Underground Ducts and Raceways For Electrical SystemsME- Building Group
SECTION 260543 - UNDERGROUND DUCTS AND RACEWAYS FOR ELECTRICAL SYSTEMS
PART 1 - GENERAL
1.1RELATED DOCUMENTS
- Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division01 Specification Sections, apply to this Section.
1.2SUMMARY
- This Section includes underground conduits and ducts, duct banks, pull boxes and handholes.
- Related Sections:
- Division31 Section "Earth Moving" for excavation, backfill, and related items for ducts, manholes, and handholes.
1.3SYSTEM DESCRIPTION
- Underground Ducts for Electrical Feeders: PVC schedule 40 and schedule 80. PVC Schedule 80 must be used if specified on drawings.
- Underground Ducts for Communication Circuits: . PVC schedule 40 and schedule 80. PVC Schedule 80 must be used if specified on drawings
1.4SUBMITTALS
- Product Data: For handholes and accessories.
- Record Documents: Show dimensioned locations of underground ducts, handholes, and manholes.
1.5QUALITY ASSURANCE
- Listing and Labeling: Provide electrically operated equipment specified in this Section that is listed and labeled.
- The Terms "Listed" and "Labeled": As defined in NFPA70, Article100.
- Listing and Labeling Agency Qualifications: A "Nationally Recognized Testing Laboratory" as defined in OSHA Regulation 1910.7.
1.6PROJECT CONDITIONS
- Existing Utilities: Do not interrupt utilities serving facilities occupied by Owner or others unless permitted under the following conditions and then only after arranging to provide temporary utility services according to requirements indicated.
- Notify Architect/Engineer not less than 5 days in advance of proposed utility interruptions.
- Do not proceed with utility interruptions without Architect/Engineer's written permission.
1.7COORDINATION
- Coordinate layout and installation of conduits and handholes with final arrangement of other utilities as determined in the field.
PART 2 - PRODUCTS
2.1MANUFACTURERS
- Manufacturers: Unless otherwise directed by the Owner, provide products by one of the following:
- Underground, Precast Concrete Utility Structures:
- Carder Concrete Products; Precast Division.
- Christy Concrete Products, Inc.
- Elmhurst-Chicago Stone Co.
- Riverton Concrete Products.
- A. Rotondo & Sons, Inc.
- Rotondo/Penn-Cast, Inc.
- Smith-Midland Corp.
- Utility Vault Co.
- Wausau Concrete Co.
- Frames and Covers:
- Campbell Foundry Co.
- East Jordan Iron Works, Inc.
- McKinley Iron Works, Inc.
- Neenah Foundry Co.
- Nonmetallic Ducts:
- Arnco Corp.
- Breeze-Illinois, Inc.
- Cantex Industries; Harsco Corp.
- Certainteed Corp.; Pipe & Plastics Group.
- Cole-Flex Corp.
- Electri-Flex Co.
- Lamson & Sessions; Carlon Electrical Products.
- Spiraduct, Inc.
2.2CONDUIT AND DUCT
- Rigid Plastic Conduit: NEMATC2, Schedule40 PVC, rated for use with 90 deg C conductors under all installation conditions.
- PVC Conduit and Tubing Fittings: NEMATC3.
- Rigid Plastic Underground Conduit: UL651A, TypeA PVC.
- Rigid Plastic Underground Conduit: High-density polyethylene, Schedule40.
2.3PULL BOXES AND HANDHOLES
- Cast-Metal Boxes: Cast aluminum, sized as indicated, with outside flanges and recessed, gasketed cover for flush mounting. Nonskid finish on cover.
- Fiberglass Handholes: Molded fiberglass, sized as indicated, with 6-inch-square cable entrance at each side and weatherproof cover with nonskid finish.
- Cover Legend: "ELECTRIC."
2.4PRECAST MANHOLES
- Comply with ASTMC858,with structural design loading to comply with MDOT highway load rating and with interlocking mating sections, complete with accessories, hardware, and features.
- Cover Legend: "ELECTRIC."
PART 3 - EXECUTION
3.1EXAMINATION
- Examine substrates, areas, and conditions to receive ducts and utility structures for compliance with requirements for installation tolerances and other conditions affecting performance of underground ducts and utility structures. Do not proceed with installation until unsatisfactory conditions have been corrected.
