270533 Conduits and Backboxes for Communications Systems.pdf

Sioux Falls VAHCS, Sioux Falls, SD VA Project 438-20-910

EHRM Infrastructure Upgrades 04-04-2022

2501 West 22nd St. Bid Documents

Sioux Falls, SD 57105

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SECTION 27 05 33

CONDUITS AND BACKBOXES FOR COMMUNICATIONS SYSTEMS

PART 1 - GENERAL

1.1 DESCRIPTION

A. This section specifies conduit, fittings, and boxes to form raceway systems for communications cabling.

1.2 RELATED WORK

A. Bedding of conduits: Section 31 20 00, EARTH MOVING.

B. Sealing around penetrations to maintain integrity of fire rated construction: Section 07 84 00, FIRESTOPPING.

C. Fabrications for deflection of water away from building envelope at penetrations: Section 07 60 00, FLASHING AND SHEET METAL.

D. Sealing around conduit penetrations through building envelope to prevent moisture migration into building: Section 07 92 00, JOINT

SEALANTS.

E. Identification and painting of conduit and other devices: Section 09 91

00, PAINTING.

F. Requirements for personnel safety and to provide a low impedance path for possible ground fault currents: Section 27 05 26, GROUNDING AND

BONDING FOR COMMUNICATIONS SYSTEMS.

1.3 SUBMITTALS

A. In accordance with Section 27 05 00, COMMON WORK RESULTS FOR

COMMUNICATIONS SYSTEMS, submit the following:

1. Size and location of cabinets, splice boxes, and pull boxes.

2. Layout of required conduit penetrations through structural elements.

3. Catalog cuts marked with specific item proposed and area of application identified.

B. Certification: Provide letter prior to final inspection, certifying material is in accordance with construction documents and properly installed.

PART 2 - PRODUCTS

2.1 MATERIAL

A. Minimum Conduit Size: 25 mm (1 inch).

B. Conduit:

1. Rigid Galvanized Steel: Conform to UL 6, ANSI C80.1.

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2. Rigid Intermediate Steel Conduit (IMC): Conform to UL 1242, ANSI

C80.6.

3. Electrical Metallic Tubing (EMT):

a. Maximum Size: 105 mm (4 inches).

b. Install only for cable rated 600 volts or less.

c. Conform to UL 797, ANSI C80.3.

4. Flexible Galvanized Steel Conduit: Conform to UL 1.

5. Liquid-tight Flexible Metal Conduit: Conform to UL 360.

6. Direct Burial Plastic Conduit: Conform to UL 651 and UL 651A, heavy wall PVC, or high-density polyethylene (HDPE).

7. Surface Metal Raceway: Conform to UL 5.

C. Conduit Fittings:

1. Rigid Galvanized Steel and Rigid Intermediate Steel Conduit

Fittings:

a. Provide fittings meeting requirements of UL 514B and ANSI/ NEMA

FB 1.

b. Sealing: Provide threaded cast iron type. Use continuous drain type sealing fittings to prevent passage of water and vapor. In concealed work, install sealing fittings in flush steel boxes with blank cover plates having same finishes as other electrical plates in room.

c. Standard Threaded Couplings, Locknuts, Bushings, and Elbows: Only steel or malleable iron materials are acceptable. Integral retractable type IMC couplings are also acceptable.

d. Locknuts: Bonding type with sharp edges for digging into metal wall of an enclosure.

e. Bushings: Metallic insulating type, consisting of an insulating insert molded or locked into metallic body of fitting. Bushings made entirely of metal or nonmetallic material are not permitted.

f. Erickson (union-type) and Set Screw Type Couplings:

1) Couplings listed for use in concrete are permitted for use to complete a conduit run where conduit is installed in concrete.

2) Use set screws of case hardened steel with hex head and cup point to seat in conduit wall for positive ground.

g. Provide OEM approved fittings.

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2. Electrical Metallic Tubing Fittings:

a. Conform to UL 514B and ANSI/ NEMA FB1; only steel or malleable iron materials are acceptable.

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

1) Use gland and ring compression type couplings and connectors for conduit sizes 50 mm (2 inches) and smaller.

2) Use set screw type couplings with four set screws each for conduit sizes over 50 mm (2 inches).

3) Use set screws of case-hardened steel with hex head and cup point to seat in wall of conduit for positive grounding.

c. Indent type connectors or couplings are not permitted.

d. Die-cast or pressure-cast zinc-alloy fittings or fittings made of

"pot metal" are not permitted.

e. Provide OEM approved fittings.

3. Flexible Steel Conduit Fittings:

a. Conform to UL 514B; only steel or malleable iron materials are acceptable.

b. Provide clamp type, with insulated throat.

c. Provide OEM approved fittings.

