Grounding_Guidelines

8/7/2019 Grounding_Guidelines

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EARTHING (GROUNDING) AND BONDING

GUIDELINES FOR UNIPRISE SOLUTIONS

FTP/SCTP CABLING SYSTEM


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CommScope Solutions Proprietary

Use pursuant to Company instructions

1.0 IntroductionThe earthing (grounding) and bonding of Uniprise Solutions FTP/ScTP cabling system incustomer premises shall follow national and/or local electrical codes/standards if thesecodes/standards exist. Examples of these codes are NFPA 70/NEC (USA), BS 7671 (UK IEE

Wiring Regulations) and VDE 0100 (Germany). Examples of these standards are ANSI/TIA/EIA-J-STD-607-A, ANSI/TIA/EIA-568-B.1-2 (USA), EN 50174-2 and EN 50310 (Europe) and IEC60364-5-548 (International).

In this document, earthing is synonymous to grounding.

The IEC technical report TR 61000-5-2 and ANSI/TIA/EIA-J-STD-607-A provide usefulguidelines for the earthing and bonding of electrical and electronic systems and installations. Itaimed at ensuring personnel safety and electromagnetic compatibility (EMC) among electricaland electronic equipment or systems.

This document outlines the earthing and bonding of Uniprise Solutions FTP/ScTP cabling systemin customer premises in relation to safety, functional and electromagnetic performance and shallbe used where specific national and/or local electrical codes/standards do not supersede.

The aim of the document is to achieve the following needs:

Safety from electrical hazards Reliable signal reference within the network Satisfactory and/or enhanced electromagnetic performance for the network

2.0 Earthing and BondingIt is important to remember that safety procedures for personnel protection will take precedenceover EMC protection procedures. The primary goal of an earthing system is to assure personnelsafety and protection of installations against damage. Two important phenomena are lightningand power system faults. These can cause circulation of large currents, which may createhazardous voltages in the installation. For lightning, the task of the earthing system is to providea path to the soil for dangerous currents, while maintaining potential differences between anytwo points of an installation as low as possible. For power system faults, it provides a safe pathfor fault currents, while also maintaining potential differences between any two points of aninstallation as low as possible. Typically, fault currents will then trip circuit breakers to removepower. Generally, national or local regulations specify maximum voltage values for personnelsafety including provision for protective earth (PE) conductor practices.


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The PE is a network of conductors that carry the currents related to safety to the main earthterminal. The main earth terminal is the point inside the building where all earth connections aregathered and where a physical connection to the soil can be verified and assured.

However, these PE conductors alone are generally not sufficient to fulfill the EMC requirements.

Low noise can only be achieved with the TN-S electrical distribution network. In a TN-Sconfiguration, the neutral (N) and PE conductors are routed separately as from the transformeror the feeding point and a continuous 5-conductor network L1/L2/L3/N/PE must exist in thebuilding. The TN-S configuration is required for optimum EMC performance. With this, all powercurrents and voltages are normally isolated from the PE and from the rest of the earthing systemin the building.

TR 61000-5-2 and ANSI/TIA/EIA-J-STD-607-A specify additional earthing conductors andspecific interconnection components and methods that augment the existing earthing system.This Telecommunications Earthing System provides an explicit earthing network thattelecommunications installers can verify for personal safety and that minimizes interference from

other building systems or equipment. Thus, a Telecommunications Earthing System allowstelecommunications personnel to manage safety and performance in a way that is far lessdependent on other building operations. Cable screens must be earthed to theTelecommunications Earthing System as outlined below.

Each telecommunications room of a building must have a connection point to theTelecommunications Earthing System to allow for bonding of equipment or systems, metalliccable baskets/trays, metallic water pipes, metallic floor tiles, racks, frames, etc. It isrecommended to connect the various apparatus at the nearest connection point of this system inorder to improve the EMC performance of an installation. These connection points should besufficiently close to provide low impedance bonding. All earth connections should be kept asshort and straight as possible to avoid creating a high impedance path.

3.0 Earthing of Uniprise Solutions FTP Cabling SystemThe Uniprise Solutions FTP cabling solution is an end-to-end system consisting of FTP cables,FTP cords, FTP outlet connectors and FTP patch panels. Table 1 provides a list of the variouscomponents. The cabling shall be installed according to the latest Uniprise Solutions FTPSolution Design and Installation Guidelines.

