Patch Cord Installation Practices
This document has been produced by Brand-Rex to assist the
installer with best practices for Patch Cord installation.
Information within has been sourced from the Brand-Rex installation
manual, many years experience in the industry and standards
documents. Together this information should assist the installer
and answer many of the usual questions surrounding patching
installation.
Revision Control
IssueDateReasonUpdated by
1.001-04-12Document CreationT.Simmons
Contents
Section 1 Copper Patch Cords
Content Page
1 CABLE INSTALLATION PRACTICES1.1 Bend Radii61.2 Copper Pulling
Forces and Twisting71.3 Dressing of Cables81.4 Cable Labelling81.5
Cable Protection8
2 ADDITTIONAL RULLES FR 10GPLUS PATCH CABLES2.1 Alien
Crosstalk92.2 Mitigation Techniques92.3 Patch Cord Management10
3 PATCHING GUIDELINES3.1 Patching Good Practices113.2 Temporary
Patches123.3 A Tidy Frame123.4 Routing Patch Cables13
4 CABLE MANAGEMENT4.1 Cable Management Bars144.2 Blanking
Panels154.3 Angled V Panels154.4 High Density Patching Frame16
Section 2 Fibre Patch Cords
Content Page
5 TIA/EIA 568C-3 Optical Patch Cords5.1 General185.2 Patch Cord
Cable185.3 Patch Cord Connectors185.4 Termination
Configuration185.4.1 Duplex System185.4.2 Simplex System185.4.3
Array System195.4.3.1 General5.4.3.2 Optical Fibre Patch Cord
195.4.3.2.1 Type A Optical Fibre Patch Cord19Section 2 Fibre Patch
Cords (continued)
Content Page
5.4.3.2.2 Type B Optical Fibre Patch Cord205.4.3.2.3 Type C
Optical Fibre Patch Cord205.4.3.2.4 A to B Patch Cord
(Standard)215.4.3.2.5 A to A Patch Cord215.4.3.3 Transition22
6 FIBRE PATCH CORDS6.1 Bend Radii236.2 Optical Losses6.2.1 Macro
Bending246.2.2 Micro Bending246.3 Polished Ends6.3.1 Polished
Connector (PC)256.3.2 Angled Polished Connector (APC)256.4 Fibre
Types266.5 Connector Types266.6 Patch Cord Types6.6.1
Simplex276.6.2 Duplex276.7 Hybrid Patch Cords286.8 Fibre Breakout
Cables286.9 Secure Fibre Patching29
7 OPTICAL PATCH CORD MAINTENANCE7.1 Lint Free Wipes307.2
Individual Pre-Saturated IPA Wipes307.3 Optical Fibre Cleaning
Cassette & Tape317.4 Swabs317.5 Ferrule Cleaner32
8 OPTICAL PATCH CORD TESTING8.1 Optical Microscope338.2 Types of
Fibre Faults8.2.1 Chip348.2.2 Crack348.2.3 Scratch358.2.4 Broken
Fibre35
Section 1
Copper Patch CordsCABLE & PATCH CORD INSTALLATION
PRACTICES
1.1. Bend Radii
The bending radius is defined as a multiplication factor of the
outside cable diameter. There are two relevant minimum bending
radii: one for patch cord installation and one for the patch cord
once it is installed (without mechanical load).
It is important to note that the minimum permissible bend radii
of a cable is greater during the installation / pulling in stage,
when the cable is under tension, than it is when the cable is
placed in its final position and is free from tension. This
criteria is also applicable when installing/dressing patch
cords.
Minimum bend radii must be observed throughout the whole cable
route in order to ensure that the design performance of the cable
is not impaired.
(IRXRXR = min radius during installation8 x sheath diameterIR=
min radius installed4 x sheath diameter)
It is also important to consider bend radii when determining the
size of containment systems such as basket tray, conduit or
trunking, as the system may have adequate capacity for the straight
runs but be too small at the turns for the minimum bend radii to be
observed. Tray work should have gussets fitted to the inside edge
of corners and conduit systems constructed to ensure that minimum
bend radius is not infringed.
