FiberGuard®
White Paper
June 2008
www.commscope.com
Where is FiberGuard installed?
What is FiberGuard®? FiberGuard
is a fiber optic cable enclosed in
an interlocking aluminum armor
with an overall jacket. The fiber
optic cable may be any riser and
plenum distribution style cables
FiberGuard should be installed anywhere the fiber cable needs extra protection. FiberGuard
provides increased physical protection to the cable versus innerduct. In this climate of increased
awareness for security in the corporate network infrastructure, aluminum armor provides superior
protection versus plastic (see Exhibit 1). The interlocking armor in FiberGuard will provide
protection from over bending and excessive pull tension of the fiber cable during the installation
process – two problems which account for many fiber optic cable failures. FiberGuard may also
be used to provide better utilization of the pathway space by eliminating the need for innerduct.
Clogged pathways in existing buildings are a significant hurdle when installing Moves-AddsChanges (MACs). FiberGuard solves this age-old problem.
FiberGuard may provide labor and cost savings for an installed fiber cable system. There is
a significant time and labor reduction when installing FiberGuard as compared to installing an
EMT conduit system or innerduct.
What are some FiberGuard applications?
•Commercial Office building backbone, zone distribution, transition of shared tenant spaces,
or under a raised floor
manufactured by CommScope
•Hospitals where fiber based media are used for new diagnostic equipment or in the
backbone for hospital network
(NEC article 770).
•Schools for the backbones to incorporate distance learning centers, computer labs, or
anywhere the fiber cable may need protection for security reasons
•Industrial environments, where the fiber cable needs extra protection, when connecting to
plant equipment where damage to the cable may occur, or to replace copper media with
fiber to eliminate EMI concern
Does FiberGuard need to be tested when it is received?
FiberGuard product will arrive at your location like any other cable, on a reel. Once the reel is
received you should verify the integrity of the fiber. CommScope tests fiber optic cable prior to
shipment and the test report for that cable is available from our web site via WebTrak. However,
damage may occur during shipment.CommScope recommends testing the fiber cable for integrity
when it is received. This test may be as simple as using a laser fault identifier (high power visible
light source) and checking the cable for continuity or you may test for attenuation or test the cable
with an OTDR. However, testing for attenuation or OTDR testing will require termination or the use
of a Bare Fiber Adapter.
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How is FiberGuard installed?
FiberGuard can be installed like any fiber optic cable installation. Reference the FiberGuard
Installation Guide for more information.
Remember, the armor may not have to extend to the termination point of the fiber cable inside the
Telecommunications Room. The end point of the armor will depend upon the entrance point inside
the Telecommunications Room, the location of the equipment rack within the room, the number of
FiberGuard runs, and the need for service loops.
If the plan is to use the fiber distribution box for connection and an equipment ground, check the
box for sufficient pre-punched knockouts or room to punch knockouts in the field.
When preparing or cutting a length of FiberGuard for installation, use an MC cable cutter to
cut the armor. Never use a hydraulic cutter because this will crush the armor and damage the
cable inside.
How often should the cable be secured in horizontal runs?
Horizontal runs must be supported at 4 to 5 foot intervals. The following may be used to secure
and support the cable: EMT straps, *Caddy™ clips, J-hooks, D-rings, or other equivalent supports.
How are the cables secured in a vertical application?
Care must be taken to ensure the cable is properly supported and not have the weight of the fiber
cable resting on the connectors. A service loop in a straight vertical run of one every 70 to 90
feet is desirable. The cable should be supported at 4 to 5 foot intervals.
Which connectors are used for FiberGuard?
When choosing a connector, the armor O.D. is the controlling factor. The jacket is not a factor
because it will be stripped away to expose the metal for bonding purposes.
•Cable O.D. of .535 or less can use; AFC-50, Arlington L-42, Bridgeport 403-DC2
•Cable O.D. of .795 or less can use; AFC-75, Arlington L-421, Bridgeport 407-DC2
•Cable O.D. of .80 to 1.00 can use; Arlington L-422, Bridgeport 408-DC2
•Cable O.D. of 1.00 to 1.30 can use; Arlington L-423, Bridgeport 410-DC2
•Or any NEC approved MC connector
How is the AFC 50/AFC75 connected to armor with an overall jacket?
Once the armor length has been determined, strip the armor jacket (see “How is the overall jacket
removed?” below) back at least 1.5” for the AFC 50 and 1.75” to expose bare armor. Attach
the connector to the exposed armor. This will serve as an equipment ground when entering a
grounded distribution box.
How is the overall jacket removed?
Make a ring cut in the jacket at the point where it is to be removed. Make a second cut along
the armor from the ring cut to the end of the cable. The jacket is then easily removed to expose
the armor.
How is the armor and cable cut?
