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MEDIUM VOLTAGE CABLE OVER VOLTS

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					STEAM EXPANSION PHASE 1                                                            PROJECT NO.: 9507400
UNIVERSITY OF CALIFORNIA, DAVIS
DAVIS, CALIFORNIA

SECTION 16135 – MEDIUM VOLTAGE CABLE (OVER 600 VOLTS)


PART 1 - GENERAL

1.1        WORK

      A.   Provide medium voltage cable complete with accessories.

      B.   Cable rated 15 kilovolt for use on 12.47 kV 3-phase, 60 hertz distribution systems.

1.2        SUBMITTALS

      A.   In addition to the requirements of Section 01334 Shop Drawings, Product Data and Samples
           and Section 16010 General Requirements for Electrical Wire, the following shall apply:

      B.   Shop Drawings:
           1.   Cable manufacturer experience
           2.   Cable shipping and handling protocol
           3.   Certified test reports.
           4.   Catalog cuts.
           5.   Splice kit information.
           6.   Separable load break connections.
           7.   List of certified cable splicers.
           8.   Pulling lubricant information
           9.   Cable Pulling Plan including set-up arrangement

1.3        QUALITY ASSURANCE

      A.   Refer to Division 1 and Section 16010 General Provisions for Electrical Work.

      B.   Cable to have 40 year warranty from date of shipment

1.4        DELIVERY, STORAGE, AND HANDLING

      A.   Delivery: Deliver cable packaged in factory-sealed containers wound on NEMA cable reels.
           Each end of each length of cable shall be hermetically sealed and securely attached to the reel.
           The minimum diameter of the real drum shall be 14 times the overall diameter of the cable. A
           pulling eye shall be installed by the manufacturer for each length of cable supplied.

      B.   Storage: Store cable in a clean dry space in original containers. Protect products from weather,
           damaging fumes, construction debris and traffic.

      C.   Cable reels shall be stored and handled in a manner which will prevent physical damage to the
           cable. Cable reels shall be stored on a hard surface to prevent contact between cable insulation
           and earth due to sinking of the reel. Impact damage between reels shall be prevented by
           aligning reels flange-to-flange or by using guards across flanges. During storage, the ends of
           all cable rated 5 kilovolt and above, shall be protected with heat shrink end caps. Heat shrink
           end caps shall be installed at the factory prior to shipment, and in the field by the Contractor on


April 13th, 2007                                      MEDIUM VOLTAGE CABLE (OVER 600 VOLTS)
Revision: 0                                                                          16135-1
STEAM EXPANSION PHASE 1                                                          PROJECT NO.: 9507400
UNIVERSITY OF CALIFORNIA, DAVIS
DAVIS, CALIFORNIA

           all cut cable ends at all termination points in switchgear and manholes prior to installing
           termination connectors.

      D.   Handling: Handle cable carefully to avoid abrading, puncturing, and tearing cable insulation
           and sheathing. Ensure that dielectric resistance integrity of cables is maintained. After
           installation, all cable sections shall be DC Hi-pot tested.


PART 2 - PRODUCTS

2.1        SINGLE CONDUCTOR SHIELDED CABLES

      A.   Overall cable rating of 105C normal, 140C emergency (1500 hours maximum), 250C short
           circuit operating temperatures, UL listed, type MV-105.

      B.   Conductor: copper, Class B compact concentric stranded. #2/0 AWG for 200 amp feeders and
           350 kcmil for 400 amp feeders.

      C.   Conductor screen: Extruded semi-conductor thermosetting “EPR” compound with resistivity
           not less than 50,000 ohm-cm at temperature of 105 degrees C, compatible with both conductor
           and insulation with an operating temperature equal to that of the insulation.

      D.   Insulation: Ethylene propylene with average thickness of 220 mils, 133 percent insulation
           level. Minimum thickness at any cross section not less than 90 percent of the average
           thickness.

      E.   Insulation screen: Extruded semiconductor thermosetting “EPR” compound with resistivity not
           in excess of 50,000 ohm-cm at 105 degrees C. Average thickness; 30 mils.

      F.   Conductor shield, insulation and insulation screen to be applied to conductor in single “triple
           extrusion” operation.

