W912P5-16-R-0002TSpecsAm2Pages.pdf

Unit 4 Rehabilitation Old Hickory Powerhouse W912P5-16-R-0002 Amendment No. 0002 Sumner County, Tennessee

SECTION TABLE OF CONTENTS

DIVISION 01 - GENERAL REQUIREMENTS

SECTION 01 11 10

SUMMARY OF WORK

PART 1 GENERAL

1.1 ASBESTOS ABATEMENT

1.2 WORK COVERED BY CONTRACT DOCUMENTS

1.2.1 Site Work and Structural

1.2.2 Turbine

1.2.3 Electrical

1.2.4 Mechanical Components

1.3 CHANGES IN SPECIFICATIONS AND DRAWINGS

1.4 DEFINITIONS

1.4.1 Directed, Required, Ordered, Designated, Prescribed

1.4.2 As Shown, As Indicated, As Detailed

1.4.3 Furnish

1.4.4 Contracting Officer (KO), Contracting Officer's Representative

(COR)

1.4.5 Government Quality Assurance Representative

1.4.6 Weekend(s)

1.4.7 Project

1.4.8 Contract Line Item Number (CLIN)

PART 2 PRODUCTS

PART 3 EXECUTION

-- End of Section Table of Contents --

SECTION 01 11 10 Page 1

SECTION 01 11 10

SUMMARY OF WORK

PART 1 GENERAL

1.1 ASBESTOS ABATEMENT

Removal and disposal of asbestos containing materials encountered during the execution of this contract will be performed by others. In generators of similar vintage, asbestos containing materials have been found in, but are not limited to, various electrical wiring insulation, electrical cabinet panel boards, windings and rotor poles. Results of Asbestos Material Survey are included, for your information, in Appendix A - FORMS

AND ATTACHMENTS.

An Asbestos Coordination Meeting, setup by the Government, will be conducted between the Government, Contractor, and the Government's asbestos contractor (GAC) to achieve a clear and mutual understanding of scope and schedule associated with asbestos removal. The Asbestos Coordination Meeting shall take place NLT 90 days after NTP and after submittal of the GAC Rotor Cleaning and Testing Procedure. The Contractor's schedule shall anticipate the inability to work in areas where asbestos abatement activities are ongoing.

1.2 WORK COVERED BY CONTRACT DOCUMENTS

The Old Hickory powerhouse is located on the Cumberland River in Tennessee, northeast of Nashville. There are four main turbine generating units at the Old Hickory powerhouse. The requirements of this contract are to provide all equipment, labor, materials and work required to refurbish Old Hickory Turbine Generating Unit 4 only. The rehabilitation of this turbine generator unit shall include the rehabilitation of the existing runner with required disassembly of the runner hub and replacement and refurbishment of internal components, rewind of the generator and replacement or rehabilitation of other components as required in the body of the specification.

The existing turbines are five bladed Kaplan type manufactured by Baldwin-Lima-Hamilton. They were designed for a maximum output of 45,000 hp, but have been operated at 35,000 hp to accommodate the existing generator nameplate of 31,250KVA at a power factor of 0.8. The units have been generator limited over their life.

The Government will provide the Contractor with formal written notice to proceed with the fabrication, delivery, and field work required for the rehabilitation of the Unit 4 turbine generating unit and refurbishment of appurtenances for this unit.

The Contractor shall also be required to rehabilitate Unit 4 by replacement of the generator stator core and stator winding; and re-insulation and testing of the field winding. The new stator winding shall be rated at 45,000 KVA at a power factor of 0.9 with a temperature rise limited to 75 degrees C above a 40 degree C ambient temperature.

The following list is a general summary of the required work and is not all-inclusive. The specifications and drawings cover the work in detail.

SECTION 01 11 10 Page 2

SECTION TABLE OF CONTENTS

DIVISION 26 - ELECTRICAL

SECTION 26 11 15.00

HIGH RESISTANCE GROUNDING SYSTEM (HRG)-MEDIUM VOLTAGE

PART 1 GENERAL

1.1 SUMMARY

1.2 REFERENCES

1.3 SUBMITTALS

PART 2 PRODUCTS

2.1 HIGH RESISTANCE GROUNDING EQUIPMENT (HRG)

2.2 MATERIALS

2.3 DISCONNECT SWITCH

2.4 TRANSFORMER

2.5 RESISTOR

2.5.1 15 kV Cable

2.6 BUS

2.7 WIRING/TERMINATIONS

2.8 ENCLOSURE

2.9 NAMEPLATES

2.10 ACCESSORIES

PART 3 EXECUTION

3.1 FACTORY TESTS

3.2 FIELD QUALITY CONTROL

3.3 FIELD TESTING

3.4 DRAWINGS

3.5 DEMOLITION

3.6 INSTALLATION OF HIGH RESISTANCE GROUND EQUIPMENT (HRG)

3.7 CONTRACTOR-FURNISHED TRAINING FOR GOVERNMENT PERSONNEL

3.8 QUALIFICATIONS OF FIELD ENGINEERING SUPERVISOR

3.9 OPERATION AND MAINTENANCE DATA

SECTION 26 11 15.00 Page 1

SECTION 26 11 15.00

HIGH RESISTANCE GROUNDING SYSTEM (HRG)-MEDIUM VOLTAGE

PART 1 GENERAL

1.1 SUMMARY

a. This section covers the supply and installation of one high resistance grounding (HRG) system at Old Hickory. The system shall be connected to the wye point of the unit 4 generator. The generator is presently rated at 31,250 kVA with a 115% overload capacity, but it will will be rewound and uprated to 45,000 kVA as part of this contract.

b. The Contractor shall remove the existing generator neutral grounding equipment, which consists of a 15 kV 500 MCM cable; air circuit breaker rated 13.8 kV, 1200 amps, 250 MVA; and a reactor rated 9200 amperes (10 sec), 0.45 ohm. The Contractor shall dispose of the removed equipment except for the air circuit breaker. The removed air circuit breaker shall be turned over to the Government and remain Government property.

c. The new HRG system shall be installed in the same location as the existing generator neutral grounding circuit breaker.

d. The grounding equipment for the system shall include a 15 kV cable connecting the generator neutral to the HRG, a single-pole hook-stick-operated disconnecting switch, a dry-type transformer, a resistor, and a Government furnished, installed, and programmed multi-function digital protective relay, and associated wiring. The contractor will install and test the wiring to the control room terminal blocks.

e. The Contractor should be aware that asbestos wipe tests have tested positive for the neutral circuit breaker arc chute rope gasket.

