Amd_0003_Combined.pdf

Transformer, Fort Peck, MT FP100

SECTION 48 19 23.01 Page 1

Please find attached the three modified Sections of the Fort Peck transformer supply contract, to be posted as an amendment to the solicitation. The changes to the Sections are primarily to allow an additional design-type of bushing which is manufactured in the U.S. These changes should not affect the due date for the proposals. The changes to each Section include:

Sections 48 19 23.01 and 48 19 23.04:

1) Paragraph 2.6.1: The requirement was added for handhole access covers to be provided in the tank sidewall for access to each de-energized tap changer switch mechanism for future maintenance.

2) Paragraph 2.8: Changed the paragraph to allow a resin-impregnated synthetic design of bushing. Changed the paragraph to require either resin-impregnated paper or resin-impregnated synthetic bushings for the high-voltage, low-voltage and neutral bushings.

3) Paragraph 2.12.8: Changed the paragraph to relax the restriction of requiring a Reinhausen Tapmotion DD de-energized tap changer control.

4) Paragraph 2.19: Additional information provided for the storage material requirements for the spare bushings.

5) Paragraph 3.4.2: Specific requirements added for bushing partial discharge and power factor testing.

Section 48 19 23.02:

1) General corrections made to remove incorrect references to cooling fans (since these are ONAN cooled transformers).

2) Paragraph 2.8: Changed the paragraph to allow a resin-impregnated synthetic design of bushing. Changed the paragraph to require either resin-impregnated paper or resin-impregnated synthetic bushings for the high-voltage bushings.

3) Paragraph 2.19: Additional information provided for the storage material requirements for the spare high-voltage bushings.

4) Paragraph 3.4.2: Specific requirements added for bushing partial discharge and power factor testing.

SECTION TABLE OF CONTENTS

DIVISION 48 - ELECTRICAL POWER GENERATION

SECTION 48 19 23.01

25,000/33,333 KVA CLASS I GSU POWER TRANSFORMER (OPTIONAL)

