W9127820R0069 Amendment 0006 with Attachment.pdf

AMENDMENT OF SOLICITATION/MODIFICATION OF CONTRACT

15A. NAME AND TITLE OF SIGNER (Type or print)

30-105-04EXCEPTION TO SF 30

APPROVED BY OIRM 11-84

STANDARD FORM 30 (Rev. 10-83) Prescribed by GSA

FAR (48 CFR) 53.243

1. CONTRACT ID CODE PAGE OF PAGES

16A. NAME AND TITLE OF CONTRACTING OFFICER (Type or print)

16C. DATE SIGNED

BY

16B. UNITED STATES OF AMERICA15C. DATE SIGNED15B. CONTRACTOR/OFFEROR

(Signature of Contracting Officer)(Signature of person authorized to sign)

8. NAME AND ADDRESS OF CONTRACTOR (No., Street, County, State and Zip Code) X W9127820R0069

X 9B. DATED (SEE ITEM 11)

22-May-2020

10B. DATED (SEE ITEM 13)

9A. AMENDMENT OF SOLICITATION NO.

11. THIS ITEM ONLY APPLIES TO AMENDMENTS OF SOLICITATIONS

X The above numbered solicitation is amended as set forth in Item 14. The hour and date specified for receipt of Offer is extended, is not extended.

Offer must acknowledge receipt of this amendment prior to the hour and date specified in the solicitation or as amended by one of the following methods:

(a) By completing Items 8 and 15, and returning copies of the amendment; (b) By acknowledging receipt of this amendment on each copy of the offer submitted;

or (c) By separate letter or telegram which includes a reference to the solicitation and amendment numbers. FAILURE OF YOUR ACKNOWLEDGMENT TO BE RECEIVED AT THE PLACE DESIGNATED FOR THE RECEIPT OF OFFERS PRIOR TO THE HOUR AND DATE SPECIFIED MAY RESULT IN

REJECTION OF YOUR OFFER. If by virtue of this amendment you desire to change an offer already submitted, such change may be made by telegram or letter, provided each telegram or letter makes reference to the solicitation and this amendment, and is received prior to the opening hour and date specified.

12. ACCOUNTING AND APPROPRIATION DATA (If required)

13. THIS ITEM APPLIES ONLY TO MODIFICATIONS OF CONTRACTS/ORDERS.

IT MODIFIES THE CONTRACT/ORDER NO. AS DESCRIBED IN ITEM 14.

A. THIS CHANGE ORDER IS ISSUED PURSUANT TO: (Specify authority) THE CHANGES SET FORTH IN ITEM 14 ARE MADE IN THE

CONTRACT ORDER NO. IN ITEM 10A.

B. THE ABOVE NUMBERED CONTRACT/ORDER IS MODIFIED TO REFLECT THE ADMINISTRATIVE CHANGES (such as changes in paying office, appropriation date, etc.) SET FORTH IN ITEM 14, PURSUANT TO THE AUTHORITY OF FAR 43.103(B).

C. THIS SUPPLEMENTAL AGREEMENT IS ENTERED INTO PURSUANT TO AUTHORITY OF:

D. OTHER (Specify type of modification and authority)

E. IMPORTANT: Contractor is not, is required to sign this document and return copies to the issuing office.

14. DESCRIPTION OF AMENDMENT/MODIFICATION (Organized by UCF section headings, including solicitation/contract subject matter where feasible.)

The subject solicitation for: Unit 1 and 2 Turbine/Generator Rehab at Philpott Powerhouse in Basset, VA

Is modified in the following: REFER TO THE ENCLOSED ADDITIONAL SPECIFICATIONS AND OR CHANGE FOR AMENDMENT NO. 0006

Except as provided herein, all terms and conditions of the document referenced in Item 9A or 10A, as heretofore changed, remains unchanged and in full force and effect.

10A. MOD. OF CONTRACT/ORDER NO.

2. AMENDMENT/

MODIFICATION NO.0006

5. PROJECT NO.(If applicable)

6. ISSUED BY

3. EFFECTIVE

DATE

CODE

ENDIST MOBILE CONTRACTING DIVISION

109 ST JOSEPH ST

MOBILE AL 36602

W91278 7. ADMINISTERED BY (If other than item 6)

4. REQUISITION/PURCHASE REQ. NO.

CODE

See Item 6

FACILITY CODECODE

EMAIL:TEL:

11/20/20

X k5ctcjar Cross-Out

Revised 11/19/20

Turbine Replacement & Rewind of Generator Units 1 and 2

Philpott Powerhouse, Bassett, VA

W9127820R0069

Amendment 0006

Amendment 006 Changes Page 1

The subject solicitation for: Unit 1 and 2 Turbine/Generator Rehab at Philpott Powerhouse in Basset, VA

Amendment No. 0006 is issued to provide for the following:

The items listed below are added or revised in the solicitation. Added sections are hereby made a part of the solicitation and are to be inserted in the proper numerical/alphabetical sequence.

SF 1442 SOLICITATION, OFFER, AND AWARD

[Change: A6.1-1]

Block 13 ADDITIONAL SOLICITATION REQUIREMENTS

A. Sealed offers in original and 0 copies to perform the work required are due at the place specified in item

8 by 14:00 (hour) local time 1 December 2020 8 December 2020 (date). If this is a sealed bid solicitation, offer must be publicly opened at that time. Sealed envelopes containing offers shall be marked to show the offeror’s name and address, the solicitation number, and the date and time offers are due.

