atch 1 16370 Electrical Distribution Systems Aerial.pdf

Electrical Distribution System, Aerial FA5000-12-R-0001 Attachment 1

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PART 1 GENERAL

1.1 REFERENCES

The publications listed below form a part of this specification to the extent referenced. The publications are referred to in the text by basic designation only.

AMERICAN NATIONAL STANDARDS INSTITUTE, INC. (ANSI)

ANSI C2 National Electrical Safety Code

ANSI C57.12.20 Distribution Transformers, Overhead-Type

ANSI C135.1 Galvanized Steel Bolts and Nuts for Overhead Line Construction

ANSI C135.2 Threaded Galvanized Ferrous Strand-Eye Anchor Rods and Nuts for Overhead Line Construction

ANSI C135.4 Zinc-Coated Ferrous Eyebolts and Nuts for Overhead Line

Construction

ANSI C135.14 Staples with Rolled or Slash Points for Overhead Line Construction

ANSI C135.17 Galvanized Ferrous Bolt-Type Insulator Pins with Lead Threads for Overhead Line Construction

ANSI C135.22 Galvanized Ferrous Pole-Top Insulator Pins with Lead Threads for

Overhead Line Construction

ANSI C135.33 Galvanized Ferrous Cross arm Gains for Overhead Line Construction

AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM)

ASTM A 123 Zinc (Hot-Dipped Galvanized) Coatings on Iron and Steel Products

ASTM A 153 Zinc Coating (Hot-Dip) on Iron and Steel Hardware

ASTM A 575 Steel Bars, Carbon, Merchant Quality, M-Grades

ASTM A 576 Steel Bars, Carbon, Hot-Wrought, Special Quality

ASTM B 1 Hard-Drawn Copper Wire

Pavements - IDIQ

FXSB 11-2102

Section 16370

Electrical Distribution System, Aerial

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ASTM B 8 Concentric-Lay-Stranded Copper Conductors, Hard, Medium-

Hard, or Soft

ASTM D 330 2-Butoxyethanol

ASTM D 923 Sampling Insulating Liquids

INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS, INC. (IEEE)

IEEE C57.12.00 Liquid-Immersed Distribution, Power, and Regulating Transformers

NATIONAL ELECTRICAL MANUFACTURERS ASSN (NEMA)

NEMA LA 1 Surge Arresters

NEMA WC 5 Thermoplastic-Insulated Wire and Cable for the Transmission and Distribution of Electrical Energy

NEMA WC 7 Cross-Linked-Thermosetting-Polyethylene Insulated Wire and

Cable for the Transmission and Distribution of Electrical Energy

NATIONAL FIRE PROTECTION ASSN (NFPA)

NFPA 70 National Electrical Code 99

UNDERWRITERS LABORATORIES, INC (UL)

UL-03 Electrical Construction Materials Directory

UL 467 Grounding and Bonding Equipment

1.2 GENERAL REQUIREMENTS

Items of the same classification shall be identical including equipment assemblies, parts, and components.

1.2.1 Code Compliance

The installation shall comply with the requirements and recommendations of NFPA 70 and ANSI C2 for medium loading districts, Grade B construction. No reduction in clearance shall be made.

1.2.2 Standard Product

Material and equipment shall be a standard product of a manufacturer regularly engaged in the manufacture of the product and shall essentially duplicate items that have been in satisfactory use for at least 2 years.

1.2.3 Nameplates

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Each major component of equipment shall have as a minimum the manufacturer's name, address, and catalog or style number on a nameplate securely attached to the item of equipment.

Nameplates for individual items of electrical equipment shall be as specified in referenced publications and shall be provided on each item of equipment. Transformer nameplates shall be permanently marked with a statement that the transformer dielectric to be supplied is non-polychlorinated biphenyl classified with less than 50 parts per million (ppm) polychlorinated biphenyl (PCB) content. If transformer nameplate is not so marked, the Contractor shall furnish manufacturer's certification for each transformer that the dielectric is non-PCB classified, with less than 50 ppm PCB content. Certifications shall be related to serial numbers on transformer nameplates. Transformer dielectric exceeding the 50 ppm PCB content or transformers without certification will be considered as PCB insulated and will not be acceptable.