      G.   Shield: Minimum five mil copper tape applied helically with a 12-1/2 percent minimum
           overlap.

      H.   Outer jacket: Sunlight resistant extruded HMW-PE, CPE or PVC, for wet, dry locations in
           conduit, cable tray or direct buried.

      I.   Cable must be free stripping without use of heat curing or need for machine removal.

      J.   Factory testing: Completed cable shall be tested per AEIC CS6 to include AC withstand, IR,
           conductor resistance and partial discharge testing.

      K.   Cable supports: Vertical or slopping runs shall be properly supported when conduit runs
           exceed 25 feet. Provide non-metallic tape to grip cable securely. Support vertical runs of cable
           at intervals not exceeding those noted in the Electrical Code.
           1.     Manholes: Support cable in manholes with standard equipment fastened by concrete
                  inserts, as follows:
                  a.       Feeders: tie feeders to non-metallic supports or arms bracket mounted.


April 13th, 2007                                     MEDIUM VOLTAGE CABLE (OVER 600 VOLTS)
Revision: 0                                                                         16135-2
STEAM EXPANSION PHASE 1                                                            PROJECT NO.: 9507400
UNIVERSITY OF CALIFORNIA, DAVIS
DAVIS, CALIFORNIA

2.2        CABLES, SPLICES, AND CONNECTORS

      A.   General: Provide Underwriters Laboratories, Inc. (UL) listed single conductor stranded copper
           cable of sizes, ampacity, temperature ratings, and insulation materials as indicated on the
           drawings. Cables shall be manufactured and tested in accordance with latest editions of ICEA
           S-68-516, AEIC CS6 and UL Standard 1072. Cable splice kits shall be manufactured and
           tested in accordance with IEEE 386.

      B.   Insulation: Provide insulation level of 133 percent.
           1.     Cable shall be manufactured by an extrusion process utilizing compounds which have
                  been formulated and mixed at the manufacturer’s facilities.
           2.     The extruded cable core shall be wrapped with a non-magnetic shielding tape with an
                  overall PVC jacket.

      C.   Splices and Termination Kits: Provide splice and termination kits containing factory formed
           parts.
           1.     Kits shall be heavy duty, pressure type fittings, designed for proper size of cables and
                  wires being spliced and terminated. Kits shall be rated for 15 kV system use and
                  approved by the University’s Representative before installation.
           2.     Splices and terminations shall not be less than the voltage rating of cable and shall
                  include shielding and stress core material.
           3.     Kits shall be suitable for interior, exterior, or submersible applications.
           4.     Premolded rubber devices shall have a minimum of 0.125 inch semi-conductive shield
                  material covering entire housing.
           5.     Grounding of metallic shield shall be accomplished by solderless connector enclosed in
                  watertight rubber housing.
           6.     All final connections to equipment shall utilize non load break elbow connectors.
           7.     All cable connections shall be made with a hexagonal compression connection sized as
                  per manufacturer’s recommendation for the cable.
           8.     Splice kits in manholes shall be rated and sized for cable installed.
           9.     Heat shrink splices shall be Raychem HVS-1520S series or equal.
           10. Separable connector elbow splices shall be Elastimold 156LR series or equal including
                  equipment bushings, dead end plugs, dead break junctions and grounding connections.
                  a.     Apparatus bushings: Universal busing well Elastimold K1601PC with approved
                         shank or equal.
                  b.     Bushing insert: Elastimold 1501A1 or equal
                  c.     Elbow connector: Elastimold 156KR non-load break elbow with grounding
                         adapter and bailing assembly or equal

      D.   Fireproof tape: Provide tape fabricated of flexible, conformable fabric of organic composition
           coated on one side with flame-retardant elastomer.
           1.    Tape shall be arc-proof, fireproof, self-extinguishing and shall not support combustion.
           2.    Tape shall not deteriorate when subjected to water, gases, salt water, sewage, or fungus
                 and shall not be resistant to sunlight and ultraviolet light.
           3.    Provide securing tape fabricated of glass cloth electric tape not less than 7 mils thick and
                 3/4 inch wide.