PART 1 GENERAL

1.1 DESCRIPTION OF WORK

1.2 GENERAL ARRANGEMENT AND CONNECTED POWERTRAIN

SECTION 48 19 23.01 Page 2

1.2.1 General Arrangement

1.2.2 Connected Powertrain

1.3 REFERENCED PUBLICATIONS

1.4 SUBMITTALS

1.5 WARRANTY REQUIREMENTS

PART 2 PRODUCTS

2.1 TYPE AND RATING

2.1.1 General

2.1.2 Transformer Limiting Dimensions and Equipment Arrangement

2.1.3 Requirements

2.1.4 Standard Products

2.1.5 Ratings and Electrical Characteristics

2.2 STRUCTURAL DESIGN CRITERIA AND SEISMIC CALCULATIONS

2.2.1 Structural Design Criteria

2.2.2 Seismic Calculations

2.2.3 Anchorage to Concrete Pad for Seismic Restraint

2.3 THERMAL DESIGN

2.4 CORE

2.5 WINDINGS

2.5.1 General

2.5.2 Insulation Levels

2.5.3 Short Circuit Capability

2.5.4 Embedded Fiber Optic Probes

2.6 TANK

2.6.1 Construction

2.6.2 Gasketing

2.6.3 Lifting and Moving Facilities

2.6.3.1 Lifting Facilities

2.6.3.2 Moving Facilities

2.6.4 Valves

2.6.5 Connections

2.6.5.1 General

2.6.5.2 Stainless Steel

2.6.6 Steel Pipe and Fittings

2.6.7 Grounding

2.6.8 Personal Fall Protection System

2.6.9 Portable Fall Arrest Anchor Post Mounting Plate

2.6.10 Structural Steel Supporting Base

2.6.11 Jack Ports

2.6.12 Center of Gravity

2.7 COOLING EQUIPMENT

2.7.1 Radiators

2.7.2 Forced-Air Equipment

2.7.3 Power Supply Equipment

SECTION 48 19 23.01 Page 3

2.7.4 Cooling Control Equipment

2.8 BUSHINGS

2.8.1 General Bushing Requirements

2.8.2 Ratings

2.8.2.1 High-Voltage Bushings

2.8.2.2 High-Voltage Neutral Bushing

2.8.2.3 Low-Voltage Bushings

2.8.3 High-Voltage Bushing Terminals

2.8.4 Low-Voltage Bushing Terminal Connections

2.8.5 Core Ground Bushings

2.8.6 SFRA Test Shipping Bushings

2.9 BUSHING-TYPE CURRENT TRANSFORMERS

2.9.1 High-Voltage Bushings

2.9.2 Low-Voltage Bushings

2.9.3 High-Voltage Neutral Bushing

2.10 LOW-VOLTAGE BUSHING THROAT

2.11 SURGE ARRESTERS

2.11.1 General

2.11.2 Ratings

2.11.3 Mounting

2.11.4 Construction

2.11.4.1 General

2.11.4.2 Housing

2.11.4.3 Line Terminal Cap

2.11.4.4 Conductor Terminals

2.11.4.5 Metal Parts

2.11.4.6 Nameplates

2.11.5 Assembly

2.11.6 Grounding

2.12 TRANSFORMER MOUNTED ACCESSORIES

2.12.1 General

2.12.2 Liquid Level Indicator

2.12.3 Analog Temperature Indicating Equipment

2.12.3.1 Liquid Temperature Indicator

2.12.3.2 Winding Temperature Equipment

2.12.4 Electronic Pressure Monitor

2.12.4.1 General

2.12.4.2 Features

2.12.5 Pressure Relief Device

2.12.5.1 General

2.12.5.2 Oil Discharge Piping

2.12.6 On-line Dissolved Gas and Moisture Content Monitor

2.12.6.1 General

2.12.6.2 Mounting and Interconnection

2.12.6.3 Communication and Data

2.12.6.4 Optional Accessories

2.12.6.5 Factory Installation

2.12.6.6 Provisions for Shipment

2.12.7 Gas and Oil Actuated Relay (Buchholz)

2.12.8 De-energized Tap Changer Control

2.12.9 Contacts and Devices

2.13 OIL

2.13.1 Quantity and Transformer Oil Certification

2.13.2 Type of Oil

2.13.3 Chemical, Physical and Electrical Characteristics

2.13.4 Sampling

2.13.5 Testing

2.14 OIL PRESERVATION SYSTEM

2.14.1 General

SECTION 48 19 23.01 Page 4

2.14.2 Air Cell, Constant-Pressure, Reservoir Tank System

2.14.2.1 General

2.14.2.2 Air Cell

2.14.2.3 Dehydrating Breather

2.14.2.4 Bushing Potential Devices

2.15 TRANSFORMER CONTROL AND POWER CABINETS

2.15.1 General

2.15.2 Mounting and Conduit Interface Provisions

2.15.3 Control Cabinet Requirements

2.15.4 Power Cabinet Requirements

2.15.5 Device Nameplates

2.16 CONTROL AND POWER CABINET EQUIPMENT

2.16.1 Cooling Control Equipment

2.16.1.1 General

2.16.1.2 Stages of Cooling

2.16.2 Electronic Temperature Monitor with Fiber Optic Winding

Temperature Measurement

2.16.2.1 General

2.16.2.2 Features

2.16.2.3 Monitoring Functions

2.16.2.4 Control Functions

2.16.2.5 Outputs

2.16.2.6 Winding Temperature Measurement

2.16.2.7 Fiber Optic Probes and Connectors

2.16.3 Local Annunciator Panel

2.16.4 Auxiliary Power Transformer

2.16.5 Magnetic Contactors

2.16.6 Molded-Case Circuit Breakers

2.16.6.1 General

2.16.6.2 Trip Units

2.16.6.3 240 V ac Circuits

2.16.6.4 120 V ac Circuits

2.16.6.5 125 V dc Circuits

2.16.7 Auxiliary and Interposing Relays

2.16.7.1 Auxiliary Relays

2.16.7.2 Interposing Relay for the Lockout Relay

2.16.8 Lockout Relay

2.16.9 Control and Instrument Switches

2.16.10 Terminal Blocks

2.16.10.1 Control Signal Type

2.16.10.2 Short-Circuiting Type

2.16.10.3 Power Distribution Blocks

2.16.11 Fuses and Fuseholders

2.16.12 Lighting, Convenience Receptacle, and Cabinet Heaters

2.17 INSULATED WIRE AND CABLE

2.18 CONDUIT SYSTEMS

2.18.1 General

2.18.2 Conduit and Fittings

2.18.3 Outlet and Junction Boxes

2.19 SPARE PARTS

2.20 NAMEPLATES

2.20.1 Transformer Nameplate

2.20.2 Lifting Nameplate

2.20.3 Device Nameplates

2.20.4 Additional Transformer Identification

PART 3 EXECUTION

3.1 TRANSFORMER DESIGN DATA REVIEW MEETING

SECTION 48 19 23.01 Page 5

3.1.1 General

3.1.2 Design Data Review Meeting Requirements

3.2 TRANSFORMER FACTORY ASSEMBLY

3.2.1 General

3.2.2 Welding

3.2.2.1 General

3.2.2.2 Welder Qualifications

3.2.2.3 Welding Materials

3.2.2.4 Welding Procedures

3.2.2.5 Preheat and Interpass Temperature

3.2.2.6 Inspection and Weld Inspector Qualifications

3.2.3 Manufacturing Inspection by Government Personnel

3.3 TRANSFORMER FACTORY ACCEPTANCE TESTS

3.3.1 General

3.3.2 Factory Acceptance Test Report

3.3.3 Control and Cooling Consumption Losses

3.3.4 Zero-Phase Sequence Impedance

3.3.5 Analog Temperature Gauges

3.3.6 Temperature Rise Test

3.3.7 Dissolved Gas-In-Oil Analysis

3.3.8 Audible Sound Level Test

3.3.9 Winding Insulation Resistance

3.3.10 Core Insulation Resistance

3.3.11 Insulation Power Factor and Capacitance

3.3.12 Low-frequency Dielectric Tests on Auxiliary Devices

3.3.13 Impulse Tests

3.3.14 Induced Voltage Test With Partial Discharge Measurements

3.3.14.1 General

3.3.14.2 7,200 Cycle Enhancement Level

3.3.14.3 Data Reporting

3.3.15 Leak Test

3.3.16 Leakage Reactance Measurement Test

3.3.17 Sweep Frequency Response Analysis Tests

3.3.17.1 Required Tests

3.3.17.2 Test Equipment and Test Parameters

3.3.17.3 Test Cable Integrity

3.3.17.4 Test Connections

3.3.17.5 Data Reporting

3.3.17.6 Data Interpretation

3.3.18 Device Operational Tests

3.3.19 De-Energized Tap Changer Test

3.3.20 Insulated Wire and Cable

3.4 BUSHING TESTS

3.4.1 General

3.4.2 Bushing Design Tests

3.4.2.1 Partial Discharge Tests

3.4.3 Bushing Withstand Test Voltages

3.4.4 Bushing Routine Tests

3.4.5 Bushing Current Transformer Tests

3.5 SURGE ARRESTER TESTS

3.5.1 General

3.5.2 Surge Arrester Design Tests

3.5.3 Surge Arrester Conformance Tests

3.5.4 Failure to Meet Tests or Specified Characteristics

3.6 FACTORY CLEANING AND PAINTING

3.6.1 General

3.6.2 Interior Surfaces

3.6.3 Exterior Surfaces

3.6.4 Machined Surfaces

SECTION 48 19 23.01 Page 6

3.7 TRANSFORMER SHIPMENT, HAULING AND SITE ASSEMBLY

-- End of Section Table of Contents --

SECTION 48 19 23.01 Page 7

SECTION 48 19 23.01

25,000/33,333 KVA CLASS I GSU POWER TRANSFORMER (OPTIONAL)

PART 1 GENERAL

1.1 DESCRIPTION OF WORK

This Section covers the manufacturing and factory testing of one three-phase generator step-up (GSU) power transformer rated 25,000/33,333 kVA, 69 kV high-voltage, 13.8 kV low-voltage, Class ONAN/ONAF cooling, for delivery f.o.b. to Fort Peck power plant switchyard No. 1. The transformer shipment, hauling, site reassembly and field testing requirements are as required in SECTION 48 20 00. Throughout this Section, the transformer tank layout is identified by Segments 1 through 4, as defined in IEEE C57.12.10, Figure 1, and indicated on drawing E-109.