4. Liquid-tight Flexible Metal Conduit Fittings:

a. Conform to UL 514B and ANSI/ NEMA FB1; only steel or malleable iron materials are acceptable.

b. Fittings must incorporate a threaded grounding cone, a steel or plastic compression ring, and a gland for tightening.

c. Provide connectors with insulated throats to prevent damage to cable jacket.

d. Provide OEM approved fittings.

5. Direct Burial Plastic Conduit Fittings: Provide fittings meeting requirements of UL 514C and NEMA TC3, and as recommended by conduit manufacturer.

6. Expansion and Deflection Couplings:

a. Conform to UL 467 and UL 514B.

b. Accommodate 19 mm (3/4 inch) deflection, expansion, or contraction in any direction, and allow 30-degree angular deflections.

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c. Include internal flexible metal braid sized to ensure conduit ground continuity and fault currents in accordance with UL 467, and NEC code tables for ground conductors.

d. Jacket: Flexible, corrosion-resistant, watertight, moisture and heat resistant molded rubber material with stainless steel jacket clamps.

D. Conduit Supports:

1. Parts and Hardware: Provide zinc-coat or equivalent corrosion protection.

2. Individual Conduit Hangers: Designed for the purpose, having a pre-assembled closure bolt and nut, and provisions for receiving a hanger rod.

3. Multiple Conduit (Trapeze) Hangers: Minimum 38 mm by 38 mm (1-1/2 by

1-1/2 inch), 2.78 mm (12 gage) steel, cold formed, lipped channels;

with minimum 9 mm (3/8 inch) diameter steel hanger rods.

4. Solid Masonry and Concrete Anchors: Self-drilling expansion shields, or machine bolt expansion.

E. Outlet, Splice, and Pull Boxes:

1. Conform to UL-50 and UL-514A.

2. Cast metal where required by NEC or shown, and equipped with rustproof boxes.

3. Sheet Metal Boxes: Galvanized steel, except where otherwise shown.

4. Install flush mounted wall or ceiling boxes with raised covers so that front face of raised cover is flush with wall.

5. Install surface mounted wall or ceiling boxes with surface style flat or raised covers.

F. Warning Tape: Standard, 4-Mil polyethylene 76 mm (3 inch) wide tape detectable type, red with black letters, and imprinted with “CAUTION

BURIED COMMUNICATIONS CABLE BELOW”.

G. Flexible Nonmetallic Communications Raceway (Innerduct) and Fittings:

1. General: Provide UL 910 listed plenum, riser, and general purpose corrugated pliable communications raceway.

2. Provide Communications Raceway with a factory installed 567 kg (1250 lb.) tensile pre-lubricated pull tape.

3. Use only metallic straps, hangers and fittings to support raceway from building structure. Cable ties are not permitted for securing raceway to building structure.

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4. Provide fittings to be installed in spaces used for environmental air made of materials that do not exceed flammability, smoke generation, ignitibility, and toxicity requirements of environmental air space.

5. Size: Metric Designator 53 (trade size 2) or smaller.

6. Outside Plant: Plenum-rated where each innerduct is 75 mm (3 inches) and larger.

7. Inside Plant: Listed and marked for installation in plenum airspaces and minimum 25 mm (1 inch) inside diameter.

8. Plenum: Non-metallic communications raceway.

a. Constructed of low smoke emission, flame retardant PVC with corrugated construction.

b. UL 94 V-O rating for flame spreading limitation.

9. Provide innerduct reel lengths as necessary to ensure ducts are continuous.

10. Provide pulling accessories used for innerduct including but not limited to, inner duct lubricants, spreaders, applicators, grips, swivels, harnesses, and line missiles (blown air) compatible with materials being pulled.

H. Outlet Boxes:

1. Flush wall mounted minimum 11.9 cm (4-11/16 inches) square, 9.2 cm

(3-5/8 inches) deep pressed galvanized steel.

2. 2-Gang Tile Box:

a. Flush backbox type for installation in block walls.

b. Minimum 92 mm (3-5/8 inches) deep.

I. Weatherproof Outlet Boxes: Surface mount two gang, 67 mm (2-5/8 inches) deep weatherproof cast aluminum with powder coated finish internal threads on hubs 19 mm (3/4 inch) minimum.

