System Considerations

There are two main considerations concerning the existing cable plant. They are thenoncode compliant system (grandfathered) and abandoned cable.

Grandfathered systems consist of nonplenum-rated cables that were installed in aplenum prior to the mandated use of plenum cables. These systems are said to beacceptable because they were installed prior to the current code. When replacingthese types of systems, the cabling installer may be required to replace all of thecables. Many localities have rules of percentage. This means that if a substantialpercentage of the cable is being replaced, it will be necessary to bring the entireinstallation up to the current code requirements. Check with the local inspectors orauthority having jurisdiction (AHJ) to determine the rule of percentage for the area.



Existing System Considerations, continued

The criteria for abandoned cable removal are specifically addressed in severalarticles within the 2005 National Electrical Code® (NEC®). The code is veryspecific about what cables shall be removed and how to identify cables for futureuse. This requirement is discussed in greater detail later in this chapter.

In ideal situations, the retrofit will take place in unoccupied spaces. This allowsfor the removal of all equipment and cables that will be abandoned and not reusedafter the new installation. With these items removed, valuable pathway andtelecommunications room (TR) space is freed up for the installation of new systemcomponents.

In most cases, the new system or components to be integrated into the existingworking system must be installed with minimal disruption to the customer. This mayinvolve installing the new system parallel to the existing system while working nightsand weekends. After the new cables and equipment have been installed and tested,the transfer to the new system can take place.

Cutover Plans

When transferring to the new system, a detailed plan must be developed to cutoverthe new components into the final working configuration. This final cutover from theold to the new system is one of the most detailed and critical steps in a retrofit. Tohelp ensure a quality transition and to expedite the cutover, cutsheets are used.Cutsheets are a type of documentation that contains the existing cross-connectterminations and shows the changes that must be performed to execute the transitionto the new system (see Table 10.1). A poorly planned cutover could causeunnecessary interruptions to the customer’s communications.

Table 10.1Detailed cutover plan

Cutsheet Project: BICSI, Tampa

Existing Temporary Cabling New System Description

KSU-4-12 TB-7-17 KSU-4-12 Temp-3-17 PBX-2-21 TB-9-1 WA 102 phone



KSU = Existing key service unitTBU = Terminal blockPBX = Private branch exchange (new phone system)WAU = Work areaTemp = Temporary cabling




Cutover Plans, continued

Another way of documenting each circuit is with a circuit layout record (CLR). CLRsprovide a quick graphical representation of how the circuit is laid out. It shows allequipment, cables, cross-connects, and their termination locations. CLRs areextremely beneficial when troubleshooting (see Figure 10.1).

Figure 10.1Circuit layout records

The first CLR shows:

• The existing key service unit (KSU) has a 25-pair cable plugged into its J-12 jackand the other end is terminated on block KSU 4, pairs 1–25.

• The voice cable for work area 102 terminates on terminal block (TB) 7,pairs 17–20.

• A cross-connect is terminated between block KSU 4, pair 12, and TB 7,pair 17.

ExistingKSU

TemporaryKSU cable

NewPBX

Equipment cable Cross-connects Horizontal cable

KSU-4 TB-7 Work area 102

KSU-4

PBX-2 TB-9

Temp-3 Work area 102

Work area 102

J-12

J-12

J-12

Pr-1-25

Pr-1-25

Pr-1-25

Pr-21

Pr-21

Pr-21 Pr-1 Pr-1-4

Pr-17

Pr-17 Pr-17-20

Pr-17-20

Equipment Terminal block Work areaTerminal block

Voice

Voice

Voice

Existing cable and cross-connectsTemporary cable and cross-connectsNew cable and cross-connects

KSU = Key service unit PBX = Private branch exchange Pr = Pair TB = Terminal block Temp = Temporary cabling



Cutover Plans, continued

The second CLR shows:

• The existing KSU has a 25-pair cable plugged into its J-12 jack and the otherend is terminated on block KSU 4, pairs 1–25.

• A temporary voice cable for work area 102 terminates on TB temporary 3,pair 17.

• A cross-connect is terminated between block KSU 4, pair 12, and TB 3, pair 17.