1.2 GENERAL ARRANGEMENT AND CONNECTED POWERTRAIN

1.2.1 General Arrangement

The transformer specified in this Section will replace one existing bank of single-phase transformers (Bank T2), presently located in the Fort Peck power plant switchyard No. 1. Reference drawings MFP-OPN93E103.6 and

MFP-OPN93E106.1 show the existing location of Transformer Bay 2. The new three-phase transformer shall be manufactured as required herein for concrete pad mounting. Interconnection of the transformer to the power plant equipment will be performed by a separate contractor.

1.2.2 Connected Powertrain

The new three-phase transformer shall be sized per the requirements of paragraph, "Ratings and Electrical Characteristics", to transmit the power of the connected hydrogenerators. The connected hydrogenerators operate at a rated power factor of 0.90.

1.3 REFERENCED PUBLICATIONS

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 SOCIETY FOR NONDESTRUCTIVE TESTING (ASNT)

ASNT SNT-TC-1A (2011) Recommended Practice for Personal

Qualification and Certification in

Nondestructive Testing

ASME INTERNATIONAL (ASME)

ASME B1.1 (2003; R 2008) Unified Inch Screw Threads

(UN and UNR Thread Form)

ASME B1.20.1 (2013) Pipe Threads, General Purpose (Inch)

ASME B16.1 (2010) Gray Iron Pipe Flanges and Flanged

SECTION 48 19 23.01 Page 8

Fittings (Classes 25, 125, and 250)

ASME B16.24 (2011) Cast Copper Alloy Pipe Flanges and

Flanged Fittings (Classes 150, 300, 600, 900, 1500, and 2500

ASME B18.2.6M (2012) Metric Fasteners for Use in

Structural Applications

ASME BPVC SECTION IX (2013) Qualification Standard for Welding and Brazing Procedures, Welders, Brazers, and Welding and Brazing Operators

ASTM INTERNATIONAL (ASTM)

ASTM A 53 (2012) Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless

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 475 (2003; R 2014) Standard Specification for

Zinc-Coated Steel Wire Strand

ASTM A 664 (2014) Standard Practice for

Identification of Standard Electrical

Steel Grades in ASTM Specifications

ASTM A 717 (2012) Standard Test Method for Surface

Insulation Resistivity of Single-Strip

Specimens

ASTM A 876 (2012) Standard Specification for

Flat-Rolled, Grain-Oriented, Silicon-Iron, Electrical Steel, Fully Processed Types

ASTM D 923 (2007) Standard Practice for Sampling

Electrical Insulating Liquids

ASTM D 1533 (2012) Standard Test Method for Water in

Insulating Liquids by Coulometric Karl

Fischer Titration

ASTM D 1535 (2014) Standard Practice for Specifying

Color by the Munsell System

ASTM D 3487 (2009) Standard Specification for Mineral

Insulating Oil Used in Electrical Apparatus

ASTM D 4059 (2000; R 2010) Standard Test Method for

Analysis of Polychlorinated Biphenyls in

Insulating Liquids by Gas Chromatography

ASTM F 1145 (2005; R 2011) Standard Specification for

Turnbuckles, Swaged, Welded, Forged

SECTION 48 19 23.01 Page 9

AMERICAN SOCIETY OF CIVIL ENGINEERS (ASCE)

ASCE 7 (2010) Minimum Design Loads for Buildings and Other Structures

AMERICAN WELDING SOCIETY (AWS)

AWS A2.4 (2012) Standard Symbols for Welding, Brazing, and Nondestructive Examination

AWS D1.1 (2010) Structural Welding Code - Steel

AWS D1.6 (2007) Structural Welding Code - Stainless

Steel

INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS (IEEE)

IEEE 693 (2005) Recommended Practice for Seismic

Design of Substations

IEEE C57.12.00 (2010) General Requirements for

Liquid-Immersed Distribution, Power, and

Regulating Transformers

IEEE C57.12.10 (2010) Requirements for Liquid-Immersed

Power Transformers

IEEE C57.12.70 (2011) Standard Terminal Markings and

Connections for Distribution and Power

Transformers

IEEE C57.12.80 (2010) Terminology for Power and

Distribution Transformers

IEEE C57.12.90 (2010) Test Code for Liquid-Immersed

Distribution, Power, and Regulating

IEEE C57.13 (2008) Requirements for Instrument

IEEE C57.19.00 (2004) General Requirements and Test

Procedures for Outdoor Power Apparatus

Bushings

IEEE C57.19.01 (2000; R 2010) Performance Characteristics and Dimensions for Outdoor Apparatus

Bushings

IEEE C57.91 (2011) Guide for Loading

Mineral-Oil-Immersed Transformers and

Step-Voltage Regulators

IEEE C57.104 (2008) Guide for the Interpretation of

Gases Generated in Oil-Immersed

IEEE C57.113 (2010) Recommended Practice for Partial

SECTION 48 19 23.01 Page 10

Discharge Measurement in Liquid-Filled

Power Transformers and Shunt Reactors

IEEE C57.149 (2012) Guide for the Application and

Interpretation of Frequency Response

Analysis for Oil-Immersed Transformers

IEEE C62.11 (2012) Metal-Oxide Surge Arresters for AC

Power Circuits (> 1 kV)

MANUFACTURERS STANDARDIZATION SOCIETY OF THE VALVE AND FITTINGS

INDUSTRY (MSS)

MSS SP-72A (2010) Ball Valves with Flanged or

Butt-Welding Ends for General Service

NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION (NEMA)

NEMA 250 (2014) Enclosures for Electrical Equipment

(1000 Volts Maximum)

NEMA C29.1 (1988; R 2012) Test Methods for Electrical

Power Insulators

NEMA C80.1 (2005) Electrical Rigid Steel Conduit

(ERSC)

NEMA CC 1 (2009; Eratta 2012) Electrical Power

Connection for Substations

NEMA FB 1 (2012) Fittings, Cast Metal Boxes, and

Conduit Bodies for Conduit, Electrical

Metallic Tubing, and Cable

NEMA ICS 1 (2000; R 2008; E 2010) Industrial Control and Systems General Requirements