PART 3 - EXECUTION

3.1 EQUIPMENT INSTALLATION AND REQUIREMENTS

A. Raceways typically required for cabling systems unless otherwise indicated:

System Specification Section Installed Method

Grounding 27 05 26 Conduit Not Required

Grounding and Bonding for Electronic Safety and Security

28 05 26 Conduit Not Required

Unless Required by Code

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System Specification Section Installed Method

Physical Access Control

System

28 13 00 Conduit to Cable Tray

Partitioned Cable Tray

Intrusion Detection

System

28 16 00 Conduit to Cable Tray, Partitioned Cable Tray

Video Surveillance 28 23 00 Complete Conduit

Fire Detection and Alarm 28 31 00 Complete Conduit

B. Penetrations:

1. Cutting or Holes:

a. Locate holes in advance of installation. Where proposed in structural sections, obtain approval of structural engineer and

COR or Designated Government Authority prior to drilling through structural sections.

b. Make holes through concrete and masonry in new and existing structures with a diamond core drill or concrete saw. Pneumatic hammer, impact electric, hand or manual hammer type drills are not permitted; COR or Designated Government Authority may grant limited permission by request, in condition of limited working space.

c. Fire Stop: Where conduits, wireways, and other communications raceways pass through fire partitions, fire walls, smoke partitions, or floors, install a fire stop that provides an effective barrier against spread of fire, smoke and gases as specified in Section 07 84 00, FIRESTOPPING.

1) Fill and seal clearances between raceways and openings with fire stop material.

2) Install only retrofittable, non-hardening, and reusable firestop material that can be removed and reinstalled to seal around cables inside conduits.

d. Waterproofing at Floor, Exterior Wall, and Roof Conduit

Penetrations: Seal clearances around conduit and make watertight as specified in Section 07 92 00, JOINT SEALANTS.

C. Conduit Installation:

1. Minimum conduit size of 25 mm (1 inch), but not less than size required for 40 percent fill.

2. Install insulated bushings on all conduit ends.

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3. Install pull boxes after every 180 degrees of bends (two 90-degree bends) or every 100ft. Size boxes per TIA 569.

4. Extend vertical conduits/sleeves through floors minimum 75 mm (3 inches) above floor and minimum 75 mm (3 inches) below ceiling of floor below.

5. Terminate conduit runs to and from a backboard in a TR or interstitial space at top or bottom of backboard. Install conduits to enter telecommunication rooms next to wall and flush with backboard.

6. Where drilling is necessary for vertical conduits, locate holes so as not to affect structural sections.

7. Seal empty conduits located in telecommunications rooms or on backboards to prevent entrance of moisture and gases and to meet fire resistance requirements.

8. Provide pull wire in all empty conduits; sleeves through floor are exceptions.

9. Complete each entire conduit run installation before pulling in cables.

10. Flattened, dented, or deformed conduit is not permitted.

11. Ensure conduit installation does not encroach into ceiling height head room, walkways, or doorways.

12. Cut conduit square with a hacksaw, ream, remove burrs, and draw tight.

13. Install conduit mechanically continuous.

14. Independently support conduit at 2.44 m (8 feet) on center; do not use other supports (i.e., suspended ceilings, suspended ceiling supporting members, luminaires, conduits, mechanical piping, or mechanical ducts).

15. Support conduit within 300 mm (1 foot) of changes of direction, and within 300 mm (1 foot) of each enclosure to which connected.

16. Close ends of empty conduit with plugs or caps to prevent entry of debris, until cables are pulled in.

17. Attach conduits to cabinets, splice cases, pull boxes and outlet boxes with bonding type locknuts. For rigid and IMC conduit installations, provide a locknut on inside of enclosure, made up wrench tight. Do not make conduit connections to box covers.

18. Do not use aluminum conduits in wet locations.

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19. Unless otherwise indicated on drawings or specified herein, conceal conduits within finished walls, floors and ceilings.

20. Conduit Bends:

a. Make bends with standard conduit bending machines; observe minimum bend radius for cable type and outside diameter.

b. Conduit hickey is permitted only for slight offsets, and for straightening stubbed conduits.

c. Bending of conduits with a pipe tee or vise is not permitted.

d. Minimum radius of communication conduit bends:

Sizes of Conduit

Trade Size

Radius of Conduit Bends mm, Inches

1 230 (9)

1-1/4 350 (14)

1-1/2 430 (17)

2 525 (21)

2-1/2 635 (25)

3 775 (31)

3-1/2 900 (36)

4 1125 (45)

21. Layout and Homeruns - Deviations: Make only where necessary to avoid interferences and only after drawings showing proposed deviations have been submitted and approved by COR.

D. Concealed Work Installation:

1. In Concrete:

a. Conduit: Rigid steel or IMC.

b. Align and run conduit in direct lines.

c. Install conduit through concrete beams only when the following occurs:

1) Where shown on structural drawings.

2) As accepted by COR or Designated Government Authority prior to construction, and after submittal of drawing showing location, size, and position of each penetration.

d. Installation of conduit in concrete that is less than 75 mm (3 inches) thick is prohibited.

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1) Conduit outside diameter larger than 1/3 of slab thickness is prohibited.

2) Space between Conduits in Slabs: Approximately six conduit diameters apart, except one conduit diameter at conduit crossings.