The third CLR shows:

• The new private branch exchange (PBX) has a 25-pair cable plugged into itsJ-05 jack and the other end is terminated on block PBX 2, pairs 1–25.

• The new voice cable for work area 102 terminates on TB 9, pairs 1–4.

• A cross-connect is terminated between block PBX 2, pair 21, and TB 9, pair 1.

Types of Cutovers

Depending upon the size and scope of the retrofit, either a flash cutover or a phasedcutover may be necessary.

A flash cutover transfers the old system to the newly installed system in onecontinuous process until completed. The flash cutover may be a hot cut, where theequipment cables are unplugged from the existing system and plugged into the newsystem. The customer is without communications during a hot-cut process. Anothertype of flash cut is the rolling cut. During a rolling cut, cross-connects are relocatedone pair after another until completed.

In a phased cutover, portions of the old system are transferred to the new system ingroups. As offices or buildings are rewired, they are phased into the new system.Both the new and old systems work in parallel until the transfer is completed.

The removal of abandoned cable is a requirement of the 2005 NEC. Abandonedcable is a fire hazard. If a fire were to break out, the old cable could become fuel,providing a path to spread the fire throughout the building. Abandoned cable takes upvaluable pathway space and places an unnecessary strain on the supporting hardware,and may even cause the support system to fail. The cable that the customer does notplan to use in the future should be removed and disposed of properly.

Remove cables carefully so as not to damage or disturb other cables. Ensure writtenpermission has been obtained from the owner to remove the cable.




Steps—Cutover, continued

Step Cutover

3 Prepare documentation.

• Label all equipment, pathways, and cabling, as appropriate.

• Update blueprints for as-built documentation.

• Provide updated cross-connect records.

• Provide interconnection drawings.

• Provide rack layout drawings.

• Compile all test results in both hard copy and electronic media for thecustomer and the installation company’s records.

Removing Abandoned Cable and Equipment

Cables may be removed only after they have been checked to verify that they donot support active circuits. Active cables must not be removed until the cutover iscompleted and the system has been accepted.

NOTE: During a retrofit installation, it is required by the 2005 NEC thatall abandoned cable be removed. NEC 800.2 defines abandonedcommunications cable as “installed communications cable that is notterminated at both ends at a connector or other equipment and notidentified for future use with a tag.”

The removal of abandoned cable requires patience and an organized method ofremoval. It is very easy to cut the wrong cable or damage the good cables.

Cables in conduits can be difficult, if not impossible, to remove without damage to theother cables in the conduit. Cables often become twisted together as they are installedin conduits. If pulled too hard, the abandoned cable may damage the cables andbecome even tighter around the other cables. Cables may be freed by:

• Gently pulling as a helper pushes from the other end.

• Gently pulling all the cables back and forth a few inches while gently pulling theabandoned cable out.

• Pulling all the cables out together with a pull string attached. Discard theabandoned cables and pull the good cables back and reterminate.

• Using an appropriate lubricant.




Removing Abandoned Cable and Equipment, continued

Cables above a suspended ceiling can offer some problems. When pulling a cable atone end, an assistant at the other end might mistake a moving cable as the correctone. Just as in the conduits, cables get wrapped around each other in cable trays andother support hardware. As it is pulled, the cable may actually be moving separatecables heading in different directions.

Cables in open ceilings are often bundled by using tie wraps. They are tie-wrapped tocable ladders and other supports. These fasteners must be removed prior to pullingthe cables out.

Remove any equipment or cross-connects from both ends of a cable prior to cuttingthe cable. When the cable is cut, all the conductors are momentarily shorted together.This can cause severe damage to electronic equipment.

Remove any cable-supporting hardware that will not be used. Abandoned hardwareclutters the spaces and could possibly be reused on another job. Recycle hardwarethat is in good condition wherever possible.

Remove all trash and debris from above the ceiling tiles, attics, and under the crawlspaces. For safety reasons, piles of tie wraps, chunks of cable, coring debris, and thecabling installer’s tools should be removed.

