33 75 19 00 26.pdf

Garrison Breakers

SECTION TABLE OF CONTENTS

DIVISION 33 - UTILITIES

SECTION 33.75.19.00.01

HIGH VOLTAGE SF6 GAS CIRCUIT BREAKERS

PART 1 GENERAL

1.1 GENERAL

1.2 REFERENCES

1.3 SUBMITTALS

PART 2 PRODUCTS

2.1 MATERIALS

2.2 CIRCUIT BREAKER RATING

2.2.1 Basic Ratings 115 kV Breaker

2.2.2 Additional Ratings

2.2.3 Supplementary Ratings

2.2.3.1 Rated Dielectric Strength

2.2.3.2 Rated Transient Recovery Voltage

2.2.3.3 Required Load Switching Capability

2.2.3.4 Rated Control Voltage Ranges

2.2.4 Basic Ratings 230 kV Breaker

2.2.5 Additional Ratings

2.2.6 Supplementary Ratings

2.2.6.1 Rated Dielectric Strength

2.2.6.2 Rated Transient Recovery Voltage

2.2.6.3 Required Load Switching Capability

2.2.6.4 Rated Control Voltage Ranges

2.3 ASSEMBLY AND MOUNTING

2.3.1 General

2.3.2 Connections

2.3.3 Grounding

2.4 INTERRUPTERS

2.4.1 Interrupter Tanks and Fittings

2.4.1.1 Interrupter Tanks

2.4.1.2 Interrupter Tank Connections And Tank Access Covers

2.4.2 Interrupter Units

2.5 BUSHINGS

2.5.1 High Voltage Terminal Bushings

2.5.2 Gas-Filled Type Bushings

2.5.3 External Top And Bottom Grading Rings

2.5.4 Manufacturer's Standard Terminals

2.5.5 Standard Test Voltages

2.6 INSTRUMENT TRANSFORMERS

2.6.1 Bushing Current-Transformers

2.7 OPERATING MECHANISM, CONTROLS AND AUXILIARIES

2.7.1 General

2.7.2 Operating Mechanisms

2.7.2.1 General

2.7.2.2 Capacity

2.7.2.3 Energy Supply and Storage Means

2.7.2.4 Special Requirements for Pneumatic Mechanisms Only

2.7.2.5 Special Requirements for Hydraulic Mechanisms Only

2.7.2.6 Special Requirements for Electric Motor Driven Spring

SECTION 33 75 19.00 26 Page 1

Mechanisms Only

2.7.3 Gas Monitoring and Service System

2.7.4 Controls, Indication and Alarms

2.7.4.1 General

2.7.4.2 Indication, Monitoring, and Alarms

2.7.4.3 Key Interlocks

2.7.5 Cabinets

2.7.5.1 General

2.7.5.2 Access

2.7.5.3 Identification

2.7.5.4 Heaters

2.7.5.5 Convenience Outlet

2.7.6 Electric Supply

2.7.7 Low-Voltage Wiring Switching and Protection

2.7.8 Internal and Remote Connections

2.7.8.1 Terminal Blocks

2.7.8.2 Current Transformer Wiring

2.7.8.3 Wire and Cable Designations

2.8 TEST OF MATERIALS

2.8.1 Materials, Supplies, And Parts

2.8.2 Requirements of Testing

2.8.3 Test Specimens and Samples

2.8.4 Payment for Testing

2.9 PRESSURE VESSELS

2.10 CABINETS

2.11 MOTORS

2.12 HEATERS

2.13 LOW-VOLTAGE ELECTRICAL CONNECTIONS

2.13.1 Conduit and Wiring

2.13.1.1 Wiring

2.13.1.2 Insulated Wire

2.13.1.3 Wire Markers

2.13.2 Terminal Blocks

2.14 AIR CIRCUIT BREAKERS (MOLDED-CASE TYPE)

2.14.1 General

2.14.2 Trip Units

2.14.3 AC Air Circuit Breakers

2.14.4 DC Air Circuit Breakers

2.15 PIPING

2.16 SULFUR HEXAFLUORIDE GAS (SF6)

2.16.1 Quality and Certification

2.16.2 Chemical, Physical and Electrical Characteristics

2.16.3 Sampling

2.16.4 Testing

2.16.5 Shipment

2.17 CONDUIT AND ELECTRICAL METALLIC TUBING

2.18 THREADED FASTENERS AND JOINTS

2.19 ELECTRIC WELDING

2.19.1 General

2.19.2 Preparation for Welding

2.19.3 Welding

2.19.4 Welding Process

2.19.5 Qualification of Welders

2.20 PAINTING

2.21 GALVANIZING

2.22 SPECIAL TOOLS AND CIRCUIT BREAKER ACCESSORIES

2.22.1 General

2.23 SPARE PARTS

2.23.1 General

SECTION 33 75 19.00 26 Page 2

2.23.2 Circuit Breaker Parts As Follows:

2.23.3 Parts For All Operating Mechanisms As Follows:

2.23.4 Parts For Pneumatic Operating Mechanisms Only As Follows:

2.23.5 Parts For Hydraulic Operating Mechanism Only As Follows:

2.24 STRUCTURAL DESIGN CRITERIA AND SEISMIC CALCULATIONS

2.24.1 Structural Design Criteria

2.24.2 Seismic Calculations

2.24.3 Anchorage to Concrete for Seismic Restraint

PART 3 EXECUTION

3.1 (NOT USED)