SECTION 48 13 16.00 26 REWIND OF HYDRAULIC-TURBINE DRIVEN

GENERATORS

[Change: A6.2-1]

3.23 FIELD WINDING TESTS

Insulation Resistance and Polarization Index. Measure the insulation resistance between winding and ground at 500 Vdc. Run the test for ten (10) minutes. Record the insulation resistance readings and the polarization index and submit in the report. For initial field winding testing, report insulation resistance values below 400 megohms to the CO. For final field winding testing, an insulation resistance value of less than 400 megohms or polarization index less than 2.0 is unacceptable.

The following attachments are incorporated into the subject solicitation.

1. 48 13 16.00 26 - W9127820R0069 – A006 – REV 20201119

2. Philpott Water Quality Report – 20180205

3. Philpott Water Quality Report – 20180801

4. Philpott Units 1 & 2 Photo

(END OF CHANGES)

THIS PAGE INTENTIONALLY LEFT BLANK

Turbine Generator Replacement 17PH01

SECTION 48 13 16.00 26

REWIND OF HYDRAULIC-TURBINE DRIVEN GENERATORS

PART 1 GENERAL

1.1 GENERAL INFORMATION

This Section covers the following work for the two (2) main unit generators at Philpott Powerhouse.

(a) Design, manufacture, test, and delivery of two (2) complete stator windings and cores for the main unit generators.

(b) Remove two (2) existing stator windings and stator cores.

(c) Install and test furnished stator cores and windings.

(d) Refurbish and test 54 field poles, including replacement of the pole iron and reinstallation on the rotors. Existing field poles may contain asbestos.

(e) Refurbish and test two rotating exciters.

(f) Refurbish main unit collector rings and supply new brushes and brush holders.

(g) Asbestos abatement as necessary to complete work covered by this section, in accordance with Section 01 57 20.00 25 , Environmental Protection, and Section 02 82 14.00 25, Asbestos Hazard Control Activities.

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.

ASME INTERNATIONAL (ASME)

ASME BPVC SEC VIII D2 (2010) BPVC Section VIII-Rules for Construction of Pressure Vessels Division 2-Alternative Rules

ASME FFS-1 (2016) Fitness-for-Service

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 2016) 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

SECTION 48 13 16.00 26 Page 1

Insulation Systems

AMERICAN WELDING SOCIETY (AWS)

AWS A5.8/A5.8M (2012) Specification for Filler Metals for Brazing and Braze Welding

INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS (IEEE)

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

IEEE 56 (2016) Guide for Insulation Maintenance of Electric Machines

IEEE 95 (2002; R 2012) Recommended Practice for Insulation Testing of Large AC Rotating Machinery with High Direct Voltage

IEEE 115 (2009) Guide for Test Procedures for Synchronous Machines: Part I Acceptance and Performance Testing; Part II Test Procedures and Parameter Determination for Dynamic Analysis

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

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

IEEE 1434 (2014) Guide for the Measurement of Partial Discharges in AC Electric Machinery

IEEE 1553 (2002; R 2007) Standard for Voltage-Endurance Testing of Form-Wound Coils and Bars for Hydrogenerators

IEEE 1799 (2012) Recommended Practice for Quality Control Testing of External Discharges on Stator Coils, Bars, and Windings

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

IEEE C57.13 (2008) Standard Requirements for Instrument Transformers

IEEE C57.13.1 (2006; R 2012) Guide for Field Testing of Relaying Current Transformers

NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION (NEMA)

NEMA FI 1 (2004) Manufactured Electrical Mica

SECTION 48 13 16.00 26 Page 2

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

NATIONAL FIRE PROTECTION ASSOCIATION (NFPA)

NFPA 70 (2017; ERTA 1-2 2017; TIA 17-1; TIA 17-2;

TIA 17-3; TIA 17-4; TIA 17-5; TIA 17-6;

TIA 17-7; TIA 17-8; TIA 17-9; TIA 17-10;

TIA 17-11; TIA 17-12; TIA 17-13; TIA

17-14) National Electrical Code

Occupational Safety and Health Act (OSHA)

54 CFR 2920 (1970) Williams Steiger Occupational Safety and Health Act

1.3 SUBMITTALS

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

submittals having an "I" are for information only. Designation following the "G" or "I" designation identifies the office that will review the submittal for the Government. Submit the following in accordance with Section 01 33 00 , SUBMITTAL PROCEDURES.

SD-01 Preconstruction Submittals ;

Within 120 calendar days after receipt of written notice to proceed

(NTP):

Stator Winding Warranty Details ; I, HDC

Stator Coil Facility ; G, HDC

Stator Coil Voltage Endurance Test Facility ; G, HDC

Stator Design Review Meeting ; I

Lamination Manufacturing Facility ; G, HDC

SD-02 Shop Drawings

Include a parts list in shop drawings as appropriate.

Within 120 calendar days after receipt of written notice to proceed

(NTP):

Cross-Sectional View of Stator Coils ; G, HDC

Exterior Dimensions of Stator Coils ; G, HDC

Winding Diagram ; G, HDC

Connection Details ; G, HDC

Winding Bracing Configuration ; G, HDC

Circuit Ring Configuration and Dimensions ; G, HDC

Surge Rings ; G, HDC

SECTION 48 13 16.00 26 Page 3

Main and Neutral Lead Details ; G, HDC

Main and Neutral Lead Arrangement ; G, HDC

Nameplate ; G, HDC

Stator Core Laminations ; G, HDC

Stator Core Vent Duct Spacers ; G, HDC

Stator Core Completed Assembly ; G, HDC

Lamination Die ; I, HDC

Core Keybars ; G, HDC

Stator Core Clamping System ; G, HDC

Rotor Pole Assembly and Details ; G, HDC

Rotor Pole Connections Assembly and Details ; G, HDC

Field Pole Body Assemblies ; G, HDC

SD-03 Product Data

Within 120 calendar days after receipt of written notice to proceed

(NTP):