Category 5e Category 6Cable 5ENS4 (CMR), 5ES4 (CMP) 65NS4+ (CMR), 65S4+ (CMP)

Cord FTP-PC5E-GYx FTP-PC6-GYx

Connector FTP-J5E FTP-J6Patch Panel FTP-PNL-24P FTP-PNL-24P

Table 1: Uniprise Solutions FTP Components


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For Uniprise Solutions FTP cable, the foil and the drain wire (also referred to as a bondingconductor) are both conductive. A connection can be realized by folding the foil back over theouter sheath such that the metallic part of the foil makes contact with the metallic surface of therear opening of the connector housing. This connection ensures high frequency performance.This must also be supported by connecting the drain wire to the bonding contact of the FTP-J5E

and FTP-J6 connectors. This connection ensures a direct connection through to the shieldedplugs. The metallized housing provides the bonding connection to the FTP patch panel. Earthingstuds are available at the back of the FTP patch panel (See Figure 1).

Figure 1: Earthing of Uniprise Solutions FTP cabling system

Earthing stud

2.1 mm2 (14 AWG)

insulated conductor[Max 150 mm (6 ins)]

Earthing stud

2.1 mm2 (14 AWG)

insulated conductor[Max 150 mm (6 ins)]

Equipment

FTP-PC5E-GYxor

FTP-PC6-GYxcord

2.1 mm2

(14 AWG)bondingconductor(Max 150 mm)

5ENS4/5ES5 or65NS4+/65S4+

cable

FTP-J5E orFTP-J6outlet

Workstation

Cabinet

FTP-PNL-24Ppanels with

FTP-J5E or FTP-J6modules

Telecommunicationearthing bar

Each panelearthed separately

Daisychain ofearth studs

NOT permitted

Earth

Terminal

Block

FTP-PC5E-GYx orFTP-PC6-GYx

cord

Equipment

FTP-PC5E-GYxor

FTP-PC6-GYxcord

2.1 mm2

(14 AWG)bondingconductor(Max 150 mm)

5ENS4/5ES5 or65NS4+/65S4+

cable

FTP-J5E orFTP-J6outlet

Workstation

Cabinet

FTP-PNL-24Ppanels with

FTP-J5E or FTP-J6modules

Telecommunicationearthing bar



Daisychain ofearth studs

NOT permitted

Daisychain of

earth studsNOT permitted

Earth

Terminal

Block

Earth

Terminal

Block

FTP-PC5E-GYx orFTP-PC6-GYx

cord


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Insulated copper earth wires (bonding conductors) with a minimum size of 2.1 mm2 (14 AWG)shall be installed from the panel earthing studs to a suitable vertical earthing busbar mountedwithin a cabinet/rack or to several earth terminal blocks mounted to the cabinet/rack verticalequipment mounting rail. The maximum length of these earth wires is 150 mm (6 ins). Thedaisy-chaining of these studs is not permitted. The earth terminal blocks shall be connected

together using 14 mm2 (6 AWG) insulated copper earth wires

All earth connections shall be crimped or screwed using components approved for the purpose.

The equipment cabinet/rack shall be earthed (see section 4.0).

Earthing of equipment at the work area is usually accomplished through the PE conductor of theequipment power connection. If present, screen connections to the work area equipment shallbe accomplished through the screen of the FTP-PC5E-GYx and FTP-PC6-GYx work area patchcords extending from the TO to the equipment through the shielded modular jack contacts.Except when required by national/local code, the TO connector screen conductor should not be

bonded to earth in the work area by any means other than through the screen of the FTP-PC5E-GYx and FTP-PC6-GYx work area patch cords extending from the TO to equipment.

4.0 Earthing of Equipment Cabinet/RackThe equipment cabinet/rack shall be earthed so that voltages that are induced into cabling (bylightning or other disturbances) are directed to earth (see Figure 2).

Earthing shall be in accordance with applicable national or local electrical codes. The earth path shall be permanent and continuous. If multiple cabinets/racks are located within one area, a telecommunication earthing

busbar shall be fitted within the area. This busbar shall be a predrilled copper busbarprovided with holes for use with standard size lugs. It shall be at least 6 mm thick, 100mm wide and variable in length. The length of the busbar shall be sufficient for theimmediate requirements and have at least a 20% allowance for future growth. Thebusbar shall be isolated from its mounting point (a 50 mm separation is recommended)and a bonding connection made to the rooms power service earth and the closestaccessible building steel. If multiple cabinets/racks exist, each cabinet/rack shall beconnected to the telecommunication earthing bar separately This assures the continuityof the earth path from each cabinet/rack. Serial connection between cabinets/racks isnot recommended. However, equipment vendors may require direct bonding betweencabinets, but this must not be in place of the busbar connections.

