SECTION 27 0532

Communications Ladder Rack

Part 1 - General

1.1 Description of Work

The work of this Section consists of providing all labor, materials, and equipment for the complete installation of a ladder rack type cable management system for support of communications cabling.

1.2 Related Work

See the following specification sections for work related to the work in this Section:
1. 27 0500 General Requirements for Communication Systems
2. 27 0526 Grounding and Bonding

1.3 Standards and Codes

Work and materials shall be in compliance with and according to the requirements of the latest revision of the following standards and codes:
1. Telecommunications Industry Association / Electronic Industries Alliance (TIA/EIA):
  1. 568-C.0-2012: Generic Telecommunications Cabling for Customer Premises
  2. 568-C.1-2012: Commercial Building Telecommunications Cabling Standard
  3. 568-C.2-2010: Balanced Twisted-Pair Telecommunications Cabling and Components Standards
  4. 568-C.3-2011: Optical Fiber Cabling Components Standard
  5. 568-C.4-2011: Broadband Coaxial Cabling and Components Standard
  6. 569-C-2012: Telecommunications Pathways and Spaces
  7. 606-B-2012: The Administration Standard for the Telecommunications Infrastructure of Commercial Buildings
  8. 607-B-2011: Telecommunications Bonding and Grounding (Earthing) for Customer Premises
  9. 942-A-2012: Standard for Data Centers
2. California Electrical Code (CEC)
3. Building Industry Consulting Service International (BICSI) Standards:
  1. Telecommunications Distribution Methods Manual, 10th Edition
4. National Electrical Manufacturers Association (NEMA):
  1. NEMA VE-1, Metal Cable Tray Systems
  2. NEMA VE-2, Metal Cable Tray Installation Guidelines
5. System shall be Underwriters Laboratories (UL)

1.4 Quality Assurance

Strictly adhere to all Building Industry Consulting Service International (BICSI), Electronic Industries Alliance (EIA) and Telecommunications Industry Association (TIA) recommended installation practices when installing communications/data cabling.

1.5 Submittals

As specified in Division 01 and Section 27 0500.
Single Submittal: A single complete submittal is required for all products covered by this Section.
Catalog Data: Provide manufacturers data/cut sheets, product drawing/specifications and installation instructions for all products.
Shop drawings shall be provided for the layout of the tray, associated supports, and seismic supports. Provide seismic bracing and calculations as necessary. Drawings to show interrelationships with ductwork, conduit racks, piping, structural members, etc.
Drawings to show all sleeves required whether shown on the contract documents or not.