1.2.4 Prevention of Corrosion

1.2.4.1 Metallic Materials

Metallic materials shall be protected against corrosion as specified.

1.2.4.2 Ferrous Metal Hardware

Ferrous metal hardware shall be hot-dip galvanized in accordance with ASTM A 153 and ASTM A 123.

1.2.6 Verification of Dimensions

The Contractor shall become familiar with details of the work, verify dimensions in the field, and advise the Contracting Officer of any discrepancy before performing any work.

1.3 SUBMITTALS

Government approval is required for all submittals. The following shall be submitted:

Components

Complete detail drawings and other descriptive data as required, after receiving complete material lists, but before installing any of these items, to demonstrate compliance with the contract documents. Provide detail drawings for the following components:

a. Transformers.

b. Pole-top switches.

Materials and Equipment:

Certificates prepared by the manufacturer, when the manufacturer's published data or drawings do not sufficiently demonstrate conformance with requirements of these specifications. Where materials or equipment are specified to conform to standards or publications, and requirements of FS, ANSI, ASTM, AWPA, IEEE, IES, NEMA, NFPA, REA, or UL, proof that the items furnished under this section of the specifications conform to such requirements. The label of, or listing in, UL-03 or the manufacturer's certification or published catalog specification data statement that the items comply with applicable specifications, standards or publications and with the manufacturer's

16370- 4 standards will be acceptable evidence of such compliance. Certifications, when specified or required, including Certificates of Compliance submitted in lieu of other proofs of compliance with these contract provisions.

Qualifications:

A certification that contains the names and the qualifications of persons that will perform electrical work under this contract. The certification shall be accompanied by satisfactory proof of the training and experience of persons as qualified electricians.

PART 2 PRODUCTS

2.1 MATERIALS

Materials shall conform to the following requirements:

2.1.1 Bare Conductors

2.1.1.2 Copper Conductors ASTM B 1 and ASTM B 8 as appropriate to the conductor size, hard-drawn temper.

2.1.2 Insulated Conductors

2.1.2.1 Low-Voltage Cables

Low-voltage cables shall be of the neutral-supported secondary and service drop type conforming to the requirements of NEMA WC 5 for thermoplastic insulation and NEMA WC 7 for cross-linked-thermosetting-polyethylene insulation.

2.1.3 Conductors

2.1.3.1 Low-Voltage Lines

Neutral-supported secondary and service drop cables shall be insulated copper with bare hard drawn copper or copper-clad steel neutrals.

2.2 COMPONENTS

2.2.1 Connectors and Splices

Connectors and splices shall be of copper alloys for copper conductors, aluminum alloys for aluminum-composition conductors, and a type designed to minimize galvanic corrosion for copper to aluminum-composition conductors.

2.2.2 Grounding and Bonding

Equipment UL 467

Wire ASTM B 8, soft drawn copper.

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2.2.3 Pole Line Hardware

Zinc-coated, ANSI C135.1, ANSI C135.2, ANSI C135.4, ANSI C135.14, ANSI C135.17, ANSI C135.22, and ANSI C135.33; and steel hardware material, ASTM A 575 and ASTM A 576. All hardware shall be hot-dip galvanized in accordance with ASTM A 153.

2.2.4 Surge Arresters

NEMA LA 1 of the zinc-oxide type suitable for outdoor installations.

2.2.5 Transformers

IEEE C57.12.00 for general requirements and ANSI C57.12.20 for specific requirements for overhead transformers.

PART 3 EXECUTION:

3.1 GENERAL INSTALLATION REQUIREMENTS

3.1.1 Conductor Installation

Conductors shall be installed in accordance with manufacturer's tables of sags and tensions.

