master_spec_16303_en.pdf

Section 16303 1

SECTION 16303

UNDERGROUND TRANSMISSION AND DISTRIBUTION LINES

PART 1 - GENERAL

1.1 APPLICABLE PUBLICATIONS

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

ITALIAN QUALITY MARK INSTITUTE (INSTITUTO ITALIANO PER IL MARCHIO DI

QUALITA’) (IMQ)

Testing and Approval of Materials.

ITALIAN NATIONAL INSTITUTE FOR THE UNIFICATION OF STANDARDS (UNI)

PUBLICATIONS

UNI 6125 (1974) Pipe Threads for Cable Conduits and

Screwed Fittings for Explosion Proof Electrical Plants

UNI 7683 (1977 )Threaded Tubes and Fittings for Cable

Conduits for Explosion Proof Electrical Installations. Unalloyed Steel Seamless and Welded Tubes, Galvanized.

UNI 8863 (1987) Seamless and Welded Pipe, in

Unalloyed Steel, Threaded IAW UNI ISO 7/1

INTERNATIONAL ELECTROTECHNICAL COMMITTEE (IEC) PUBLICATIONS

IEC 60811 (2001) Common test methods for insulating and sheathing materials of electric cables and optical cables.

IEC 614 (1994) Conduits for electrical installation.

IEC 60454-1-3 (1992) Specification for pressure-sensitive adhesive tapes for electrical purposes.

IEC 60502 (2004) Power cables with extruded insulation and their accessories for rated voltages from 1 kV (Um = 1,2 kV) up to 30 kV (Um = 36 kV)Cavi di energia con isolamento in dielettrico solido estruso per tensioni di valore da 1 KV a 30 KV.

ITALIAN ELECTROTECHNICAL COMMITTEE (COMITATO ELETTROTECNICO ITALIANO) (CEI)

PUBLICATIONS

CEI 11-1 (1999) Power installation exceeding 1 kV a.c.

CEI 11-17 (2003) Plant for production, transmission and distribution of electrical power. Cable lines.

CEI 15-15 (2002) Adhesive Tapes for Electrical

Purposes.

Section 16303 2

CEI 20-13 (1999) Cables Insulated with extruded rubber, from 1 kV to 30 kV.

CEI 20-24 (1998) Terminals and Splices for Energy

Cables.

CEI EN 50086 (1996) Protective PVC duct and accessories

CEI 64-8 (2004) Electrical System with Rated Voltage

Below 1000 V a.c. and 1500 V d.c.

ELECTROTECHNICAL STANDARDIZATION (UNIFICAZIONE ELETTROTECNICA) (UNEL)

PUBLICATIONS

UNEL 37118 (1972) Rigid Protective Conduits and

Accessories in Thermoplastic Material.

Polyvinyl Chloride Conduit; Heavy Duty Type.

UNEL 00722 (1978) Cable Color Code for Cable No. 4

Insulation Degree.

1.2 GENERAL REQUIREMENTS

Section 16050, "Basic Electrical Materials and Methods", applies to this section with additions and modifications specified herein.

1.2.1 Underground Service

Underground service into buildings shall terminate at a point 1.5 meters outside the building and projections thereof, except that service conductors shall be continuous to the interior terminating point indicated.

Connections of the underground service to the substation are included in this section. Ends of underground conduit shall be protected with removable caps until connections are made.

1.2.2 Laboratory Tests

Determine soil-density relationships as specified for soil tests in Section

02315, "Excavation and Fill".

1.3 SUBMITTALS

1.3.1 Shop Drawings (S) or , Manufacturer's Data (M)

a. Conduit (M)

b. Insulating tape (M)

c. Medium-voltage cables (M)

d. Medium-voltage terminating kits (M)

e. Manhole cast in place (S)

f. Manhole frame and cover (M)

g. Ground rods (M)

h. Low Voltage Cable (M)

1.3.2 Manufacturer's Instructions

a. Manufacturer's directions for use of ground megger with proposed method indicated.

b. Terminator manufacturer's installation instructions.