Stator Coil Insulation System ; G, HDC

PDA System ; G, HDC

RTDs and RTD Extension Cable Catalog Cuts ; G, HDC

Stator Assembly Materials and Dimensions ; G, HDC

Current Transformer Catalog Cut ; G, HDC

Spring Type Washers Loading ; G, HDC

Generator Heaters ; G, HDC

SD-05 Design Data

Within 120 calendar days after receipt of written notice to proceed

(NTP):

Wedging System Deflection Characteristics ; G, HDC

DC I²R Copper Losses Design Calculations ; G, HDC

Stray Load Losses Design Calculations ; G, HDC

Maximum Temperature Rise ; G, HDC

Temperature Rise Calculations ; G, HDC

SECTION 48 13 16.00 26 Page 4

Core Losses Design Calculations ; G, HDC

Pole Body Analysis ; G, HDC

Amortisseur Winding Design ; G, HDC

Core Resonances Analysis ; G, HDC

SD-06 Test Reports

Within 14 calendar days after the completion of the test:

Coil Test Record ; G, HDC

Current Transformer Routine Test Report ; I, HDC

Prototype Coil Voltage Endurance Test Report ; G, HDC

Production Run Coil Voltage Endurance Test Report ; G, HDC

Dissection and Examination Report ; G, HDC

Coil Factory Test Report ; G, HDC

Spring Type Filler Material Test Report ; G, HDC

RTD Test Report ; I, HDC

Lamination Test Report ; G, HDC

Rotor Pole Factory Test Report ; G, HDC

PDA Test Report ; G, HDC

Field Winding Final Test Report ; G, HDC

Interlaminar Insulation Test Report ; G, HDC

SD-08 Manufacturer's Instructions

Within 120 calendar days after receipt of written notice to proceed

(NTP):

Voltage Endurance Test Methods ; G, HDC

Coil Factory Test Procedure ; G, HDC

Stator Winding Installation Procedure ; G, HDC

Initial Acceptance Test Procedures ; G, HDC

Final Acceptance Test Procedures ; G, HDC

Generator Special Field Tests Procedure ; G, HDC

Lamination Test Procedure ; G, HDC

Stator Core Keybars Installation Procedure ; G, HDC

SECTION 48 13 16.00 26 Page 5

Rotor Pole Removal and Reinstallation Procedure ; G, HDC

Pole Transportation Procedure ; G, HDC

Field Coil Reinsulation Procedure and Materials ; G, HDC

Interlaminar Insulation Test Procedure ; G, HDC

Field Leads Replacement Procedure ; G, HDC

SD-09 Manufacturer's Field Reports

Within 14 calendar days after the completion of the inspection or test:

Stator Frame Inspection Report ; G, HDC

Stator Core Final Check Report ; G, HDC

Stator Winding Final Inspection Report ; G, HDC

Winding Installation Test Report ; G, HDC

Initial Acceptance Test Report ; G, HDC

Final Acceptance Test Report ; G, HDC

Generator Special Field Test Report ; G, HDC

SD-10 Operation and Maintenance Data

Within 120 calendar days after receipt of written notice to proceed

(NTP):

Spare Parts List ; I, HDC

Within 30 calendar days after completion of generator commissioning:

Generator Operations and Maintenance Manual ; G, HDC

1.4 EXISTING GENERATOR INFORMATION

1.4.1 Unit Identification and Nameplate

Philpott Units 1 and 2 are air-water heat exchanger cooled, vertical hydro-generators, manufactured by the General Electric Company. The units were brought online in 1952. Generator ratings, as defined by the nameplate information, are as follows.

7,500 kVA

0.9 Power Factor

13,800 V 3-phase 60 Hz

277 RPM

115% continuous overload capability

SECTION 48 13 16.00 26 Page 6

1.4.2 Description of Generator

The generators are designed for wye-connection of the stator windings with each phase consisting of one (1) parallel path of 54 coils with five (5) turns per coil. The stator core has 162 slots, a bore diameter of approximately 123 inches, and a height of approximately 30 inches. The field windings are comprised of twenty-six (26) field coils.

1.4.3 Test Report Data

The following information is from the field test performed on December 2, 1953 on Unit 1. The original construction of the Philpott Units 1 and 2 generators did not include the existing air-water heat exchange coolers.

Following the addition of the coolers, new heat run data was not gathered.

The data that appears in subparagraph 1.4.3(a) is based on the original forced air system that brought cool air through the generator from the turbine pit.

(a) Operating Temperature Degrees Celsius (°C), at 7,500 kVA, 14,500 V and

93.0 Power Factor.

Maximum Temperature Rise of Armature Winding, by RTD

44.9

Average Temperature of Inlet Air 30.4

(b) Losses in Kilowatts (kW).

(1) Losses at rated voltage and power factor.

Percent Load 25 50 75 100 115 Friction & Windage Loss (Generator & Exciter)

66.0 66.0 66.0 66.0 66.0

Core Loss 71.5 71.5 71.5 71.5 71.5

Armature DC I²R Loss (75°C)

2.4 9.6 21.5 38.3 50.4

Field I²R Loss (75°C) 14.4 19.7 27.2 36.1 43.0

Stray-Load Loss

Excitation (& Rheostat) Loss

Voltage Regulator

TOTAL LOSSES 155.9 174.6 206.0 251.9 286.4

(2) Losses at rated voltage and unity (1.0) power factor.

Percent Load 25 50 75 100 115

SECTION 48 13 16.00 26 Page 7

Friction & Windage (Generator & Exciter) Loss

66 66 66 66 66

Core Loss 71.5 71.5 71.5 71.5 71.5

Armature DC I²R Loss (75°C)

2.4 9.6 21.5 38.3 50.4

Field I²R Loss (75°C) 11.4 13.1 15.9 20.2 23.5

Stray-Load Loss

Excitation (& Rheostat) Loss

Voltage Regulator

TOTAL LOSSES 152.9 168.0 194.7 236.0 266.9

(c) Resistance at 25°C.

