enhanced short span aerial optic fibre › wp-content › uploads › ... · horizontal cabling...

Copyright © CREATIVE AVENUE. All Rights Reserved. Reproduction in whole or in part without permission is prohibited. 12

CFSCatalogue Cover & Content #1

CoverCategory Deviders

Category Inner - similar to datasheet

POWER YOUR NETWORK www.meganetworking.com

copper & fibre optic cabling | active equipment | enclosures | security products

MEGAnet Installation Guide

OPTIC FIBRE SOLUTIONS

HDR-V6304 Four Channel HD-SDI Recorder HDR-V6308 Eight Channel HD-SDI RecorderHDR-V6316 Sixteen Channel HD-SDI RecorderOPTIONAL HD2 TB – Two TB Hard Drive (installed

HD3 TB – Three TB Hard Drive

ORDERING INFORMATION

Enhanced Short Span Aerial Optic Fibre

MEGAnet™ ENHANCED SHORT SPAN AERIAL OPTIC FIBRE is constructed of fi bres inside multiple gel fi lled loose tubes. The cable is strengthened by a glass reinforced plastic strength member (GRP), encased in polyethylene bed-ding and diff erent layers of aramid yarn, sheathed with UV resistant polyethylene.

• UV resistant polyethylene outer sheath (Black)

• Multiple layers aramid yarn strength member Polyethylene bedding

• PBT loose tube (Thixotropic gel fi lled)

• Optical fi bres

• Glass reinforced plastic centre strength member (GRP)

FEATURES:● LIGHTspeed ENHANCED SHORT SPAN AERIAL cable is designed for installation on pole routes or medium

voltage towers, with span lengths up to 150m. (No ice loading)

● The non-metallic construction of the cable allows for it to be installed and maintained, without the need to disrupt power services.

● A non-metallic construction ensures lightning immunity.

● Enhanced Short span aerial cable is constructed with high modulus, creep resistant, aramid strength member which enable the cable to withstand sustained everyday stress, as well as the high loading during environmental extremes. The aramid yarn is applied contra-helically in layers to eliminate torsion stress.

● The smooth circular profi le inhibits galloping, and the gel in the tubes provides additional protection against vibration, ensuring excellent optical reliability for all service conditions.

● Extensive cable/clamp compatibility tests were carried out to ensure optimum load transfer properties over a wide temperature range. We recommend only approved installation hardware.

● The Polyethylene sheath contains carbon black for UV resistance. The cable is also available with a Low Smoke Zero Halogen sheath (LSZH) in order to comply with specifi ed building regulations.

6

mduplessis

Typewritten Text

P.O. Box 10000, Kempton Gate, 1617, South Africa | 8 Chilworth Road, Founders View North, Edenvale, 1610, South Africa Tel: 0861 666 237 | +27(0)11 452 1684 | Fax: +27(0)11 452 3173

Contents

Scope ............................................................................................................................................ 2

Overview ....................................................................................................................................... 2

MEGAnet Installation Guidelines and Requirements ................................................................... 3

Cabinets/ Equipment Racks ................................................................................................... 3

Cabling ................................................................................................................................... 4

Horizontal Cabling. ........................................................................................................... 4

Permanent Link ................................................................................................................. 4

Copper Terminations ........................................................................................................ 4

Consolidation Point (CP) ................................................................................................... 6

Multi-User Telecommunication Outlet Assembly (MUTOA) ............................................. 7

Channel ............................................................................................................................. 7

Backbone Cabling. ................................................................................................................ 7

Cable Installation. .................................................................................................................. 9

Tension. ............................................................................................................................ 9

Strapping & Suspending. .................................................................................................. 9

Pathways and Routing. ..................................................................................................... 9

Cable Bending Radii. ......................................................................................................... 9

Twisted Pair Cable Types. ............................................................................................... 11

Labelling .................................................................................................................................. 11

Testing – Copper Cabling System ............................................................................................ 12

Testing - Optical fibre .............................................................................................................. 13

Fibre connector inspection and cleaning ....................................................................... 14

Power meter and light source testing ............................................................................ 15

OTDR testing ................................................................................................................... 15

MEGAwarranty Administration & Documentation .................................................................. 18

References .................................................................................................................................. 19

P.O.Box 10000, Kempton Gate, 1617, South Africa | 8 Chilworth Road, Founders View North, Edenvale, 1610, South Africa Tel:0861666CFS(237) | +27(0)114521684 | Fax:+27(0)114523173

P a g e | 2

Scope

This document describes the minimum requirements and procedures for installing MEGAnet balanced twisted‐pair copper and optical fibre cabling that transport telecommunications voice, data and video signals to meet or exceed the performance guidelines of the ANSI/TIA‐568‐C, ANSI/TIA‐ 569‐D and ISO/IEC 11801 (Generic Cabling for Customer Premises) standards.