1.3.3 Certificates of Compliance

Section 16303 3

1.3.3.1 Material and Equipment

Provide manufacturer's statement certifying that the product supplied conforms to the requirements specified.

a. Manhole frame and cover.

b. High-voltage cable.

c. High-voltage terminating and splice kits.

1.3.3.2 Workmen's Competency

Thirty days before splicing or terminating is scheduled to begin, submit cable slicer's certificate of competency which shall include a certificate of completion from a splice/terminating kit manufacturer's instruction course, number of years of experience splicing high-voltage cable, and number of successful splices.

PART 2 - PRODUCTS

2.1 MATERIALS AND EQUIPMENT

Provide materials and equipment listed by CEI or approved by IMQ and complete with CE certifications, when such equipment is listed or approved.

2.1.1 Conduit

Conduit for use above grade and as indicated on the drawings shall be rigid hot dipped galvanized steel; conduit for use below grade shall be heavy wall plastic, either direct buried or encased in concrete as indicated. Conduit shall conform to the following:

2.1.1.1 Rigid steel conduit UNI 7683, IEC 614 and UNI 6125 shall have an interior and exterior zinc-coating of uniform quality and appearance throughout all surfaces. They shall consist of steel tubes with threaded fittings, couplings and connecting devices. The tubes shall have nominal trade sizes in inches, outside diameters and wall thickness equal to standard American "Schedule 40" steel pipe. Rigid conduit and fittings shall be manufactured specially for electric wiring purposes. When manufactured by a continuous weld process, weld beads both inside and outside the tube shall be completely removed prior to galvanizing. Conduit, coupling and fitting threads shall be tapered to conform to the normal iron pipe thread taper of 3/4 inch per foot (6.2%).

2.1.1.2 Plastic conduit and fittings shall be PVC and shall conform to CEI

Norms 23-8 for underground large diameter pipes with the Italian mark of Quality, CE certifications. Wall thickness shall be minimum 4.5 millimeters.

2.1.2 Tape

Plastic insulating tape shall conform to the requirements of IEC Section 454 and CEI 15-15.

2.1.3 Wire and Cable

2.1.3.1 Wire and cable conductor sizes are designated by their nominal cross sectional area given in square millimeters.

2.1.3.2 Conductors rated 600/1000 volts and less, including service entrances, shall conform to C.E.I. Norm 20-13. All conductors shall be stranded

Section 16303 4 copper. Conductor size and number of conductors in each cable shall be as indicated. Cable shall be color coded. Conductor identification shall be provided within each enclosure where a tap, splice or termination is made.

Conductor identification shall be by color coded insulated conductors or plastic coated self sticking tape or markers. Control circuit terminations shall be identified.

Colors for coding conductors shall be:

380/220 Volt System

Phase L1 - Black Phase L2 - Brown Phase L3 - Red Neutral - Light Blue Grounding Conductor - Green Yellow

2.1.3.3 Cable for 20 kV underground distribution system shall be ozone resistant ethylene propylene rubber insulated cable conforming to CEI 20-13 and IEC Publication 502. Cable shall be single conductor, employing compact round stranded copper conductors. Cable shall have conductor and insulation shielding. Insulation shielding shall be helically applied copper wire or tape. Cable shall be rated 24 kV with insulation and jacket thickness of

8.5 mm and 2.0 mm respectively. Cable shall have a polyvinyl chloride jacket.

2.1.3.4 Termination; Porcelain Insulator Type Terminator

Except as otherwise indicated, terminators for solid insulation non-metallic jacketed cables shall be porcelain insulator type. Apply terminators to single-conductor cables or to each conductor of multiple-conductor cables which are exposed to the weather. The terminator and components shall be the product of one manufacturer and furnish in a package or kit form compatible with the insulation and conductor material. The kit shall include complete assembly and installation instructions. Contractor shall supply one complete copy of manufacturer's instructions and information.