Stator Resistance (line-to-line) 0.109 ohms

Field Resistance 0.190 ohms

1.4.4 Inspection by Contractor

The Government will make a generator available at the Contractor's request to permit the Contractor to inspect the generator and obtain dimensions required to design the replacement stator windings and cores. Coordinate the inspection schedule and access requirements with the Contracting Officer (CO). The generator rotor will not be removed for this inspection.

The Government will remove two upper shrouds and two lower shrouds, in the vicinity of the main and neutral leads to permit inspection. The Government will remove up to four upper deck plates to allow access into the generator. The Contractor is responsible for obtaining and verifying dimensions and other information, including information contained in this specification, that may be required to design replacement stator windings and cores. Take measurements on the generator as necessary to ensure that coils and materials supplied under this contract will meet all contract requirements. A spare coil is available at the powerhouse for measurement by the Contractor. The Government will not assume any responsibility for the accuracy of the dimensions of the coil. Laminations from the existing cores will not be allowed to be removed for measurements before or after award. The Contractor is responsible for developing the necessary information required for design. Bring any discrepancies between information given in this document and information developed to the attention of the Government before proceeding.

1.5 WARRANTY

The warranty period for the complete installed windings is to be five (5) years after the successful completion of tests and acceptance. The Contractor is responsible for repairing or replacing any component failing to perform its function as specified and documented at no additional cost to the Government within the five (5) year period. Respond to the Government and perform an assessment of the failure within four (4) weeks of the incident. Include disassembly and reassembly sufficient to make

SECTION 48 13 16.00 26 Page 8 repairs, repair any surrounding equipment as a result of the failure, and any necessary testing to confirm the efficacy of the repair. Replace any spare parts used during the repair in kind within one year of the completion of the repair. Submit for approval the Stator Winding Warranty Details , to include duration of warranty coverage and items and labor covered by the warranty.

1.6 FAILURE TO MEET PERFORMANCE GUARANTEES

Determine the measured combined stator DC I²R (copper) and stray load losses in accordance with paragraph 3.33.2(a), Losses Tests. Include the resistance of the circuit rings in the measured combined losses. Should the measured combined losses be greater than the guaranteed value and the Contractor fail to modify the winding within in a reasonable time to meet the loss guarantees and the winding be in otherwise satisfactory operational condition, the CO may accept the winding conditionally in lieu of pursuing other remedies allowed by the contract. In that event, the Contractor will pay the Government or the Government will withhold any monies otherwise due in the amount of $7,620 per kW of measured combined losses above the loss guaranteed for each generator.

PART 2 PRODUCTS

2.1 MATERIALS

Conform all materials to the applicable specifications and standards listed and to the additional requirements specified herein. Obtain approval for the intended purpose of any materials required for the work, but not covered by the specifications, prior to the material incorporation. Reference to any equipment, article, or catalog number within this specification is to establish a standard of quality and not intended to limit competition.

2.2 WINDING RATING AND INSULATION CLASS

Supply a stator winding rated at 9,430 kVA at 13.8 kV +/- 5%. Provide stator coils and winding installation materials capable of operation at Class F temperature limits as defined in IEEE C50.12 . Design and provide a stator winding such that the temperature rise does not exceed 75°C above a cooler discharge air temperature of 40°C, when operated at rated load.

2.3 NAMEPLATE

Submit for approval the nameplate drawing. Include details on material, dimensions, and arrangement of information on the drawing. Make the nameplates of cast, stamped or etched brass or stainless steel similar in size and thickness to the original nameplates. Include the following information on the nameplates:

(a) Winding manufacturer's name

(b) Rated kVA

(c) Power factor

(d) Stator current

(e) Field voltage at rated kVA and power factor

SECTION 48 13 16.00 26 Page 9

(f) Field current at rated kVA and power factor

(g) Stator temperature rise

(h) Date of rewind

(i) Rated kV

(j) Insulation class

2.4 STATOR COILS

2.4.1 General

Incorporate modern practice in design, material, and workmanship for the stator coils manufactured under this specification. Design coils to be the hard, multi-turn type with minimized eddy current loss. Use annealed copper, free from splinters, flaws, rough spots, or short radius bends for the strands. Round all finished outside edges of each coil with a minimum radius of 1/16 inch. For the narrow side of the slot portion of each stator coil, provide a flat bearing surface of at least 3/8 inch. Continue insulation of coil start and finish leads for no less than four (4) inches of the lead from the finished coil to allow a sufficient scarf joint with field applied insulation. Do not cut or tailor any coil leads for any particular slot; design each coil for use in any slot. Submit the following for approval:

(a) Stator Coil Facility . The name, address and qualification of the stator coil facility.

(b) Cross-Sectional View of Stator Coils . A cross-sectional view of the stator coil in a stator slot, describing the stranding arrangement, strand dimensions, copper cross-sectional area, strand and turn insulation details (including insulating material types and thicknesses), slot fillers, wedging details, and partial discharge suppressive treatments. Include groundwall insulation materials and thickness on the drawing.

(c) Exterior Dimensions of Stator Coils . Include bending radii, dimensions of slot semi-conductive compound and grading tape on the drawing.

(d) Winding Diagram . A drawing that shows the three phases in different colors, coupling capacitors for the partial discharge analysis (PDA) system, and RTD locations. Include a tabular listing of the winding showing the progression from line end to neutral end for all parallel circuits with the diagram.

(e) Stator Coil Insulation System . A description of the stator coil insulation system, including processes and materials employed to meet specification requirements. Include data sheets for materials used in the coil construction and calculations for the V/mil of the groundwall insulation.