All the insulated earth wires shall be connected to the telecommunication earthing barand must not be coiled or doubled-back on themselves. These wires shall have the

following dimension:o A minimum size of 25 mm2 (3 AWG) for installations where no or a poor

protective earth system exist (for example, in old buildings). The maximum lengthis 4 meters (13 ft). Larger size earth wires shall be used if the length is greaterthan 4 meters.

o A minimum size of 14 mm2 (6 AWG) for any other installations where a goodprotective earth system exist (for example, in buildings with a telecommunications


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earthing system). The maximum length is 4 meters (13 ft). Larger size earth wiresshall be used if the length is greater than 4 meters.

If the telecommunication earthing busbar is located under a raised floor or above a falseceiling, an identification label shall be fixed to the floor or ceiling tile and to an adjacent wall to

identify its position. The location of the telecommunication earthing busbar shall be such that itis accessible.

Figure 2: Earthing and bonding of Equipment cabinets/racks

5.0 Measuring Earth Potential DifferenceIf the earthing procedure outline in section 3 is followed, then the earth potential between wiring

closets should be within an acceptable limit of 1 Vac. However, if there is a problem with earthpotential difference, the procedures outline in Annex A may be implemented to identify the

location of this problem.

Telecommunication earthing busbar 100 mm (W), 6 mm (T) copper with predrilled holes

EquipmentCabinet/Rack



Separate earth connections.Maximum 4 meters.

[25 mm2(3 AWG) for old buildingsor 14 mm2(6 AWG) for buildings withtelecommunication earthing system]

PE

Serial earthconnections Is

not recommended.However, equipmentvendors may require

direct bonding betweencabinets, but this mustnot be in place of thebusbar connections

Telecommunication earthing busbar 100 mm (W), 6 mm (T) copper with predrilled holesTelecommunication earthing busbar 100 mm (W), 6 mm (T) copper with predrilled holes




Separate earth connections.Maximum 4 meters.

[25 mm2(3 AWG) for old buildingsor 14 mm2(6 AWG) for buildings withtelecommunication earthing system]

PE

Serial earthconnections Is

not recommended.However, equipmentvendors may require

direct bonding betweencabinets, but this mustnot be in place of thebusbar connections


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ReferencesEN 50310 Application of equipotential bonding and earthing in

buildingswith information technology equipment

EN 50174-2 Information Technology Cabling installation Part 2:Installation planning and practices inside buildings

IEC TR 61000-5-2 Installation and mitigation guidelines Earthing and cabling

IEC 60364-5-548 Earthing arrangements and equipotential bonding forinformation technology installations

ANSI/TIA/EIA-J-STD-607-A Commercial building grounding and bonding requirements forTelecommunications

ANSI/TIA/EIA-568-B.1-2 Grounding and Bonding Specifications for ScreenedBalanced Twisted Pair Horizontal Cabling


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Annex AMeasuring Earth Potential Difference

DANGERBe careful when measuring unverified equipment earthing terminals. There may be dangerousvoltages present.

A.1 Measuring earth potential difference between wiring closetsThe following must be performed to ensure that the difference in earth potential between wiringclosets is acceptable:

Cut a RJ45 work area cord into two halves. Connect the orange conductor to the drain wire (screen) for one half of the cord. This will

be referred to as the shorted cord. The other half will be referred to as the measurement

cord. Locate the FTP cabling that connects the two wiring closets. Connect the shorted cord to one end of this cabling and the measurement cord to the

other.

Connect the voltmeter to the orange conductor and drain wire of the measurement cord. If more than 1 Vac is measured, please contact the responsible party and have the

condition corrected.

If more than two wiring closets are connected, repeat the above procedure.

A.2 Measuring earth potential difference between wiring closet and outletDANGERBe careful when measuring from the equipment earthing terminal of the power receptacle. Thevoltage present at the receptacle is hazardous.The following must be performed to ensure that the difference in earth potential between wiringcloset and the outlet is acceptable:

Connect the measurement cord to the outlet. Measure the voltage between the measurement cord drain wire (screen) and the

equipment earthing terminal of the AC power receptacle. Make sure the powerreceptacle is the same one that the equipment uses.

If more than 1 Vac is measured, please contact the responsible party and have thecondition corrected.

Measure the resistance between the measurement cord shield and the equipmentearthing terminal of the AC power receptacle.

If more than 21 ohms is measured, contact the responsible party and have the conditioncorrected. 21 ohms is the effective maximum DC loop resistance of a permanent link.

Repeat the procedure for all outlets.


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