The terminator shall conform to CEI NORM 20-24. The terminator shall not exude any insulating filler compound under either test or service. The terminator shall consist of a porcelain insulator, copper cable connector-hoodnut assembly and copper aerial lug as required, metal body and supporting bracket, sealed cable entrance, internal stress relief device for shielded cable, and insulating filler compound or material.

2.1.3.5 Pull Wire

Pull wire shall be plastic having a minimum tensile strength of 100 kg force. Minimum 1 meter of slack shall be left at each end of raceway.

2.1.3.6 Connectors and Terminals

Connectors and terminals shall be designed and approved for use with the associated conductor material, and shall provide a uniform compression over the entire contact surface. Solderless terminal lugs shall be used on all stranded conductors.

2.1.4 Grounding Equipment

Section 16303 5

CEI 11-8, ground rods shall be commercially rolled round shape from a welded copper-clad steel manufactured by the molten-welding process or by the electro-formed process (molecularly bonded). They shall have an ultimate tensile strength of 5,270 kg/sq cm. The rods shall be not less than 20 millimeters in diameter by 3.0 meters in length and shall have a hard, clean, smooth, continuous copper surface and the proportion of copper shall be uniform throughout the length of the rod. The copper shall have a minimum wall thickness of 0.5 millimeters at any point on the rod.

Sectional rods are not acceptable.

2.1.5 Manholes

Manholes are referred to throughout this section as "structures" or

"underground structure".

2.1.5.1 Provide manholes, frames, covers and accessories as indicated on the drawings and specified herein.

2.1.6 Concrete

Concrete for electrical requirements shall have a compressive strength of

Rck=250 (250 kilograms per square centimeter) conforming to the requirements of Section 03300, "Cast-in-Place Concrete".

PART 3 - EXECUTION

3.1 INSTALLATION

Underground installation shall conform to CEI 11-17 CEI 11-18 except as otherwise specified or indicated.

3.1.1 Contractor Damage

The Contractor shall promptly repair any indicated utility lines or systems damaged by Contractor operations. Damage to lines or systems not indicated, which are caused by Contractor operations, shall be treated as "changes" under the terms of the General Provisions of the contract. If the contractor is advised in writing of the location of a non-indicated line or system, such notice shall provide that portion of the line or system with "indicated" status in determining liability for damages. In any event, the Contractor shall immediately notify the Contracting Officer’s Technical Representative of any such damage.

3.1.2 Underground Duct with Concrete Encasement

Shall be constructed of individual conduits encased in concrete. The type of conduit used shall not be mixed in any duct bank. Ducts shall be a minimum of 110 mm in diameter unless otherwise indicated. The concrete encasement surrounding the bank shall be rectangular in cross-section and shall provide at least 75 mm of concrete cover for ducts. Separate conduits by a minimum concrete thickness of 50 mm, except separate light and power conduits from control, signal, and telephone conduits by a minimum concrete thickness of 75 mm.

3.1.2.1 The top of the concrete envelope shall be a minimum of 500 mm below grade, except under roads and pavement, concrete envelope shall be a minimum of 600 mm below grade.

Section 16303 6

3.1.2.2 Duct banks shall have a continuous slope downward toward underground structures and away from buildings with a minimum pitch of 75 mm in 30 meters. Except at conduit risers, changes in direction of runs exceeding a total of 10 degrees, either vertical or horizontal, shall be accomplished by long sweep bends having a minimum radius of curvature of 7.5 meters; sweep bends may be composed of one or more curved or straight sections or combinations thereof. Manufactured bends shall have a minimum radius of 50 cm for use with conduits of less than 80 mm in diameter and a minimum radius of 1.5 meters for ducts of 80 mm in diameter and larger. Excavate trenches along straight lines from structure to structure before ducts are laid or structure constructed so the elevation can be adjusted, if necessary, to avoid unseen obstructions.

