260513 - Medium-Voltage Cables.pdf

Upgrade Chiller Plant @JLM: Project 1 JLM Memorial Veterans Hospital

598-19-101 01-01-17

Construction Documents 2020.12.30

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SECTION 26 05 13

MEDIUM-VOLTAGE CABLES

PART 1 - GENERAL

1.1 DESCRIPTION

A. This section specifies the furnishing, installation, and connection of medium-voltage cables, indicated as cable or cables in this section, and medium-voltage cable splices and terminations.

1.2 RELATED WORK

A. Section 26 05 11, REQUIREMENTS FOR ELECTRICAL INSTALLATIONS:

Requirements that apply to all sections of Division 26.

B. Section 26 05 26, GROUNDING AND BONDING FOR ELECTRICAL SYSTEMS:

Requirements for personnel safety and to provide a low impedance path for possible ground fault currents.

C. Section 26 05 33, RACEWAY AND BOXES FOR ELECTRICAL SYSTEMS: Conduits for medium-voltage cables.

1.3 QUALITY ASSURANCE

A. Quality Assurance shall be in accordance with Paragraph, QUALIFICATIONS

(PRODUCTS AND SERVICES) in Section 26 05 11, REQUIREMENTS FOR

ELECTRICAL INSTALLATIONS.

1.4 FACTORY TESTS

A. Factory Tests shall be required.

B. Factory Tests shall be in accordance with Paragraph, MANUFACTURED

PRODUCTS in Section 26 05 11, REQUIREMENTS FOR ELECTRICAL

INSTALLATIONS, and the following requirement:

1. A representative sample of Medium-voltage cables from each lot shall be factory tested per NEMA WC 74 to ensure that there are no electrical defects in that specific lot of cable.

1.5 SUBMITTALS

A. Submit in accordance with Paragraph, SUBMITTALS in Section 26 05 11, REQUIREMENTS FOR ELECTRICAL INSTALLATIONS, and the following requirements:

1. Shop Drawings:

a. Submit sufficient information to demonstrate compliance with drawings and specifications.

b. Submit the following data for approval:

1) Complete electrical ratings.

2) Installation instructions.

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2. Samples:

a. After approval of submittal and prior to installation, Contractor shall furnish sample in accordance with Section 26 05 11, REQUIREMENTS FOR ELECTRICAL INSTALLATIONS.

3. Certifications:

a. Factory Test Reports: Submit certified factory production test reports for approval.

b. Field Test Reports: Submit field test reports for approval.

c. Compatibility: Submit a certificate from the cable manufacturer that the splices and terminations are approved for use with the cable.

d. Two weeks prior to final inspection, submit the following.

1) Certification by the manufacturer that the cables, splices, and terminations conform to the requirements of the drawings and specifications.

2) Certification by the Contractor that the cables, splices, and terminations have been properly installed and tested.

3) Certification by the Contractor that each splice and each termination were completely installed in a single continuous work period by a single qualified worker without any overnight interruption.

4. Qualified Worker Approval:

a. Qualified workers who install cables, splices, and terminations shall have a minimum of five years of experience splicing and terminating cables, including experience with the materials in the approved splices and terminations. Qualified workers who perform cable testing shall have a minimum of five year of experience performing electrical testing of medium-voltage cables, including the ability to understand, interpret test results and develop test report.

b. Furnish satisfactory proof of such experience for each qualified worker who splices or terminates the cables.

1.6 APPLICABLE PUBLICATIONS

A. Publications listed below (including amendments, addenda, revisions, supplements, and errata) form a part of this specification to the extent referenced. Publications are referenced in the text by designation only.