(f) DC I²R Copper Losses Design Calculations . Detailed design calculations demonstrating how the stator DC I²R (copper) losses are determined at 75°C. Illustrate with the calculations the composition of the various portions of winding circuit resistance, including number of coils in series, parallel connections, end connections, circuit rings, etc.

SECTION 48 13 16.00 26 Page 10

(g) Stray Load Losses Design Calculations . Detailed calculations showing how the stray load loss is determined.

(h) Maximum Temperature Rise . Maximum temperature rise of the copper conductor above 40°C ambient at rated load, voltage, and power factor.

(i) Temperature Rise Calculations . Calculated stator winding temperature rise as indicated by embedded temperature detectors and calculated stator winding hot spot temperature at rated load, voltage, and power factor. Correlate the relationship between the operating "hot spot" temperature of the stator coils and the temperature measured by RTD demonstrated by direct measurement or recognized methods of calculation to special factory tests on a basically similar machine.

(j) Core Resonances Analysis . Analyze the proposed winding and core design to demonstrate that the new stator winding will not excite resonances in the supplied core during operation. Resonances can result in unacceptable vibration or noise levels in generators.

2.4.2 Coil Design

2.4.2.1 Conductor Strand Insulation

Make strands continuous (splice free) within the entire mean turn length of each coil. Insulate strands with continuous filament glass, dacron-glass fibers, or mica tape, bonded to the copper with a suitable bonding agent. Size and arrange conductor strands to minimize eddy and circulating current losses.

2.4.2.2 Turn Insulation

Insulate each turn with multiple layers of mica tape in combination with suitable backing materials. Turn insulation may be applied to individual strands in lieu of dedicated turn insulation. Alternative methods for insulating turns may be proposed and are subject to Government approval.

2.4.2.3 Ground Insulation

Provide ground insulation that consists of multiple overlapped layers of mica tapes applied continuously throughout the entire length of the coil for equal thickness. Meet the requirements of NEMA FI 1 , Table 5-2 for the mica tape. Use mica tapes constructed with a glass or polyester fabric backing material. Apply a suitable protective covering tape over the ground insulation mica tape. For coils in which the ground insulation is applied by machine, a scarf joint will be allowed between the machine insulated slot section and the hand wound end turn. If used, place scarf joints no closer than four inches to the conductive slot treatment.

2.4.2.4 Coil Consolidation

Bond the slot and end winding portions of the assembled strands and turns into a homogenous structure of controlled size using heat and pressure.

Use strand bonding resins with 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.

SECTION 48 13 16.00 26 Page 11

2.4.3 Coil Manufacturing Methods

2.4.3.1 Vacuum Pressure Impregnation (VPI)

After drying treatments, completely fill the coil insulation with a solventless epoxy resin using a vacuum pressure impregnation process.

After impregnation, cure the coil insulation system by the application of heat and pressure to the slot and end winding portions of the coils. Size slot portions to closely controlled dimensions and restrain end portions with suitable pressure devices to ensure a well-compacted insulation structure. No internal voids, as determined by the COIL DISSECTIONS in paragraph 3.4, are allowed in the insulation between the copper strands and the outer edge of the stator coils in the slot portion and under the grading paint of the stator coils, including those coils subjected to the Voltage Endurance tests as described in paragraph 3.3, VOLTAGE ENDURANCE

TESTS.

2.4.3.2 Resin Rich Tapes

Resin rich, B stage, or loaded tapes may be used in lieu of the resin impregnation process. Cure the coil insulation system by the application of heat and pressure to the slot and end winding portions of the coils.

Size slot portions to closely controlled dimensions and restrain end portions with suitable pressure devices to ensure a well-compacted insulation structure. No internal voids, as determined by the COIL DISSECTIONS in paragraph 3.4, are allowed in the insulation between the copper strands and the outer edge of the stator coils in the slot portion and under the grading paint of the stator coils, including those subjected to the Voltage Endurance tests as described in paragraph 3.3, VOLTAGE

ENDURANCE TESTS.

2.4.4 Finish and Partial Discharge Suppression Treatment

Treat slot portions of the stator coils, and a suitable distance beyond, with a semiconductive compound capable of giving positive electrical contact between the treated portions of the coil surface and the entire length of the core slot walls. Design this semiconductive treatment to eliminate surface discharge (corona) between the coil and slot surfaces and between top and bottom coil sides.

2.4.5 Graded Suppression Treatment

Apply a voltage grading semiconductive tape to the stator coil surface extending outward from the semiconductive treatment. Apply the voltage grading semiconductive tape to be of a length and resistivity to limit coil surface voltage gradients to levels well below corona onset levels under normal operating voltage stresses at normal operating temperatures.

Leave the voltage grading semiconductive treatment exposed and accessible for inspection and possible repair. During a black-out test at 9.2 kV, as described in paragraph 3.27(d), Blackout Test, no visible corona is allowed to be produced by the winding. Treat coil surfaces beyond the discharge suppressive treatments 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 operating life.

2.4.6 Coil Test Record

Give each coil a unique identification. Keep a permanent Coil test record

SECTION 48 13 16.00 26 Page 12 for each coil, whether the coil is included in the finished winding or not. Include the results of all coil tests and the slot number where each coil has been installed in this record.

2.4.7 Prototype Coils

Use entire coils for prototype stator coils, complete with all armor tapes and stress control materials applied. Omit materials normally bonded to the coil that are used to secure the coil in the slot. Manufacture prototype coils to be identical to those manufactured under paragraph 2.4, STATOR

COILS.

2.4.8 Quantity

(a) Prototype Coils. Prior to manufacturing the production run coils, manufacture at least Four (4) stator prototype coils for voltage endurance testing. Also manufacture any additional coils which may be required due to failure. Do not manufacture the production run coils before the prototype coils are tested and dissected and the test report is approved.