1.2 REFERENCES

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

AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI)

ANSI C57.12.50 Ventilated Dry-Type Distribution Transformers, 1 to 500 kVA, Single-Phase, and 15 to 500 kVA, Three-Phase, With High-Voltage 601 to 34,500 Volts, Low-Voltage 120 to 600 Volts

INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS (IEEE)

IEEE C2 (2007) National Electrical Safety Code

IEEE C37.20.2 (1999; R 2005) Metal-Clad Switchgear

IEEE C37.20.4 (2001) Indoor AC Switches (1 kV - 38 kV)

SECTION 26 11 15.00 Page 2

SECTION TABLE OF CONTENTS

DIVISION 48 - ELECTRICAL POWER GENERATION

SECTION 48 13 16.00

GENERATOR REWIND AND REFURBISHMENT

PART 1 GENERAL

1.1 GENERAL

1.2 REFERENCES

1.3 SUBMITTALS

1.4 EXISTING GENERATOR INFORMATION

1.4.1 Unit Identification and Nameplate

1.4.2 Description of Generator

1.4.3 Test Report Data

1.4.4 Unit 4 Failure History

1.4.5 Inspection By Contractor

PART 2 PRODUCTS

2.1 MATERIALS

2.2 PROTOTYPE STATOR COILS

2.3 WINDING RATING AND INSULATION CLASS

2.4 NEW STATOR COILS

2.4.1 General

2.4.2 Conductor Strands

2.4.3 Turns

2.4.4 Ground Insulation

2.4.5 Drying

2.4.6 Resin Impregnation and Curing

2.4.7 Alternate Construction

2.4.8 Finish and Partial Discharge (Corona) Suppression Treatments

2.4.9 Graded Suppression Treatment

2.4.10 Testing

2.4.11 Coil Identification and Record

2.4.12 Quantity

2.4.13 Submittals

2.5 RESISTANCE TEMPERATURE DETECTORS (RTDs)

2.6 NEW CIRCUIT RINGS

2.6.1 General

2.6.2 Design Drawings

2.6.3 Electrical Configuration

2.6.4 Physical Construction

2.6.5 Insulation

2.6.6 Neutral Current Transformers

2.7 FILLERS, WEDGES, TIES, AND BLOCKING MATERIAL

2.7.1 General

2.7.2 Side Packing

2.7.3 Center Filler and Bottom Filler

2.7.4 Spring-Type Filler Material

2.7.5 Wedges and Top Fillers

2.7.6 Two-Part Wedges

2.7.7 End Winding Bracing and Blocking Material

2.8 NEW STATOR CORE

2.9 PARTIAL DISCHARGE ANALYSIS SYSTEM

2.9.1 General

SECTION 48 13 16.00 Page 1

2.9.2 Coupling Capacitors

2.9.2.1 General

2.9.2.2 Rating

2.9.2.3 Construction

2.9.3 Leads

2.9.4 Termination Panel

2.9.5 Analyzer

2.10 SPARE PARTS

2.10.1 General

2.10.2 Stator Coils and Supplies

2.10.3 RTDs and RTD cable

2.10.4 Laminations

2.10.5 Stator Core Vent Duct Laminations

2.10.6 Packaging and Storage

2.11 NEW NAMEPLATE

2.12 NEW TERMINAL BOARD

PART 3 EXECUTION

3.1 GENERAL TESTING REQUIREMENTS

3.2 ACCELERATED LIFE TESTS

3.2.1 Test Procedure

3.2.2 Prototype Coils

3.2.3 Production Run Coils

3.3 Thermal Cycling Test

3.4 COIL TESTS AT FACTORY

3.5 SPRING TYPE FILLER MATERIAL TEST

3.6 RESISTANCE TEMPERATURE DETECTOR (RTD) TESTS AT FACTORY

3.7 STATOR CORE PUNCHING TESTS

3.8 GENERATOR DISASSEMBLY

3.9 REMOVAL OF EXISTING WINDING BY GOVERNMENT ASBESTOS CONTRACTOR

3.10 STATOR CORE REPLACEMENT

3.10.1 General

3.10.2 Stator Core Removal

3.10.3 Inspection

3.10.4 Center and Round Stator

3.10.5 Stack Stator Iron

3.10.6 Final Check

3.11 STATOR CORE INTERLAMINAR INSULATION TEST

3.11.1 General

3.11.2 Test Procedure

3.12 Application of Epoxy

3.13 Application Of Varnish

3.14 INSTALLATION OF NEW STATOR WINDING

3.15 TESTS DURING WINDING INSTALLATION

3.16 PARTIAL DISCHARGE ANALYSIS (PDA) SYSTEM INSTALLATION

3.16.1 Coupling Capacitors

3.16.2 Leads

3.16.3 Termination

3.17 PARTIAL DISCHARGE ANALYSIS (PDA) SYSTEM TESTS, BASELINE PDA

MEASUREMENTS, AND TRAINING

3.17.1 General

3.17.2 Test Equipment

3.17.3 PDA Tests

3.17.4 PDA Test Report

3.17.5 Stator Winding Baseline PDA Measurements

3.17.6 PDA System Training

3.18 CLEANING ROTATING MAIN AND PILOT EXCITERS AND TRUING COLLECTOR

RINGS

SECTION 48 13 16.00 Page 2

3.19 REINSULATION OF ROTOR POLES

3.19.1 General

3.19.2 Rotor Pole Removal

3.19.3 Government Asbestos Contractor to Transport Rotor Poles

3.19.4 Reinsulation of Rotor Poles

3.19.5 Factory Tests Of Rotor Poles

3.19.6 Transportation of Rotor Poles to Job Site

3.19.7 Inspect and Clean Rotor

3.19.8 Reinsulation of the Field Leads

3.19.9 Rotor Pole Installation, Connections, and Final Testing

3.20 INITIAL ACCEPTANCE TESTS

3.21 GENERATOR REASSEMBLY

3.22 GENERATOR DRY-OUT

3.23 FINAL ACCEPTANCE TESTS

3.24 GENERATOR SPECIAL FIELD TESTS

3.24.1 General

3.24.2 Verification Tests

3.25 STATOR FOUNDATION GROUT REPAIR

3.26 NEW TERMINAL BOARD INSTALLATION AND NEW WIRING

3.27 WIRING REMOVAL BY GOVERNMENT ASBESTOS CONTRACTOR

SECTION 48 13 16.00 Page 3

SECTION 48 13 16.00

GENERATOR REWIND AND REFURBISHMENT

PART 1 GENERAL

1.1 GENERAL