Dispose of trash in a responsible manner. Scrap cable can be recycled. On largeprojects, a salvage yard may leave a dumpster for usable scrap materials. At the endof the project, the salvage yard will pick up the scrap and pay the company for thematerials.

Recycle the cardboard containers that come with the new systems, user instruments,and horizontal cable reels.

Bibliography

© 2004 BICSI® B-7 ITS Installation Manual, 4th edition

———. ISO/IEC 18010, Information Technology—Pathways and Spaces for CustomerPremises Cabling. Geneva, Switzerland: International Electrotechnical Commission, 2002.

———. ISO/IEC TR 14763-2, Information Technology—Implementation and Operationof Customer Premises Cabling—Part 2: Planning and Installation of Copper Cabling.Geneva, Switzerland: International Electrotechnical Commission, 2000.

———. ISO/IEC TR 14763-3, Information Technology—Implementation and Operationof Customer Premises Cabling—Part 3: Acceptance Testing for Optical Cabling. Geneva,Switzerland: International Electrotechnical Commission, 2000.

Italian Electrotechnical Committee. CEI 64-8, Electric Plants with Nominal Voltage NotExceeding 1000 V in AC and 1500 V in DC. Milan, Italy: Italian ElectrotechnicalCommittee, 1998.

———. CEI 81-1, Protection of Structures Against Lightning. Milan, Italy: ItalianElectrotechnical Committee, 1998.

National Fire Protection Association. NFPA 70, National Electrical Code®. Quincy, MA:National Fire Protection Association, 2004.

———. NFPA 70E, Standard for Electrical Safety Requirements for EmployeeWorkplaces. Quincy, MA: National Fire Protection Association, 2004.

———. NFPA 72®, National Fire Alarm Code®. Quincy, MA: National Fire ProtectionAssociation, 2002.

———. NFPA 75, Standard for the Protection of Information Technology Equipment.Quincy, MA: National Fire Protection Association, 2003.

———. NFPA 76, Recommended Practice for the Fire Protection of TelecommunicationsFacilities. Quincy, MA: National Fire Protection Association, 2002.

———. NFPA 90A, Standard for the Installation of Air-Conditioning and VentilatingSystems. Quincy, MA: National Fire Protection Association, 2002.

———. NFPA 101®, Life Safety Code®. Quincy, MA: National Fire Protection Association,2003.

———. NFPA 255, Standard Method of Test of Surface Burning Characteristics ofBuilding Materials. Quincy, MA: National Fire Protection Association, 2000.

———. NFPA 262, Standard Method of Test for Flame Travel and Smoke of Wires andCables for Use in Air-Handling Spaces. Quincy, MA: National Fire Protection Association,2002.

———. NFPA 780, Standard for the Installation of Lightning Protection Systems. Quincy,MA: National Fire Protection Association, 2000.

———. NFPA 5000®, Building Construction and Safety Code®. Quincy, MA: NationalFire Protection Association, 2002.


Bibliography

ITS Installation Manual, 4th edition B-8 © 2004 BICSI®

New Zealand Ministry of Consumer Affairs’ Energy Safety Service. Integrated ElectricityRegulations 1997/2004. Wellington, New Zealand: New Zealand Ministry of ConsumerAffairs, 2004.

Standards Australia/Australian Communications Industry Forum. AS/ACIF S008,Requirements for Authorised Cabling Products. Sidney, Australia: Standards Australia,2001.

———. AS/ACIF S009, Installation Requirements for Customer Cabling. Sidney,Australia: Standards Australia, 2001.

———. HB 243, Telecommunications Cabling Manual, Module 1: AustralianRegulatory Arrangements. Sidney, Australia: Standards Australia, 2000.

———. HB 29, Telecommunications Cabling Manual, Module 2: TelecommunicationsCabling Handbook. Sidney, Australia: Standards Australia, 2000.

Standards Australia/Standards New Zealand. AS/NZS 3000, Electrical Installations. Sidney,Australia: Standards Australia, 2000.

———. AS/NZS 3080, Telecommunications Installations—Generic Cabling forCommercial Premises. Sidney, Australia: Standards Australia, 2003.