NEMA ICS 2 (2000; R 2005) Industrial Control and

Systems: Controllers, Contactors, and

Overload Relays Rated 600 Volts

NEMA ICS 5 (2000; R 2010) Industrial Control and

Systems: Control-Circuit and Pilot Devices

NEMA LA 1 (2009) Surge Arresters

NEMA MW 1000 (2014) Magnet Wire

NEMA SG 4 (2009; R 2013) Alternating-Current

High-Voltage Circuit Breakers

NATIONAL FIRE PROTECTION ASSOCIATION (NFPA)

NFPA 70 (2014) National Electrical Code

UNDERWRITERS LABORATORIES (UL)

UL 248-8 (2011) Low-Voltage Fuses - Part 8: Class

J Fuses

SECTION 48 19 23.01 Page 11

UL 360 (2013; Rev thru Jan 2015) Liquid-Tight

Flexible Metal Conduit

UL 489 (2013; Rev thru Mar 2014) Molded-Case

Circuit Breakers, Molded-Case Switches and

Circuit-Breaker Enclosures

UL 508 (1999; Rev thru Oct 2013) Industrial

Control Equipment

UL 508A (2013; Rev thru Jan 2014) Industrial

Control Panels

UL 514B (2012; Rev thru Nov 2014) Conduit, Tubing, and Cable Fittings

UL 969 (1995; Rev thru Sep 2014) Safety Marking and Labeling Systems

UL 4248-8 (2007; Rev thru Oct 2013) Fuseholders -

Part 8: Class J

U.S. ARMY CORPS OF ENGINEERS (USACE)

EM 385-1-1 (2008; Errata Jul 2011) Safety and Health

Requirements Manual

1.4 SUBMITTALS

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

submittals not having a "G" designation are for information only or as otherwise designated. 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", unless otherwise indicated below:

SD-02 Shop Drawings

a. Outline and Assembly Drawings; G, HDC

Outline and assembly drawings of the transformer shall be submitted for approval within 150 calendar days after date of award to demonstrate that the equipment will conform to the requirements and intent of the specifications. These drawings shall include the following, at a minimum:

(1) Transformer nameplate information. Drawings shall be provided for the main transformer nameplate and lifting nameplate, as required in paragraph "NAMEPLATES".

(2) Outline drawing. An outline drawing shall be provided indicating the following:

(a) Layout and dimensions of the assembled transformer, including centers of gravity with the transformer empty and filled with oil. An elevation view for each side of the transformer and a plan view shall be provided.

SECTION 48 19 23.01 Page 12

(b) Jacking, lifting and pulling-eye locations.

(c) Locations of all ancillary equipment, dimensioned to the transformer centerlines or edges, as appropriate, including bushings, control and power cabinets, valves, gauges, relays, conservator tank, radiators and fans, on-line monitors, and grounding pads.

(d) Drawing legend and transformer weight information.

(e) A transformer elevation view indicating clearances required for untanking or disassembling.

(3) Transformer winding layout and configuration diagram. The winding diagram shall be a sectional elevation view of sufficient detail to identify the following basic features of the core/coil construction:

(a) Core legs

(b) High-voltage winding

(c) Low-voltage winding

(d) Winding taps

(e) De-energized tap changer and lead support structure

(f) Bushing configuration and connections

(g) Shielding (if present)

(h) Pressboard

(i) Tank wall surface

(4) Control schematic diagrams.

b. Detail Drawings; G, HDC

Detail drawings shall be submitted for approval within 210 calendar days after date of award. These drawings shall include the following:

(1) Further refinement of the outline and assembly drawings, including the routing of conduit, piping, locations of junction boxes and external devices, and bushing throat flanges and bolt pattern. The final locations of the conduit routing and junction boxes may be included in the manufacturer's as-built drawings after manufacture of the transformer has been completed.

(2) Shipping drawing showing the outline of the transformer disassembled as required for shipment, including the following:

(a) Overall shipping dimensions, including indication of centers of gravity for the transformer in the shipping configuration. All devices remaining installed on the transformer during shipment shall be indicated.

(b) Lifting details and overall height required for the slings and crane hook, including recommended sling length and ratings.

(c) Location of temporary covers for bushings, valves and control and power cabinets left installed during shipment.

(d) Detail indicating the method of installing the SFRA

SECTION 48 19 23.01 Page 13 test shipping bushings, their locations, and a description of the method of bracing the winding leads to these bushings during shipment.

(e) Location of impact recorders, shipping gas pressure gauge and pressure regulator system.

(3) Wiring connection diagrams showing terminal block and conductor designations. These drawings shall include detailed control and power cabinet interconnections and device locations, and shall be prepared based upon the actual equipment arrangement.

(4) Seismic anchoring location details.

(5) A transformer outline drawing indicating the locations of all gaskets on the transformer, a schedule of gasket types and sizes, and a detail for each design of gasket showing the groove and compression requirements.

(6) A transformer outline drawing indicating the locations of typical welds, with structural weldment details.

(7) A drawing of the transformer fall protection system, indicating the locations and mounting details of the posts, routing of the wire rope, method of attaching and tensioning the wire rope, location of the storage cabinet, and a materials list.

SD-05 Design Data

a. Descriptive Data; G, HDC

Descriptive data or catalog data of all accessory devices and ancillary equipment provided with the transformer shall be submitted for approval within 240 calendar days after date of award, to demonstrate fully that all parts of the equipment will conform to the requirements and intent of the specifications.

b. Spare Parts List; G, HDC

A listing of all required spare parts to be provided with the transformers shall be submitted for approval within 240 calendar days after date of award. (see paragraph "SPARE PARTS")

c. Structural Design Criteria and Seismic Calculations; G, HDC

Structural design criteria and seismic calculations shall be submitted for approval within 210 calendar days after date of award. Design criteria and calculations shall be performed by qualified civil or structural engineers who are presently registered professional engineers (PE). A cover sheet for the submittal shall be provided and stamped or sealed and signed by a

PE.

d. Electronic Temperature Monitor Settings and Software

Configuration; G, HDC

Electronic Temperature Monitor Settings and Software

Configuration data shall be submitted for approval a minimum of 60 calendar days prior to the performance of the factory acceptance

SECTION 48 19 23.01 Page 14 tests. (see paragraph "Electronic Temperature Monitor with Fiber

Optic Winding Temperature Measurement").