This section covers rehabilitation of the Old Hickory Unit 4 generator to include the supply of a stator winding and accessories, stator core, reinsulated rotor poles, neutral current transformers, PDA system, and spare parts; removal and installation of the stator core, rotor poles, and current transformers; installation of the stator winding, and the PDA system. Additionally, this section also covers factory and field tests for the stator winding and accessories, the stator core, the rotor poles, and special field tests. The generator stator winding, generator stator and turbine wiring, and generator rotor pole insulation will be removed under a seperate contract by the Government Asbestos Contractor. The Contractor will be required to coordinate with the Government Asbestos Contractor.

1.2 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.

ASTM INTERNATIONAL (ASTM)

ASTM A 343 (2014) Standard Test Method for Alternating-Current Magnetic Properties of Materials at Power Frequencies Using Wattmeter-Ammeter-Voltmeter Method and 25-cm Epstein Test Frame

ASTM A 717 (2012) Standard Test Method for Surface Insulation Resistivity of Single-Strip Specimens

ASTM A 720 (2002; R 2011) Standard Test Method for Ductility of Nonoriented Electrical Steel

ASTM D 1868 (2013) Standard Test Method for Detection and Measurement of Partial Discharge (Corona) Pulses in Evaluation of Insulation Systems

AMERICAN WELDING SOCIETY, INC. (AWS)

AWS A5.8 (2011) Specification for Filler Metals for Brazing and Braze Welding

CEA TECHNOLOGIES INC. (CEATI)

CEATI T052700 0329 (2008) Hydroelectric Turbine Generator Units - Guide for Erection Tolerances and Shaft System Alignment

SECTION 48 13 16.00 Page 4

INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS (IEEE)

IEEE 43 (2013) IEEE Recommended Practice for Testing Insulation Resistance of Rotating Machinery

IEEE 56 (1976; R 1991 Withdrawn) Guide for Insulation Maintenance of Large Alternating-Current Rotating Machinery Note: The requirements of IEEE 56 are part of this specification even though the standard is no longer in publication. The Contractor shall obtain a historical copy of the standard for use.

IEEE 95 (2002; R 2007) IEEE Recommended Practice for Insulation Testing of AC Electric Machinery (2300 V and Above) With High Direct Voltage

IEEE 115 (1995; R 2002) IEEE Guide for Test Procedures for Synchronous Machines

IEEE 286 (2000; R 2012) IEEE Recommended Practice for Measurement of Power Factor Tip-Up of Electric Machinery Stator Coil Insulation

IEEE 522 (2004; R 2009) IEEE Guide for Testing Turn Insulation of Form-Wound Stator Coils for Alternating-Current Electric Machines

IEEE 1043 (1996; R 2009) IEEE Recommended Practice for Voltage-Endurance Testing of Form-Wound Bars and Coils

IEEE 1310 (2012) IEEE Recommended Practice for Thermal Cycle Testing of Form-Wound Stator Bars and Coils for Large Rotating Machines

IEEE C50.12 (2005; R 2010) Standard for Salient Pole 50 HZ and 60 Hz Synchronous Generators and Generation/Motors for Hydraulic Turbine Applications Rated 5 MVA and above

NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION (NEMA)

NEMA LI 1 (1998; R 2011) Industrial Laminated Thermosetting Products

1.3 SUBMITTALS

Government approval is required for submittals with a "G" designation;

submittals not having a "G" designation are for information only. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government. The following shall be submitted in accordance with SECTION 01 33 00 SUBMITTAL PROCEDURES:

SD-01 Preconstruction Submittals

SECTION 48 13 16.00 Page 5

Within 60 calendar days after date of receipt of written notice to proceed:

Coil Transposition: G, HDC A description of the transposition within each stator coil and/or in external coil to coil connections.

Coil Insulation System; G, HDC A description of the coil insulation system, including processes and materials employed to meet specification requirements.

Winding Capacitance Provide the winding capacitance for each phase.

Factory Test Methods; G, HDC An outline and description of the test methods and equipment to be employed in the factory test for the stator coils including all required test values.

Facility Information; G, HDC The name and address of the facilities proposed to perform the accelerated life testing of the prototype coils and the production run coils; and the thermal cycling test.

Within 90 calendar days after date of receipt of written notice to proceed:

Thermal Cycling Test; G, HDC Provide a detailed test procedure for the thermal cycling test.

DC I²R Copper Losses; G, HDC Detailed design calculations illustrating how the stator DC I²R (copper) losses are determined at 75 degrees C. Calculations shall illustrate the composition of the various portions of winding circuit resistance, including number of coils in series and parallel connections, end connections, circuit rings, etc.

Stray Load Losses; G, HDC Detailed calculations showing how the stray load loss is determined.

Temperature Rise; G, HDC Maximum temperature rise of the new winding above 40 degrees C ambient at rated load, voltage, and power factor.