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B. American Society for Testing and Materials (ASTM):

B3-13...................Standard Specification for Soft or Annealed

Copper Wire

C. Institute of Electrical and Electronics Engineers, Inc. (IEEE):

48-09...................Test Procedures and Requirements for

Alternating-Current Cable Terminations Used on

Shielded Cables Having Laminated Insulation

Rated 2.5 kV through 765 kV or Extruded

Insulation Rated 2.5 kV through 500 kV

386-06..................Separable Insulated Connector Systems for Power

Distribution Systems above 600 V

400-12..................Guide for Field Testing and Evaluation of the

Insulation of Shielded Power Cable Systems

400.2-13................Guide for Field Testing of Shielded Power Cable

Systems Using Very Low Frequency (VLF)

404-12..................Extruded and Laminated Dielectric Shielded

Cable Joints Rated 2500 V to 500,000 V

D. National Electrical Manufacturers Association (NEMA):

WC 71-14................Non-Shielded Cables Rated 2001-5000 Volts for

Use in the Distribution of Electric Energy

WC 74-12................5-46 KV Shielded Power Cable for Use in the

Transmission and Distribution of Electric

Energy

E. National Fire Protection Association (NFPA):

70-17...................National Electrical Code (NEC)

F. Underwriters Laboratories (UL):

1072-06 ................Medium-Voltage Power Cables

1.7 SHIPMENT AND STORAGE

A. Cable shall be shipped on reels such that it is protected against physical, mechanical and environmental damage. Each end of each length of cable shall be hermetically sealed with manufacturer’s end caps and securely attached to the reel.

B. Cable stored and/or cut on site shall have the ends turned down, and sealed with cable manufacturer’s standard cable end seals, or field-installed heat-shrink cable end seals.

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PART 2 - PRODUCTS

2.1 CABLE

A. Cable shall be Okonite MV105 in accordance with ASTM, IEEE, NEC, NEMA and UL, and as shown on the drawings.

B. Single conductor stranded copper conforming to ASTM B3.

C. Voltage Rating:

1. 15,000 V cable shall be used on all distribution systems with voltages ranging from 5,000 V to 15,000 V.

D. Insulation:

1. Insulation level shall be 133%.

2. Types of insulation:

a. Cable type abbreviation, EPR: Ethylene propylene rubber insulation shall be thermosetting, light and heat stabilized.

E. Insulation shield shall be semi-conducting. Conductor shield shall be semi-conducting.

F. Insulation shall be wrapped with copper shielding tape, helically-applied over semi-conducting insulation shield.

G. Heavy duty, overall protective polyvinyl chloride jacket shall enclose every cable. The manufacturer's name, cable type and size, and other pertinent information shall be marked or molded clearly on the overall protective jacket.

H. Cable temperature ratings for continuous operation, emergency overload operation, and short circuit operation shall be not less than the NEC, NEMA WC 71, or NEMA WC 74 standard for the respective cable.

2.2 SPLICES AND TERMINATIONS

A. Materials shall be compatible with the cables being spliced and terminated, and shall be suitable for the prevailing environmental conditions.

B. Splices:

1. Shall comply with IEEE 404. Include all components required for complete splice, with detailed instructions.

C. Terminations:

1. Shall comply with IEEE 48. Include shield ground strap for shielded cable terminations.

2. Load-break terminations for indoor and outdoor use: 200 A loadbreak premolded rubber elbow connectors with bushing inserts, suitable for submersible applications. Separable connectors shall comply with the

26 05 13 - 5 requirements of IEEE 386, and shall be interchangeable between suppliers. Allow sufficient slack in medium-voltage cable, ground, and drain wires to permit elbow connectors to be moved to their respective parking stands.

3. Ground metallic cable shields with a device designed for that purpose, consisting of a solderless connector enclosed in watertight rubber housing covering the entire assembly.

4. Provide insulated cable supports to relieve any strain imposed by cable weight or movement. Ground cable supports to the grounding system.

PART 3 - EXECUTION

3.1 GENERAL

A. Installation shall be in accordance with the NEC, as shown on the drawings, and manufacturer’s instructions.

B. Cable shall be installed in conduit above grade

C. All cables of a feeder shall be pulled simultaneously.

D. Splice the cables only in manholes and pullboxes.

E. Ground shields in accordance with Section 26 05 26, GROUNDING AND

BONDING FOR ELECTRICAL SYSTEMS.

F. Cable maximum pull length, maximum pulling tension, and minimum bend radius shall conform with the recommendations of the manufacturer.

G. Use suitable lubricating compounds on the cables to prevent pulling damage. Provide compounds that are not injurious to the cable jacket and do not harden or become adhesive.