SD-06 Test Reports

a. Transformer Factory Acceptance Test Report; G, HDC

The transformer factory acceptance test report shall be submitted for approval not later than 14 calendar days following completion of the factory acceptance tests. (see paragraph

"Factory Acceptance Test Report").

b. Bushing Design Tests; G, HDC

The transformer bushing design test reports shall be submitted for approval not later than 30 calendar days following completion of the tests (see paragraph "Bushing Design Tests"). If certified copies of bushing design tests previously conducted within five

(5) years are submitted in-lieu of new test results, they shall be submitted when the bushing selection is made, but not later than

60 calendar days prior to the performance of transformer factory acceptance tests.

c. Bushing Routine Tests; G, HDC

The transformer bushing routine test reports shall be submitted of the tests. (see paragraph "Bushing Routine Tests").

d. Bushing Current Transformer Tests; G, HDC

The transformer bushing current transformer test reports shall be submitted for approval not later than 30 calendar days following completion of the tests. (see paragraph "Bushing Current

Transformer Tests").

e. Surge Arrester Design Tests; G, HDC

The surge arrester design test reports shall be submitted for approval not later than 30 calendar days following completion of the tests (see paragraph "Surge Arrester Design Tests"). If certified copies of previously conducted surge arrester design tests are submitted in-lieu of new test results, they shall be submitted not later than 30 calendar days prior to performance of transformer factory acceptance tests.

f. Surge Arrester Conformance Tests; G, HDC

The surge arrester conformance test reports shall be submitted of the tests. (see paragraph "Surge Arrester Conformance Tests").

SD-07 Certificates

a. Transformer Oil Certification; G, HDC

Transformer oil certification shall be submitted for approval a minimum of 14 calendar days prior to the delivery of transformer oil to the Fort Peck power plant. (see paragraph "Quantity and

SECTION 48 19 23.01 Page 15

Transformer Oil Certification").

b. Notification of the Date of the Transformer Design Data Review

Meeting; G, HDC

The contractor shall notify the COR 30 calendar days in advance of when the transformer manufacturer will be ready for performance of a design data review meeting, to be held at the manufacturer's facility. (see paragraph "TRANSFORMER DESIGN DATA REVIEW MEETING").

c. Notification of the Date of Factory Tests; G, HDC

The contractor shall notify the COR, in writing, 30 calendar days in advance of when the transformer will be ready for factory acceptance tests, so that the tests may be witnessed by a

Government Representative. If factory testing in a foreign country is proposed, the Contractor shall notify the COR in writing of the preliminary testing dates, not later than 60 days prior to the start of factory tests. (see paragraph "TRANSFORMER

FACTORY ACCEPTANCE TESTS").

d. Welder Qualifications; G, HDC

The welding operators and welders qualifications shall be submitted a minimum of 30 calendar days prior to their performance of work. (see paragraph "Welder Qualifications").

e. Weld Inspector Qualifications; G, HDC

The qualifications for the Contractor's Quality Assurance personnel responsible for performing weld inspections shall be submitted a minimum of 30 calendar days prior to the performance of weld inspections. (see paragraph "Inspection and Weld

Inspector Qualifications").

SD-08 Manufacturer's Instructions

a. Factory Test Procedures; G, HDC

The transformer factory test procedures shall be submitted for approval a minimum of 60 calendar days prior to the performance of the factory acceptance tests. (see paragraph "TRANSFORMER FACTORY

ACCEPTANCE TESTS").

b. Welding Procedures; G, HDC

Welding procedures and specifications and copies of test reports shall be submitted a minimum of 30 calendar days prior to the performance of work. (see paragraph "Welding Procedure").

c. Prequalified Weld Procedures; G, HDC

Applicable prequalified weld procedures per the requirements of

AWS shall be submitted a minimum of 30 calendar days prior to the performance of work. (see paragraph "Welding Procedure").

1.5 WARRANTY REQUIREMENTS

In addition to the requirements outlined in FAR 52.246-17, the

SECTION 48 19 23.01 Page 16 manufacturer’s warranty for the power transformers shall continue for a period of five (5) years from the date of final acceptance of the work. If the Government takes possession of any part of this work before final acceptance, this warranty shall continue for a period of five (5) years from the date the Government takes possession. The following transformer issues will also be considered warranty repair items:

a. Transformer gassing rates beyond the Condition 1 level as defined in Tables 2 and 3 of IEEE C57.104, or concentrations exceeding the

Condition 1 limits as defined in Table 1 of IEEE C57.104

b. Transformer oil leaks.

PART 2 PRODUCTS

2.1 TYPE AND RATING

2.1.1 General

The transformer to be furnished under these specifications shall be three-phase, two-winding, with one high-voltage and one low-voltage winding per phase, oil-immersed type suitable for outdoor operation. The transformer shall be self-cooled/forced air-cooled type, Class ONAN/ONAF, and shall be of a design that has an established record of satisfactory operation with the type of oil preservation system specified. The transformers shall be manufactured for transportation by rail and trucking by heavy hauler, and for shipment by sea if the transformers have a probability of being transported by this method.

2.1.2 Transformer Limiting Dimensions and Equipment Arrangement

The transformer manufacturing, configuration, and dimensions shall be as indicated on the contract drawings, and the transformer shall not exceed the limiting dimensions.

2.1.3 Requirements

Except as otherwise specified herein, the transformer, accessories, and spare parts shall conform to the applicable requirements of IEEE C57.12.00, IEEE C57.12.10, IEEE C57.12.70, IEEE C57.12.80 and IEEE C57.12.90.

2.1.4 Standard Products

Material and equipment provided with the transformer shall be standard products from a manufacturer regularly engaged in their production, and shall essentially duplicate items that have been in satisfactory use for at least 3 years prior to bid opening, unless otherwise specifically approved. All materials shall conform to the requirements of these specifications. Materials shall be of industrial quality, free from defects and imperfections, of recent manufacture, and of the classification and grades designated. All materials, supplies, and articles not manufactured by the Contractor shall be the products of other recognized reputable manufacturers. If the Contractor desires for any reason to deviate from the standards designated in these specifications, a statement shall be submitted for approval describing the exact nature of the deviation, including complete specifications for the materials that are being proposed for use.

SECTION 48 19 23.01 Page 17

2.1.5 Ratings and Electrical Characteristics

The ratings and electrical characteristics of the transformer shall be as follows:

a. Continuous ratings, at the 65 degrees-C temperature rated temperature rise, on all taps, kVA:

(1) ONAN Rating: 25,000

(2) ONAF Rating: 33,333

b. Frequency, Hz: 60 c.