Wedging Deflection Characteristics; G, HDC The wedging deflection characteristics shall include the following:

a. Initial deflection of slot wedging spring-type filler and radial pressure applied to stator coils in slot portions.

b. Minimum acceptable deflection of the slot wedging spring-type filler after extended operation, and the radial pressure applied to stator coil at the minimum acceptable deflection.

c. Method for verifying spring type filler material at the three quarter points of the slot.

SECTION 48 13 16.00 Page 6

d. Calculations to show that the radial pressure wedging system forces will exceed the non-fault-condition forces throughout the life of the winding. Forces shall be calculated at rated load, voltage, power factor, and at worst fault condition.

Stator Winding Assembly Materials; G, HDC A description of the materials for the assembly of the stator coils into the generator. This shall include all wedging, filler, brazing materials, and end-winding bracing and blocking materials.

Catalog cuts for the RTDs and RTD cable; G, HDC

Within 120 calendar days after date of receipt of written notice to proceed:

Spare Parts List; G, HDC

Rotor Pole Removal and Reinstallation Procedure; G, HDC Provide a procedure for rotor pole removal and reinstallation, including laydown and laydown tooling and crating. Include brazer qualifications.

Procedure for Cleaning, Inspecting and Testing the Rotor; G, HDC Provide procedures for cleaning, inspecting, and testing the rotor. Include detailed test procedures, including sketches and test equipment information for the insulation resistance, pole drop, AC high potential, and winding resistance tests. State the pole drop test voltage and rotor pole varnish minimum and maximum thickness as well as catalog data for the varnish.

Cleaning and Truing Procedures; G, HDC

Rotor Pole Reinsulation Procedure; G, HDC

Field Leads Reinsulation procedure; G, HDC

Lamination Test Procedure; G, HDC An outline and description of the test methods and equipment to be employed in the Epstein test, Franklin test, and Ductility test for the stator core laminations, including all required test values and acceptance criteria.

Stator Core Stacking Procedure; G, HDC Detailed procedures for stacking the stator core including stacking tolerances.

Interlaminar Insulation Test Procedure; G, HDC Technical details of the interlaminar insulation test including power requirements.

Stator Winding Installation Procedure; G, HDC The procedure shall include sufficient detail for the Government inspectors to determine if work is being performed in accordance with the manufacturer's and contract's requirements. The procedure shall include a description of the brazing methods for winding connections and the quality control checks to be used in those operations. The procedure shall also include calculations of the loading of the spring-type washers.

SECTION 48 13 16.00 Page 7

Final Acceptance Test Procedures; G, HDC An outline and description of the test methods and equipment to be employed in the field tests for the completed winding.

Generator Special Field Tests Procedure; G, HDC An outline and description of the test methods and equipment to be employed in the special field tests for the completed winding.

The procedure shall include the following:

(1) Setup, including sketches of connections

(2) Step-by-step procedure of each test

(3) Responsible party for each step of each test

(4) Testing schedule, including setup and teardown

Within 150 calendar days after date of receipt of written notice to proceed:

Stator Foundation Grout Repair; G, HDC An outline and description of the repair areas including the methods proposed for repairing the spalling and the materials proposed for the repair.

Field Current Calculations; I, HDC Provide the calculated field current required for 25, 50, 75, and 100 percent of rated load operation.

Generator Losses Calculations; I, HDC Provide the calculated generator losses for 25, 50, 75, and 100 percent of rated load operation.

Neutral Current Transformer Manufacturer's Information; G, HDC

SD-02 Shop Drawings

Note: Shop drawings shall include a parts list as appropriate.

Within 60 calendar days after date of receipt of written notice to proceed:

Cross-Sectional View of the Proposed Stator Coils; G, HDC A cross-sectional view of the proposed stator coils in a stator slot, describing the stranding arrangement, strand dimensions, copper cross-sectional area, strand insulation details (including insulating material types and thicknesses), slot fillers, wedging details, and partial discharge suppressive treatments. Drawing shall also include groundwall insulation materials and thickness.

Exterior Dimensions of the Stator Coils; G, HDC Drawing shall include bending radii, dimensions of slot paint and grading paint.

Dimensions and Details of the Wedges and Fillers; G, HDC

Bracing Configuration for the Winding; G, HDC

Circuit Ring Configuration and Dimensions; G, HDC

Details of the Connections; G, HDC

SECTION 48 13 16.00 Page 8

This shall include connection from coils to circuit rings and from circuit rings to main and neutral leads.

Details of the Main and Neutral Leads; G, HDC

Winding Diagram; G, HDC A drawing that shows three phases in different colors and showing partial discharge analysis (PDA) and RTD location.

Partial Discharge Analysis (PDA) System; G, HDC Details of the PDA system and installation, including coupling capacitor details, coupling capacitor location and mounting, termination panel details, termination panel location, and coaxial cable routing and mounting.

Nameplate; G, HDC Dimensions, material, and arrangement of information on the new nameplate.

New Stator Core Design; G, HDC Include a lamination fabrication procedure and detailed manufacturing drawings for all new components. Include bills of material and overall assembly drawing.

Within 120 calendar days after date of receipt of written notice to proceed:

Terminal Board Drawings; G, HDC Provide detailed drawings of the new generator terminal board.

Include assembly details, mounting details, terminal block arrangements, etc.

SD-06 Test Reports Except as noted, test reports shall be submitted within 30 calendar days after the completion of testing.

Prototype Coil Test Report; G, HDC

Thermal Cycling Test Report; G, HDC

Production Run Coil Test Report; G, HDC

Spring Test Report or Catalog Cut; G, HDC

RTD Factory Test Report; G, HDC

Factory Coil Test Report; G, HDC

Stator Inspection Report; G, HDC The report shall include any unusual conditions, any problems that need to be corrected, any recommendations for correcting the problems, and an estimate of labor, materials, and time required to correct the conditions.