Part 2 - Products

2.1 Ladder Rack, Supports and Accessories

Provide all components of the ladder rack system (ladder rack, turns, splices, supports, and accessories) from a single manufacturer.
Finish shall be gray epoxy-polyester hybrid powder coat paint.
Ladder Rack:
1. Ladder rack shall be manufactured from tubular steel. Stringers (sides) will be made from 3/8” wide by 1-1/2” high tubular steel with 0.065” wall thickness. Cross members (rungs) will be made from 1” wide by .” high tubular steel with 0.065” wall thickness.
2. Ladder rack (stringers) will be 9’-8. “ long. Cross members will be welded in between stringers on 9” centers beginning 4-1/4” from one end so that there are thirteen cross members per ladder rack. There will be 8” of open space in between each cross member.
3. Manufacturer: Chatsworth Products, Inc., TELCO-Style Cable Runway, 11252 Series or approved equal.
Horizontal 90° Turns:
1. Horizontal 90° turns shall be manufactured from 3/8” wide by 1-1/2” high tubular steel with 0.065” wall thickness.
2. Stringers (sides) will be formed in a 90° arc. Cross members will be welded in between stringers on approximate 23° increments so that there are 5 cross members per turn. The welded assembly will have a 15” inside radius and will create a smooth horizontal 90° turn.
3. Manufacturer: Chatsworth Products, Inc., Cable Runway E-Bend, 10822 Series or approved equal.
Vertical-To-Horizontal 90° Turns:
1. Vertical-to-horizontal 90° turns shall be manufactured from 3/8” wide by 1-1/2” high tubular steel with 0.065” wall thickness.
2. Stringers (sides) shall be formed in a 90° arc with a 12-1/2” outside radius. Cross members will be welded in between stringers on approximate 23° increments so that there are 3 cross members per turn. The welded assembly will create a smooth 90° vertical-to-horizontal turn.
3. Manufacturer: Chatsworth Products, Inc., Cable Runway Outside Radius Bend, 10723 Series or approved equal.
Horizontal-To-Vertical 90° Turns:
1. Horizontal-to-vertical 90° turns shall be manufactured from 3/8” wide by 1-1/2” high tubular steel with 0.065” wall thickness.
2. Stringers (sides) shall be formed in a 90° arc with a 12-1/2” outside radius. Cross members will be welded in between stringers on approximate 23° increments so that there are 3 cross members per turn. The welded assembly will create a smooth 90° horizontal-to-vertical turn.
3. Manufacturer: Chatsworth Products, Inc., Cable Runway Inside Radius Bend, 10724 Series or approved equal.
Corner Brackets:
1. Corner brackets shall be manufactured from 3/8” wide by 1-1/2” high tubular steel with 0.065” wall thickness.
2. The inside stringers of the corner bracket shall be formed at 90° with a small chamfer at the vertex. The outside stringer of the corner bracket shall be formed in a 90° arc that is either 15” or 24” in radius. A single cross member will connect the chamfered portion of the inside stringer to the outside stringer. The welded assembly shall create a smooth 90° turn within the L-shaped corner created by two intersecting ladder racks.
3. Corner brackets will be available in the size(s) specified below. Installation hardware will be included with the corner bracket. Corner bracket installation hardware does not include the junction splice kit required to form the L-shaped intersection between two ladder racks.
4. Manufacturer: Chatsworth Products, Inc., Cable Runway Corner Bracket, 11959 Series or approved equal.
Ladder Rack Splices:
1. Splice kits shall provide a method of mechanically connecting ladder rack sections and turns together end-to-end or side-to-end to form a continuous pathway for cables.
2. Grounding kits shall provide a method of bonding ladder rack sections and turns together that is independent of the pathway splices. The grounding kit shall be constructed of UL Listed components. Utilize a #6 AWG green insulated stranded copper conductor connected on both ends to ladder rack using two-hole compression lugs and stainless steel hardware.
3. Splices (splice plates) will be manufactured from steel. Splice, grounding and insulator bar kits will include installation hardware.
4. Manufacturer: Chatsworth Products, Inc., Runway Splice and Grounding Kits, 11298, 11299, 12061-001 or approved equal.
Ladder Rack Supports:
1. Provide supports as recommended by the manufacturer.
2. Supports shall be sized to match the width of the ladder rack that is supported.
3. Each support will include a means of securing ladder rack to the support.
4. Supports shall be manufactured from steel or aluminum.
Ladder Rack Accessories:

Provide accessories as recommended by the manufacturer.
Cable straps used for attaching cable bundles to the ladder rack cross members must be reusable with a hook and loop-style closure, at least 3/4" wide, and sized for cable bundles that are 2”, 3” or 4” in diameter.
Cable retaining posts used to keep cable from falling off of the side of the ladder rack shall be manufactured from 1” by .” tubular steel with 0.065” wall thickness. Cable retaining posts will be 8” high and will attach to the side stringer of the ladder rack with included hardware. The top of the cable retaining posts will be fitted with a rubberized end cap to protect cables.
End caps used to cover the ends of ladder rack will be manufactured from a black fire-retardant rubberized material. End caps will be sized for 3/8” wide by 1-1/2” high side stingers and will be sold in pairs.
End closing kits used to cover the end of ladder rack will be manufactured from 3/8” wide by 1-1/2” high tubular steel with 0.065” wall thickness. Kits will consist of a bar cut to match the width of the ladder rack and the hardware required to attach the bar to the end of a length of ladder rack.
Radius drops used to create a radius to form cables over as the cables exit or enter the ladder rack will be manufactured from aluminum extrusion. The extrusion will be formed in a 90° arc with a minimum bend radius of 3”. Radius drops will attach to either the side stringer or the cross member of the ladder rack using a clevis pin. Radius drops will include 1-1/2” high cable spools that attach to the top of the radius drop to guide cables.
Movable cross members used to support cross member radius drops in between welded cross members on ladder rack will be manufactured from 3/8” by 1-1/2” aluminum bar. Movable cross members will attach to ladder rack at the side stringers with included hardware so that the location of the movable cross member can be adjusted. Moveable cross member will support a cross member radius drop.
Cable spools used to separate ladder rack into multiple cable pathways will be made from a black flame retardant ABS. Cable spools will attach to the cross members with a clip that allows the width of the ladder rack to be divided into any proportion. The spools will be 3.94” tall, with a 1.94” diameter top, and a body that tapers from 0.88” (diameter) at the top to 0.62” (diameter) at the bottom.
Auxiliary support brackets used to support cables that should be physically separated from the cables in the ladder rack will be made from 1/8” x 1” steel bar. The bracket will be L-shaped and will attach to the side stringer of the ladder rack. The bracket will hang below the ladder rack a minimum of 4”. The bracket support surface will be 4” long. The bracket will be zinc plated with a gold chem. finish.
Touch-up paint used on ladder rack and ladder rack system components will be color-matched to the finish on the ladder rack or component. A spray on and brush on option will be available.

Part 3 - Execution

3.1 Installation

All cable and equipment shall be installed in a neat and workmanlike manner.
Ladder rack shall be installed with side stringers facing down so that the ladder forms an inverted U-shape and so that welds between the stringers (sides) and cross members (middle) face away from cables.
Ladder rack shall be secured to the structural ceiling, building truss system, wall, floor or the tops of equipment racks and/or cabinets using the manufacturer’s recommended supports and appropriate installation hardware and methods as defined by local code or the authority having jurisdiction (AHJ).
Ladder rack splices will be made in mid-span, not over a support, with the manufacturer’s recommended splice hardware.
Ladder rack shall be supported every 5’ or less in accordance with TIA-569-B. Ladder rack shall be supported within 2’ of every splice and within 2’ on both/all sides of every intersection. Support ladder rack within 2’ on both sides of every change in elevation. Support ladder rack every 2’ when attached vertically to a wall.
Heavy-duty splices are required for ladder rack in excess of 18” width (18” wide ladder rack). Heavy-duty splices are required for any splice formed in the vertical orientation including changes in elevation formed using vertical-to-horizontal 90° turns or horizontal-to-vertical 90° turns. Use heavy-duty splices to secure all overhead turns to the overhead horizontal pathway(s).
The quantity of cables within the ladder rack will not exceed a whole number value equal to 50% of the interior area of the ladder rack divided by the cross-sectional area of the cable. The interior area of ladder rack will be considered to be the width of the ladder rack multiplied by a height of 2”, unless cable retaining posts are added to the ladder rack. The interior area of ladder rack equipped with cable retaining posts will be considered to be the width of the ladder rack multiplied by a height of 6”. Actual cable fill for ladder rack that is not equipped with cable retaining posts will not exceed 2” in height. Actual cable fill for ladder rack equipped with cable retaining posts will not exceed 6” in height. For applications in wiring closets, dressed bundles of cable shall be one row in height.
The combined weight of cables within the ladder rack will not exceed the stated load capacity of the ladder rack as stated in the manufacturer’s product specifications or load/design tables.
Cables (cable bundles) will be secured to the cross members of ladder rack with 3/4" wide reusable straps. Straps are not required when ladder rack is equipped with cable retaining posts.
Add 8” high cable retaining posts to the open sides of ladder rack when cable fill exceeds 2” in height or when cable bundles cannot be secured directly to the ladder rack cross members with a strap. Cable fill within any ladder rack should not exceed 6” in height.
When a single ladder rack supports different types of cable media, the cable media will be separated within the pathway by cable spools that attach to the cross members on the ladder rack. Treat each type of cable media and divided area of the ladder rack separately when determining cable fill limits.
Use a radius drop to guide cables wherever cable exits overhead ladder rack to access a rack, cabinet, wall-mounted rack, or termination field. Provide a moveable cross member also to attach and align the radius drop in between the welded cross members of a ladder rack.
Cover the exposed ends of cable runway that do not terminate against a wall, the floor or the ceiling with end caps or an end closing kit.
Use auxiliary support brackets that attach to the side stringer of the ladder rack to support interconnect cabling (patch cords, equipment cords, jumper cords) that is routed between racks using the ladder rack. Auxiliary support brackets can be used to support other conductors that should be physically separated from cables within the ladder rack as defined by local code or the authority having jurisdiction (AHJ).
The installer will provide touch-up paint color-matched to the finish on the ladder rack and will correct any minor cosmetic damage (chips, small scratches, etc.) resulting from normal handling during the installation process prior to delivery to the owner. If a component is cosmetically damaged to the extent that correction in the field is obvious against the factory finish, the component will be replaced with a new component finished from the factory. If a component is physically damaged due to mishandling or modification during the installation process, it shall not be used as part of the ladder rack system.