(b) Production Run Coils. Following the approval of the prototype coil testing and dissection, provide 6 production run coils, plus any additional coils which may be required due to failure, for the Voltage Endurance testing specified in paragraph 3.3, VOLTAGE ENDURANCE TESTS.

Do not use or provide as spares coils subjected to Voltage Endurance testing in the final winding. Provide sufficient coils to make up two

(2) complete windings. Also supply the spare coils listed in paragraph 2.14, SPARE PARTS. In the event that the two complete windings and spare coils are not manufactured in a single continuous batch, manufacture and test a set of production run coils for each additional batch.

2.5 RESISTANCE TEMPERATURE DETECTORS (RTDs)

Supply for installation in the stator winding of each unit eighteen (18) 3-wire resistance temperature detectors (RTDs) suitable for operation in a Class F insulation system. Provide 100 ohm platinum dual-element RTDs (±0.12% at 0°C) with a TCR of 0.00385 ohm/ohm/°C. Supply RTDs with a semiconductive coating on the body. Supply and locate RTDs in accordance with clause 7.3 of IEEE C50.12 . Replace existing RTD extension wires to the generator terminal cabinet with new extension wires. Use No. 16 AWG tinned stranded copper, three-conductor cable immune to electrical noise for RTD extension wires. Use oil and water resistant cable with 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. Do not use mechanically spliced leads.

Splices are not allowed within the slot portion. Submit RTDs and RTD Extension Cable Catalog Cuts .

2.6 FILLERS, WEDGES, TIES, AND BLOCKING MATERIAL

2.6.1 General

Provide materials suitable for use in conjunction with a Class F winding insulation system for use in the stator slots, such as fillers, wedges, ties and blocking.

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2.6.2 Stator Assembly Materials and Dimensions

Submit for approval a description of materials used for the assembly of the stator coils in the generator core. Include all end-bracing and blocking materials, wedging, filler, and brazing materials. Include drawings detailing the dimensions of all wedges and fillers used in the stator.

2.6.3 Side Packing

Systems using a non-spring-type filler inserted in the slot after inserting the coil are not acceptable. Use one of the following side packing systems:

(a) Apply a semiconductive silicone rubber compound to the sides of the coil and cure before insertion. Form an interference fit between the silicone rubber and the sides of the slot.

(b) Apply a semiconductive coil wrapper in conjunction with conducting putty continuously applied throughout the length of the slot.

(c) Drive a ripple spring between one side of the coil and the slot to form an interference fit. Submit the acceptable ripple spring deflection.

2.6.4 Center and Bottom Filler

Fabricate center and bottom fillers from semiconductive materials. Provide semiconductive material impregnated throughout and not coated on top of an insulating backing. Provide a center filler between the two coil sides in a slot sized to prevent interference between the top and bottom coils in the straight part extension. In specified slots, install RTDs in place of the center filler. Use bottom filler between the bottom coil side, or furthest from the center of the bore, and the bottom of the slot.

2.6.5 Spring-Type Filler Material

Install spring-type filler material between the top filler and the wedge.

2.6.6 Wedges and Top Filler

Manufacture slot wedges from NEMA LI 1 Grade G11 material with a cross-sectional shape to match the groove shape of the stator laminations and provide a snug, sliding fit when placed in position in the slot.

Include a wedge cutback at the cooling air passages designed to enhance the air flow. Furnish top fillers of various thicknesses to ensure acceptable radial wedging pressures. Furnish a top filler of at least

0.020 inch for use against the coil. Provide a locking system for restricting the possible axial movement of the wedges. Furnish three check wedges per slot, located at quarter points in the slot. Design check wedges with no less than five (5) holes to measure spring-type filler deflection. Upon completion of the wedging, all wedges along the length of the slot must be independently tight in the slot.

2.6.7 Two-Part Wedges

If using a two-part wedging system, assemble the wedges and slides using a master slide to select the correct slide thickness. Provide slide lengths that neither project above the top of the wedge nor touch the wedge below.

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Install all wedges so that all slides are driven from above.

2.6.8 Wedging System Deflection Characteristics

Submit the wedging deflection characteristics for approval including:

(a) Initial deflection of slot wedging spring-type filler and radial pressure applied to the 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 the stator coil at the minimum acceptable deflection.

(c) Calculations to show that the radial pressure wedging system forces will exceed the non-fault condition forces throughout the life of the winding. Calculate forces at rated load, voltage, power factor and at worst fault condition.

2.6.9 End Winding Bracing and Blocking Material

End winding bracing material consists of resin-impregnated conforming materials, blocks, and glass twine. Use Dacron felt thoroughly impregnated with resin for conforming material between the coils. Use glass-based blocks when the space cannot be filled with the conforming material.

Saturate all ties with resin during installation.

2.7 CIRCUIT RINGS AND STATOR CONNECTIONS

2.7.1 General

Provide circuit rings, complete with all necessary connections, taps, adapters, braces, supports, and materials for making line and neutral connections between the winding, the terminals of the phase buses, and the terminals of the neutral current transformer bus assembly. Provide drawings of the Connection Details including coil-to-coil connections, jumper connections, connections from coils to circuit rings, details of any external transpositions and connections from the circuit rings to the main and neutral leads, Winding Bracing Configuration , and Circuit Ring Configuration and Dimensions .

2.7.2 Electrical Configuration

Design the stator windings to be wye-connected, with each phase of the stator winding consisting of multi-turn coils with neutral leads and the common main lead brought out within the generator housing at their existing location.