3.1.2.3 Terminate conduits in end-bells where ducts enter underground structures. Stagger the joints of the conduits by rows and layers to strengthen the duct bank. Provide plastic duct spacers that interlock vertically and horizontally. Spacer assembly shall consist of base spacers, intermediate spacers, and top spacers to provide a completely enclosed and locked-in duct bank. Install spacers as per manufacturer's instructions, but provide a minimum of two spacer assemblies for each 3 meters of duct bank. Before pouring concrete, anchor duct bank assemblies to prevent the assemblies from floating during concrete pouring. Anchoring shall be done by driving reinforcing rods adjacent to every other duct spacer assembly and attaching to rod to the spacer assembly.

3.1.2.4 As each section of a duct bank is completed from structure to structure, a testing mandrel not less than 30 cm long with a diameter 6 mm less than the inside diameter of the conduit shall be drawn through each conduit, after which a stiff-bristled brush, having the diameter of the conduit, shall be drawn through until the conduit is clear of earth, sand, and gravel particles. Conduit plugs shall then be immediately installed.

3.1.2.5 New conduit indicated as being unused or empty shall be provided with plugs on each end. Plugs shall contain a weephole or screen to allow water drainage. Provide a plastic pull rope having 1 meter of slack at each end of unused or empty conduits.

3.1.2.6 Connections to Manholes

Duct bank envelopes connecting to underground structures shall be flared to have an enlarged cross-section at the manhole entrance to provide additional shear strength. The dimensions of the flared cross-section shall be larger than the corresponding manhole opening dimensions by no less than 30 cm in each direction. The perimeter of the duct bank opening in the underground structures shall be flared toward the inside or keyed to provide for a positive interlock between the duct bank and the wall of the structure.

Vibrators shall be used when this portion of the envelope is poured to ensure a seal between the envelope and the wall of the structure.

3.1.2.7 Partially Completed Duct Banks

During construction wherever a construction joint is necessary in a duct bank, prevent debris such as mud, sand, and dirt from entering ducts by providing suitable conduit plugs. Fit concrete envelope of a partially completed duct bank with reinforcing steel extending a minimum of 60 cm back into the envelope and a minimum of 60 cm beyond the end of the envelope.

Provide one Ø10 mm bar in each corner, 75 mm from the edge of the envelope.

Secure corner bars with two DN 10 mm ties, spaced approximately 30 cm apart. Restrain reinforcing assembly from moving during concrete pouring.

3.1.3 Underground Conduits for Service Conductors Into Buildings

Section 16303 7

Shall be rigid steel conduits from the service equipment to a point 1.5 meter beyond the building and projections thereof. Protect the ends of the conduit by caps or bushings. Clean and plug conduit until conductors are installed. Encase the underground portion of the conduit in a concrete envelope and bury as specified for underground duct with concrete encasement.

3.1.4 Concrete for Electrical Requirements

Concrete shall be 250 kg/sq. cm minimum ultimate 28-day compressive strength with 25 mm maximum aggregate conforming to the requirements of Section 03300, "Cast-in-Place Concrete".

3.1.5 Buried Utility Warning and Identification Tape

Provide detectable aluminum foil plastic-backed tape or detectable magnetic plastic tape manufactured specifically for warning and identification of direct buried cable, conduit and ductbank. Tape shall be detectable by an electronic detection instrument. Provide tape in rolls, 5 cm minimum width, color coded for the utility involved with warning and identification imprinted in bold black letters continuously and repeatedly over entire tape length. Warning and identification shall be CAUTION BURIED (ELECTRIC) (TELEPHONE) CABLE BELOW or similar. Use permanent code and letter coloring unaffected by moisture and other substances contained in trench backfill material. Bury tape with the repainted side up at a depth of 30 cm below the top surface of earth or the top surface of the subgrade under pavements.

