B09_Attachment_3_B_-_Pathways_for_Comm_Systems_0001.docx

SECTION - PATHWAYS FOR COMMUNICATIONS SYSTEMS

GENERAL

SUMMARY

This section includes pathways for communications systems.

Section Includes:

Related documents Administrative requirements Conduits and fittings Boxes and enclosures Installation All cabling installed under Division 27 and 28 sections will be in conduit.

RELATED DOCUMENTS

Section 27 05 00 Common Work Results For Communications

PRODUCTS

CONDUIT and FITTINGS General Requirements:

Listed and labeled as defined in NFPA 70, by a qualified testing agency, and marked for intended location and application.

Minimum conduit size of 1 inch, but not less than the size shown on the drawings. All horizontal cabling will be in conduit from workout or device to telecom space.

Outdoors: Apply pathway products as specified below unless otherwise indicated:

Exposed conduit: GRC.

Concealed conduit, aboveground: EMT, EPC-40-PVC.

Underground conduit: RNC, Type EPC-40-PVC Boxes and enclosures, aboveground, Type 4.

Indoors: Apply pathway products as specified below unless otherwise indicated:

Exposed, not subject to severe physical damage: EMT.

Concealed in Ceilings and Interior Walls and Partitions: EMT.

In Floor Pathways: Walker Duct Exposed and subject to severe physical damage: GRC. Example locations include, but not limited to the following:

Loading dock.

Corridors used for traffic of mechanized carts, forklifts, and pallet-handling units.

Mechanical rooms.

Damp or Wet Locations Do not install aluminum conduits, boxes, or fittings in contact with concrete or earth.

Electrical Metallic Tubing (EMT) Only steel or malleable iron materials are acceptable.

Couplings and connectors: Concrete tight and rain tight, with connectors having insulated throats.

Use gland and ring compression type couplings and connectors for conduit sizes 2 inches and smaller.

Use set screw type couplings with four set screws each for conduit sizes over 2 inches. Use set screws of case-hardened steel with hex head and cup point to firmly seat in wall of conduit for positive grounding.

In Floor Systems Thin in floor duct system Walker Double Ducts System Manufacturer: Legrand or Approved Equal Expansion Fittings: Match conduit type, rated for environmental conditions and including flexible external bonding jumper.

BOXES AND ENCLOSURES

General Requirements:

Provide boxes and enclosures designed and identified as defined in NFPA 70, for intended location and application.

All equipment and associated hardware shall be fabricated and installed in accordance with the manufacturer’s specified recommendations.

Box extensions used to accommodate building finishes shall be of same material as recessed box.

Cast-Metal access, pull and junction boxes: galvanized with cover.

Gangable (expandable) boxes are prohibited.

Hinged Cover Enclosures: Continuous-hinge cover with flush latch unless otherwise indicated.

Metal Enclosures: Steel: finished inside and out with manufacturer’s standard enamel.

Boxes and Enclosures: NEMA 250 Type 1, except use NEMA 250 Type 4 stainless steel in institutional and damp or wet locations.

EXECUTION

INSTALLATION

General Requirements Bond all conduits and piping entering the equipment room to the TGB at the perimeter of the room.

Examine surfaces and spaces for compliance with installation tolerances and other conditions affecting performance installation. Do not proceed with installation until unsatisfactory conditions have been corrected.

Deviations: Make only where necessary to avoid interferences and only after drawings showing the proposed deviations have been submitted and approved by the Contracting Officer Representative.

Flattened, dented, or deformed conduit is not permitted. Remove and replace the damaged conduits with new undamaged material. Assure conduit installation does not encroach into the ceiling height head room, walkways, or doorways.

Notify the Contracting Officer Representative of conditions that may adversely affect the installation, subsequent use, or cause the pathway (or circuits to be subsequently installed in the pathway) to not comply with ANSI/TIA/EIA standards.

Keep pathways at least 6 inches (150 mm) away from parallel runs of flues and steam or hot-water pipes. Install horizontal pathway runs above water and steam piping.

Complete pathway installation before starting cable installation.

Arrange stub-ups so curved portions of bends are not visible above finished slab.

No telecommunication Work Area Outlet (WAO) conduit shall have bends less than 90 degrees.

"Daisy Chaining" of telecommunication Work Area Outlet (WAO) conduit is not permitted.

Install no more than the equivalent of two 90-degree bends in any pathway run. Support within 12 inches (300 mm) of changes in direction. Utilize long radius elbows for all optical-fiber cables.

Conceal conduit and EMT within finished walls, ceilings, and floors unless otherwise indicated. Install conduits parallel or perpendicular to building lines.

Clearance requirements for cable tray accessibility:

Maintain a clearance of 6” between top of cable tray and ceiling structure or other equipment or raceway.

Maintain a clearance of 8” between at least one side of cable tray and nearby objects.