———. AS/NZS 3084, Telecommunications Installations—Telecommunications Pathwaysand Spaces for Commercial Buildings. Sidney, Australia: Standards Australia, 2003.

———. AS/NZS 3085.1, Telecommunications Installations—Administration ofCommunications Cabling Systems—Basic Requirements. Sidney, Australia: StandardsAustralia, 2004.

———. AS/NZS 3086, Telecommunications Installations—IntegratedTelecommunications Cabling Systems for Small Office/Home Office Premises. Sidney,Australia: Standards Australia, 1996.

———. AS/NZS 3087.1, Telecommunications Installations—Generic Cabling Systems—Specification for Testing of Balanced Communication. Sidney, Australia: StandardsAustralia, 2003.

Telecommunications Industry Association. 2002 TIA Engineering Manual, 3rd ed. Arlington,VA: Telecommunications Industry Association, 2002.

———. TIA-526-7, Measurement of Optical Power Loss of Installed Singlemode FiberCable Plant. Arlington, VA: Telecommunications Industry Association, 1998. (ANSI approvalwithdrawn June 2003)

———. TIA-526-14-A, Optical Power Loss Measurements of Installed Multimode FiberCable Plant. Arlington, VA: Telecommunications Industry Association, 1998. (ANSI approvalwithdrawn August 2003)

Index

© 2004 BICSI® I-11 ITS Installation Manual, 4th edition

link, G-27liquid crystal display, 8-53local area network, 3-21, 8-3, 9-2, G-27Local Area Network Specialty, 1-7local codes and ordinances, 2-35location, 1-85logical topology, G-27loop resistance, 9-19, G-27loose tube, G-27loose-tube fiber, G-27loss

budget, 8-27, G-27connector insertion, 1-157, G-27insertion, 1-157, 1-161level, G-27measurement, 8-65overall, 8-65resolution, 8-56, G-27return, 1-162section, 8-65splice, 8-65structural return, 1-157

loudness, 1-154low-intensity laser, G-27low-voltage mounting bracket, G-27low-voltage system, 3-6LSA, 8-66

MMAC, 4-44macrobend, G-28magabit, 1-156magnetic reasonance imaging, 1-151main

building ground electrode, G-28cross-connect, 8-24cross-connect distributor, G-28distribution frame, G-28distribution panel, 3-65, G-28

mainframe, 8-59maintenance hole, G-28MAN, G-29Manchester encoding, G-28mandrel, G-28manhole, G-28MasterFormat, 1-95, 1-99, 2-3material safety data sheet, G-28, 5-14, 1-242material, 10-27

list, 2-24, 2-5, G-28staging, 2-24

Mb, 1-156Mb/s, 1-9MC, 8-24MDP, 3-65measurement parameters, 8-61measurement resolution, G-28

mechanicaldevice, 1-127splice, 8-64splicing, G-28

media, 1-103, 4-2, G-29meeting

construction, 2-18progress, 2-18

megabits per second, 1-9, G-29megahertz, 1-154, 1-156, 6-26, G-29megahertz kilometer 6-30, G-29megger, G-29megohmmeter, 1-190membrane penetration, 5-38mesh grip, G-29metallic shield, 1-231, 7-14meters, 8-26metropolitan area network, G-29MH, 1-271MHz, 1-156, 6-26MHz.km, 6-30microbend, G-29micron, 1-117, G-29Microwave Communications, Inc. Decision, 1-3milliwatt, 1-157modal dispersion, 1-173, G-29mode, field diameter, G-29modem, G-29modular

connector, 1-149, 7-10, G-30furniture, 4-33, G-30jack, 1-131, 1-145, 2-33, 6-25, G-30patch panel, G-30plug, 1-129, 1-131, G-30

module, 7-7bridge, 7-9half-tap, 7-9straight, 7-9

movement, 1-151moves, adds, or changes, 4-44MRI, 1-151MSDS, 1-242, 1-266, 1-269, 5-14, G-28mud ring, G-30multi-user

telecommunciations outlet assembly, 8-13, G-30multimeter, 8-2, 8-26, 10-15multimode, 1-103, 1-119

fiber, G-30multiple rods, 1-204multiplexer, G-30multisplicing module pair, 7-4multiweave wire mesh grip, 4-63mushroom, 3-16, G-30MUTOA, 8-13mutual capacitance, 1-165, G-30mux, G-30