2.7.3 Physical Construction

Design the circuit rings, supports, and connecting leads for installation in the same general location as the existing equipment, without alteration of the air baffling system or modification of structural parts. Do not use more than twelve pieces to make up each circuit ring. Braze all factory joints in accordance with the requirements of AWS A5.8/A5.8M . Manufacture circuit ring blocking from NEMA LI 1 Grade G11 material.

2.8 SURGE RINGS

Provide upper and lower stainless steel surge rings, insulated with Class

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F insulation. Submit for approval a drawing of the surge rings including dimensions and material.

2.9 MAIN AND NEUTRAL LEADS

Redesign and replace the main and neutral leads. Design the new leads to be easily disconnected during disassembly without damage to the lead insulation. Design the leads to be of a self-supported bus assembly construction that can accept bolted connections to the existing non-segregated bus stabs. Silver surface all bolted connections and make connections using Belleville spring-type washers with stainless steel fasteners, or approved equal. Submit calculations to demonstrate the adequacy of the Spring Type Washers Loading . Design and supply main and neutral lead supports to firmly maintain the connections in place. Provide Main and Neutral Lead Details and Main and Neutral Lead Arrangement drawings.

2.10 PDA SYSTEM

2.10.1 General

Furnish partial discharge analysis (PDA) systems for all units. Submit for approval the PDA system. The submittal should provide installation instructions, coupling capacitor details, coupling capacitor location and mounting, termination panel details, termination panel location, and coaxial cable routing and mounting.

2.10.2 Coupling Capacitors

Furnish and install two (2) coupling capacitors per phase for each winding. Provide coupling capacitors capable of withstanding the DC and AC high potential generator tests.

2.10.3 Leads

Furnish Sufficient leads to go from the coupling capacitors to the termination panel. Use RG58A/U coaxial cable for the leads. Terminate each lead with a BNC connector.

2.10.4 Termination Panel

Size each termination panel to accommodate all coaxial cable leads, BNC connectors, terminal boards, and termination and protective devices.

Terminate each coaxial cable with a 1.5 kilo-ohm, 1 watt, non-inductive resistor and a gas discharge surge arrestor at the rear of the BNC.

2.10.5 Analyzer

Provide a portable partial discharge analyzer specifically designed and equipped for use with the permanently installed capacitive couplers.

Furnish an Iris Power Engineering Inc. model PDA-IV, or approved equal, for the analyzer unit. Include the following features:

(a) The PDA differential amplifier rejects system noise, amplifies the partial discharge pulses, and sorts them with respect to magnitude, polarity, and phase.

(b) The analyzer provides printouts of the monitored activity.

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(c) Provide all cables and connectors required for connecting the analyzer with the BNC panel and with a high-speed oscilloscope.

(d) Provide with the analyzer a partial discharge analyzer tester, a test guide for operating personnel, an instruction manual for maintenance personnel, a standard operating spares kit, and a transit case.

(e) Bandwidth of no less than 350 MHz (at 3 dB down).

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

(g) Equipment connected to all six (6) connectors simultaneously.

(h) An accessory to extend the dynamic range for testing individual coils.

2.11 STATOR CORE MATERIALS

2.11.1 Stator Core Laminations

Provide drawings of the Stator Core Laminations and Stator Core Vent Duct Spacers including dimensions, materials and tolerances. Submit an assembly drawing of the Stator Core Completed Assembly , including dimensions and tolerances, for the completed stator core.

(a) Furnish the required number of new laminations to completely stack the new stator cores, continuously without splits. Make the laminations from high-grade non-aging silicon steel. Submit for approval Core Losses Design Calculations based upon design factors including, but not limited to, the proposed lamination steel and stacking factor.

Match or improve upon (less than or equal to) the total core losses at rated voltage of the original core for the supplied laminations. Make the steel thickness no greater than the original steel. Coat each lamination on both sides with an insulating varnish or other suitable material to minimize eddy current losses.

(b) Furnish the required number of new stator vent duct spacers to completely stack the new stator cores.

Submit for approval the name, address and qualifications for the proposed Lamination Manufacturing Facility .

2.11.2 Stator Lamination Die

Furnish to the Government a die for the new laminations. Design the die to be of the straight cut type, suitable for punching all the laminations needed for the work. Submit a drawing of the Lamination Die . Include dimensions, dimensional tolerances, materials, method of securing die set to the press, identification of fasteners, and operating instructions on the drawing. Also include the number of sharpenings the die can withstand and the number of laminations that can be punched between sharpenings.

Sharpen and package the die in a clearly labeled box prior to turning over to the Government at the end of the contract.

2.11.3 Stator Keybars

Furnish new keybars for all furnished stator cores. Furnish detailed drawings of the Core Keybars , including materials and dimensions and stator frame modifications if applicable. Submit the Stator Core Keybars Installation Procedure .

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2.11.4 Stator Clamping System

Furnish a new stator clamping system for all furnished cores. Include flanges and fingers, tightening nuts and through bolts in new clamping systems. Do not use cast iron for flanges. Weld fingers to the flanges. If the clamping system design includes through bolts that are welded or attached to the frame, do not make the weld or attachment until the bolts have been properly torqued. Provide detailed drawings of the Stator Core Clamping System , including materials, dimensions and torque values of the new clamping system, and stator frame modifications, if applicable.

2.12 GENERATOR AUXILIARY EQUIPMENT

2.12.1 Neutral Current Transformers

For each generator, provide three (3) current transformers (CTs) (one for each phase) with a rating of 600:5, single ratio only, for use in the differential protection scheme. Provide CTs with an accuracy rating of C200 and a BIL rating of 95 kV. Comply with IEEE C57.13 for CTs. Submit a Current Transformer Catalog Cut for approval. Install in accordance with paragraph 3.24.1.1, Neutral Current Transformer Installation.