The same applies to containment within cabinets, around frames
and between patch panels.
1.2. Pulling Forces and Twisting
Maximum pulling forces should not be infringed to ensure that
the cable is not damaged or its performance impaired during
installation.
Ensure that adequate containment, patch management is
available.
Minimise the twisting, pulling and bending of patch cords during
installation..
The following installation parameters must be observed for four
pair cables this table should always be referenced for patch cord
installation:-
ParameterUnits4 pair U/UTP Unit*4 pair F/UTP Unit *4 pair S/FTP
Unit*
Temperature rating:
Installationo C 0 to 50 0 to 50 0 to 50
Operationo C-20 to 60-20 to 60-20 to 60
Storageo C-40 to 60-40 to 60-40 to 60
Min. bending radiusGigaPlus
During installationmm405060
Installedmm202530
Max. pulling loadN858585
CAT6Plus
Min. bending radiusPIMF
During installationmm5070
Installedmm2535
Max. pulling loadN7095
10GPlus
Min. bending radiusPIMF
During installationmm72N/a65
Installedmm36N/a32
Max. pulling loadN98N/a9510GPlus
10G Plus Zone CableMin. bending radiusPIMF
Min. bending radiusU/FTPDuring installationmm72N/a65
During installationmmN/a45N/aInstalledmm36N/a32
InstalledmmN/a22N/a
Max Pulling LoadNN/a98N/aMax. pulling loadN98N/a95
During installation, cable management precautions that should be
observed include the elimination of cable stress caused by
excessive tension, sharp bends and tightly bunched cords.
Temperature variations should not exceed those stated above, it
should be noted that attenuation increases with temperature,
typically 0.4% per C for Cat5e cables.
1.3. Dressing of Cables
Dressed into neat groups and fix into place using the patch
management systems.
It is good practice to keep the groups as small as possible;
this will aid cable identification and future maintenance.
1.4. Cord Labelling
ANSI/TIA/EIA 606A is the latest labelling standard that covers
labelling standards across your cabling infrastructure.
It does not mention that individual patch cords should be
labelled but it can be good practice to do so. If you do choose to
label, 606A states that the use of printed self-laminated wrap
around labels is recommended.
There are many guides available on the web that covers the
requirements of this standard or a copy can be purchased at
http://global.ihs.com/search_res.cfm?RID=TIA&INPUT_DOC_NUMBER=TIA-606
1.5. Cord Protection
Take care to prevent damage to cords during and after
installation.
Where possible all redundant cords should be removed.
2. ADDITIONAL RULES FOR 10GPLUS CABLES
2.1. Alien Crosstalk
Alien crosstalk (AXT) is electromagnetic noise that can occur in
a cable that runs alongside one or more other signal-carrying
cables. The term "alien" arises from the fact that this form of
crosstalk occurs between different cables in a group or bundle,
rather than between individual wires or circuits within a single
cable.
Alien crosstalk can be particularly troublesome because, unlike
simple crosstalk caused by a single interfering signal, it cannot
be eliminated by the phase cancellation techniques used in Digital
Signal Processing. Alien crosstalk arises from multiple signals,
from multiple cables and includes mixing products in which signals
at innumerable frequencies blend with the originating signals.
The result is a mix of electromagnetic interference that is too
complex to be dealt with by Digital Signal Processing measures.
Because it resembles noise rather than signals, alien crosstalk
degrades the performance of a communications system by reducing the
signal-to-noise ratio (SNR).
2.2. Mitigation Techniques
Alien crosstalk can be minimized or eliminated by avoiding
configurations in which cables are bundled together or run parallel
to one another in close proximity.
In the first part of the link is imperative and non-more so than
the patch lead, not to run the cables or patch leads perfectly
parallel to each other, or cable tie them together or dress them in
cramped cable management products. Avoid cable management products
that will compress or kink the cables and in the case of cable ties
ensure that they are not over tensioned. If a cable tie has been
over tightened then the balance of the cable will be affected. This
will make this area of the cable susceptible to noise.
Use patch panels that stagger the jacks or leave additional
space between the jacks. The additional spacing will dramatically
reduce the effects of alien crosstalk.