3) Install conduits approximately in center of slab to ensure a minimum of 19 mm (3/4 inch) of concrete around conduits.

e. Make couplings and connections watertight. Use thread compounds that are NRTL listed conductive type to ensure low resistance ground continuity through conduits. Tightening set screws with pliers is not permitted.

E. Furred or Suspended Ceilings and in Walls:

1. Rigid steel or IMC. Different type conduits mixed indiscriminately in same system is not permitted.

2. Align and run conduit parallel or perpendicular to building lines.

3. Tightening set screws with pliers is not permitted.

F. Exposed Work Installation:

1. Unless otherwise indicated on drawings, exposed conduit is only permitted in telecommunications rooms.

a. Provide rigid steel or IMC.

b. Different type of conduits mixed indiscriminately in system is not permitted.

2. Align and run conduit parallel or perpendicular to building lines.

3. Install horizontal runs close to ceiling or beams and secure with conduit straps.

4. Support horizontal or vertical runs at not over 2400 mm (96 inches) intervals.

5. Painting:

a. Paint exposed conduit as specified in Section 09 91 00, PAINTING.

b. Refer to Section 09 91 00, PAINTING for preparation, paint type, and exact color.

c. Provide labels where conduits pass through walls and floors and at maximum 6000 mm (20 foot) intervals in between.

G. Expansion Joints:

1. Conduits 75 mm (3 inches) and larger, that are secured to building structure on opposite sides of a building expansion joint, require

27 05 33 - 10 expansion and deflection couplings. Install couplings in accordance with manufacturer's recommendations.

2. Provide conduits smaller than 75 mm (3 inches) with pull boxes on both sides of expansion joint. Connect conduits to expansion and deflection couplings as specified.

3. Install expansion and deflection couplings where shown on plans or existing expansion joints exist and are encountered by contractor.

H. Conduit Supports, Installation:

1. Select AC193 code listed mechanical anchors or fastening devices with safe working load not to exceed 1/4 of proof test load.

2. Use pipe straps or individual conduit hangers for supporting individual conduits. Maximum distance between supports is 2.5 m (8 foot) on center.

3. Support multiple conduit runs with trapeze hangers. Use trapeze hangers designed to support a load equal or greater than sum of the weights of the conduits, wires, hanger itself, and 90 kg (200 pounds). Attach each conduit with U-bolts or other accepted fasteners.

4. Support conduit independent of pull boxes, luminaires, suspended ceiling components, angle supports, duct work, and similar items.

5. Fastenings and Supports in Solid Masonry and Concrete:

a. New Construction: Use steel or malleable iron concrete inserts set in place prior to placing concrete.

b. Existing Construction:

1) Code AC193 listed wedge type steel expansion anchors minimum 6 mm (1/4 inch) bolt size and minimum 28 mm (1-1/8 inch) embedment.

2) Power set fasteners minimum 6 mm (1/4 inch) diameter with depth of penetration minimum 75 mm (3 inches).

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

6. Fastening to Hollow Masonry: Toggle bolts are permitted.

7. Fastening to Metal Structures: Use machine screw fasteners or other devices designed and accepted for application.

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

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

10. Do not support conduit from chain, wire, or perforated strap.

11. Spring steel type supports or fasteners are not permitted except horizontal and vertical supports/fasteners within walls.

12. Vertical Supports:

a. Install riser clamps and supports for vertical conduit runs in accordance with NEC.

b. Provide supports for cable and wire with fittings that include internal wedges and retaining collars.

I. Box Installation:

1. Boxes for Concealed Conduits:

a. Flush mounted.

b. Provide raised covers for boxes to suit wall or ceiling, construction and finish. In spaces not controlled by VA (i.e., common hallways) covers must be lockable.

2. In addition to boxes shown, install additional boxes where needed to prevent damage to cables during pulling.

3. Remove only knockouts as required and plug unused openings. Use threaded plugs for cast metal boxes and snap-in metal covers for sheet metal boxes.

4. Stencil or install phenolic nameplates on covers of boxes identified on riser diagrams; for example "SIG-FA JB No. 1".

5. Outlet boxes mounted back-to-back in same wall are not permitted. A minimum 600 mm (24 inches) center-to-center lateral spacing must be maintained between boxes.

J. Flexible Nonmetallic Communications Raceway (Innerduct), Installation:

1. Install Innerduct in cable tray. Innerduct may not be free-hung.

2. Install only in accessible spaces not subject to physical damage or corrosive influences.

3. Make bends manually to assure internal diameter of tubing is not effectively reduced.

4. Extend each segment of innerduct minimum 300 mm (12 inches) beyond end of service conduit tie or cable tray. Restrain innerduct ends with wall mount clamps and seal when cable is installed.

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3.2 TESTING

A. Examine fittings and locknuts for secureness.

B. Test RMC, IMC and EMT systems for electrical continuity and resistance to ground.

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