Interlaminar Insulation Test Report; G, HDC The report shall include thermal couple readings, setup photos, infrared photos of hot spots, and repair recommendations if hot

SECTION 48 13 16.00 Page 9 spots are found.

Report of Tests During Winding Installation; G, HDC

Partial Discharge Analysis System Test Report; G, HDC

Initial Acceptance Test Report; G, HDC

Final Acceptance Test Report; G, HDC

Generator Special Field Test Report; G, HDC

Exciter Inspection Report; G, HDC

Rotor Inspection Report; G, HDC The report shall include any unusual conditions, any problems that need to corrected, any recommendations for correcting the problems, and an estimate of labor, materials, and time required to correct the conditions.

Rotor Test Report; G, HDC

Coil Test Record; G, HDC

Preliminary Coil Inspection Report; G, HDC

Stator Winding Final Inspection Report; G, HDC

Stator Core Final Check Report; G, HDC

Lamination Test Report; G, HDC

1.4 EXISTING GENERATOR INFORMATION

1.4.1 Unit Identification and Nameplate

The Old Hickory generators are air-cooled, vertical hydro-generators, manufactured by the General Electric Company. The units were commissioned in 1957. Generator ratings, as defined by the nameplate stamping information are as follows:

31,250 kVA

0.80 Power Factor

13,800 V 3-phase 60 Hz

75 RPM

115 percent overload capability

1.4.2 Description of Generator

The generator is designed for star connection of the stator winding with each phase consisting of four parallel circuits and each circuit containing 42 five-turn coils, for a total of 504 coils and slots.

1.4.3 Test Report Data

The following information is extracted from General Electric Field Test

SECTION 48 13 16.00 Page 10 report no. RT-193022:

a. Temperature rise in degrees C above 38.86 degrees C ambient at a generator output of 31,250 kVA, 0.833 power factor, and 14,450 line voltage:

Stator Winding by RTD 58.14 Field coil by V/A 50.64 Stator core by thermocouple 36.04 Air temperature rise 22.41

b. Losses in Kilowatts:

(1) Losses at 13.8 kV and 0.80 power factor:

Percent Load 25 50 75 100 115 Friction and Windage Loss 174 174 174 174 174 Core Loss 244 246 249 250 256 Stray-Load Loss 6 37 72 117 164 Armature DC I²R Loss (75 C) 11 44 99 176 232 Field I²R Loss (75 C) 54.3 78 113 161.5 206

TOTAL LOSSES* 489.3 579 707 878.5 1032

*Exciter friction and windage is included as part of the generator losses, but other exciter and rheostat losses are not included.

(2) Losses at 13.8 KV and 1.0 power factor:

Percent Load 25 50 75 100 115 Friction and Windage Loss 174 174 174 174 174 Core Loss 244 246 249 250 256 Stray-Load Loss 6 37 72 117 164 Armature DC I²R Loss (75 C) 11 44 99 176 232 Field I²R Loss (75 C) 40.1 46.8 57.9 73.8 86.5

TOTAL LOSSES* 475.1 547.8 651.9 790.8 912.5

*Exciter friction and windage is included as part of the generator losses, but other exciter and rheostat losses are not included.

c. Resistance Values at 75 degrees C:

Armature (line-to-line), 0.0686 ohm Field, 0.167 ohm

1.4.4 Unit 4 Failure History

Unit 4 has experienced stator coil failures on three separate occasions as follows: (1) May 18, 1998. Coil #33, B-Phase; (2) January 29, 2000.

Coils #218 and #219, A-phase and C-phase respectively; and (3) May 2002.

Coil #405. Failed coils were electrically cut out of the stator winding.

There are no known failures of the stator core or field winding.

SECTION 48 13 16.00 Page 11

1.4.5 Inspection By Contractor

The Government will make the generator available at the Contractor's request to permit the Contractor to inspect and obtain dimensions required to design the stator winding and core replacement. The inspection schedule shall be coordinated with the Contracting Officer (CO). The generator rotor will not be removed for this inspection. The Contractor shall be responsible for obtaining and verifying dimensions and other information, including information contained in this specification, that may be required to design a replacement stator winding and stator core. Measurements shall be made on the generator as necessary to ensure that all materials supplied under this contract will meet all contract requirements. A spare coil is available at the powerhouse for measurement by the Contractor. However, the Government will not assume any responsibility for the accuracy of the dimensions of the coil. The Contractor shall be responsible for developing the necessary information required for design. Any discrepancies between information given in this document and information developed shall be brought to the attention of the Government before proceeding.

PART 2 PRODUCTS

2.1 MATERIALS

All materials shall conform to the applicable specifications and standards listed and to the additional requirements specified herein. Any materials required in the work, but not covered by the specifications, shall be approved for the purpose intended prior to their incorporation. Reference to any equipment, article, or catalog number shall be regarded as establishing a standard of quality and shall not be construed as limiting competition. The Contractor may use any equipment, material, or article that in the judgment of the Contracting Officer is equal to that named.

2.2 PROTOTYPE STATOR COILS

Prior to manufacture of the stator winding, 7 prototype coils, plus any additional coils which may be required because of failures, shall be manufactured for accelerated life and thermal cycle testing. Four coils shall be subjected to accelerated life testing and three coils shall be used for the thermal cycling test(one of the three will be the temperature control coil). The prototype coils shall use the same approved materials and follow the same manufacturing process described in paragraph 2.4, and they shall have passed all the factory tests specified in paragraph 3.4 and a report submitted for approval prior to the accelerated life and thermal cycling tests. The accelerated life testing procedure shall be as stated in paragraph 3.2.1 and the thermal cycling test procedure shall be as stated in paragraph 3.3.

2.3 WINDING RATING AND INSULATION CLASS

The new stator winding shall be rated at 45,000 kVA at a 0.9 power factor.

The stator coil and winding installation materials shall be capable of operation at Class F temperature limits as defined in IEEE C50.12. The stator winding temperature rise shall not exceed 75 degrees C above a cooler discharge air temperature at 40 degrees C, when operated at rated load.