April 13th, 2007                                      MEDIUM VOLTAGE CABLE (OVER 600 VOLTS)
Revision: 0                                                                          16135-3
STEAM EXPANSION PHASE 1                                                          PROJECT NO.: 9507400
UNIVERSITY OF CALIFORNIA, DAVIS
DAVIS, CALIFORNIA

      E.   Grounding: Equipment grounding conductors are required for medium voltage (2.3 kilovolt
           and above) cable equipped with metallic sheath, or provided with ground conductor in cable
           interstices and bonded to non-current carrying metallic equipment at both ends.

      F.   Shielding: Provide shielding as follows:
           1.    Ethylene propylene (EP) or ethylene propylene rubber (EPR), single conductor cables
                 shall be shielded for grounded and ungrounded neutral voltage ratings of more than
                 8,000 volts

      G.   Cable Identification: Provide on each cable outer jacket showing the name of the manufacturer,
           the year in which the cable was manufactured, and a number for identification purposes. The
           information shall be closely grouped on the cable at standard intervals to permit complete
           identification and in accordance with AEIC CS6 and UL listed for type MV-90 cable.

      H.   Flammability: Cables not enclosed in metallic conduit shall be tested for flammability. The
           assembly shall not support combustion for more than 3 seconds after application of flame or
           spark and shall not convey flame during or after application or flame or spark.

2.3        MANUFACTURERS

      A.   Medium Voltage Cable:
           1.   Kerite.
           2.   Okonite.
           3.   Pirelli.
           4.   Rome.
           5.   Or equal

      B.   Splice Kits:
           1.    Raychem, or equal.

      C.   Load Break Connectors:
           1.   Elastimold, or equal.


PART 3 - EXECUTION

3.1        INSTALLATION OF CABLE

      A.   General: Install cable in accordance with applicable codes and manufacturer’s recommendation
           under observation of University’s Representative using approved pulling set-up and approved
           pulling plan with nylon or manila rope.

      B.   Shielding: Provide continuous shielding in cable runs grounded at each end and at each splice.

      C.   Personnel Qualification: The personnel involved in splicing and assembling medium voltage
           termination shall be qualified. Qualifications of cable splicers shall be submitted to the
           University’s Representative for review. Once a termination of spice has been started by a
           worker, the same person shall complete that particular splice. Each termination and splice shall
           be started and completed in one continuous work period.

April 13th, 2007                                     MEDIUM VOLTAGE CABLE (OVER 600 VOLTS)
Revision: 0                                                                         16135-4
STEAM EXPANSION PHASE 1                                                             PROJECT NO.: 9507400
UNIVERSITY OF CALIFORNIA, DAVIS
DAVIS, CALIFORNIA

      D.   Splices and Terminations: Make splices and terminations as follows:
           1.    Splices shall be kept to a minimum and shall be made in manholes except where cable
                 terminations are specifically indicated. Splicing and terminating of cables shall be
                 expedited to minimize exposure and cable deterioration.
           2.    Cables shall be terminated as herein specified. Dry terminations with high voltage
                 pennants, preformed, or pre-fabricated stress cones may be used for terminating cables.
           3.    Terminations shall be field fabricated from termination kits supplied by and in
                 accordance with the manufacturer’s recommendations for the type, size, and electrical
                 characteristics of the cable.
           4.    The installation shall include heat or cold shrink stress-relief cones at the terminals of all
                 shielded cables and at the terminals of single conductor cables rated 15 kilovolt and
                 above, ungrounded.
           5.    Dielectric tests on insulators shall be conducted and certified by the manufacturer.
                 Thermal and routing tightness tests on factory-assembled kits shall be in accordance with
                 IEEE 48.
           6.    Cable splices shall be field fabricated from splicing kits supplied by and in accordance
                 with the cable manufacturer’s recommendations for the type, size, and electrical
                 characteristics of the cable specified. Cable splices in manholes shall be located midway
                 between cable racks on walls of manholes and supported with cable arms.
           7.    Contractor shall provide equipment to allow for proper bailing to avoid premature
                 connection failure.
           8.    Cable manufacturer shall review connectors and methods proposed by Contractor. Cable
                 manufacturer shall be notified by the Contractor prior to any terminations being
                 performed, and at the discretion of the manufacturer, be present for all field terminations
                 in order to assure that the warranty is maintained.
           9.    Do not exceed manufacturer’s recommended maximum cable pulling tension during
                 pulling. For cable pulls exceeding 200 feet, and/or exceeding two 90 degree bends,
                 provide calculations of pulling tension.         Pulling tension to be monitored via
                 dynamometer during installation. Do not exceed pulling tension of 100 lbs or value of

                    TM = No of conductors in run x cross section area of conductor in cmils x 0.008

           10.     Use only pulling compounds recommended by the cable manufacturer.
           11.     Cables shall be dressed around the perimeter of all pull boxes and manholes.