3.2EARTHWORK
- Excavation and Backfill: Comply with Division31 Section "Earth Moving" but do not use heavy-duty, hydraulic-operated, compaction equipment.
- Restore surface features at areas disturbed by excavation and reestablish original grades, unless otherwise indicated. Replace removed sod immediately after backfilling is completed.
- Restore all areas disturbed by trenching, storing of dirt, cable laying, and other work. Restore vegetation and include necessary topsoiling, fertilizing, liming, seeding, sodding, sprigging, and mulching. Perform according to applicable Sections of Division32.
- Restore disturbed pavement.
3.3CONDUIT INSTALLATION
- Install nonmetallic conduit as indicated, according to manufacturer's written instructions.
- Slope: Pitch ducts a minimum of 4 inches/100 feet to drain toward manholes and handholes and away from buildings and equipment. Slope ducts from a high point in runs between 2 manholes to drain in both directions.
- Curves and Bends: Use manufactured elbows for stub-ups at equipment and at building entrances. Use manufactured long sweep bends with a minimum radius of 25 feet, both horizontally and vertically, at other locations.
- Make joints in ducts and fittings watertight according to manufacturer's written instructions. Stagger couplings so those of adjacent ducts do not lie in the same plane.
- Building Entrances: Make a transition from underground duct to conduit at least 10 feet outside the building wall. Use fittings manufactured for that purpose. Follow appropriate installation instructions below:
- Direct-Buried, Nonencased Duct at Nonwaterproofed Wall Penetrations: Install a Schedule40, galvanized steel pipe sleeve for each duct. Calk space between conduit and sleeve with duct-sealing compound on both sides for moisture-tight seal.
- Separation between Direct-Buried, Nonencased Ducts: Minimum 3 inches for like services and minimum 6 inches between power and signal ducts.
- Stub-ups: Use rigid steel conduit for stub-ups to equipment. For equipment mounted on outdoor concrete bases, extend steel conduit a minimum of 5 feet from edge of base. Install insulated grounding bushings on terminations. Couple steel conduits to ducts with adapters designed for the purpose and then encase coupling with 3 inches of concrete.
- Sealing: Provide temporary closure at terminations of ducts that have cables pulled. Seal spare ducts at terminations. Use sealing compound and plugs to withstand at least 15-psig hydrostatic pressure.
- Pulling Cord: Install 100-lbf-test nylon cord in ducts, including spares.
3.4INSTALLATION OF HANDHOLES AND PULL BOXES OTHER THAN PRECAST CONCRETE
- Install handholes and pull boxes level and plumb and with orientation and depth coordinated with connecting ducts to minimize bends and deflections required for proper entrances. Use pull box extension if required to match depths of ducts, and seal joint between box and extension as recommended by the manufacturer.
- Unless otherwise indicated, support units on a level 6-inch- thick bed of crushed stone or gravel, graded from 1/2-inch sieve to No.4 sieve and compacted to same density as adjacent undisturbed earth.
- Elevation: Set so cover surface will be flush with finished grade.
- Install handholes and pull boxes with bottom below the frost line.
- Field-cut openings for ducts and conduits according to enclosure manufacturer's written instructions. Cut wall of enclosure with a tool designed for material to be cut. Size holes for terminating fittings to be used, and seal around penetrations after fittings are installed.
3.5FIELD QUALITY CONTROL
- Duct Integrity: Rod ducts with a mandrel 1/4 inch smaller in diameter than ID of ducts. Where rodding indicates obstructions in ducts, remove obstructions and retest.
- Correct installations where possible and retest to demonstrate compliance. Remove and replace defective products and retest.
3.6CLEANING
- Pull brush through full length of ducts. Use round-bristle brush with a diameter 1/2 inch larger than the ID of duct.
- Clean internal surfaces of manholes, including sump. Remove foreign material.
END OF SECTION
Page 1 of 5
Revision Date: 01/21/14 Project & Bid Package
File name: 260543 UNDERGROUND DUCTS AND RACEWAYS FOR ELECTRICAL SYSTEMS