SECTION 48 13 16.00 Page 12

2.4 NEW STATOR COILS

2.4.1 General

The new stator coils to be supplied under this specification shall incorporate modern practice in design, material, and workmanship. Coils provided under this section should be equal or better quality as those provided in paragraph 2.2 Coils shall be of the hard, multi-turn type designed to minimize eddy current loss. The span of the coils shall be changed from the original 4 slots to 5 slots. The strands shall be annealed copper, free from splinters, flaws, rough spots, or short radius bends. All finished outside edges of each coil shall be rounded with a minimum radius of 1/16 inch. The narrow side of the slot portion of each stator coil shall have a flat bearing surface of at least 3/8 inch. Coil leads shall not be cut or tailored for any particular slot and shall be designed for use in any slot. The Contractor shall submit for approval coil transposition, coil insulation system, and winding capacitance per phase.

2.4.2 Conductor Strands

Strands shall be continuous (splice free) within the entire mean turn length of each coil and shall be insulated with continuous filament glass or dacron-glass fibers, or mica tape, bonded to the copper with a suitable bonding agent. A brick type construction may be used in which alternate strands are insulated with continuous filament glass or dacron-glass, with the remaining strands insulated with a high temperature enamel. The enamel-insulated strands shall be smaller than the other strands, or a separator strip shall be provided in the center of the turn, so that the corners of the enamel-insulated strands are not able to touch. Conductor strands shall be sized and arranged to minimize eddy and circulating current losses.

2.4.3 Turns

The slot and end winding portions of the assembled strands shall be bonded into a homogenous structure of controlled size using heat and pressure.

Strand bonding resins shall have properties and characteristics to prevent bond failure due to the mechanical, thermal, and chemical effects associated with thermal cycling while operating within the Class F temperature limits for which the winding is to be designed. The turns shall be insulated with multiple layers of mica tape in combination with suitable backing materials.

2.4.4 Ground Insulation

Ground insulation shall consist of multiple overlapped layers of mica splitting and/or mica flake tapes applied continuously and of equal thickness throughout the entire length of the coil. In coils that are machine-wound in the slot section, a scarf joint will be allowed between the machine-wound slot section and the hand wound end turn. The entire scarf joint shall be at least four inches above the slot paint or conductive slot tape. The mica splitting tape, if used, shall consist of large white mica splittings, NEMA Grade C or better. All mica tapes shall be constructed with a glass or polyester fabric backing material. A suitable protective covering tape shall be applied over the ground insulation mica tape.

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2.4.5 Drying

After the application of all insulation, the coils shall be given appropriate drying treatments to remove absorbed or trapped moisture and gases from the insulation system.

2.4.6 Resin Impregnation and Curing

After drying treatments, the coil insulation shall be completely filled with a solventless epoxy resin using a vacuum pressure or mechanical impregnation process. After impregnation, the coil insulation system shall be cured by the application of heat and pressure to the slot and end winding portions of the coils. Slot portions shall be sized to closely controlled dimensions and end portions shall be restrained with suitable pressure devices to assure a well-compacted insulation structure. The insulation in the slot portion and under the grading paint shall be free of internal voids visible, when dissected, to the naked eye.

2.4.7 Alternate Construction

B stage or loaded tapes may be used in lieu of the resin impregnation process described in paragraph 2.4.6. After the drying treatments, the coils shall be formed by heat and pressure in the same manner described in paragraph 2.4.6. The fill and void-free requirements described in paragraph 2.4.6 must be met.

2.4.8 Finish and Partial Discharge (Corona) Suppression Treatments

Slot portions of the stator coils, and a suitable distance beyond, shall be treated with a semiconducting compound capable of giving positive electrical contact between the treated portions of the coil surface and the entire length of the core slot walls. This semiconducting treatment shall be designed to eliminate corona discharges between coil and slot surfaces and between top and bottom coil sides.

2.4.9 Graded Suppression Treatment

A voltage grading semiconducting compound shall be applied to a suitable portion of the stator coil surface extending outward from the semiconducting treatment. This voltage grading semiconducting treatment shall be of a length and resistivity to limit coil surface voltage gradients to levels well below surface discharge (corona) onset levels under normal operating voltage stresses. The semiconducting treatment shall be exposed and accessible for inspection and possible repair. The winding shall exhibit no visible corona during the Blackout test described further in this section under Initial Acceptance Tests. Coil surfaces beyond the discharge suppressive treatments shall be treated with a finish capable of resisting exposure to dampness, oil vapors, Contractor-recommended cleaning solvents, or other materials to which the winding may be exposed during its operating life.

2.4.10 Testing

The new coils shall all be subjected to the tests listed in paragraph 3.4.

2.4.11 Coil Identification and Record

Each coil shall be given a unique identification. A permanent coil test record for each coil shall be kept, whether the coil is included in the

SECTION 48 13 16.00 Page 14 finished winding or not. The record shall include the results of all coil tests. The Contractor shall include the slot number where each coil has been installed in this record.

2.4.12 Quantity

Sufficient coils to make up one complete winding shall be supplied. In addition, 4 production run coils, plus any which may be additionally required because of failure, shall be supplied for the accelerated life testing specified in paragraph 3.2. Coils subjected to accelerated life testing shall not be used in the final winding.

2.4.13 Submittals

Drawings showing the following details shall be submitted for approval:

Cross sectional view of the proposed stator coils Exterior dimensions of the stator coils Winding diagram

The following calculations shall be submitted for generator operation at 25, 50, 75, and 100 percent of rated load. These submittals shall be provided for information only:

Field current calculations Generator losses calculations

2.5 RESISTANCE TEMPERATURE DETECTORS (RTDs)

Twenty-four 3-wire class F resistance temperature detectors (RTDs) shall be supplied for installation in the stator winding. RTDs shall be 100 ohms platinum, ±0.12% at 0 degrees C with a TCR of 0.00385 ohm/ohm/deg. C. The RTD body shall have a semiconductive coating. The detectors and their location shall be in accordance with paragraph 7.3 of IEEE C50.12. Replace existing RTD extension wires to the generator terminal box with new extension wires. New extension wires shall be No. 16 AWG tinned stranded copper, three-conductor cable immune to electrical noise. The cable shall be oil and water resistant and have an overall metallic armor for mechanical protection. Polyvinyl chloride (PVC) will not be allowed. RTD leads will be solder-spliced to the RTD extension wires outside the stator slot. Mechanically spliced leads shall not be used. Splices within the slot portion shall not be allowed. Submit catalog cuts for the RTDs and RTD cable.