Shielded solutions may well be one very practical approach in
reducing alien crosstalk. The foil, and foil and braid types, will
act as a screen to alien crosstalk. The use of shielded patch leads
will dramatically reduce alien crosstalk and Brand-Rex recommends
their use on all 10G Plus installations.
As with any shielded system the earthing and bonding
arrangements are paramount to their success and any shielded system
must be installed and designed by trained and experienced
installers of shielded systems.
2.3. Patch cord management
When designing patch cord management systems it is important to
understand what the maximum capacities and performance is
required.
Avoid running Copper and Fibre patch cords in the same
management routes.
Important Note
Try not to mix cable types in the same paths as 10GPlus
products. If you must lay 10GPlus cables in the same paths as CAT5
or CAT 6 cables then leave at least a 10mm space between them.
3 Patching Guidelines
3.1Patching Good Practice (Ports 13-24) (Ports 1-12)
Ports 1-12 patch to the left side of the cabinet Ports 13-24
patch to the right side of the cabinet 1U Management Bar for every
2 panels of patching Copper and Fibre patching to be separated as
much as possible Beware of servers on rails that need to move Avoid
obstructing removal switch blades and cooling fans Use correct
lengths to avoid birds nest Make sure correct patching cabinets are
used Always remove redundant cords Ensure no service exists before
disconnecting or re-patching Always use Brand-Rex patch cables on a
Brand-Rex installation to keep the 25 Year Warranty Avoid through
Cabling patching from one side of the frame to the other should be
avoided if possible. If unavoidable, make sure the cabinets are
installed with sufficient management bars to cope i.e. 2U top,
middle and bottom.
3.2. Temporary Patch Cables
(If allowed, temporary patch cables can mount up to look like
this. One thing leads to another and 6 months after a new
installation youre faced with an unmanageable patching frame and s
of re-patching bills.Time to fix faults and moves and changes can
take up to 10 times longer. After all Time is money!!!Cables
protruding from the cab can also be a Health & Safety issue as
well as increase the risk of accidental disconnection of circuits.
)
3.3. A Tidy Frame
(Keep your frame looking like this and your patching can be
achieved in a fraction of the time.Unique IDs on patch cables and
the use of a patching database will help quickly identify cables
which will save time and money on each patch change.With a tidy
frame, capacity can also easily be monitored.)
Label patch cables with a unique number to help identify leads.
Use the correct Category patch cords to match the installed system.
The link will only be as good as the slowest part of the network.
Avoid sharp bends in cables, this will increase attenuation. Make
sure cables are tidied inside cabs. Cables protruding can cause
trip hazards and may get trapped in floor tiles. Use Brand-Rex
Angled V panel to reduce number of bends in patch cords Never
install Temporary patches, they never get patched correctly and are
usually left on the frame.3.4. Routing Cables
Follow the 10 Rule Guide to maintaining patching frames and you
will help keep your frame in a good condition.
4 CABLE MANAGEMENT
4.1Cable Management Bars
Ensure there are sufficient cable management bars installed in
the cabinets. Brand-Rex manufacture a range of panels as above. If
using regular 24 port copper patch panels it is recommended to
install 1 x 1U Cable management bar for every 2 patch panels.
If using the Brand-Rex angled V 24 port patch panels it is not
necessary to use a management bar, however a finger system should
be installed vertically to take the weight of the patch cables and
keep them managed.
Most patching frames require inter-cab patching. Routing these
longer patch cables through the cabinet 1U management bars should
be avoided. To enable best practices a 2U management bar should be
installed Top, Middle and Bottom of the frame, this will avoid
congestion for patch cables within the cabinet.
It should be noted that this is best practice and the use of 2U
cable management bars will greatly reduce the frames capacity. A
well designed system should avoid inter-cabinet patching with a
single patch cord as much as possible, this can be achieved by
distributing the services regularly
4.2Blanking Panels
Brand-Rex also manufactures a range of Blanking panels for
cabinets. Primarily these are designed to fill U space in cabinets
to allow the correct circulation of air and allow the air
conditioning to operate efficiently.