Number of phases: 3 d.

Rated voltage, kV:

(1) High-voltage windings:

(2) Low-voltage windings: 13.8 e.

Winding connections:

(1) High-voltage windings: Grounded-Wye

(2) Low-voltage windings: Delta

f. Impedance, at ONAN rated current, subject to IEEE tolerances, percent: 7.0

g. Angular displacement, low-voltage lags high-voltage by, degrees: 30

h. Basic impulse insulation levels (BIL), kV:

(1) Line ends of the high-voltage windings, not less than: 350

(2) Neutral ends of the high-voltage windings, not less than:

(3) Low-voltage windings, not less than: 110

i. Taps in low voltage windings: None

j. Taps (full capacity) in high voltage winding

(1) Tap 1, percent of high-voltage rating: 105.0

(2) Tap 2, percent of high-voltage rating: 102.5

(3) Tap 3, percent of high-voltage rating: 100.0

(4) Tap 4, percent of high-voltage rating: 97.5

(5) Tap 5, percent of high-voltage rating: 95.0

k. Maximum no-load losses at rated voltage and frequency, kW: 30

l. Maximum load losses at maximum ONAN rated kVA and 1.0 power factor, kW: 95

m. Maximum average sound level at rated voltage and frequency, with all cooling groups in operation, dB: 68

2.2 STRUCTURAL DESIGN CRITERIA AND SEISMIC CALCULATIONS

Structural design criteria and seismic calculations shall be provided for the transformer manufacturing, to include the main tank and all major

SECTION 48 19 23.01 Page 18 components such as bushings, cooling equipment, and oil preservation equipment.

2.2.1 Structural Design Criteria

Structural design criteria shall include the following:

a. Indicate the industry design standards and allowable stresses or capacities to which steel plate, structural steel shapes, welds, bolts and studs shall conform.

b. Indicate the industry standards used in developing the seismic forces and analysis techniques used in manufacture of the transformer and transformer components.

c. Seismic design for equipment restraint shall be in accordance with

Chapter 13, "Seismic Design Requirements for Nonstructural Components," of ASCE 7 with the seismic design force computed as per Section 13.3

"Seismic Demands on Nonstructural Components". Electrical equipment restraint shall manufactured in accordance with the provisions in

IEEE 693 Annex D, or Section 13.3 of ASCE 7 whichever produces the more adverse seismic effects. For ASCE 7, use a spectral acceleration S

DS

0.105, I P = 1.50, and z=h=1. For IEEE 693, the seismic qualification level shall be moderate.

2.2.2 Seismic Calculations

Seismic calculations shall include the following:

a. Derivation of seismic forces and load cases. Load cases used for developing seismic anchorage of the complete transformer shall account for the effect of the righting force of the weight of the transformer.

b. Calculations for use in the design of anchorage to resist overturning and base shear. The maximum uplift and shear force per anchor shall be provided in pounds or kips.

c. A schematic depicting the location of the center of gravity, the applied seismic forces relative to the base, and the location of seismic anchors.

d. Calculations for individual components and their attachment to the transformer.

2.2.3 Anchorage to Concrete Pad for Seismic Restraint

The transformer shall be manufactured for mounting on a new concrete pad.

For the purposes of performing seismic calculations, the transformer base will be welded to steel plates attached to the concrete pad, as indicated in paragraph, Structural Steel Supporting Base.

2.3 THERMAL DESIGN

The temperature rise above ambient temperature of the transformer or parts thereof, when tested in accordance with its ratings, shall not exceed the limits of observable temperature rise for oil immersed apparatus as stated in IEEE C57.12.00 (paragraph 5.11.1). The winding temperature rise by resistance shall not exceed 65 degrees-C, and the hottest spot winding temperature rise shall not exceed 80 degrees-C on the tap connections that

SECTION 48 19 23.01 Page 19 give the highest losses, at all self-cooled and forced-air cooled ratings.

2.4 CORE

The transformer core shall be constructed of high-quality, non-aging, cold-rolled, grain-oriented steel especially suitable for the purpose. The core steel laminations shall meet the requirements of ASTM A 664 and

ASTM A 876, shall have a maximum thickness of 0.270 mm, and the design flux density shall not exceed 1.70 Tesla. The use of paper insulation in the core will not be acceptable. Electrical core steel core loss, rms exciting power, rms and peak exciting current, and ac permeability shall be tested in accordance with ASTM A 343. Each roll of sheet steel used shall have the surface insulation resistivity tested in accordance with ASTM A 717.

The core shall be carefully assembled and rigidly clamped to ensure adequate mechanical strength to support the windings and to prevent shifting of the laminations during shipment, and also to reduce vibration to a minimum under operating conditions. Core joints shall be interleaved. The transformer core manufacturing methods shall be in such a manner to assure that the average sound level due to operation of the transformer and accessories will not exceed 68 dB at rated voltage and frequency as measured in accordance with IEEE C57.12.90.

2.5 WINDINGS

2.5.1 General

The transformer shall be manufactured with windings meeting the requirements of paragraph "Ratings and Electrical Characteristics", consisting of one high-voltage winding (H) per phase and one low-voltage winding (X) per phase. The winding conductors shall be of high-conductivity copper magnet wire meeting the applicable requirements of NEMA MW 1000, and if of a core-form design shall be of a circular coil construction. Conductor insulation shall consist of thermally upgraded Kraft paper. Consideration shall be given to all factors of service, such as high dielectric and mechanical strength of insulation, coil characteristics, and minimum restrictions to free circulation of oil.

Coils shall be made up, shaped, and braced to provide for expansion, contraction, and shrinkage due to temperature changes and aging in service in order to avoid abrasion of insulation and to provide resistance to movement and distortion caused by abnormal operating conditions. Adequate barriers shall be provided between windings and core and between high-voltage and low-voltage windings. End coils shall have additional protection, if required, against normal line disturbances. The delta and wye winding connections shall be made inside the transformer tank. A de-energized tap changer shall be provided, with taps located in the high-voltage windings. The tap changer contacts shall be silvered, and capable of withstanding the full short circuit current of the transformer without injury.