3.1.6 Reconditioning of Surfaces

3.1.6.1 Unpaved surfaces disturbed during the installation of duct or direct burial cable shall be restored to the original elevation and condition as specified in Section 02921, "Turf."

3.1.6.2 Paving Repairs

Where trenches, pits, or excavations are made in existing roadways and other areas of pavement where surface treatment of any kind exists, such surface treatment or pavement shall be restored as specified in Section 02741, "Bituminous Concrete Paving."

3.1.7 Cable Pulling

Cables shall be pulled down grade with the feed-in point at the manhole or buildings of the highest elevation. Flexible cable feeds shall be used to convey cables through the manhole opening and into the ducts. Cable lubricants shall be specifically recommended by the cable manufacturer.

Cable-pulling tensions shall not exceed the maximum pulling tension recommended by the cable manufacturer. Do not exceed the specified cable bending radii when installing cable under any conditions, including turnups into switches, transformers, switchgear, switchboards, and other enclosures.

Cable with tape shield shall have a bending radius not less than 12 times the overall diameter of the completed cable. Cable with wire shield shall have a bending radius not less than eight times the overall diameter of the completed cable. If basket-grip type cable-pulling devices are used to pull cable in place, cut off the section of cable under the grip before splicing and terminating.

3.1.7.1 Secondary cable runs, 1000 Volts and less, shall include a copper grounding conductor sized in accordance with CEI 11-8.

3.1.7.2 Installation of Cables in Manholes

Route cables along walls providing the longest route and the maximum spare

Section 16303 8 cable lengths. Form cables to closely parallel walls without interference to duct entrances. Support cables on brackets and cable insulators at a maximum of 1 meter.

3.1.8 Fireproofing (Arc Proofing) for Cables in Manholes

Provide for individual cable conductors which will carry current at 2200

Volts or more.

3.1.9 Manholes

3.1.9.1 Workmanship

Underground structures shall be poured in place. Horizontal concrete surfaces of floors shall have a smooth trowel finish. Cure concrete by applying two coats of white pigmented membrane forming-curing compound in strict accordance with the manufacturer's printed instructions. Locate duct entrances and windows near the corners of side walls (longer) to facilitate cable racking and splicing. Covers for underground structures shall fit the frames without undue play. Iron shall be formed to shape and size with sharp lines and angles. Castings shall be free from warp and blow holes that may impair strength or appearance. Exposed metal shall have a smooth finish and sharp lines and arises. Provide necessary lugs, rabbets, and brackets. Set pulling-in irons and other built-in items in place before depositing concrete.

3.1.9.2 Metal Frames and Covers

Provide cast iron frames and covers for manholes. The words "electric" and

"telephone" shall be cast in the top face of power and telephone manhole covers, respectively.

3.1.9.3 Pulling-in irons shall be steel bars bent as indicated, and cast in the walls. Alternatively, pipe sleeves may be precast into the walls and floors where required to accept U-bolts or other types of pulling-in devices possessing the strengths and clearances stated herein. The final installation of pulling-in devices shall be made permanent. Cover and seal exterior projections of thru-wall type pulling-in devices with an appropriate protective coating. In the floor the irons shall be a minimum of 15 cm from the edge of the sump, and in the walls the irons shall be located within 15 cm of projected center of the duct bank pattern in the opposite wall. However, the pulling-in iron shall not be located within 15 cm of an adjacent interior surface, or duct located within the same wall as the iron. If a pulling-in iron cannot be located directly opposite the corresponding duct bank due to this clearance limitation, locate the iron directly above or below the projected center of the duct bank pattern or precast window the minimum distance required to preserve the 15 mm clearance previously stated. Pulling-in irons shall have a clear projection into the structure of approximately 10 cm and shall be designed to withstand a minimum pulling-in load of 3000 kg. Irons shall be zinc-coated after fabrication.

