Mesa Lab 15kV Feeder Replacement Project 10/10/08
Project # 07-1834
27 05 43 Communications underground ducts, structures and raceways
PART 1:General
The Contractor is held responsible to be familiar with the provisions contained herein and with other Sections of this Specification as applicable to the completion of the installation.
The approved vendor, designated agent or employee is held responsible to be familiar with the provisions contained and is assumed to possess the knowledge, manpower, and materials applicable to the completion of the installation
1.01 work required
A. The work required under this section consists of providing all primary, secondary, telecommunications/data underground ducts and raceways, including handholes for the project as shown on drawings and/or as specified herein. The contractor is not responsible for network cabling or devices.
1.02 work required but specified elsewhere
A. Section 310000 – Earthwork (excavation, backfill, compaction, etc.)
B. Section 020000 – Site Improvements (concrete work, blacktop, etc.)
C. Section 260533 – Raceways and Fittings
1.03 related sections:
A. Division 27, Section 270526 Grounding and Bonding for Communications Systems
B. Division 27, Section 270553 Identification for Communications Systems
PART 2: products
2.1 Non-metallic Raceways
1. PVC Type Schedule 80
2. Plastic duct to meet NEMA TC-6 Standards.
3. Plastic duct with straight couplings and appropriate cement. Couplings to be staggered horizontally and vertically.
4. Use for all raceways except where rigid conduit is required.
5. The number, size, raceway duct material and arrangement shall be as indicated on Drawings and/or as specified herein.
7. All conduits will minimally be 4” in diameter.
8. Orange locatable caution tape shall be installed above all underground conduits
9. May be non-metallic (PVC) or galvanized heavy wall (GMC) conduit.
10. Shall be capped with manufactured caps (Duct Plugs).
11. Shall be provided with continuous 200lb measuring tape in each duct
12. (1) 4”3-Cell Maxcell Innerduct with ground wire, will be installed in (1) 4” conduit the entire length from the pumphouse to the Mesa.
Maxcell PN: MXD4003BK2650 or acceptable equivalent as approved by the NETS Infrastructure Engineers.
2-2 Handholes:
1. Handholes (HH) shall be constructed of polymer concrete with fiberglass cloth reinforcement.
Handhole PN: FCB366048A04, 62”x41”,48” deep or acceptable equivalent as approved by the NETS Infrastructure Engineers.
2. The HH shall be design with a straight wall design.
3. The HH depth shall be a minimum of 36 inches with an approximate length and width of 40 by 62 inches.
4. The cover shall be a two piece heavy duty flat slab and shall have a service load of 15,000 lbs over a 10" square and shall have a communication logo attached to the top.
5. The cover shall be securable with security bolts (five sided bolts).
6. The Handhole Loading Requirements per ANSI/SCTE 77-2002 Specifications for Underground Enclosures Integrity, shall be TIER 15, vertical loads of 15000 lbs and lateral loads of 800 lbs/sgft. TIER 15 is defined as Driveway, parking lot, and off-roadway applications subject to occasional non-deliberate heavy vehicular traffic.
PART 3: execution
3.01 excavation
1. Coordinate with other trades
2. Have elevations and arrangements verified on job.
3. If soil conditions are such that because of the depth or any other reasons the trench/excavation cannot conform to the size of the duct bank, provide forms and bracing as required.
5. Depth of excavation shall be such that the required bury depths are met. NETS Infrastructure Engineer shall approve any deviation from required depths.
3.02 RACEWAY INSTALLATION
1. All bends must be long, sweeping bends with a ten times the internal diameter.
2. In underground raceways, angle couplings and bends alone or in combination with straight sections shall be used for direction changes; direction changes made by skewing straight sections of conduit will not be permitted.
3. Orange locatable caution tape shall be installed 12” above all underground conduits.
4. Shall be capped with manufactured caps (Duct Plugs) when installation in temporarily discontinued.
5. Shall be checked by pulling a round wood or steel test mandrel, sized for each duct from both directions to remove obstructions.
6. Shall be cleaned by passing a wire brush mandrel and/or rubber duct swab (or approved alternative) of appropriate size back and forth until all foreign materials and water are removed.
7. Shall be encased by a concrete envelope 10ft on each side of roads and from Mesa Lab building past first road crossing, minimum 3” cover on all sides or flowable backfill as specified.
8. Shall be installed using long radius sweeps. No more than 180 degrees of total bends in any one section of conduit.
9. Conduit runs shall contain no continuous sections longer than 350 feet, unless shown on drawings or specified by NETS Infrastructure Engineers. If runs total more than 350 feet, pull points, (handholes) need to be installed.
10. Conduit shall have no more than 180 degrees of cumulative bends between pull points or more than 90 degrees of bends within any 50 feet.
11. Shall be installed with minimum of 3” fall per 100 foot run toward handholes and away from buildings.
12. Shall be provided with Greenlee or equal continuous conduit measuring tape in each duct.
13. Following the requirements of the NEC but minimally separate facilities as follows:
a. Power
12 in. of well packed soil
4 in. of masonry
3 in. of Concrete
b. Gas, Oil, Water, etc.
12 in. when parallel
6 in. when crossing
14. A minimum of 2’ 6” bury depth is required. Exceptions may be granted to avoid interference’s with approval of NETS Infrastructure Engineer
15. Install (1) Maxcell 4” 3 Cell innerduct with tracer wire from the Mesa ER to the Pumphouse.
3.03 NON-METALLIC RACEWAY INSTALLATION
1. Complete with threaded adapter when attaching to rigid conduit.
2. Protect from deformation during stockpiling.
3. Perfectly circular in shape. Other configurations will not be permitted.
4. Have joints made with materials provided by, and installed per manufacturer’s directions. Comply with manufacturers requirements for bending and cutting.
5. Have joints covered with Scotch #88 tape as temporary seal.
3.04 HANDHOLE INSTALLATION
1. Shall have drainage provisions (e.g., drain holes, open bottom, sump-hole).
2. Conduits entering a HH should be aligned on opposite walls at the same elevation.
3. When installed without bottom a 4 inch layer of small rock should be installed to prevent mud from intruding into the HH.
4. Where HH enclosures without bottoms are installed, all enclosed conductors shall be listed as suitable for wet locations.
5. The HH shall be installed in offset pairs with two 4 inch conduits into each HH for total of (4) 4 inch conduits.
6. The conduits shall be run in as straight a manner as possible.
7. Handholes are to be used as pull-through points, no splices shall be installed in a HH.
8. Handholes shall be installed as shown on the drawings or as directed by the NETS Infrastructure Engineer.
9. The handhole excavation shall have bedding material of 6 Inches covering the entire bottom of the excavation and the handhole shall be placed so the top of the handhole is level with the existing grade.
10. The location of each handhole will be indicated by a stake and reviewed by NETS Infrastructure Engineer prior to installation.
11. The locate wire shall be bonded to a ½" x 5' copper bonded pointed ground rod driven 4' into undisturbed earth at each new handhole. The locate shall be wire bonded to the ground rod (inside of the handhole) with a bronze ground rod clamp suitable for direct burial.
END OF SECTION
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