2.5.2 Insulation Levels

The transformer shall be manufactured with a BIL rating of the windings as specified in paragraph "Ratings and Electrical Characteristics", and shall be capable of withstanding IEEE Standard dielectric tests, in accordance with paragraph "Power Transformer Tests", corresponding to the specified winding insulation levels.

SECTION 48 19 23.01 Page 20

2.5.3 Short Circuit Capability

The transformer shall be capable of withstanding without injury the mechanical and thermal stresses caused by short circuits on the external terminals of any winding or windings, with rated voltages maintained across the terminals of all other windings intended for connection to sources of energy, under the conditions listed in IEEE C57.12.00 (paragraph 7.1.1).

2.5.4 Embedded Fiber Optic Probes

Fiber optic probes used for direct winding temperature measurement shall be embedded in the high and low voltage windings. Quantities and distribution shall be as indicated in paragraph "Electronic Temperature Monitor with

Fiber Optic Winding Temperature Measurement." Probes shall be embedded in the calculated hottest spot for each winding.

2.6 TANK

2.6.1 Construction

The transformer shall be provided with an oil-tight steel tank, with oil-tight covers per the requirements of IEEE C57.12.10 (paragraph 5.8).

The tank shall be provided with one or more unobstructed manholes in the cover with minimum dimensions of 24 inches by 24 inches, or 24 inches minimum diameter, to afford easy access to the lower ends of bushings, terminals, and the upper portions of the coils. Handhole access covers shall be provided in the tank sidewall for access to each de-energized tap changer switch mechanism for future maintenance. Suitable positioning guides shall be provided inside the tank to assure the core and windings are in the correct position during assembly. The main transformer tank and any attached compartment that is subjected to operating pressures shall be manufactured to withstand, without leakage or permanent deformation, an internal pressure not less than 10 psi. The tank shall be manufactured for vacuum filling (essentially full vacuum) in the field, and all valves, fittings and piping affected by vacuum filling shall be rated for such filling. Auxiliary compartments such as reservoir tanks, when not rated vacuum filling, shall be so designated, and suitable isolating valves shall be provided. The joints between the tank and cover, and between tank sections shall be welded, and the joint shall be manufactured to prevent weld splatter from entering the inside of the tank.

2.6.2 Gasketing

Gaskets between metal surfaces shall be set in expansion-limiting grooves or held in position by retainers so arranged that all contact surfaces are metal-to-metal when tightened. The gaskets shall be made of Nitrile NBR

(Buna N) with a Durometer rating between 50 and 60. Gaskets shall be rated for compression by at least 25% of their original thickness. O-ring gaskets shall not be used for gasket grooves of rectangular cross-section.

2.6.3 Lifting and Moving Facilities

2.6.3.1 Lifting Facilities

Design loads for lifting eyes shall be two times the actual load to allow for possible unequal lifting forces, with a safety factor (using design loads) in accordance with IEEE C57.12.10 (paragraph 5.3.1). Lifting eyes shall positively keep the lifting cable in place even when the cable is slack. The transformer shall be provided with the following lifting

SECTION 48 19 23.01 Page 21 facilities:

a. Lifting attachments on the tank cover.

b. Adequate means for lifting the core and coil assembly from the tank.

c. Lifting eyes on the tank, adequate for lifting the complete transformer filled with oil, and located at the top of the tank sidewalls for a transformer of core-form type. The placement of the lifting eyes shall allow for lashing of the transformer during shipment.

2.6.3.2 Moving Facilities

Moving features shall be furnished as required for moving the transformer to its final location as shown, and shall be in accordance with

IEEE C57.12.10 (paragraph 5.3.3).

2.6.4 Valves

The transformer shall be provided with valves conforming with IEEE C57.12.10

(paragraph 5.1.8), unless otherwise specified, below. All valves, shall be of stainless steel construction conforming to MSS SP-72A, circular flanged, reinforced PTFE valve seats, and shall be ball-type unless otherwise specifically indicated. The valves shall be of full-port type, when available, rated for use with insulating oil, have a 120 degrees

Celsius minimum temperature rating, and shall be include provisions for locking of the handle. Valve handles shall be of a circular, or oval, type. Weather resistant locks shall be provided for all valves, keyed the same. All valves which have an outbound connection remaining open shall be provided with either a blind-flange, including a gasket and associated hardware, or a plug/cap on the NPT threaded connection. Valves shall be provided for the following:

a. Upper filter connection. A 2-inch valve shall be located on the

Segment 4 tank sidewall such that it can be used to fill the transformer with oil while the transformer is under vacuum. The outbound connection shall be a 2-inch female NPT thread, provided with a threaded plug.

b. Vacuum pump connection. A 3-inch valve shall be located on the tank cover for use in connecting a vacuum pump during the vacuum filling process. The outbound valve connection shall be a circular

4-bolt flanged, provided with a gasketed blind flange cover with an integral 3-inch NPT female connection with threaded plug.

c. Main drain. A 3-inch valve shall be located at the extreme bottom of the tank on Segment 2 tank sidewall for use in gravity draining of the transformer. The outbound valve connection shall be circular

4-bolt flanged, provided with a gasketed blind flange cover with an integral 3-inch NPT female connection with threaded plug.

d. Oil sampling valve. A sampling valve shall be located at the bottom of the tank on the Segment 2 tank sidewall with a 1/2-inch NPT threaded discharge end. This valve may be integral to the lower filter valve. A 1/2-inch threaded sampling device, complete with protective cover, shall be provided for the purposes of obtaining oil samples, and shall be a United Brass Works Model 86, or approved equal.

e. Lower filter connection. A 2-inch valve shall be located at the

SECTION 48 19 23.01 Page 22 extreme bottom of the tank on the Segment 2 tank sidewall. The outbound connection shall be a 2-inch female NPT thread, provided with a threaded plug.

f. Tank air vents. Valves shall be provided for venting of the conservator tank.

g. Isolation valves. The following isolation valves shall be provided:

(1) Electronic pressure monitor transducers. Isolating the electronic pressure monitor transducers. The outbound valve connection shall be circular 4-bolt flanged, and sized to match the bolt pattern of the electronic pressure monitor transducers' manifold.

(2) Radiators. At the inlet and outlet of each radiator to permit removal without draining the oil from the tank. Radiator isolation valves at the transformer tank may be of a butterfly type, and may be of steel with a corrosion resistant paint.