Overview

Figure1 The TIA Structured Cabling System Model

Although the drawing above depicts the TIA cabling systems model, the ISO standard uses a similar model, but some terminology is different. See below for ISO equivalents.

Figure2 The ISO Structured Cabling System Model


P a g e | 3

The models depicted above are scalable to suit the environment. For example, depending on the size and extent of the structured cabling requirement on a customer’s premises, all, or only some of the described components may be required. For instance, in a campus type environment with multiple buildings, all the components described may be implemented. On the other hand, in a simpler scenario encompassing only a single floor of one building, several of the components may be omitted, e.g. backbone cabling, Intermediate Cross‐connect (Building Distributor), Main Cross‐ connect (Campus Distributor) etc. The total installation may consist of just the Horizontal Cross‐connect (Floor Distributor) and the Horizontal cabling and the Telecommunications Outlets(TO). In a simplified form it is quite conceivable that there could be no requirement or capacity for a dedicated Telecommunications room(TR), in which case a Telecommunications Enclosure(TE) - Dedicated Equipment Rack/Cabinet will suffice.

MEGAnet Installation Guidelines and Requirements

Cabinets/ Equipment Racks Where possible cabinets or equipment racks installed should conform to the following clearances:

• 1m from equipment and patching fields

• 1.2m from centre of rack to wall in front/back

• Aisles of 810mm wide

• 300mm from side of rack to wall

• 150mm off the wall for wall mount equipment

Cabinets should be grounded to the building’s earthing system using a dedicated 6mm2 stranded conductor. The grounding conductor should be as short as possible, without kinks or loops and must be connected directly between the Cabinet/ Rack and the grounding point or busbar. Binding of grounding conductors are not permissible. Cabinets should ideally have adjustable front and rear rails so that if patch panels are installed on the front or rear of cabinets, the front or rear rails should be recessed at least 100 mm to allow for cable management. Twisted 4‐pair cables (shielded or unshielded) terminating in an equipment cabinet or rack shall be bundled in quantities not exceeding 24 cables per bundle. Data/power separation must be maintained as far as possible. It is highly recommended that all data cables be installed on one side of the cabinet or rack, with the power cables on the other side. Horizontal cable management panels (brush panels) to be used at the rate of maximum one for each 48 patched ports. Patch panels should be labelled clearly, in a consistent and in a logical manner using a permanent printed or engraved label. Adequate cooling is essential due the fact that a 10ºC increase in temperature can result in 40% more attenuation!


P a g e | 4

Cabling Horizontal Cabling

Please note that only MEGAnet® branded or approved cable, patch panels, modules, outlets, MUTO and consolidation points are allowed for the installation of a MEGAnet systems warranty installation. There are two types of cabling in the standards models namely Horizontal Cable and Backbone Cable.

Horizontal Cabling includes horizontal cable; telecommunications outlets and connectors in the work area (WA); mechanical terminations and patch cords or equipment cords located in a telecommunications room (TR) or telecommunications enclosure (TE); and may incorporate multiuser telecommunications outlet assemblies (MUTOA) and consolidation points (CP). Horizontal cabling should be twisted 4 pair, unshielded, shielded or fibre optic cable usually configured in a star topology, with the patch panel at the centre and the end points at the Telecommunications Outlets(TO).

Permanent Link

The twisted pair cable must be of a solid conductor type and continuous, with no joints, terminated onto IDC (Insulation Displacement Connector) type contacts on either side. (I.e. patch panel, telecommunications outlet and/or consolidation point). This model is referred to as the Permanent Link (PL) and excludes any patch cords, equipment cords or any flexible (stranded conductor) cables.

The Horizontal Cabling Permanent Link my not exceed a total length of 90m, independent of media type.