3.2 FACTORY INSPECTION AND TESTS

3.2.1 General Information

3.2.2 Circuit Breaker Tests

3.2.2.1 General

3.2.2.2 General - Design Tests

3.2.2.3 Bushings

3.2.3 Production Tests

3.2.3.1 General

3.2.3.2 Pressure Tests

3.2.3.3 Dielectric Tests

3.2.3.4 Bushing Tests

3.2.4 Circuit Breaker Operation Tests

3.2.5 Bushing Current Transformer Tests

3.2.6 Control Circuit Dielectric Tests

3.2.7 Air System Test

3.3 SF6 GAS TESTS

3.4 OPERATION AND MAINTENCE MANUALS

-- End of Section Table of Contents --

SECTION 33 75 19.00 26 Page 3

SECTION 33.75.19.00.01

HIGH VOLTAGE SF6 GAS CIRCUIT BREAKERS

PART 1 GENERAL

1.1 GENERAL

The circuit breakers to be furnished under these specifications shall be three-pole, single-throw, fully automatic, outdoor dead tank type with single pressure interrupter units using the puffer principle and with pneumatic, hydraulic, or spring operating mechanism. The breakers shall use sulfur hexafluoride (SF6) gas as a dielectric and as an arc extinguishing medium. Except as otherwise specified, the circuit breakers shall conform to the applicable requirements of ANSI C37.012, IEEE C37.04, IEEE C37.09,IEEE C37.010,IEEE C37.011, and IEEE C37.06.1, and NEMA SG 4.

Application will be outdoors in unconfined air, in a hydroelectric powerhouse substation at an altitude below 3,300 feet, within ambient temperature extremes of -30 C to +40 C.

1.2 REFERENCES

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

AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI)

ANSI C37.012 (1991) Application Guide for Capacitance Current Switching for AC High Voltage Circuit Breakers Rated on a Symmetrical Current Basis.

ASME INTERNATIONAL (ASME)

ASME B1.1 (2003; R 2008) Unified Inch Screw Threads (UN and UNR Thread Form)

ASME B1.20.1 (1983; R 2006) Pipe Threads, General Purpose (Inch)

ASME BPVC SEC VIII (2007) Boiler and Pressure Vessel Codes:

Section VIII Rules for Construction of Pressure Vessels, Division 1

ASME BPVC SEC IX (2007; Addenda 2008) Boiler and Pressure Vessel Code; Section IX, Welding and Brazing Qualifications

ASTM INTERNATIONAL(ASTM)

ASTM A123/A123M REV A (1997) Specification for Zinc (Hot-Dip Galvanized)Coatings on Iron and Steel Products (Edited E1-1998)

ASTM A153.82 (1998) Specification for Zinc Coating

SECTION 33 75 19.00 26 Page 4

(Hot-Dip) on Iron and Steel Hardware

ASTM A269 (1998) Specifications for seamless and welded austenitic stainless steel tubing for general service

ASTM B68 (1995) Specifications for seamless copper tube, bright annealed

ASTM B88 (1996) Specifications for seamless copper water tube

ASTM D2472 (1992; R 1997) Specification for Sulfur Hexafluoride

AMERICAN WELDING SOCIETY (AWS)

AWS D1.1 (1998) Structural Welding Code - Steel

INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS (IEEE)

IEEE 693 (2005) Recommended Practice for Seismic Design of Substations

IEEE C37.04 (1979; R 1989) Rating Structure for AC High Voltage Circuit Breakers rated on a Symmetrical Current Basis. Supplements through C37.04I, 1991

IEEE C37.06 (2000) AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis - Preferred Ratings and Related Required Capabilities

IEEE C37.06.1 (2000) Guide for High-Voltage Circuit Breakers Rated on Symmetrical Current Basis Designated “Definite Purpose for Fast Transient Recovery Voltage Rise Times” - Replaces NEMA C37.06.1-2000

IEEE C37.09 (1979; R 1989) Test Procedure for AC High Voltage Circuit Breakers Rated on a Symmetrical Current Basis. Supplements through C37.09G, 1991

IEEE C37.010 (1979; R 1988) Application Guide for AC High Voltage Circuit Breakers. Rated on a Symmetrical Current Basis. Supplements thought C37.010E, 1991

IEEE C37.011 (1994) Application Guide for Transient Recovery Voltage for AC High Voltage Circuit Breakers Rated on a Symmetrical Current Basis.

