COE Installation Quality BulletinInstallation 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 : YES: NO: 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 DescriptionPART No. 2199930285

STOCKLISTItem

Qty.

Description

1 2 10-32 X ½ TYPE F HEX HD CAP SCR SS2 4 WIRE / CABLE DISTRIBUTION SPOOL3 1 CABLE RACK SIDE DROP-OUT 2.004 4 THREADED ROD CAP (not shown)5 AR 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

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 AssuranceJeff Bostow612-798-2460mailto: jbostow@qwest.com