Figure3 Permanent Link vs Channel

Copper Terminations

Punching down of conductors onto an IDC must be done using the appropriate punch‐down tool only. (This is typically a 110 type tool.) Other implements such as screwdrivers, utility knives or proprietary, non‐MEGAnet approved tools are forbidden as it will affect the integrity of the termination by deforming the IDC contact.

When terminating the wires on the IDC, take care not to untwist the pairs too much as this will lead to degradation of performance due to increased crosstalk. Although older standards allowed for up to 13mm untwisting of pairs for Cat 5e and 6mm for Cat 6, the contemporary consensus is to maintain the pair‐twist integrity as much as possible. This is especially true for new generation cabling (Cat 6A and later).


P a g e | 5

LSA Style(Also called Krone) VS 110 style Impact Tool

Figure4 LSA Style/110 style

A LSA-Style (Krone) tool can only be used for LSA-Style IDC terminals and not 110 IDC terminals. A 110 Style tool can only be used for 110 Style IDC terminals and not LSA Style terminals. The wires must be terminated on the IDC with the wire end cut close or flush to the block. The cable’s overall jacket should also be stripped back as little as possible. This not only assists in maintaining the cable’s performance integrity, but makes for a much neater installation. Refer to figure 5 below.

Figure5 Detail of cable terminated onto IDC block

The TIA 568‐C standard describes two different, but similar wiring schemes named T568A and T568B respectively. The only difference between the two being the sequence of the pair colours. T568A utilizes pair 1 (Blue pair) on pins 4 & 5, Pair 2 (Orange pair) on pins 3 & 6, Pair 3 (Green pair) on pins 1 & 2 and pair 4 (Brown pair on pins 7 & 8. Wiring scheme T568B utilizes pair 1 (Blue pair) on pins 4 & 5, Pair 2 (Orange pair) on pins 1 & 2, Pair 3 (Green pair) on pins 3 & 6 and pair 4 (Brown pair on pins 7 & 8. Note that in both cases the solid colour wire of each pair is terminated on the even‐numbered pins. Extremely important is to remain consistent throughout an installation and not to combine the two wiring schemes.

LSA-Style 110-Style

MEGAnet – CAT3 Panels/Modules & Outlets MEGAnet – CAT6a Panels/Modules & Outlets

MEGAnet – CAT5e Panels/Modules & Outlets

MEGAnet – CAT6 Panels/Modules & Outlets


P a g e | 6

Figure6 Detail of T568A and T568B wiring schemes

Cable should be terminated with connecting hardware of the same performance or higher. The Category of the installed link should be suitably marked and noted in the installation records. The 4‐pair ethernet cable at the equipment outlet shall be terminated in an 8‐position modular jack.

Consolidation Point (CP)

The CP is an interconnection point within the horizontal cabling. It may be useful when reconfiguration is frequent, but not so frequent as to require the flexibility of a MUTOA (see below). The CP allows the relocation of Telecommunication outlets (TO) without having to replace the full cable run all the way to the patch panel, as only the cable between CP and TO needs to be rerouted/ replaced. The MEGAnet CP comprise of WIREspeed 6/12 port, 8‐pin plug, RJ45 panel/enclosure. Fundamental guidelines installing consolidation points:

• A CP shall only contain passive components and shall not be used in a cross‐connect configuration.

• A CP shall be considered as part of the administration system.

• A CP shall be located installed in an accessible location.

• A CP shall serve a maximum of twelve work areas.

• A CP should be located at least 15m away from the floor distributor (TR, TE, Cabinet).

• Cross‐connections shall not be used at a CP. A Interconnect configuration must be used. (See figure 7)

Figure7 Interconnect VS Crossconnect

Telecommunications outlets may be part of a MUTOA. Each horizontal cable extending to the Work Area


P a g e | 7

(WA) outlet from the CP shall be terminated to a telecommunications outlet (TO). The cable between the patch panel in the cabinet (TR or TE) and the CP must be a solid conductor cable. The cable between the CP and the TO must also be a solid conductor cable.

Figure8 Consolidation Point is part of the Permanent Link

Multi-User Telecommunication Outlet Assembly (MUTOA)

The permanent link may terminate in a Multi User Telecommunications Outlet (Assembly) (MUTO or MUTOA), which is really nothing more than a concentration of Telecommunications Outlets (TO), but which permits for the use of longer equipment cords (Fly Leads) to service users in open office areas. It is not recommended that a MUTO serves more than 12 work areas(WA) and it shall be located in an open work area so that each work area(WA) group is served by at least one MUTO. The total length of the channel, from the user port on the active equipment (switch) in the cabinet up to the port on the user workstation may not exceed 100m. Should a MUTO be deployed, the maximum horizontal balanced twisted‐pair copper cable length has to be reduced in accordance with Table 1 (below).