Index

ITS Installation Manual, 4th edition I-12 © 2004 BICSI®

NN, 4-2N-connector, G-31nanometer, G-31nanosecond, G-31National Building Code of Canada, 1-58National Electrical Code 1-51, 1-52, 2-35, 3-20, 5-2, 7-1,

9-9, 10-2, G-31National Electrical

and Communications Association, 1-66Contractors Association, 1-62, 3-3Manufacturers Association, 3-49

National Electrical Safety Code, 1-55, 2-35National Fire Code of Canada, 1-58National Fire Protection Association 1-51, G-31National Institute for Standards and Technology, 1-55National Research Council Canada, 1-58nationally recognized testing labotatory, 5-3NBC, 1-58NBR-12942, 1-68NBR-14565, 1-68NBR-14683-1, 1-68NBR-14702, 1-68NBR-14703, 1-68NBR-14705, 1-68NBR-14770, 1-68near-end crosstalk 8-4, 9-4, G-31near-field radiation, G-31near infrared, G-31NEC, 1-51, 1-52, 1-104, 1-181, 3-39, 3-61,

3-65, 3-66, 5-2, 7-1, 7-5, 7-26, 9-9, 10-2, 10-4,10-10, 10-35, G-31

NEC 250.114, 1-219NEC 250.138, 1-219NEC 250.58, 1-187NEC 800.90, 1-233NEC 800.90(A), 1-236NEC 800.90(B), 1-233NEC 800.90(C), 1-235NEC 800.100(A)(3), 1-217NEC 800.133, 1-227NEC 820.93, 1-210NEC Article 250, 1-186NEC articles, 3-27NEC Handbook, 1-181, 1-188NEC Section 250.94, 1-187, 1-209NEC Section 800.53, 1-185NECA, 1-62, 1-66, 3-3NECA/BICSI-568, 3-3Neill-Concelman connector, 1-115NEIS, 1-80NEMA, 1-80, 3-49, 3-50NESC, 1-55, 2-35network

interface card, 9-10, 10-33, G-31interface device, G-31transport systems, 1-7

network application, 1-144Network Design Reference Manual, 1-7Newton, 4-2NEXT, 1-107, 1-162, 8-4, 8-14, 9-4, 9-15, 9-22, G-31NFC, 1-58NFPA, 1-51, 1-52, 1-81, G-31NFPA 70E, 1-51NFPA 72, 1-51NFPA 75, 1-51NFPA 76, 1-51NFPA 90A, 1-51NFPA 101, 1-51NFPA 255, 1-51NFPA 262, 1-51NFPA 780, 1-51, 1-182, 1-184, 1-185, 1-206NFPA 5000, 1-51NFPA articles, 1-54nibble, G-31NIC, 9-10, 10-33, 10-34, G-31NiCd, 8-23nickel cadmium battery, 8-23NIST, 1-55, 1-81node, G-31noise, 8-22, 9-19

continuous, 9-20, G-31impulse, 9-20

NOM-001-SEDE-1999, 1-51nominal velocity

of propagation, 1-164, 8-6, G-31of propagation calibration, 9-18

Nominal Velocity of Propagagtion Calibration, 8-10nomograph, 1-194, G-32nonreflective break, 8-68, G-32nonreturn-to-zero, G-32NRC, 1-58NRC-IRC, 1-81NRCC 38726, 1-58NRCC 38727, 1-58NRTL, 5-3, 5-5NTIS, 1-81NTS, 1-7numerical aperture, G-32nuts, 3-55NVP, 1-164, 8-6, 8-10, 9-17, 9-18

OO&M, 2-12OAS Charter, 1-68Occupational Safety and Health Administration, 1-239,

2-17, 7-11, 9-9, G-32OD, 3-40, 3-61, 4-19office locator kit, 10-15offset, 3-38, G-32ohm, 1-159, 6-27, G-32ohmmeter, 1-202, G-32Ohm’s law, 1-159, G-32


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