3.1.9.4 Cable rack arms shall be steel or malleable iron and shall be of the removable type. Insulators shall be dry-process glazed porcelain. The metal portion of racks shall be zinc-coated after fabrication. Cable racks, including rack arms and insulators, shall be sufficient to accommodate the cables. Racks in power manholes shall be spaced not more than 90 cm apart, and each manhole wall shall be provided with a minimum of two racks. Racks in telephone manholes shall be spaced not more than 420 mm apart with the end rack being no further than 300 mm from the adjacent wall.

The wall bracket shall be 100 mm by approximately 40 mm by 5 mm by 1200 mm long (minimum) channel steel. Slots for mounting cable rack arms shall be spaced at 200 mm intervals. Methods of anchoring cable racks shall be as

Section 16303 9 follows:

a. Provide a 16 mm diameter by 130 mm long anchor bolt with 75 mm foot cast in structure wall with 50 mm protrusion of threaded portion of bolt into structure. Provide 16 mm steel square head nut on each anchor bolt.

Coat threads of anchor bolts with white lead immediately prior to installing nuts.

b. Provide concrete channel inserts with a minimum load rating of 400 kg per 30 cm. Insert channel shall be steel of the same length as "vertical rack channel"; channel insert shall be cast flush in structure wall. Provide 16 mm steel nuts in channel insert to receive 16 diameter by 75 mm long steel, square head anchor bolts.

c. Provide concrete "spot insert" at each anchor bolt location, cast flush in structure wall. Each insert shall have minimum 40 kg load rating.

Provide 16 mm diameter by 75 mm long steel, square head anchor bolt at each anchor point. Coat threads of anchor bolts with white lead immediately prior to installing bolts.

3.1.9.5 Field Painting

Cast-iron frames, covers, and gratings not buried in masonry shall be cleaned of mortar, rust, grease, dirt, and other deleterious materials, and coated with bituminous paint. Surfaces that cannot be cleaned satisfactorily by blasting shall be cleaned to bare metal by wire brushing or other mechanical means. Surfaces contaminated with rust, dirt, oil, grease, or other contaminants shall be washed with solvents until thoroughly cleaned.

Paint shall be as specified for shop painting in Section 16050, "Basic Electrical Materials and Methods".

3.1.10 Excavating, Backfilling, and Compacting

Provide under this section as specified in Section 02315 “Excavation and

Fill”.

3.1.11 Cable Terminating

Protect terminations of insulated power and lighting cables from accidental contact, deterioration of coverings, and moisture by the use of terminating devices and materials. Make terminations by using materials and methods indicated or specified herein or as designated by the written instruction of the cable manufacturer and termination kit manufacturer. Termination of high-voltage cables shall be rated, and be capable of withstanding test voltages, in accordance with CEI 11-17. Terminations of single cables shall include the securing and sealing of the sheath and insulation of the cable conductors, stress relief and grounding of cable shields of shielded cable, and grounding of neutral conductors, metallic sheaths, and armor.

Adequately support cables and cable terminations to avoid any excessive strain on the termination and the conductor connection.

3.1.12 Grounding

Non-current carrying metallic parts associated with electrical equipment shall have a maximum resistance to solid earth ground not exceeding the following values.

Ground in manholes 25 Ohms

Grounded other metal enclosures of primary voltage electrical and electrically-operated equipment 10 Ohms

Section 16303 10

Grounded secondary distributions system neutral and non-current-carrying metal parts associated with distribution systems and grounds not otherwise covered 10 Ohms

When work in addition to that indicated or specified is directed in order to obtain the specified ground resistance, the provisions of the contract covering "Changes" shall apply.

3.1.12.1 Grounding electrodes shall be cone-pointed ground rods, driven full depth plus 45 cm installed when indicated to provide an earth electrode subsystem ground of the appropriate value for the equipment being grounded.