Table1 Maximum MUTO Work Area Cable (Fly lead) length

Channel The length of the cross‐connect jumpers and patch cords that connect horizontal cabling with equipment or backbone cabling should not exceed 5m. For each horizontal channel, the total length allowed for cords in the WA, plus patch cords or jumpers and equipment cords in the TR or TE, shall not exceed 10 m (total) unless a MUTOA is used, in which case the WA cables will be determined by following the information in Table 1.

Backbone Cabling

Backbone cabling can consist of copper twisted pair, multimode fibre or single mode fibre.

Maximum Horizontal Cable Length 90m 85m 80m 75m 70m

Maximum Work Area Cable Length 3m 7m 11m 15m 20m

Maximum Calculated Patch Cable Length 7m 7m 7m 7m 7m

Maximum Total Channel Cable Length 100m 99m 98m 97m 97m


P a g e | 8

Figure9 Cabling hierarchy model

Backbone cabling lengths are media dependent as indicated in the tables below.

Application Media type Distance

Ethernet 10Base‐T Category 3, 5e, 6, 6A 100m

Ethernet 100Base‐T Category 5e, 6, 6A 100m

Ethernet 1000Base‐T Category 5e, 6, 6A 100m

Ethernet 10GBase‐T Category 6A 100m

ADSL Category 3, 5e, 6, 6A 5000m

VDSL Category 3, 5e, 6, 6A 5000m

Analogue Phone Category 3, 5e, 6, 6A 800m Table2 Maximum Twisted Pair Backbone Cabling Lengths

850nm 1300nm 850nm 1300nm 850nm 1300nm 1310nm 1550nm

dB 4.0 - 4.0 - 4.0 - - -

m 300 - 300 - 300 - - -

dB - 6.0 - 6.0 - 6.0 - -

m - 2000 - 2000 - 2000 - -

dB 3.6 - 4.5 - 4.8 - - -

m 550 - 800 - 880 - - -

dB - 2.3 - 2.3 - 2.3 4.5 -

m - 550 - 550 - 550 5000 -

dB 2.3 - 2.6 - 3.1 - - -

m 82 - 300 - 450 - - -

dB - 2.0 - 2.0 - 2.0 6.3 -

m - 300 - 300 - 300 10000 -

dB - 1.9 - 1.9 - 1.9 6.2 -

m - 220 - 220 - 220 10000 -

dB - - 1.9 - 1.9 - - -

m - - 100 - 125 - - -

dB - - - - - - 6.7 -

m - - - - - - 10000 -

dB - - - - - - 6.3 -

m - - - - - - 10000 -

Ethernet 10GBASE‐LX4

Ethernet 10GBASE‐LRM

Ethernet 40GBASE‐SR4

Ethernet 40GBASE‐LR4

Ethernet 100GBASE‐LR4

Ethernet 10/100BASE‐SX

Ethernet 100BASE‐FX

Ethernet 1000BASE‐SX

Ethernet 1000BASE‐LX

Ethernet 10GBASE‐S

Multi Mode Single Mode

OM2 OM3 OM4 OS2Application


P a g e | 9

Table3 Maximum Optical Fibre Backbone Cabling Lengths

Cable Installation

Tension

• The pulling tension for a 4‐pair balanced twisted‐pair cable shall not exceed 110 N during installation.

• For optic fibre parameters, please consult the relevant optic fibre cable data sheet. Strapping & Suspending

• MEGAnet cable installed in an open space, and not contained in enclosed channels o Should be bundled by strapping it in 500 mm intervals o Only Velcro strapping and ties are allowed for any MEGAnet installations of CAT6 and above. o Nylon cable ties will only be allowed for MEGAnet CAT5e installations. Care should be taken

not to over tighten cable strapping. Over tightening of cable ties will cause distortion of the cable sheath resulting in undue signal loss. As a rule of thumb one should be able to move the cable tie with elective ease. Indentation of the bundle is indicative of a cable strap that is too tight.

o Under no circumstances may cables be glued, stapled or fixed in place using cable saddles. Pathways and Routing

• Data cable routes should be planned avoiding other services

• Data cable has to follow a well-defined route and be separated as much as possible from power cable.