Another good feature of the blanking panel is they prevent
temporary patch cables being installed from front to back, can help
reserve U space for future panels and keep the cabs/frames looking
neat and tidy.
4.3Brand-Rex Angled V Panels
Brand-Rex have designed an Angled V Panel to assist with the
growing demands within a patching cabinet. The panel allows more
patch panels in each rack as the modules are angled to the side so
that patch cables naturally flow into the management at the side
(should be used with finger management). As the modules are angled
to the side the 90 degree bend that normally occurs with patch
cables is removed, when installing 10G systems every loss saving
counts.
4.4Brand-Rex High Density Patching Frame
Vertical Finger Management
The Brand-Rex High density patching frame is designed to house a
higher number of patch panels than a regular patching rack. By
using the Angled V panel seen in section 4.3 along with the
vertical finger management system you no longer need the 1U cable
management bars, this could save as much as 8U per rack. If
patching between different racks it is still recommended to use a
2U management bar to allow for through patching.
The high Density patching Frame can be used for both Copper and
Fibre installations.
Section 2
Fibre Patch Cords5TIA/EIA 568-C.3 Optical Patch Cords
Section 5 has been taken directly from the 568C-3 standard.
Heading numbers are as they are found in the standard document.
OPTICAL FIBER PATCH CORDS
5.1 GeneralThis clause contains the performance specifications
for optical fiber patch cords recognized in premises cabling
standards. These patch cords are used to connect optical fiber
links at cross- connects, interconnects, and to connect
telecommunications equipment.
NOTE - Requirements for application specific assemblies are
outside the scope of this Standard.
5.2 Patch cord cableThe optical fiber patch cord shall contain
the same number of fibers as the connector used (e.g., duplex
connectors using duplex patch cord cable), be of the same fiber
type as the optical fiber cabling, of an indoor construction, and
meet the requirements of subclauses 3.2 and 3.3.1.
5.3 Patch cord connectorsThe patch cord connector shall meet the
requirements of subclause 4.2.
5.4 Termination configuration
5.4.1 Duplex systemDuplex optical fiber patch cords shall be of
an orientation such that Position A goes to Position B on one
fiber, and Position B goes to Position A on the other fiber of the
fiber pair (figure 3). Each end of the optical fiber patch cord
shall be identified to indicate Position A and Position B if the
connector can be separated into its simplex components. For
alternate connector designs utilizing latches, the latch defines
the positioning in the same manner as the keys.
Figure 3 - A-to-B duplex optical fiber patch cord
NOTE SC connectors are shown, but this assembly may be built
using any duplex single-fiber connectors or connectors with two
fixed fibers.
5.4.2 Simplex systemThe connector that plugs into the receiver
shall be considered Position A, and the connector that plugs into
the transmitter shall be considered Position B.
5.4.3 Array system
5.4.3.1 GeneralEach of the three array system methods
illustrated in ANSI/TIA-568-C.0, requires a specific combination of
components (array patch cables, transitions, duplex patch cords) to
maintain polarity. Some of the components are common to other
connectivity methods such as duplex systems.
5.4.3.2 Optical fiber cable or patch cordThe cables or patch
cords should be clearly identified.
NOTE - The patch cord shown is unpinned on both ends. In some
instances, such as when supporting parallel signals, it may be
necessary to use a combination of unpinned and pinned connectors on
cables and patch cords. (Move in general of cables)
5.4.3.2.1 Type-A optical fiber cable or patch cordAs shown in
figure 4, a Type-A connector patch cord has a sequential number
assigned to each fiber as follows:
a) On one end of the patch cord, the fibers are fixed within the
array connector in consecutive number (1,2,3,412) from left to
right as viewed looking at the end-face of the connector with the
connector key up.
b) On the other end of the patch cord, the fibers are fixed
within the array connector also in consecutive number (1,2,3,412)
from left to right as viewed looking at the end-face of the
connector with the connector key up.