3.1.1.1 Supports

Connectors, supports, clamps, and ties shall be designed for the particular purpose, shall be comprised of the proper material and size, and shall be installed in accordance with standard practice.

3.1.1.2 Splices and Connectors

Splices and connectors shall be mechanically and electrically secure under tension and shall be of the non-bolted compression type. The tensile strength of any splice shall be not less than the rated breaking strength of the conductor. Splice materials, sleeves, fittings, and connectors shall be noncorrosive and shall not adversely affect conductors. Connectors which are factory-filled with an inhibitor are acceptable. Inhibitors and compression tools shall be of types recommended by the connector manufacturer. Primary line apparatus taps shall be by means of hot line clamps attached to compression type bail clamps (stirrups). Low-voltage connectors for copper conductors shall be of the solderless pressure type. Non-insulated connectors shall be smoothly taped to provide a waterproof insulation equivalent to the original insulation, when installed on insulated conductors.

3.1.222 Fuse Cutouts and Fuses

Primary-fuse cutouts shall be of the load-break open type construction rated 15 kV and of the heavy-duty type. Open-link cut-outs are not acceptable. Fuses shall be either indicating or dropout type. Fuse ratings shall be equal to approximately 150 percent of transformer full-load ratings, 100 percent of cable ratings for aerial to underground transitions which serve more than one transformer, or shall be as indicated. Fuse cutouts shall be equipped with mounting brackets suitable for the indicated installations.

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3.1.3 Surge Arresters

Surge arresters shall be provided for protection of aerial-to-underground transitions, automatic circuit re-closers, capacitor equipment, group-operated load-interrupter switches, transformers and other indicated equipment. Arresters shall be distribution-valve class rated. Arresters shall be equipped with mounting brackets suitable for the indicated installations.

3.1.4 Overhead Distribution Transformers

Overhead distribution transformers shall be of the two-winding per phase, outdoor, oil-immersed type, single-phase or three-phase as indicated. Transformers shall be provided with necessary auxiliary mounting devices suitable for the indicated installation.

3.1.4.1 Requirements

Transformers shall have two 2-1/2 percent rated kVA high-voltage taps above and below rated primary voltage. Transformer tanks shall be given a rust-inhibiting treatment and shall have a standard gray finish. Transformer installations shall include one primary fuse cutout and one surge arrester for each ungrounded phase conductor. Self-protected transformers are not acceptable.

3.1.4.2 Installation

Transformers shall be carefully installed so as not to scratch finishes or damage bushings. After installation, surfaces shall be inspected and scratches shall be touched up with a finish furnished by the transformer manufacturer for this purpose.

3.1.4.3 Fused Switches

Fused switches shall be provided with integral power fuses of the dropout type. Fuse ratings shall be equal to approximately 150 percent of transformer full-load ratings, 100 percent of cable ratings for aerial to underground transitions which serve more than one transformer, or shall be as indicated. Each switch shall have a continuous current rating.

3.2 GROUNDING

Equipment, neutral, and surge arrester ground systems shall be installed at poles where indicated.

3.2.1 General Requirements

A resistance of not greater than 25 ohms shall be provided, unless otherwise specified. Ground resistances shall be measured in normally dry conditions not less than 24 hours after rainfall.

Resistances of systems requiring separate ground rods shall be measured separately before bonding below grade. The combined ground resistance of separate systems bonded together below grade may be used to meet the specified ground resistance, but the minimum number of rods indicated must still be provided.

3.2.1.1 Ground Rods

Ground rods shall be of copper-clad steel conforming to UL 467 not less than 3/4 inch in diameter by 10 feet in length of the sectional type. Ground rods shall be driven into the ground until tops of

16370- 7 rods are approximately 1 foot below finished grade. Where the specified ground resistance cannot be met with the indicated number of ground rods, additional ground rods, longer ground rods, or deep-driven sectional rods shall be installed and connected until the specified resistance is obtained, except that not more than three additional 10-foot ground rods shall be required at any one installation. Ground rods shall be spaced as evenly as possible at least 6 feet apart and connected 2 feet below grade. The Contractor may, at his option, provide copper-coil-type grounds at wood poles in lieu of ground rods where the required ground resistance can be obtained by this method.