• Never strap cable bundles onto other services such as plumbing, power cables or air‐conditioning ducts etc.

• Any cable support infrastructure should be of such a nature to ensure that the cable transmission performance is not compromised.

• Cable trunking, cable trays and support brackets should not impose sharp bends smaller than the minimum bend radius nor introduce any other factors that may impede the transmission performance.

• Where no cable support infrastructure is available, the cable bundles should be anchored to the building infrastructure at intervals not exceeding 1500 mm.

• Cables should be protected from sharp edges to avoid accidental damage and chafing due to movement. Unfitting places for instance, locations where the cables go through sheet metal, grommets or sleeves should be installed.

• Cables may not be laid directly on suspended ceiling tiles but should rather be supported by hangers, wire baskets, cable trays or cable channels attached to roof trusses or concrete soffits.

• Where Cable trays and baskets could not be used, please utilise J/S-hooks.

• Where cables/cable bundles penetrate firewalls, the integrity of the firewall should be reinstated by means of approved fire stopping material. This is a legal requirement.

Cable Bending Radii

• Sharp bending of the cables should be avoided at all cost and the minimum bending radii should be adhered to. Both TIA and ISO standards prescribe a minimum bend radius for unshielded and shielded copper cables of 4 x the diameter of the cable. For example, if a cable has a diameter of 6mm, then the minimum bend radius will be 24mm. Refer to the drawing below for clarity.


P a g e | 10

Figure10 Minimum Bend Radius Calculation

• For optic fibre parameters, please consult the relevant optic fibre cable data sheet. Electromagnetic Interference (EMI) The influence of electromagnetic interference on the performance of telecommunication and data network cable can be detrimental. Thought must be given to the proximity thereof. Most common sources of EMI in building cabling includes:

• Large UPS systems of 100kva and bigger

• Electric motors and generators.

• X-ray and Radio Frequency sources.

• Electrical power cable. There are specific procedures and rules that needs to be adhered to. Separation distances different types of installations is extremely important and indicated in Table 4.

In addition to these distances:

• Power cable and telecommunication cable may only cross at 90 degrees.

• Minimum distance of 130mm must be sustained between fluorescent fittings and telecommunication cable.

• Horizontal cable less than 35m does not have to comply to separation distances. Should the cable exceed 35m, the complete length of the link has to comply.

• The equipment cord of maximum 15m is exempted.

Non-Metallic

or

No divider

Aluminium divider Steel divider

Unscreened Power Cable

with

Unscreened Data Cable

200 mm 100 mm 50 mm

Unscreened Power Cable

with

Screened Data Cable

50 mm 20 mm 5 mm

Screened Power Cable

with

Unscreened Data Cable

30 mm 10 mm 2 mm

Screened Power Cable

with

Screened Data Cable

Zero Zero Zero

Installation Type

Seperation distance between Power and Data cable


P a g e | 11

Table4 Separation distances between Power and Telecommunication cable

Twisted Pair Cable Types

Table5 Guide to twisted pair cabling types abbreviations

Labelling

Accurate labelling procedures is fundamental with any warranty system as well as for maintaining the system thereafter. Please adhere to the following:

• All cable ends must be labelled with permanent, legible markers

• All cable must be identified and labeled on both ends within 100mm of the termination

• Both ends of a cable must have matching numbers

• The Telecommunications outlet and the patch panel port must be labelled with the same number as the corresponding cable ends

• The numbers used on the labels must correspond with the numbers indicated on floor plans and test results

• Where consolidation points(CP) or Multi-User Telecommunication Outlet Assembly(MUTOA) are used, the numbers must also correspond to the cable end numbers.