Figure 4 - Type-A optical fiber cable or patch cord (key-up to
key-down)
5.4.3.2.2 Type-B optical fiber cable or patch cord
As shown in Figure 8, a Type-B array connector patch cord has a
sequential number assigned to each fiber as follows:a) On one end
of the cable, the fibers are fixed within the array connector in
consecutive number (1,2,3,412) from left to right as viewed looking
at the end-face of the connector with the connector key up.
b) On the other end of the cable, the fibers are fixed within
the array connector in reverse consecutive number (12,11,10,91)
from left to right as viewed looking at the end-face of the
connector with the connector key up.
When MPO connectors are used in the construction of these cables
they shall be flat polished
Figure 5 - Type-B optical fiber cables or patch cord (key-up to
key-down)
5.4.3.2.3 Type-C optical fiber cable or patch cord
As shown in figure 9, Type-C patch cords have a sequential
number assigned to each fiber as follows:a) On one end of the
cable, the fibers are fixed within the array connector in
consecutive number (1,2,3,412) from left to right as viewed looking
at the end-face of the connector with the connector key up.b) On
the other end of the cable, the fibers are pair-wise flipped within
the array connector (2,1;4,3; 6,512,11) from left to right as
viewed looking at the end-face of the connector with the connector
key up.
Figure 6 - Type-C optical fiber cable or patch cord (pair-wise
flipped, key-up to key-down)
5.4.3.2.4 A-to-B patch cord (standard duplex patch cord)The
A-to-B patch cords shall be built as specified in subclause
5.4.1.
5.4.3.2.5 A-to-A duplex patch cordAs shown in figure 7, A-to-A
duplex patch cords shall be built as specified in subclause 5.4.1,
exceptPosition A shall be routed to Position A and Position B
routed to Position B.
A-to-A patch cords do not reverse the fiber positions. The
A-to-A Duplex optical fiber patch cords shall be of an orientation
such that Position A goes to Position A on one fiber, and Position
B goes to Position B on the other fiber of the fiber pair (figure
3).The A-to-A duplex patch cords shall be clearly identified (by
color or prominent labeling) to distinguish them from A-to-B patch
cords.
NOTE SC connectors are shown, but this assembly may be built
using any duplex single-fiber connectors or connectors with two
fixed fibers.
Figure 7 - A-to-A duplex optical fiber patch cord
5.4.3.3 TransitionAs shown in figure 5, transitions have a
sequential number assigned to each fiber as follows:
a) On one end of the transition the fibers are fixed within the
array connector in consecutive number (1,2,3,412) from left to
right as viewed looking at the end-face of the connector with the
connector key up.b) On the other end of the transition the fibers
are fixed within the connectors in consecutive numbering (1,2; 3,4;
5,611,12) from left to right as viewed looking through the adapters
with the adapter key up.
Figure 8 - Array optical fiber transition
NOTES
1 SC connectors are illustrated; however this assembly may use
single-fiber connectors or connectors with two fixed fibers.
2 For ease of illustration, this transition is shown with duplex
adapters, although they are not necessarily part of the
assembly
6FIBRE PATCH CORDS
6.1 Bend Radii
Due to the sensitivity of most Fibre the bend radii is different
to that of copper. The bending radius is defined as a
multiplication factor of the outside cable diameter. There are two
relevant minimum bending radii: one for patch cord installation and
one for the patch cord once it is installed (without mechanical
load).
It is important to note that the minimum permissible bend radii
of a cable is greater during the installation / pulling in stage,
when the cable is under tension, than it is when the cable is
placed in its final position and is free from tension. This
criteria is also applicable when installing/dressing patch
cords.
Minimum bend radii must be observed throughout the whole cable
route in order to ensure that the design performance of the cable
is not impaired. (IRXRXR = min radius during installation15 x
sheath diameterIR= min radius installed10 x sheath diameter)
It is also important to consider bend radii when determining the
size of containment systems such as basket tray, conduit or
trunking, as the system may have adequate capacity for the straight
runs but be too small at the turns for the minimum bend radii to be
observed. Tray work should have gussets fitted to the inside edge
of corners and conduit systems constructed to ensure that minimum
bend radius is not infringed.