3.2        CERTIFICATION

      A.   Provide the following:
           1.    Prior to installation of cable, deliver 4 certified copies of all factory tests required by
                 referenced NEMA standards, including quality control. Tests on each length of cable
                 shall include conductor resistance; thickness of lead sheath, where specified; ionization
                 high voltage; and flammability, where specified. Tests on each sample of cable shall
                 include mechanical integrity, bending test, high-voltage time test, dielectric power loss,
                 and power-factor tests.
           2.    Furnish 4 copies of manufacturer’s written certification that the products furnished for
                 this project meet or exceed referenced NEMA standards and NFPA 70 requirements.



April 13th, 2007                                       MEDIUM VOLTAGE CABLE (OVER 600 VOLTS)
Revision: 0                                                                           16135-5
STEAM EXPANSION PHASE 1                                                           PROJECT NO.: 9507400
UNIVERSITY OF CALIFORNIA, DAVIS
DAVIS, CALIFORNIA

           3.      After testing, submit 4 certified copies of each graph, specified hereinafter under field
                   testing. Include adequate information identifying cable locations, types, voltage rating
                   and sizes.
           4.      After splices and terminations have been installed and tested, deliver 4 copies of
                   certificate which includes the following:
                   a.     A statement that materials, detail drawings and printed instructions were those
                          contained in kits approved for this Contract.
                   b.     A statement that each splice and each termination was completely installed
                          without any overnight interruption.
                   c.     A statement that field made splices and terminations conform to these
                          specifications.

3.3        CERTIFIED FIELD TESTS AFTER INSTALLATION

      A.   Perform visual and mechanical inspection after cable installation, splices, and terminations
           have been made, but before connection to equipment, as follows:
           1.    Inspect exposed sections for physical damage.
           2.    Verify cable is supplied and connected in accordance with single-line diagram.
           3.    Inspect for shield grounding, cable support, and termination.
           4.    Check for visual cable bends against ICEA or manufacturer’s minimum allowable
                 bending radius.
           5.    Inspect for proper fireproofing in common cable area.
           6.    If cables are terminated through window-type CT’s make an inspection to verify that
                 neutrals and grounds are properly terminated for proper operation of protective devices.
           7.    Visually inspect jacket and insulation condition.
           8.    Inspect for proper phase identification and arrangements.

      B.   Contractor shall hire an Independent Testing Company to perform electrical tests prior to
           connecting equipment and in the presence of Quality Control Engineer hired by the Contractor.
           Contractor shall provide minimum of 7 work days notice before testing. University’s
           Representative shall also be present. Tests shall be as follows:
           1.    Perform a shield continuity test on each power cable by the ohmmeter method. Record
                 ohmic value.
                 a.     Shielding must exhibit continuity. Investigate resistance values in excess of
                        10 ohms per 1000 feet of cable.
           2.    Perform an insulation-resistance test utilizing a megohmmeter with a voltage output of at
                 least 2500 volts and capable of measuring 2,000 megohms minimum. Individually test
                 each conductor with all other conductors and shields grounded. Test duration shall be
                 one minute. Minimum acceptable insulation resistance is 750 megohms.
           3.    Perform a dc high-potential test on all cables. Adhere to all precautions and limits as
                 specified in the applicable NEMA/ICEA standard. Perform tests in accordance with
                 ANSI/IEEE Std. 400. Test procedure shall be as follows, and the results shall be
                 recorded as specified herein. Test voltage shall not exceed 80 percent of cable
                 manufacturer’s factory test value or the maximum test voltage in NETA ATS.
                 Overpotential tests shall not be performed until insulation-resistance levels are above
                 minimum values. If splices or terminations are included in the tested length, the
                 accessory manufacturer is to be consulted for maximum permissible test voltages.