• Consolidated points and Multi-User Telecommunication Outlet Assembly must be labelled with unique numbers

• Numbering systems should be logical, consistent and kept simple and unambiguous

Foiled Screen F/*TP

Braid Screen S/*TP

Braid and Foil Screen SF/*TP

Unscreened */UTP

Foil Screened */FTP

Balanced Element Twsted Pair */*TP

Overall Screen

Element Screen

* Refers to type of screening


P a g e | 12

Testing – Copper Cabling System

Contractually, testing essential so that installer and user can have an unambiguous set of parameters to determine when the cable system is performing to set international standards. In ISO/IEC Standards, structured cabling components (i.e. cables, connecting hardware, and patch cords) are characterized by a performance “category” and are mated to form a permanent link or channel that is described by a performance “Class”. In TIA Standards, components and cabling are both characterized by a performance “Category”. Refer to the table below for equivalent designations

Table6 Guide to Standards equivalents

The performance category of all components must be the same throughout the entire link. MEGAnet performance warranty testing specifies:

• Only MEGAnet approved certifiers accepted for warranty puposes. Fiel test equipment needs to comply to certiin accuracy levels.

o Field tester accuracy for ISO/IEC 11801:2010 defined ▪ – Level IIe, supports Class D (100 MHz) ▪ – Level III, supports Class E (250 MHz) ▪ – Level IIIe, supports Class EA (500 MHz) ▪ – Level IV, supports Class F (600 MHz) ▪ – Level V, supports Class FA (1,000 MHz)

o Field tester accuracy for ANSI/TIA-568-C.2 defined

▪ – Level IIe, supports Category 5e (100 MHz) ▪ – Level III, supports Category 6 (250 MHz) ▪ – Level IIIe, supports Category 6A (500 MHz

(Please consult with MEGAsystems before testing as technology and support on equipment changes over time)

• Copper test equipment requirements o Calibration certificate to be produced. Has to be calibrated within a 12 month period. o Nominal Velocity of Propagation (NVP) – As per printing on cable sheath

• Appropriate Testing standard (Refer Table 6)

• Select correct cable type and screening.(ref: Table5)

• Permanent Link Testing. Only Permanent Link testing permissible for warranty puposes

TIA Designation

(Cabling & Components)

ISO EquivalentDesignation

(Components)

ISO Equivalent Designation

(Cabling)

Category 5e Category 5e Class De

Category 6 Category 6 Class E

Category 6A Category 6A Class EA

No Equivalent Category 7 Class F and Class FA

Category 8 Category 8.1 Class I

No Equivalent Category 8.2 Class II


P a g e | 13

• Use the correct main and remote adaptors as they differ for different equipment brands. Should the incorrect adaptors be used, the test results will be null and void.

• Carefully select a descriptive and unique range of cable ID’s for no duplicate ID’s will be accepted within the same MEGAwarranty. Pre setup and selection is always advised.

• Direct terminated links will not be considered for a MEGAwarranty.

IEC 61935‐1 requires the following tests:

• Wire map, including cable screen if present

• Attenuation (called insertion loss in ISO 11801 2nd edition

• NEXT, pair to pair, local and remote

• Power sum NEXT, local and remote

• ELFEXT, pair to pair

• Power sum ELFEXT, pair to pair

• Return loss, local and remote.

• Propagation delay.

• Delay skew.

• DC loop resistance.

• Length (not listed as a required test but described in the text as part of the ‘inspection of workmanship’ requirements)

Testing - Optical fibre

The parameters of interest in an optical cable installation:

• Link attenuation.

• Individual component attenuation.

• Return loss.

• System bandwidth.

• Link length. Bandwidth optical cable are not measured in the field. The designer and installer are reliant on of the optical fibre cable manufacturer and supplier specifying the bandwidth of their product in terms of megahertz kilometers (MHz.km). Return loss is the amount of light reflected back from connectors. It can be problematic for laser systems, especially analogue video systems where a high level of return loss close to the laser itself will either damage it or cause unacceptable signal distortion. Link length relates to the overall link attenuation and propagation delay.


P a g e | 14

Individual component attenuation is of significance should a problem be suspected within the component i.e. splice, connector or length of the fibre cable itself. With short distance optical fibre links, the only test parameter of real interest is the overall link attenuation. This measured parameter is usually a strong indication whether the optical link will actually work or not., The most accurate method to measure the link loss is with a Stabilised optical source and Power meter.

TIER 1 testing Optical loss test set. (OLTS) Measure the total loss, length and polarity of an optical path. A power meter (pm) and light source (LS) most closely simulates system losses. TIER 2 testing Optical time domain reflectometry. (OTDR) The same as for TIER1 testing with the added benefits OTDR testing brings.

• It provides evidence that a cable is installed without degrading events

• Sets optical budgets for individual events

Tier 1 testing does not provide the level of visibility required to fully consider the condition of the optical path, this is where Tier 2 testing plays a part. Tier 1 can identify if ‘n optical link passes or fails, but cannot determine the root cause or location of the fault.

