COE Installation Quality Bulletin
Installation Quality Bulletin Number: 06-04
To: All Installation Service Suppliers / Central Office
Operations Representatives / Design Engineering Representatives /
Quality Managers / Field Engineering Representatives / AMC
Representatives
Date: Friday, March 31, 2006
From: QWEST Installation Quality Assurance
Subject: Fiber Optic Cable Rack: Proper Use of Transition
Brackets
Action Required:
NO:
YES:

Description of Bulletin:
The purpose of this Quality Bulletin is to clarify engineering and installation information for use
of a Qwest-approved fiber optic cable rack transition bracket in the central office environment.
The Qwest-approved Newton® fiber transition bracket, (Part No. 2-199930285) may be used at
the discretion of Design Engineering, on a restricted basis, while adhering to the rules listed
below. Substitutions of this bracket with any unapproved bracket, or the use of any other fiber
optic cable transition bracket, is strictly prohibited.
Transition Bracket Application Requirements

Fiber optic cable transition brackets are approved to support fiber optic cable
exiting the horizontal fiber optic ladder-type cable rack and dropping vertically
into equipment bays.

Placement of fiber optic cable rack transition brackets above Fiber Distribution
Frames (FDF) is strictly prohibited due to the ultimate cable capacity and
congestion at the FDF.

These transition brackets are designed to ease cable stress where fiber optic
cables break off of the cable rack stringer and to horizontally extend the last
cable securing point before dropping vertically into an equipment bay.

The primary application for the fiber optic cable transition bracket is in the 7-ft.,
floor-supported central office environment where the orange-colored, “Fiber
Optic Cable Only” cable rack is centered in the front (or rear) aisle of an
equipment lineup at a height of 9’-6”. Care must be taken to position the
transition brackets so that they don’t inadvertently impede HVAC ventilation
required for front-aisle equipment cooling.

Placement of the fiber optic cable transition brackets in existing 11’-6” and 9-ft.
(and non-standard 7-ft.) environments is restricted due to space limitations,
existing cable rack location, cable pileup, ventilation ductwork, and the restricted
access to high level ironwork (e.g., ceiling supports and/or auxiliary framing).
Transition Bracket Description
PART No. 2199930285
STOCKLIST
Item Qty.
2
1
4
2
1
3
4
4
AR
5
Description
10-32 X ½ TYPE F HEX HD CAP SCR SS
WIRE / CABLE DISTRIBUTION SPOOL
CABLE RACK SIDE DROP-OUT 2.00
THREADED ROD CAP (not shown)
SERRATED GROMMET 13”
SK-A

Transition brackets are made of steel, painted orange, sized for cable rack with a
2-in. stringer, and can be ordered individually from Newton (CLMC = NNIT) with
part number 2199930285. Refer to SK-A.

The transition brackets attach to the cable rack stringer and are positioned where
fiber optic cables feed into the equipment frame. Refer to SK-B
Rules for Use

Fiber cables (single, dual, quad, and 12-fiber) must be wrapped with sheet fiber
paper, bundled together, and secured with No. 9 lacing cord to the holes
provided in the curved portion of the bracket.

Where obstructions will interfere with the use of fiber optic cable transition
brackets, the transition brackets from horizontal cable rack to vertical fiber duct
will be installed using the currently-approved method. The fiber optic cables
(single, dual, quad, 12-fiber) must still be bundled together, wrapped with sheet
fiber paper, and tied to the cable rack stringer at an angle (where necessary) so
as not to violate the minimum bend radius of the fiber cable.

Fiber optic cable transition brackets must not be placed:
º Where access to any existing cable rack(s) or ceiling access will be inhibited.
º Where placement of the brackets will block installation of future cable support
systems of any type (e.g., fiber optic cable duct, cable rack, etc.)
º Directly in the path of heating/cooling ventilation ductwork.

Due to the ultimate volume of fiber optic cabling above the Fiber Distribution
Frame, the transition brackets are not approved for placement on the fiber optic
cable racks located above the FDF. The maximum 7” fiber optic cable pile up on
the cable racks above the FDF would exceed the height of the bracket’s 2.96”
cable distribution spools.

A side-view depiction of the transition bracket is located in the diagram section of
the Fiber Optic Cable Standard Configuration Guides under the heading, “Fiber
Cable Rack Transition Bracket – Not Approved above FDF.” Refer also to SK-B.
SK-B
2.96"
4.09"
6.18"

Because of the overall size of the transition bracket (9.14” – measured from the
inside of the cable rack stringer to the top of the horizontal cable distribution
spool), placing it on a 5” or 12” ladder-type fiber optic cable rack is prohibited
without the approval of the Architecture, Models, and Configuration (AMC) author
prior to installation.

One transition bracket will be placed on the cable rack above two adjacent fiber
optic equipment frames to accommodate the fiber optic cable for both frames. A
dedicated fiber optic transition bracket for each individual equipment frame will
not be required due to the 7-1/2” width of the bracket, limited space, and fiber
optic cable bend radius requirements.

Placement of the transition brackets shall not push the fiber optic cabling beyond
the entrance into the frame or cabinet. The fiber optic cabling should make a
smooth transition into the equipment (maintaining the minimum bend radius).

Fiber optic cable must not drop more than 3-ft. unsecured from the cable rack
break-off point to the top of the equipment frame without the placement of an
interim securing tie point to provide strain relief.
Acknowledgements to Diana Unser, (Qwest AMC) for her contribution to the technical content
of this Bulletin.
Qwest Installation Quality Assurance
Jeff Bostow
612-798-2460
mailto: jbostow@qwest.com