(3) Conservator tank. Isolating the conservator tank from the main transformer tank, and isolating the Buchholz relay.

Isolation valves adjacent to the Buchholz relay shall be of a butterfly type.

(4) On-line dissolved gas-in-oil monitor. Two 1.5-inch valves shall be provided on the Segment 3 tank sidewall for connection to the on-line dissolved multi-gas and moisture content monitor. The outbound connections shall be a 1.5-inch female NPT thread, provided with a threaded plug.

h. Conservator tank drain valve. A valve shall be located at the bottom of the conservator tank for use in gravity draining.

2.6.5 Connections

2.6.5.1 General

All bolts, studs, machine screws, nuts, and tapped holes intended for customer connection shall be in accordance with ASME B1.1 (inch fasteners), or ASME B18.2.6M (metric fasteners). Bolting hardware shall be Grade 5 minimum, or equivalent, and all hardware not internal to the tank shall be galvanized. Threads for sizes 1/4-inch to 1-inch, inclusive, shall be NC or UN series. The sizes and threads of all valves, pipe and fittings, conduit and fittings, tubing and fittings, and connecting equipment, shall be in accordance with ASME B1.20.1. Manufacturers' standard threads and construction may be used on small items which are integrally replaceable, except that threads for external connections to these items shall meet the above requirements.

2.6.5.2 Stainless Steel

All stainless steel connecting hardware shall be installed using an anti-galling compound such as molybdenum disulfide on the threads prior to connection.

2.6.6 Steel Pipe and Fittings

Steel pipe shall conform to ASTM A 53, Weight A, Class 2. Dimensions of

SECTION 48 19 23.01 Page 23 terminating flanges shall conform to ASME B16.1 and ASME B16.24. If the bushing turret configuration is such that any gasses generated may accumulate within the turret enclosure, piping shall be provided for the purposes of venting these gases to the conservator tank piping, passing through the Buchholz relay.

2.6.7 Grounding

Four ground pads shall be provided on the transformer for grounding the tank and base. The grounding provisions shall be in accordance with

IEEE C57.12.10 (paragraph 5.5). A #4/0 AWG insulated copper conductor shall be installed on the transformer to connect the terminal of the neutral bushing for the high-voltage windings to one of the ground pads at base of tank. The conductor shall be supported against the transformer tank a minimum of every 36-inches.

2.6.8 Personal Fall Protection System

A fall protection system, consisting of removable safety posts and wire rope railing shall be provided. The post and railing system shall be configured such the components can be installed with, or without, the low-voltage bus connections in-place. A removable storage cabinet shall be provided for fall protection system components, mounted to the base of the transformer tank, as indicated. The fall protection system shall be manufactured to meet the applicable provisions of EM 385-1-1, Section 21, and meet the following requirements:

a. Post holders shall be welded around the perimeter of the transformer tank top cover, shall have provisions for draining standing water, and include holes for the installation of securing pins which align with holes in the posts.

b. The posts shall be made of powdercoated yellow aluminum 2-1/2 inch

Schedule 80 pipe a minimum of 48-inches tall, spaced a maximum of

6-feet apart, and shall have looped-guides for the positioning of each wire rope rail. The looped guides shall be sufficiently sized to allow for routing of the wire rope railing during installation.

c. Two wire rope rails shall be provided (a toprail and a midrail).

The toprail wire rope shall be positioned 42-inches above the transformer top cover, and the midrail wire rope shall be positioned

21-inches above the transformer top cover.

d. Each rail shall consist of a 5/16-inch 7x19 stranded core, galvanized-steel wire rope with a red vinyl-coating, meeting the requirements of ASTM A 475. Each wire rope shall be constructed with a swage clevis fitting on one end and a swage eye fitting on the other end. The clevis fitting end shall be configured to connect to a post looped guide, and the eye fitting shall be configured to connect to the jaw-end of a turnbuckle. The wire rope shall be configured so that when fully assembled and tensioned with the tensioning hardware, a maximum 3-inch rope deflection may be achieved under a 200 pound applied force.

e. One forged galvanized steel turnbuckle, with an open body jaw end type and 800 pound minimum working load limit, shall be provided with each wire rope for tensioning purposes. The turnbuckle jaw ends shall be sized for connection to the wire rope swage eye fitting and the post looped guides. The turnbuckle shall meet all applicable requirements

SECTION 48 19 23.01 Page 24 of ASTM F 1145, Type 1, Grade 1.

2.6.9 Portable Fall Arrest Anchor Post Mounting Plate

A minimum of two portable fall arrest system anchor post mounting plates shall be provided on the transformer cover. Sufficient mounting plates shall be provided so that each transformer cover manhole access is within

24 inches of a mounting plate. Each mounting plate shall be welded onto the tank cover, and shall be a Uni-Anchor Plate and Lug, Model 17412, or approved equal, intended for use with a portable fall arrest system anchor post Model 16691, as manufactured by Western Safety Products.

2.6.10 Structural Steel Supporting Base

The transformer shall be provided with a structural steel supporting base manufactured for pad mounting, of a minimum six inches thickness. The steel supporting base shall include two skid channels oriented parallel to the high-voltage bushings, and two skid channels oriented perpendicular to the high-voltage bushings, which will be welded on the outer ends to steel plates on the concrete pad after the transformer is placed into position.

Welding of the transformer structural base skids to the steel plates on the concrete pad will be performed by others. The steel supporting base and anchoring shall be manufactured to withstand seismic forces as required in paragraph "STRUCTURAL DESIGN CRITERIA AND SEISMIC CALCULATIONS". The transformer shall be manufactured to be suitable for moving on rollers or skids when completely assembled and filled with oil, and shall permit moving of the transformer in a direction parallel to either centerline, with suitable pulling eyes provided.

2.6.11 Jack Ports

The transformer base shall be provided with jack ports, bosses, or lugs, to permit jacking the complete transformer filled with oil per the requirements of IEEE C57.12.10 (paragraph 5.3.4). The design loads for jacking bosses or lugs shall be at least two times the actual loads to allow for possible unequal jacking forces.

2.6.12 Center of Gravity

The transformer base shall be manufactured so that the center of gravity of the transformer, with or without oil as normally prepared for shipment, will not fall outside the base support members for a tilt of the base of 15…