Fibre connector inspection and cleaning

All testing should start with inspection and cleaning. Tight loss budgets require clean connectors A single particle mated into the core of a fibre can cause significant back reflection, insertion loss and even equipment damage. The contact pressure between the enfaces is approximately 344KPa. Contamination between the two end faces subjected to this pressure will permanently damage the connector enface

There are four major zones on the end face that have a profound impact on the signal quality if contaminated.


P a g e | 15

Zone A is the most import of all three zones. Manual visual testing equipment uses a judgement call, and therefore cannot conforms to IEC 61300-3-5. Digital video scope that conforms to IEC 61300-3-5 can be used for inspection and verification purposes. A photo of the end face connections must be included in the test reports. MEGAnet Sticklers is recommended to use for all your connector cleaning jobs. It is also a non-film residue wet cleaner. It is very important to:

• Inspect the end face.

• Clean the end face. (Start with a double click spaced 90° dry clean, and if the contaminates is still stubborn to remove, use a wet clean non-film residue wet cleaner, follow up with a dry clean)

• Inspect the end face, only if the end face conforms to IEC 61300-3-35 then the end face is clean enough to be connected.

• Only then connect. Power meter and light source testing

A stabilised light source is a laser or light‐emitting diode that emits a steady stream of light, at a constant optical power, at one of the wavelengths normally used in optical fibre transmission. These are the first, second and third windows, which operate at around 850, 1300 and 1550nm, respectively. Multimode light source must be Encircled Flux (EF) compliant. The stabilised light source injects its light into the optical link under test and at the receiving end is the power meter. This is a light sensitive diode device that will display a reading indicating how much power has been received through the optical link. The power meter will give the reading in decibels but for the figure to be valid the power meter has to know how much optical power was launched into the link. This is why calibration of the light source and the power meter is essential. Otherwise the power meter reading will be a purely random number. The calibration must take place before every sequence of tests and if the test lead from the light source is ever decoupled from the output connector, or if the light source is switched off, then the calibration must be done again. ‘One Cable’ reference as per TIA/OFSTP-14 (Preferred method)

This method use one reference grade cord between the source and the power meter. Once the reference is set ‘Zero’ the cord should not be removed from the source.

‘Two Cable’ reference as per TIA/OFSTP-14 Two reference cords are attached to the source and the power meter. The two reference cords are mated to set the reference value ‘Zero’. The launch reference cord should not be removed from the source.

This literally means setting the scale to read zero. The cable under test is then inserted between the two reference cords ‘Two Cable’ or between the end of the reference cord and the power meter ‘One Cable’ Remember that the light source is never turned off or disconnected from reference grade lead. All that remain is to record the value and compare it to the optical loss calculated expected for that class and length of link. If the measured value is less than or equal to the calculated loss then the link has passed the acceptance test. The standards only require a test from one end but many people prefer to test from both directions because a single ended test can mask some connector problems. A chipped connector, for example, can output light fairly well yet will reflect a large portion of light away when the circuit is reversed and it is attempted to launch light into it.


P a g e | 16

The link should also be tested at all the wavelengths at which it is expected to operate and from both ends.

OTDR testing Applications of an OTDR

• Measure fibre length

• Check for breaks

• Measure splice loss

• Measure distance to fibre events

• Optical return loss (ORL) of spans

• Measure component reflectance

• Measure loss as dB or dB/km

• Documentation

Generic operating procedure of an OTDR

• Switch on the OTDR and wait a few minutes for the OTDR to warm up.

• Inspect and clean all mating connectors.

• Attach a launch cable to the OTDR and couple it to the Device/Cable under test (DUT). Attach a

receive cable on the far end of the cable as often as possible. The launch and receive cable must have

a minimum length of a 100m. Make sure the connector polish match. (APC to APC)

• Set up the testing parameters on the OTDR.

• Acquire a trace.

Above show two OTDR traces of the same optical link but showing a traditional and an icon/graphic version of the OTDR trace. Non-reflective events:

• Fusion splices

• Splitters


P a g e | 17

• Macrobends

• Microbends

Reflective events:

• Connectors

• Mechanical splices

• Fibre ends

Optical gain:

Bidirectional measurements are compulsory to evaluate a true splice loss, an single direction OTDR measurement exaggerate the real splice loss. Index of refraction(IOR): It is paramount that the correct IOR values is entered into the OTDR set-up. Length measurements can be up to 0.7% out if the incorrect IOR values was used. Each manufacturer of optical fibre has its own IOR values. Pulse width:

• General rule is to use the shortest possible pulse width needed for a clean optical trace.