2.12.2 Generator Heaters

For each generator, replace the existing generator heaters and heater wiring. Provide three (3) heaters with adjustable dew point control.

Submit the Generator Heaters product data for approval. Existing heater power supply wiring has been identified as containing asbestos and has been removed. Install in accordance with paragraph 3.24.1.2, Generator Heaters Installation and provide power supply wiring in accordance with Section 26 05 19.00 26 .

2.13 FIELD WINDING REFURBISHMENT

2.13.1 Field Pole Body Assemblies

Provide field pole body assemblies to replace the existing pole bodies.

Submit for approval drawings of the pole body construction, including dimensions, materials, weight, and amortisseur winding details. All pole body assemblies must be identical in construction.

2.13.2 Field Pole Bodies

2.13.2.1 General

Design and provide 54 new pole bodies (52 for installation on to the units and 2 spare) that meet the following requirements:

(a) Construct the pole bodies of thin steel laminations secured by rivets or bolts.

(b) Design the pole bodies to match the existing field pole mounting arrangement, utilizing a T-tail type system with four tapered mounting keys. Design the pole body so that the base of the pole bears evenly on the rim of the rotor.

(c) Furnish each pole body with an amortisseur winding embedded in the pole face. Design the amortisseur winding to be of low resistance and

SECTION 48 13 16.00 26 Page 18 rugged construction capable of withstanding unbalanced short circuits in accordance with IEEE C50.12 . Design the amortisseur winding for a calculated ratio of quadrature-axis subtransient reactance to direct-axis subtransient reactance not to exceed 1.10. Design the windings to be embedded in each pole face, making good physical contact with the pole body laminations, and to be connected between poles. Ensure that the amortisseur interpole connections maintain adequate clearance to the field winding interpole connections to allow the field winding to pass the AC High Potential Test required by subparagraph 3.23(c).

(d) Modifications to the rotor rim are not permitted, but re-contouring or other modifications to the pole body T-tail are allowed.

2.13.2.2 Pole Body Analysis

Perform an analysis of the existing rotor pole T-tail attachment to the rotor and determine if the T-tail design can be modified or contoured to reduce the stress concentrations that are present in the current design.

If modifications are to be made, include the additional analysis for the modifications.

Use allowable stresses per ASME BPVC SEC VIII D2 or ASME FFS-1. Perform a fatigue analysis with the operating scheme listed below. Include analysis of the exceptional loading condition of unit runaway at maximum permissible speed. If the Contractor prefers to use an alternative method of fatigue analysis or different values for allowable stresses, submit justification for Government Approval. Provided any assumptions, modifications, and interpretations of the code chosen to clearly demonstrate any limiting stress conditions of the model.

Consider the following unit operating scheme when performing the fatigue analysis:

(a) 2 start-stop cycles per day

(b) 15 overspeed events per year

(c) 50 years of operation

If finite element analysis (FEA) is used to determine stress levels, use ANSYS version 16.0 or greater, or Solidworks Simulation 2015 or greater.

Provide all model files to the Government at the completion of the analysis.

Submit analysis in the form of a technical report for approval. The report shall clearly relay, through narrative and pictures/drawings, what analysis was performed and how, if any, modifications will improve the stress state and/or fatigue life of the rotor pole. If FEA is used in the analysis, include the following information from the FEA model:

(a) Material properties and assumptions

(b) Model boundary conditions

(c) Loading scenarios

(d) Analysis settings

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(e) Mesh settings, details, and validation (convergence)

(f) Areas of significant stress

(g) Areas of stress concentration

(h) Areas of high combined stress

(i) Types of stress (eg. von Mises, principle, shear)

(j) Areas subject to cyclic loading/fatigue

2.13.3 Tapered Mounting Keys

Provide four (two sets) of new tapered pole mounting keys for each pole for use in the installation of the rotor poles on the rotor rim. Comprise the tapered mounting key sets of one stationary key and one drive key of a sufficient length, thickness and taper to secure the rotor poles to the rotor rim.

2.13.4 Reinsulation of Field Coils

Use materials suitable for operation in a generator with Class F insulation to reinsulate the field coils (ground insulation and turn insulation). Do not use asbestos materials. Make the turn insulation of two layers of Nomex 410, bonded in place with brush on epoxy resin or B-stage epoxy Nomex. Support proposals for alternative insulations with data sheets demonstrating equivalence or superiority of specified materials. Use materials suitable for operation in a generator at Class F limits for pole collars. Fabricate collars from single sheets such that the collars have no joints. Suitably brace field coils against the pole iron. Seal any gaps left between pole collars and the pole body and field coils to prevent foreign material ingress. Submit drawings of the Rotor Pole Assembly and Details .

2.13.5 Interpole Connectors

Furnish new interpole connectors on reinsulated field poles. Fabricate interpole connections to be flexible and either the laminated copper type or the bolted braided copper type. Coordinate the design of the interpole connectors with the design of the amortisseur winding connectors and the existing rotor fan blades to ensure that the three components will not cause an arc during the testing specified in this section or normal operation. Submit drawings of the Rotor Pole Connections Assembly and Details including materials, dimensions and details.

2.13.6 Amortisseur Winding

Deign a new amortisseur winding to be installed in the face of each pole body. Manufacture the winding of oxygen-free copper alloy 102 or approved equal. Design the new amortisseur winding to be connected between each pole in order to increase the negative sequence capability of the machine.

Submit for approval the Amortisseur Winding Design , including arrangement drawings, dimensions, and calculations supporting the design. Supply all necessary connectors to connect the amortisseur shorting bars between poles when installed on the rotor. Supply amortisseur connectors of the bolted flexible braided copper type.

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2.14 SPARE PARTS

2.14.1 General

Ship all spare parts to Philpott when the feature of work with which the spare parts are…