3.2 Penetrations of Fire Rated Assemblies

Provide UL listed fire stopping to maintain rating for penetration of fire rated assemblies.
All tray penetrations thru fire rated assemblies must be installed with appropriate frames and re-enterable “pillows” to allow fire-seal around the cables after they are installed.
This contract is to include the installation of the “pillows” after the cable installation is completed, tested, and accepted by the owner.
The use of tray-based mechanical fire stop systems instead of transition to conduit is required when the tray must penetrate a fire barrier.
All sleeve penetrations thru fire rated assemblies are to extend on either side of the assembly per fire stopping manufacturer’s recommendations.
1. Exterior of sleeves are to be fire stopped prior to the fire rated assembly being painted and the fire stopping validated by the inspector of record.
2. The interior of sleeves are to be fire stopped under this contract after the cable installation is completed, tested, and accepted by the owner.

3.3 Bonding

Within each telecommunications room, ladder rack should be bonded together, electrically continuous, and bonded to the Telecommunications Grounding Busbar (TGB), unless otherwise noted in the specifications and contract documents. Ladder rack and turns shall be bonded across each splice with a bonding kit. Ladder rack shall be bonded to the TGB using an approved ground lug on the ladder rack and a minimum #6 grounding wire or as required by the AHJ. Remove paint from the ladder rack where bonding/ground lugs contact the ladder rack so that the lug will contact bare metal. Use antioxidant joint compound in between the bare metal on the ladder rack and ground lug. Use antioxidant joint compound in between the bus bar and the ground lug. Verify continuity through the bonds at splices and intersections between individual ladder rack sections and turns and through the bond to the TGB.

3.4 Clearances

When the pathway is overhead, ladder rack shall be installed with a minimum clearance of 12” above the ladder rack. Leave a minimum of 12” in between ladder rack and ceiling/building truss structure. Leave a minimum of 3” in between ladder rack and the tops of equipment racks and/or cabinets. Multiple tiers of ladder rack shall be installed with a minimum clearance of 12” in between each tier of ladder rack. When located above an acoustical drop ceiling, leave a minimum of 3” clearance between the top of the drop ceiling tiles and the bottom of the ladder rack.
Whenever possible, maintain a 2’ separation between ladder rack used for communications cables and pathways for other utilities or building services.

3.5 Closeout

Provide letter noting that the grounding is installed and has been tested by an independent testing service.
Provide a letter noting that the fire stopping has been installed in all appropriate locations and that the installation has been validated by the inspector of record.
Provide a letter noting that the installation is in accordance with the indicated seismic zone from a licensed in the State of California structural engineer.
Provide record drawings.

End Section

Version 20130214.1115