Summary

• Clean connectors are a must

• Today’s high-speed networks are not as forgiving as the < 10gbit networks of the past

• Testing is a critical part of maintaining a high- performance fibre optic network.

• Small things can add up to big problems

• Accuracy and repeatability matter!

• Get the right equipment for the job at hand.

Bad habits or shortcuts can cause big problems


P a g e | 18

MEGAwarranty Administration & Documentation

Set an appointment with your MEGAnet® sales representative and the MEGAnet® warranty consultant before the installation commences. The MEGAnet® warranty consultant will review the application and address all procedures and protocols.(copy of procedures available on request) In order to certify any site as a “MEGAwarranty site”, it is compulsory to be registered as a MEGAinstaller. MEGAnet® offers a training program to all interested parties wishing to become certified MEGAinstallers. At the very least, the head designer, technician and team leaders should attend The installer must submit final test results in the original file format as created by the test equipment. A copy of the said software should be made available if required. No TEXT or PDF files will be accepted. The MEGAwarranty application form must be completed in detail and in a legible format. The MEGAwarranty application will be rejected unless the above is completed in a correct and accurate manor. The following documents must be attached to the application form:

• Final test results in the original file format. No exceptions!

• Final system drawings indicating: o Floor outlets positions o Pathways (including risers and outdoor runs) o Floor, building and campus distributors (equipment racks) o Equipment rooms (data centres, service provider entrance facilities)

• Outlet ‘ID’ and labels must be printed and exact on: o Patch panel label o Outlet label o Horizontal cable end (patch panel) 6.3.4 Horizontal cable end (outlet)

• Rack drawings (labelled) Only approved MEGAnet® products will be allowed for MEGAwarranty purposes. No copper clad aluminium (CCA) products will be accepted All warranty applications must be submitted to your MEGAnet® warranty consultant The warranty site will be inspected to evaluate and verify the application. The installation must adhere to relevant international and local standards or practices specified by MEGAsystems. We may ask you to make changes to the site in order to adhere to said standards. Failure to adhere to these requests may result in links being excluded from the MEGAwarranty or a complete rejection of the MEGAwarranty application. Under no circumstances are we obliged to provide a MEGAwarranty

NO EXCEPTIONS. THIS IS THE MINIMUM DOCUMENTATION AN INSTALLER SHOULD RENDER.


P a g e | 19

References SANS 11801:2004/ISO/IEC 1 180 1 :2002 (SANS I1801:1995 (SABS ISO/IEC 11801)) Information technology‐ Generic cabling for customer premises. Specifies a generic cabling for use

within premises, which may comprise single or multiple buildings on a campus. It covers balanced cabling and

optical fibre cabling, and is optimised for premises in which the maximum distance over which

telecommunication services can be distributed is 2 000 m. Safety and EMC fall outside the scope of this standard.

ISO/IEC technical corrigendum No. 1. Corrected to add a new abbreviation, and a new note referring to the

relationship and requirements of classes and categories in earlier editions of this standard, and to delete three

references in the Bibliography ISO/IEC technical corrigendum No. 2. Corrected

to change a reference to an incorrectly numbered clause. ISO/IEC 11801:2002/Amd 2:2010

ISO/IEC 11801 Edition 2.2 “Information Technology – Generic Cabling for Customer Premises” as developed by

subcommittee 25: Interconnection of information technology equipment, of ISO/IEC joint technical committee 1:

Information technology. Second edition (2002) of ISO/IEC 11801,

Amendment 1 (2008), including Corrigenda 1 (2002) and 2 (2002), and Amendment 2 (2010). Published June 2011. Latest information from TIA, IEEE, ISO/IEC JTC 1/SC 25/WG 3 (Customer Premises Cabling), IEC SC 48B (Connectors), and BICSI (Various sources including TDMM 13 and ANSI/NECA/BICSI 568‐2006 FOA Guide 5 Fibre Optics & Premises cabling Cabling Installation – Tier1 & Tier2

enhanced short span aerial optic fibre › wp-content › uploads › ... · horizontal cabling...

Documents