The same applies to containment within cabinets, around frames
and between patch panels.1. 2. 3. 4. 5. 6. 6.1. 6.2. Optical
Losses
All optical fibres exhibit some loss or attenuation of the
transmitted signal, much of this loss is intrinsic, that is due to
the glass itself. However other conditions such as excessive
bending connectors and splices also contribute to the loss.
6.2.1. Macro Bending
Macro bending loss shows up when fibre bend radius decreases, as
the bend gets tighter light rays within the fibre begin reflecting
at angles allowing them to pass through the cladding. The more the
fibre is bent the higher the attenuation.
6.2.2. Micro Bending
Micro bending losses are caused by from stresses on the fibre
such as tight clamps and tie wraps pressing against the fibre. They
can also be caused by deviations in the core, measured from the
axis of the fibre.
6.3 Polished ends
There are 2 main typed of polished end for Fibre connectors, see
below. The Polished Connector (PC) is commonly used in Multimode
cables and the Angled Polished Connector (APC) is an option with
the singlemode connectors.
6.3.1Polished Connector (PC)
6.3.2Angled Polished Connector
6.4Fibre Types
Brand-Rex manufacture all types of Fibre Optic cable that may be
required in the DataCentre. Below is a table highlighting the types
available. Fibre Patch Cords are available in any fibre type.
OM1OM2OM3OM4OS1OS2
62.5/12550/12550/12550/1258/258/125
62.5/125 was the industry standard 10 years ago however OM3 has
now become the customer choice as it more than meets the
requirements of todays network infrastructure.
As network demands are increasing the use of OM4 fibre is
becoming more popular.
NOTE: Make sure that the correct choice of cable is made when
purchasing new Fibre patch cords. If possible try to keep a
standard across your site to avoid future confusion.
6.5Connector Types
Over the years there have been many different types of connector
used to terminate the fibre optic cable. Below is a list of some of
the more popular. Just as 62.5/125 multimode fibre was the most
commonly installed cable, the SC connector was the most
popular.
The LC connector is now the preferred connector for all new
installations. However legacy cabling and equipment mean that you
may need a cable to convert from one type to another, see section
6.4 for the types available.
6.6Patch Cord Types
6.6.1Simplex
Simplex is usually used to describe a single strand of Fiber
Optic cable. This is sometimes used when a signal only needs to go
in one direction, like a simple video feed from a security
camera.
6.6.2Duplex
Duplex (sometimes called "zipcord") is two strands of Fiber
Optic cable joined by a thin connection between the two jackets.
This is much more commonly used than simplex as with two fibers you
can get synchronous communication between devices. Duplex cables
are often labeled with A and B to determine which is the transmit
and which is the receive.
6.7Hybrid Patch Cords
As explained in section 6.3 is may be likely that you will need
to convert from one connector to another when patching a circuit.
It may be because you have an LC presentation for your cabling
infrastructure and your equipment only has SC or ST connectors. If
the ports on your equipment are modular, it may be best to upgrade
to the LC module to try and keep the requirements for patching
infrastructure as simple/standard as possible.
Brand-Rex manufacture all cable varieties below and in a range
of lengths. 1m, 2m, 3m and 5m are the standard lengths however
different sizes can easily be supplied.
Cable Varieties (Duplex)
LC-LCSC-STST-STFC-FC
LC-SCST-MTRJMTRJ-SCSC-SC
LC-MTRJMTRJ-MTRJLC-STMTP-MTP
6.8Fibre Breakout Cables
Although not really a patch cable, Fibre breakout cables are
being use more commonly in the data centres as part of the new MTP
design. A 12 core cable between point A and B can be installed and
then a breakout assembly connected via an MTP connector. Therefore
a fibre core can easily be patched to 6 LC duplex ports on a piece
of equipment.
This is a simple way to install 12 cores using a plug and play
design, removing the need to field terminate or splice on site.
6.9Secure Fibre Patching
Secure Fibre patching is a new product from Brand-Rex which
gives you the opportunity to lock patch cords in place or block
ports that you dont want used. This product has a high value in
secure customer environments or for important/critical circuits
that should not be accidently disconnected.