April 13th, 2007                                      MEDIUM VOLTAGE CABLE (OVER 600 VOLTS)
Revision: 0                                                                          16135-6
STEAM EXPANSION PHASE 1                                                           PROJECT NO.: 9507400
UNIVERSITY OF CALIFORNIA, DAVIS
DAVIS, CALIFORNIA

                   a.   Current-sensing circuits in test equipment shall measure only the leakage current
                        associated with the cable under test and shall not include internal leakage of test
                        equipment.
                   b.   Record wet-and dry-bulb temperatures or relative humidity and temperature.
                   c.   Test each section of cable individually.
                   d.   Individually test each conductor with all other conductors grounded. Ground all
                        shields.
                   e.   Terminations shall be properly corona-suppressed by guard rings, field reduction
                        sphere, or other approved methods as necessary.
                   f.   Ensure that the maximum test voltage does not exceed the limits for terminations
                        specified in IEEE Standard 48 or manufacturer’s specifications.
                   g.   Apply a DC high-potential test in at least five (5) equal increments starting with
                        initial voltage of 15 kV until maximum test voltage of 63 kV or splice or
                        termination voltage limits is reached. No increment shall exceed the voltage
                        rating of the cable. Record DC leakage current at each stop after a constant
                        stabilization time consistent with system charging current.
                   h.   Raise the conductor to the specified maximum test voltage and hold for five
                        minutes. Record readings of leakage at 30 seconds and one minute and at one
                        minute thereafter. Investigate any leakage current readings in excess of
                        10 microamps for each 1000 feet of cable under test.
                   i.   Reduce conductor test potential to zero and measure residual voltage at discrete
                        intervals.
                   j.   Apply grounds for a time period adequate to drain all insulation stored charge.
                   k.   For DC high-potential test:
                        1)         Step voltage slope shall be reasonable linear.
                        2)         Absorption slope shall be flat or negative. In no case shall slope exhibit
                                   positive characteristic.
                   l.   Maximum leakage current shall not exceed IL corrected to 60 degrees F where
                        IL = E/KLOG p/d.
                        K = insulation specific resistance Megohm/MFT at 60 degrees F.
                        D = diameter over insulation.
                        d = diameter under insulation.
                        E = maximum test voltage.
                   m.   A log-log graphic plot shall be made with leakage current (Y-axis) versus voltage
                        (X-axis) at each increment. The step voltage slops shall be reasonably linear.
                        Graph shall include current vs. time recorded at 1 minute intervals after final
                        voltage reached. Absorption slope shall be flat or negative. In no case shall slope
                        exhibit a positive characteristic.
                   n.   Submit written report to University’s Representative. Each report sheet to include
                        the following data:
                        1)         Date
                        2)         Name of test operator
                        3)         Section of cable tested
                        4)         Cable insulation type
                        5)         Cable length
                        6)         Nominal cable rating
                        7)         Cable manufacturer and product identification


April 13th, 2007                                      MEDIUM VOLTAGE CABLE (OVER 600 VOLTS)
Revision: 0                                                                          16135-7
STEAM EXPANSION PHASE 1                                                           PROJECT NO.: 9507400
UNIVERSITY OF CALIFORNIA, DAVIS
DAVIS, CALIFORNIA

                        8)         Conductor size
                        9)         Test equipment identification
                        10)        Test type
                        11)        Each test report page shall be signed by the test operator and endorsed
                                   by the Contractor.
                   o.   Correct or replace cable testing below manufacturer’s standards at no additional
                        cost to the University.

3.4        INSPECTION

      A.   The Contractor shall hire a Quality Control Engineer to conduct periodic inspections of the
           installation of cable, and shall report in writing to the Contractor any deviations from good
           installation practice observed.

      B.   On completion of cable installation, the Quality Control Engineer shall inspect the complete
           system and report in writing any installation errors or fault in the system that could affect the
           performance of the system.

      C.   The Contractor shall submit a report to the University’s Representative including the Quality
           Control Engineer’s final report indicating all reported as properly installed or requiring
           correction, and include a report by the Contractor on steps taken to properly complete the work.


END OF SECTION 16135




April 13th, 2007                                     MEDIUM VOLTAGE CABLE (OVER 600 VOLTS)
Revision: 0                                                                         16135-8

				
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