2.6 NEW CIRCUIT RINGS

2.6.1 General

New circuit rings, complete with all necessary connections, taps, adapters, braces, supports, and materials for making the necessary line and neutral connections between the winding, the terminals of the phase buses, and the terminals of the neutral current transformer bus assembly shall be supplied for installation.

2.6.2 Design Drawings

The Contractor shall submit the following drawings for approval:

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Circuit ring configuration and dimensions;

Details of the main and neutral leads;

Details of the connections.

2.6.3 Electrical Configuration

The stator winding shall be wye-connected. Each phase of the stator winding shall consist of multi-turn coils, with the circuits per phase connected to give two parallel paths, as nearly equal as feasible, with neutral leads and the common main lead brought out within the generator housing at an approved location. The individual coils in each of the two parallel paths which are connected to the circuit rings, shall be connected in locations such that the differential protection of the winding will not be adversely affected by circulating currents between the parallel paths caused by misalignment of the rotor with respect to the stator. False tripping of differential relays due to circulating currents shall be considered an adverse effect. Readjustment of relay restraint settings to correct such a condition will not be permitted.

2.6.4 Physical Construction

The circuit rings, supports, and connecting leads shall be designed for installation in the same general location as the existing equipment, without alteration of the air baffling system or modification of structural parts. Each circuit ring shall be made up of not more than twelve pieces.

All factory joints shall be brazed in accordance with the requirements of

AWS A5.8.

2.6.5 Insulation

The circuit rings and connections shall be insulated for 15 kV with full Class F insulation, or better, composed of mica or glass tapes.

2.6.6 Neutral Current Transformers

Provide three new current transformers to replace the existing neutral current transformers. The new current transformers shall be in-kind replacements. The existing winding has multi-turn coils with the circuits per phase connected to provide two equal parallel paths, with General Electric type JKL-5, model YBD51, 1000:5 ratio, 15 kV insulation class, 110 kV BIL current transformers installed in the neutral end of one half winding in each phase. The current transformers are part of the generator split-phase differential relaying protective scheme which is to be retained. If a different differential current transformer is required as a result of a change in the circuit ring configuration, CTs of suitable ratings for use in the differential protection scheme shall be supplied.

Provide neutral current transformer manufacturer's information to include drawings, nameplate data, and routine factory test results.

2.7 FILLERS, WEDGES, TIES, AND BLOCKING MATERIAL

2.7.1 General

All material in the slot or used in bracing the winding shall be of an approved Class F, or higher, insulation. The Contractor shall submit for approval the following:

Stator winding assembly materials;

Wedging deflection characteristics;

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Dimensions and details of the wedges and fillers;

Bracing configuration for the winding.

2.7.2 Side Packing

One of the following side packing systems shall be used. No systems will be approved which require non-spring-type side filler to be inserted in the slot after the coil has been inserted:

a. A semiconducting silicone rubber compound shall be applied to the sides of the coils and cured before coil insertion. The silicone rubber shall form an interference fit with the sides of the slot.

b. A semiconductive coil wrapper used in conjunction with conducting putty shall be continuously applied throughout the length of the slot.

The coil shall be inserted into the slot before the putty has cured.

c. A ripple spring shall be driven between one side of the coil and the slot to form an interference fit. Acceptable deflection of the spring shall be submitted.

d. Other approved systems.

2.7.3 Center Filler and Bottom Filler

All center filler and bottom filler shall be fabricated from semiconducting material. The semiconducting material shall be impregnated throughout and shall not be coated on top of an insulating backing. A center filler between the two coil sides in a slot shall be supplied of such a thickness as to prevent interference between the coils in the straight part extension. RTDs shall be installed in place of the center filler in specified slots. A bottom filler shall be used between the bottom coil side (furthermost from the bore) and the bottom of the slot.

2.7.4 Spring-Type Filler Material

Spring-type filler material, or other approved follow-up, shall be installed between the front filler and the wedge. Spring-type filler material shall pass the tests of paragraph 3.5.

2.7.5 Wedges and Top Fillers

Stator slot wedges shall be manufactured from NEMA LI 1, Grade G11 material. The slot wedge cross-sectional shape shall match the wedge groove shape of the stator laminations. Wedge width shall result in a snug, sliding fit when placed in position in the slot. Top fillers shall be furnished in a variety of thicknesses to ensure that a proper thickness combination is available to produce a satisfactory radial wedging pressure. Provide three special check wedges per slot, unless two part wedges without a spring-type filler are provided. These special check wedges shall have five or more holes for checking spring-type filler deflection. Locate these special check wedges at the quarter points of each slot. A method for verifying spring-type filler material compression for all wedges in the slot shall be submitted for approval. End wedges shall be secured in place to prevent axial movement or migration of slot wedges or wedge fillers, but in no case shall epoxy be used to secure the wedges. Wedges shall be furnished with cutbacks at the cooling air passages. These cutbacks shall be designed to enhance the air flow.

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2.7.6 Two-Part Wedges

If two-part wedges are used, the wedges and slides shall be assembled using a master slide to select the slide of correct thickness. Acceptable wedge deflection, after slide is driven, shall be specified. The slide shall neither project above the top of the wedge nor touch the wedge below. All wedges shall be installed so that all slides are driven from above. A locking system for restricting the possible vertical movement of the wedges shall be provided, but in no case shall epoxy be used to secure the wedges. All wedges shall be tight upon completion of the wedging.