7 OPTICAL PATCH CORD MAINTENENCE
It is highly important to ensure you have a clean Fibre Optic
infrastructure. Cleaning new and existing patch cords before each
insertion into a coupler is critical. There are also methods of
cleaning the fibre coupler to guarantee you are maintaining your
physical network in the best possible way.
Section 7 highlights some of the products that can be used to
maintain your fibre network.
7.1 Lint Free Wipes
Lint free wipes are one of the most basic methods of cleaning
your fibres, Lint free and non abrasive to ensure you are left with
a clean fibre. To be used with IPA solution.
7.2Individual Pre-saturated IPA Wpies
IPA wipes provide the same solution as the Lint Free wipes above
but are supplied pre-saturated for convienience.7.3Optical Fibre
Cleaning Cassette and Tape
Great alternative to alcohol or other cleaning solutions. Offers
lint-free, clean room grade cleaning media which effectively
removes dirt, dust, oil, grease and debris from connector end
faces. Resilient rubber pad beneath the cleaning surface prevents
scratching. Sliding cover protects the cleaning media from
contamination when not in use. Reel refills available.
7.4Swabs
Used for cleaning connector ferrule end faces, adaptors and
difficult areas.
7.5Ferrule cleaner
Easy pushing motion engages connector and initiates cleaner.
Minimum of 800 cleans Made from anti static resin Cleaning micro
fibers are densely stranded and debris free. Extendable tip allows
acces to hard to reach recessed connectors. Cleaning system rotates
180 degrees for optimim cleaning. Audible click to inform when
engaged. Compliant with EU/95/2002/EC Directive(RoHS). Effective
with a variety of contaminants.
8 OPTICAL PATCH CORD TESTING
8.1Optical Microscope
Optical microscopes come in a variety of shapes and sizes.
Pictured above is an example of 2 portable units. Each have
connectors that can be easily changed to suit the type of fibre
connector being checked.
When looking through the microscope you should be looking for
obvious signs of dirt and contaminants. After the connector has
been cleaned you should see a perfect surface.
Section 8.2 indicates some of the more severe faults that can be
found when viewing the connectors.
Before CleanAfter Clean
Without the use of a microscope it may be that by blowing on the
connector or rubbing it on your shirt may be good enough but such
actions lead to the image on the left. By using the microscope its
clear to see the contaminants on the surface. A clean or maybe a
re-polish may be needed to bring this connector up to spec.
8.2Types of Fibre Faults
8.2.1Chip (These show up as dark areas off to one side of the
fibre. They are usually caused by poor cleaving of the excess
fibre, resulting in a crack extending beneath the connector end
face. Because the ceramic is harder than the fibre, this section of
the fibre cannot be polished and so remains dark. Acceptance: Chips
on the core or on the inner cladding are unacceptable. Chips in the
outer cladding region extending more than 25% round the
circumference are also unacceptable. )
8.2.2Crack
(Dark lines, often going straight through the middle of the
core, or looking like crazy paving indicate cracks. These often
show up more clearly when the connector is back illuminated. These
cracks are caused by excessive heating or uneven curing of the
epoxy resin. They are rarely seen when a properly temperature
controlled curing oven is used, but are much more common if heat
guns are used. Acceptance: Cracks on the core or on the inner
cladding are unacceptable. Cracks in the outer cladding region
extending more than 25% round the circumference are also
unacceptable. )
8.2.3Scratch
(When multiple lines run parallel to each other this usually
indicates that the end face is scratched. This may be due to dirt
and dust contaminating the polishing paper, or by neglecting to
clean the polishing puck and connector face when moving from a
coarse grade of lapping film to a finer one. Acceptance: The core
should be free from scratch defects. )
8.2.4Broken Fibre
(If the fibre is broken, no light will get through. This will
result in a dark ring from the cladding to the core of the
fibre.Acceptance: Broken fibres are unacceptable. )
If further assistance/guidance is required then please contact
our Technical support team on [email protected] and your
enquiry will be dealt with promptly with a relevant engineer
assigned. More information on everything from Datasheets and White
Papers to our latest training videos can also be found on the
Brand-Rex website www.brand-rex.com.
(BR_TSS_Patch_Cable_Installation_Practices) April 2012 Page 1 of
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