3.1.12.2 System Ground (earth electrode subsystem)

The system ground comprises a ring ground around the perimeter of the substation. The mid points of the secondary windings of the substation transformer shall be connected to this ground together with the Fault Protection Subsystem.

The system ground shall be located as indicated.

3.1.12.3 Grounding connections which are buried or otherwise normally inaccessible, and excepting specifically those connections for which access for periodic testing is required, shall be made by exothermic weld.

Exothermic welds shall be made strictly in accordance with the weld manufacturer's written recommendations. Welds which are "puffed up" or which show convex surfaces, indicating improper cleaning, are not acceptable. Mechanical connectors are not required at exothermic welds.

Exothermic connections between copper ground conductor and copper clad steel ground rod shall be sealed against moisture penetration with RTV sealant.

3.1.12.4 Grounding conductors shall be stranded bare copper conforming to CEI

7-4. Conductor size shall be as indicated.

3.1.13 Special Conditions

During the construction of duct banks and underground structures located in streets, the streets shall remain open to traffic. Plan and execute the work to meet this condition.

3.2 FIELD TESTS

As an exception to requirements that may be stated elsewhere in the contract, notify the Contracting Officer’s Technical Representative in writing at least 5 working days prior to each test(s). Furnish labor, equipment, and incidentals required for testing, except that the Government will provide electric power required for the tests. Correct defects in the work provided by the Contractor and repeat tests until the work is in compliance with contract requirements. Show by demonstration in service that circuits and devices are in good operating condition. Tests shall be such that each item of control equipment will function not less than five times.

3.2.1 Distribution Conductors 600/1000 Volt Class or Less

After wiring is completed and connected ready for operation, but prior to placing systems in service and before any branch circuit breakers are closed, perform insulation resistance test in all circuits. Measure the insulation resistance between conductors and between each conductor and ground. Use an instrument capable of making measurements at an applied potential of 500 Volts. Take readings after the voltage has been applied

Section 16303 11 for a minimum of 1 minute. The minimum insulation resistance for circuits of 4 sq. mm conductors shall be 1,000,000 Ohms. For circuits of 6 sq. mm or larger conductors, a resistance based on the allowable ampere capacity of the conductor shall be as follows:

Amperes Ohms

25 through 50 250,000

51 through 100 100,000 101 through 200 50,000 201 through 400 25,000 401 through 800 12,000 Over 800 5,000

3.2.2 High-Voltage Cables

After installation and before splicing and terminating, perform a field acceptance test on cables. Prior to testing, the cables shall not be connected to any equipment. The test procedure shall be in accordance with IEC 538 and IEC 502. If cable fails to pass initial test, perform subsequent acceptance tests until the work is in compliance with contract requirements.

3.2.3 Ground Rods

Test each ground rod for ground resistance value before any wire is connected and record the values measured and compile in a report. In addition to the individual ground rod resistance, the Contractor shall measure the entire earth electrode subsystem as a whole. Both of these measurements shall be made using the three rod fall in potential method following the test instrument manufacturers test method. Perform ground resistance measurements in normally dry weather, not less than 48 hours after rainfall. Use a portable ground testing megger to test each ground or group of grounds. The instrument shall be equipped with a meter reading directly in ohms or fractions thereof to indicate the ground value of the ground electrode under test. Provide one copy of the ground megger manufacturer's directions, indicating the method to be used.

3.2.4 Sequence

Prior to energizing a high voltage cable, tests shall be performed to verify the phase sequence of all splices and terminations.

3.2.5 Test Report

a. 1000 Volt or Less Cables: Identify each cable and test result.

b. High-Voltage Cables: Identify each cable and test result.

c. Grounding Electrodes and Systems: Identify electrodes and systems for each test, as well as the resistance and soil conditions at the time the measurements were made.

-- End of Section --

SECTION 16303 UNDERGROUND TRANSMISSION AND DISTRIBUTION LINES