2.7.7 End Winding Bracing and Blocking Material

End winding bracing material shall be Class F and shall include resin-impregnated conforming material, blocks, and glass twine. The conforming material shall be Dacron felt and shall be impregnated thoroughly with resin before use between the coils. The blocks shall be glass-based and shall be used when the space cannot be filled with resin-impregnated Dacron felt. After installation the ties are to be saturated with the resin.

2.8 NEW STATOR CORE

The Contractor shall furnish and install a new stator core including the clamping system. Provide all required new stator laminations, vent laminations, clamping plates, clamping fingers, key bars, clamping bolts and nuts, etc. The stator core laminations shall be made from high-grade non-aging silicon steel. The stator core loss for the new core shall improve upon the existing stator core loss. After punching, deburr each lamination and coat with an insulating varnish to minimize eddy current losses. The insulating system for the new laminations shall be Class F.

The Contractor shall submit for approval the new stator core design. The submittal shall include a lamination fabrication procedure and detailed manufacturing drawings for all new components including bills of material and overall assembly drawing.

2.9 PARTIAL DISCHARGE ANALYSIS SYSTEM

2.9.1 General

A complete Partial Discharge Analysis (PDA) system that is suitable for on-line testing of the generator stator winding shall be designed and furnished for installation. The system shall provide on-line partial discharge measurements as required to frequently and randomly monitor the condition of the stator winding without a service outage. The system shall include protective devices and circuitry as necessary to prevent circulating currents and unsafe voltages from appearing at the termination cabinet. All parts of the system shall be furnished.

2.9.2 Coupling Capacitors

2.9.2.1 General

Six coupling capacitors shall be furnished for permanent installation in the winding, two in each phase. The capacitors shall be potted mica-type.

The type proposed must have been in use on at least two 10 MW or larger generators for at least 12 months as PDA coupling capacitors, two per phase.

SECTION 48 13 16.00 Page 18

2.9.2.2 Rating

The coupling capacitors shall be rated 80 or 100 pF ±5 percent, 20,000 peak working volts, noise- and corona-free to a minimum of 15 kV AC rms and capable of withstanding 40 kV AC rms for one minute.

2.9.2.3 Construction

The capacitors shall be the potted mica-type, equal to or better than, Iris EMC available from Iris Power Engineering Inc. They must withstand (with suitable bracing) vibration and shock levels typical of mounting locations on circuit rings, end turns, and coil-circuit ring connections.

2.9.3 Leads

Sufficient leads shall be furnished to go from the coupling capacitors to the termination panel. The leads shall be RG58A/U coaxial cable. Each lead shall be terminated with a BNC connector.

2.9.4 Termination Panel

The termination panel shall be sized to accommodate all coaxial cable leads, BNC connectors, terminal boards, and termination and protective devices. Each coaxial cable shall be terminated with a 1.5 kilo-ohm, 1 watt, non-inductive resistor and a gas discharge surge arrestor at the rear of the BNC.

2.9.5 Analyzer

One portable partial discharge analyzer, which is designed and equipped for use with the permanently installed capacitive couplers specified in paragraph 2.9.2, shall be provided. The analyzer unit furnished shall be an Iris Power Engineering Inc. model PDA-IV or approved equal. It shall include the following:

a. The PDA differential amplifier shall reject system noise and amplify the partial discharge pulses and sort them with respect to magnitude, polarity, and phase.

b. The analyzer shall provide printouts of the monitored activity.

c. The analyzer unit shall be equipped with a portable computer-based controller equipped with a hard drive and color monitor, and shall be equipped with the latest instrument control and display software.

d. A color printer shall be furnished, with spare color cartridges.

e. A traveling case shall be furnished for the printer and analyzer.

f. All cables and connectors required for connecting the analyzer with the BNC panel, and also with a high-speed oscilloscope, shall be provided.

g. The analyzer shall be provided with a partial discharge analyzer tester, a test guide for operating personnel, an instruction manual for maintenance personnel, and a transit case.

h. Bandwidth of no less than 350 MHz at 3 dB down.

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i. Data display in 3-D (three axis) format.

j. Equipment connected to all six connectors simultaneously.

k. An accessory to extend the dynamic range for testing individual coils.

2.10 SPARE PARTS

2.10.1 General

All spare parts shall be shipped to the Powerhouse when work begins at the Project site. A spare parts list shall be submitted. The part numbers in the spare parts list shall be identical to the part numbers given on the various drawings.

2.10.2 Stator Coils and Supplies

A set of twenty-five spare coils, including end connectors, shall be supplied, along with all non-deteriorating parts necessary for their installation, packing, and wedging. All spare coils shall be interchangeable with, and shall be of the same material and workmanship as, those specified in paragraph 2.4.

2.10.3 RTDs and RTD cable

A set of two spare RTDs and RTD cable, identical to those provided under paragraph 2.5 shall be provided. Cable length shall be equal to the longest provided under paragraph 2.5 and shall conform to the requirements of that paragraph.

2.10.4 Laminations

A set of twenty-five spare laminations shall be supplied. These laminations shall be identical to those specified in paragraph 2.8.

2.10.5 Stator Core Vent Duct Laminations

A set of five spare stator core vent duct laminations shall be supplied.

These laminations shall be identical to those specified in paragraph 2.8.

2.10.6 Packaging and Storage

The Contractor shall provide suitable packing for long term storage of all spare parts. The Contractor shall provide long term storage instructions for all spare parts, including temperature and humidity requirements for the storage area.

2.11 NEW NAMEPLATE

A new nameplate shall be provided for the new winding and mounted adjacent to the existing nameplate. Dimensions, material, and arrangement of information on the new nameplate shall be submitted for approval. The nameplate shall be brass or stainless steel, similar in size to the original nameplate, and shall be cast, stamped, or etched with the following information:

a. Winding manufacturer's name

b. KVA rating

c. Power factor

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d. Stator current

e. Field voltage at rated kVA

f. Field current at rated kVA

g. Stator temperature rise

h. Date of rewind

2.12 NEW TERMINAL…