H. Seal the cable ends prior to pulling, to prevent the entry of moisture or lubricant.

3.6 CIRCUIT IDENTIFICATION OF FEEDERS

A. In each pullbox, install permanent identification tags on each circuit's cables to clearly designate the circuit identification and voltage. The tags shall be the embossed brass type, 40 mm (1.5 inches) in diameter and 40 mils thick. Attach tags with plastic ties. Position the tags so they will be easy to read after the fireproofing tape is installed.

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3.7 ACCEPTANCE CHECKS AND TESTS

A. General:

1. Perform tests in accordance with the latest IEEE 400 and 400.2, manufacturer's recommendations, and as specified in this specification.

2. Contractor shall make arrangements to have tests witnessed by the

COR. Contractor shall proceed with tests only after obtaining approval from the COR.

B. Visual Inspection: Perform visual inspection prior to electrical tests.

1. Inspect exposed sections of cables for physical damage.

2. Inspect shield grounding, cable supports, splices, and terminations.

3. Verify that visible cable bends meet manufacturer’s minimum bending radius requirement.

C. Electrical Tests - New Cables: Perform preparation and tests in order shown below:

1. Preparation Prior to Testing: Splices and terminations applied to new cables shall be completed prior to testing. For renovation installation, ends of new cables intended to be spliced to existing service-aged cables shall be prepared (cut back) to allow testing without flashover or tracking. Cables shall not be connected to other equipment while under test.

2. Perform Insulation-Resistance Test. Test all new cables with respect to ground and adjacent cables. All adjacent cables shall be grounded during testing.

a. Apply test voltage for a period sufficient to stabilize output voltage and insulation resistance measurement.

b. Test data shall include megohm, applied test voltage, and leakage current readings.

c. Further testing shall not continue unless the insulation resistance test results meet or exceed the values listed below.

Test voltages and minimum acceptable resistance values shall be:

Voltage Class Test Voltage Min. Insulation Resistance

5kV 2,500 VDC 1,000 megohms

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15kV 2,500 VDC 5,000 megohms

25kV 5,000 VDC 20,000 megohms

35kV 15,000 VDC 100,000 megohms

3. Perform Tan Delta test. Review test readings with the COR prior to proceeding with the Very Low Frequency (VLF) Withstand test

4. Perform Very Low Frequency (VLF) Withstand test. Utilize test voltages in accordance with IEEE 400.2.

D. Electrical Tests - Service-Aged Cables: Tests shall be performed for serviced-age cables before inter-connecting to new cables. Perform tests in order shown below:

1. Preparation Prior to Testing: Splices and terminations applied to cables shall be completed prior to testing. Ends of cables intended to be spliced to existing service-aged cables shall be prepared (cut back) to allow testing without flashover or tracking. Cables shall not be connected to other equipment while under test.

2. Perform Insulation-Resistance Test. Test all cables with respect to ground and adjacent cables. All adjacent cables shall be grounded during testing.

a. Test data shall include megohm readings.

3. Perform Tan Delta test. Review test readings with COR prior to proceeding with the VLF Withstand test.

4. Perform VLF Withstand test. Utilize test voltages in accordance with IEEE 400.2.

F. Field Test Report: Submit a field test report to COR that includes the following information:

1. Project Name, Location, Test Date.

2. Name of Technician and Company performing the test.

3. Ambient temperature and humidity at time of test.

4. Name, Model Number and Description of Test Equipment used.

5. Circuit identification, cable length, cable type and size, insulation type, cable manufacturer, service age (if any), voltage rating, description of splices or terminations.

6. Visual field inspection notes, findings, and photographs.

7. Insulation Resistance Test results:

a. Test voltage.

b. Measurement in Megohms.

c. Leakage current.

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8. Tan Delta results:

a. Test voltage.

b. Waveform (sinusoidal or cosine-rectangular).

c. Mean Tan Delta at V0.

d. Stability measured by Standard Deviation at V0.

e. Differential Tan Delta.

f. IEEE Condition Assessment Rating.

9. VLF Withstand results:

1) Test voltage.

2) Waveform (sinusoidal or cosine-rectangular).

3) Pass/Fail Rating.

10. Conclusions. If any deficiency is discovered based on test results, provide recommendations for corrective action.

G. Final Acceptance: Final acceptance shall depend upon the satisfactory performance of the cables under test. No cable shall be put into service until all tests are successfully passed, and field test reports have been approved by the COR.

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