Using a MC cable cutter, place the cable in the cable guide, adjust as necessary and rotate the
handle until the armor is cut. The MC cutter is designed to cut through with only one revolution of
the cutter to protect the fiber cable inside. Separate the armor ends and then use the fiber shears
to cut the fiber cable.
*Caddy™ is a trademark name of Erico International Corporation.
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Should FiberGuard be grounded?
The simple answer is YES. FiberGuard must be bonded to ground. When the cable run is started
and terminated in a metal distribution box, the NEC approved MC connector will serve as the
bond. Remember the metal distribution box must be bonded to ground. If the armor is stopped
short of a metal box at least one end must be grounded. One method is using a piece of 15/8”
x 15/8” U shaped metal strut. Mount a ground lug to the strut and attach a separate ground
wire and use a strut clamp to secure the FiberGuard run to the strut. The ground wire should be
ran to the Telecommunications grounding bus bar.
Multiple FiberGuard runs entering the Telecommunication Room can be handled by using
a 15/8” x 15/8” metal strut. The strut can be field modified to the length necessary to
handle the number of FiberGuard runs necessary for the installation at that location. Mount a
ground lug to the strut and attach the ground wire (recommend a minimum of 6 AWG) to the
Telecommunications grounding bus bar.
Designing the cable plan using FiberGuard
Remember, when designing a cable plant with conduit for the fiber optic cable runs, use
FiberGuard and save time and money. If the fiber optic cable is going to be installed in the “red
iron”, FiberGuard will provide extra protection. Also, the armor carries more of the stresses of the
installation and support the fiber optic cable. Compared to installing innerduct in existing duct
work and then pulling in the fiber optic cable, FiberGuard will provide a time and cost savings.
FiberGuard is an excellent solution when installing a fiber cable in an existing cable plant.
Labor Units
On new construction, contractors who were surveyed typically reported labor units in the
11 to 15 hour per thousand-foot range. See “You Do The Math” on the back cover.
Code References
The National Electrical Code section that deals with optical fiber is Article 770:
•770.5 B defines FiberGuard® as conductive because of the aluminum armor.
•770.50 Cable markings will be either OFCP, OFCR or OFC
•770.51 Listing Requirements
•770.52 Installation of Optical Fiber section (c) grounding
•770.53 Applications of Listed Optical Fiber Cables
Other code sections of interest are:
•330 Metal-Clad Cable: Type MC (334 in the 1999 edition)
•645 Information Technology Equipment
For hazardous locations, see Articles 501, 502, 503, 504 and 505.
This is not a flexible metal conduit, nor is it a liquid tight conduit. This is a factory assembled
“cable assembly” and listed per Article 770.51 of the NEC.
Summary
FiberGuard will reduce the installed cost of fiber cabling while providing greater protection during
the installation process and better utilization of the pathway space available. It also increases
design flexibility, versus a metal conduit system, for last minute changes and provides more
physical protection for critical fiber optic cable runs.
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Fiber Optic Premises Distribution Cable Standard:
ANSI/ICEA S-83-596-1994
All Fiber Counts
Standard Requirement
Standard Aluminum
10.0 N/mm (57 Lbf/in)
85 N/mm (485 Lbf/in)
Fiber Optic Outside Plant Cable (non-armored type):
ANSI/ICEA S-87-640-1992
All Fiber Counts
Standard Requirement
Standard Aluminum
22 N/mm (126 Lbf/in)
85 N/mm (485 Lbf/in)
*Note: Figures are derived from testing performed according to FOTP-41 in TIA/TIA-455-41A standards.
Some modifications to FOTP-41 had to be made to accommodate the test environment.
You Do The Math
Since labor rates and material cost vary from region to region, CommScope has provided the
following worksheet to allow customers to compare the cost of installing FiberGuard versus
conduit or interduct.
Step 1: Call your CommScope distributor for pricing for FiberGuard and a comparable fiber
optics cable.
Step 2: Insert the materials cost into the worksheet.
Step 3: Insert the labor rate (hourly rate x hours) for installation
Step 4: Total cost.
Installation
of FiberGuard
Installation
of Fiber Cable in Conduit
Installation
of Fiber Cable in Interduct
Materials
FiberGuard $
Materials
Conduit $
Fiber Cable $
Materials
Interduct $
Fiber Cable $
Labor (Hours X Rate)
Install FiberGuard $
Labor
Install Conduit $
Install Fiber Cable $
Labor
Install Interduct $
Install Fiber Cable $
Total $
Total $
Total $
We think you will find that installing FiberGuard versus conduit or interduct and cable will save
you money. You do the math!
www.commscope.com
Visit our Web site or contact your local
CommScope representative for more information.
© 2011 CommScope, Inc. All rights reserved.
All trademarks identified by ® or ™ are registered trademarks
or trademarks, respectively, of CommScope, Inc.
This document is for planning purposes only and is not
intended to modify or supplement any specifications or
warranties relating to CommScope products or services.
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