Maintain a clearance of 6” between bottom of cable tray and ceiling grid or other equipment or raceway.

Clearance requirements from sources of electromagnetic interference (EMI):

Maintain a clearance of 5” or more from fluorescent lighting.

Maintain a clearance of 12” or more from conduit and cables used for electrical power distribution.

Maintain a clearance of 48” or more from motors or transformers.

Pathways shall cross perpendicularly to electrical power cables or conduits.

Firestopping Provide UL listed firestop assemblies for penetrations through rated walls, floors and partitions to restore original rating approved for use by the Authority having Jurisdiction.

Conduit Supports Support multiple conduit runs with trapeze hangers that are designed to support a load equal to or greater than the sum of the weights of the conduits, wires, hanger itself, and 90 kg (200 pounds).

Support conduit independently of junction boxes, pull boxes, fixtures, suspended ceiling T bars, angle supports, and similar items.

J Hooks may not be used to support cables. Outlet conduits to extend to accessible basket tray.

Fasteners and Supports in Solid Masonry and Concrete:

Existing Construction:

Steel expansion anchors not less than 1/4 inch bolt size and not less than 1 1/8 inch embedment.

Power set fasteners not less than 1/4 inch diameter with depth of penetration not less than 3 inches.

Use vibration and shock resistant anchors and fasteners for attaching to concrete ceilings.

Hollow Masonry: Toggle bolts are permitted.

Bolts supported only by plaster or gypsum wallboard are not acceptable.

Metal Structures: Use machine screw fasteners or other devices specifically designed and approved for the application.

Attachment by wood plugs, rawl plug, plastic, lead or soft metal anchors, or wood blocking and bolts supported only by plaster is prohibited.

Chain, wire, or perforated strap shall not be used to support or fasten conduit.

Do not rely on locknuts to penetrate nonconductive coatings on enclosures. Remove coatings in the locknut area prior to assembling conduit to enclosure to assure a continuous ground path.

Cut conduit perpendicular to the length. For conduits of 2-inch (53-mm) trade size and larger, use roll cutter or a guide to ensure cut is straight and perpendicular to the length.

Use polypropylene or monofilament plastic line with not less than 200-lb (90-kg) tensile strength. Leave at least 12 inches (300 mm) of slack at each end of pull wire.

Cap underground pathways designated as spare above grade alongside pathways in use.

Pathways for Optical-Fiber Cable: Install pathways between pullboxes, metal and nonmetallic, rigid and flexible, as follows:

Install pathways in maximum lengths of 75 feet.

Install with a maximum of two 90-degree bends or equivalent for each length of pathway with pull or junction boxes or terminations at distribution frames or cabinets where necessary to comply with these requirements.

Install devices to seal pathway interiors at accessible locations. Locate seals so no fittings or boxes are between the seal and the following changes of environments. Seal the interior of all pathways at the following points:

Where conduits pass from warm to cold locations, such as boundaries of refrigerated spaces.

Where an underground service pathway enters a building or structure.

Where otherwise required by NFPA 70.

Expansion-Joint Fittings:

Conduits 3 inches and larger, that are secured to the building structure on opposite sides of a building expansion joint, require expansion and deflection couplings. Install the couplings in accordance with the manufacturer's recommendations.

Provide conduits smaller than 3 inches with junction boxes on both sides of the expansion joint. Connect conduits to junction boxes with sufficient slack of flexible conduit to produce 15 inch vertical drop midway between the ends. Flexible conduit shall have a copper green ground bonding jumper installed. In lieu of this flexible conduit, expansion and deflection couplings as specified above for 15 inches and larger conduits are acceptable.

Seismic Areas: In seismic areas, provide conduits rigidly secured to the building structure on opposite sides of a building expansion joint with junction boxes on both sides of the joint. Connect conduits to junction boxes with 15 inches of slack flexible conduit. Flexible conduit shall have a copper green ground bonding jumper installed.

Install type and quantity of fittings that accommodate temperature change listed for each of the following locations:

Indoor Spaces Connected with Outdoors without Physical Separation: 125 deg F (70 deg C) temperature change.

Install fitting(s) that provide expansion and contraction for at least 0.00041 inch per foot of length of straight run per deg F of temperature change for PVC conduits. Install fitting(s) that provide expansion and contraction for at least 0.000078 inch per foot of length of straight run per deg F of temperature change for metal conduits.

Install expansion fittings at all locations where conduits cross building or structure expansion joints.

Install each expansion-joint fitting with position, mounting, and piston setting selected according to manufacturer's written instructions for conditions at specific location at time of installation. Install conduit supports to allow for expansion movement.

Horizontally separate boxes mounted on opposite sides of a wall so they are not in the same vertical channel.

END OF SECTION - PATHWAYS FOR COMMUNICATIONS SYSTEMS