The copper-coil-type ground shall consist of a coil of at least 12 feet of No. 6 minimum bare copper wire stapled to the butt of the pole.

3.2.1.2 Connections

Connections above grade shall be made with bolted solderless connectors, and those below grade shall be made by a fusion-welding process. Where ground wires are connected to aluminum-composition conductors specially treated or lined copper-to-aluminum connectors suitable for this purpose shall be utilized.

3.2.2 Neutral Grounding

Neutral conductors shall be grounded where indicated. Ground wire sizes, not otherwise indicated, shall have a current-carrying capacity of at least 20 percent of the largest neutral conductor to which a ground wire is connected, but in no case smaller than No. 6 AWG. Each connection to earth shall consist of a ground wire connected to a ground rod driven into the ground approximately 3 feet out from the base of the pole. Ground wires on wood poles shall be protected by half-round wood, plastic, or fiber molding from a point 18 inches above the ground line up the length of the pole. Rigid galvanized steel, schedule 80 sunlight resistant PVC or intermediate steel conduit shall protect ground wires on poles from a point 14 inches above grade to a point 6 inches below grade. The ground wire shall pass through the protective conduit unbroken. Steel protective conduit shall be terminated with a grounding bushing at each end. The ground wire shall be made electrically continuous with the steel protective conduit by jumpers of the same size as the ground wire from each bushing to the ground wire with a compression type connection at both ends.

Conduits shall be held in place by two, two-hole, galvanized, rigid conduit straps spaced approximately 9 inches apart. Moldings shall be stapled to wood poles at intervals not exceeding 2 feet, with one staple not more than 3 inches from each end of the molding. Single-point serrated staples of a type suitable for use with the molding shall be used for stapling molding to wood poles.

When not covered by molding, ground wires shall be stapled to wood poles at intervals not exceeding 2 feet. On metal poles, a preformed galvanized steel strap, 5/8-inch wide by 22-gauge minimum by length as required, secured by a preformed locking method standard with the manufacturer, shall be used to support a ground wire installation on the pole and spaced at intervals not exceeding 5 feet with one band not more than 3 inches from each end of the vertical ground wire. Bends greater than 45 degrees in ground wires are not permitted.

3.2.3 Equipment Grounding

Noncurrent-carrying metal parts of equipment and conductor assemblies, medium-voltage cable terminations and messengers, metal poles, operating mechanisms of pole top switches, panel enclosures, transformers, capacitors, recloser frames (cases) and other noncurrent carrying metal items shall be grounded as required. Ground wire sizes, not otherwise indicated, shall be not smaller than No. 6 AWG. Connections to earth shall be made in the same manner as required for secondary neutral grounding. Equipment or devices energized at less than 750 volts may be

16370- 8 connected to secondary neutral grounds of transformers with windings connected in open-delta or grounded-wye configurations. Metal poles shall be grounded at each pole and these grounds shall not be interconnected with any other grounds.

3.4.1 Operating Test

After the installation is completed, the Contractor shall conduct an operating test for approval.

Equipment shall be demonstrated to operate in accordance with the requirements herein. Tests shall be performed in the presence of the Contracting Officer. The Contractor shall furnish instruments and personnel required for the test, and the Government will furnish the necessary electric power.

3.4.2 Ground-Resistance Measurements

Ground-resistance measurements of each ground rod shall be taken and certified by the Contractor to the Contracting Officer. No part of the electrical distribution system shall be energized prior to the resistance testing of that system's ground rods and grounding systems and submission of test results to the Contracting Officer. Test reports shall indicate the location of the ground rod and grounding system and the resistance and the soil conditions at the time the test was performed.

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