IEEE C57.13 (1993; R 2003) Standard Requirements for Instrument Transformers

IEEE C57.19.00 (1991; R 1997) General Requirements and

SECTION 33 75 19.00 26 Page 5

Test Procedure for Outdoor Apparatus Power Bushings. (Redesignation of Std 21-1976)

IEEE C57.19.01 (1991) Performance Characteristics and Dimensions for Outdoor Apparatus Bushings. (Redesignation of Std 24-1984)

IEEE C37.24 (2003) Evaluating the Effect of Solar Radiation on Outdoor Metal-Enclosed Switchgear

IEEE C37.90 (1989; R 1994) Relays and Relay Systems Associated with Electric Power Apparatus

NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION (NEMA)

NEMA 107 (1987; R 1993) Methods of Measurement of Radio Influence Voltage (RIV) of High-Voltage Apparatus

NEMA AB 1 (2002) Molded-Case Circuit Breakers, Molded Case Switches, and Circuit-Breaker Enclosures

NEMA C37.06 (1997) Preferred Ratings and Related Required Capabilities for AC High Voltage Circuit Breakers Rated on a Symmetrical Current Basis.

NEMA C80.1 (2005) Electrical Rigid Steel Conduit

(ERSC)

NEMA C80.3 (1991; R 1994) Electrical Metallic Tubing

- Zinc Coated

NEMA CC 1 (1993) Electric Power Connectors for Substations

NEMA FB 1 (1993) Fittings, Cast Metal Boxes, and Conduit Bodies for Conduit and Cable Assemblies

NEMA ICS 1 (1993) General Standards for Industrial Control and Systems

NEMA ICS 2 (1993) Industrial Control Devices, Controllers and Assemblies

NEMA ICS 6 (1993) Enclosures for Industrial Control and Systems

NEMA MG 1 (1998) Motors and Generators

NEMA SG 4 (2000; R 2005) Alternating-Current High-Voltage Circuit Breaker

UNDERWRITERS LABORATORIES (UL)

UL 44 (2005) UL Standard for Safety

SECTION 33 75 19.00 26 Page 6

Thermoset-Insulated Wires and Cables-

UL 1063 (1998) Machine-Tool Wires and Cables

UL 1581 (1997) Reference Standard for Electrical Wires, Cables, and Flexible Cords.

1.3 SUBMITTALS

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

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 00.00 10 SUBMITTAL

PROCEDURES:

SD-02 Shop Drawings

Circuit Breakers

a. Outline drawings and mounting details of all equipment to be furnished under this contract.

b. Internal drawings of the interrupter pole, and operating mechanism showing all components with dimensions.

c. Electrical schematic and control diagrams showing locations and connections of components, terminal blocks, and conductor designations.

d. Diagrams of SF6 gas and other piping systems and locations.

e. Drawings of miscellaneous devices including piping system components, stored operating energy mechanisms, receiver tank or accumulator, connections and safety valves.

f. Seismic anchoring details of steel supporting legs, and locations of bolted connections.

Shop Drawings; G

SD-03 Product Data; G, HDC

Descriptive Literature; G, HDC for the following:

a. 115 kV Circuit Breaker

b. 230 kV Circuit Breaker

c. Relays

d. Meters

e. Instrument Transformers

f. Wire and Cable

SPECIAL TOOLS AND CIRCUIT BREAKER ACCESSORIES; G, HDC

SECTION 33 75 19.00 26 Page 7

SD-05 Design Data a. Descriptive Data; G, HDC

a. 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.

SD-06 Test Reports; G

Circuit Breaker Tests

SF6 Gas Tests

Factory Test Procedures

Factory Test Reports

Spare Parts List

Six (6) complete reproducible copies of the factory inspections results and six (6) complete reproducible copies of the factory test results in booklet form, including all plotted data curves, all test conditions, a listing of test equipment complete with calibration certifications and all measurements taken.

SD-07 Certificates

Factory Inspection and Tests; G, HDC

The Contractor shall notify the Contracting officer thirty (30) calendar days (45 days for foreign travel) prior to the proposed date of the tests so that arrangements can be made for the Contracting Officer to be present at the tests. Test Procedures shall be submitted at the time of notification of tests.

SD-08 Manfacturer's Instructions

Operation and Maintenance Manuals; G, HDC

PART 2 PRODUCTS

2.1 MATERIALS

All articles, materials and equipment shall conform to the requirements of these specifications. Materials, components, and equipment shall be of high quality, free from defects and imperfections, of recent manufacture, and of the classification and grades designated. Particular care shall be taken to provide materials and equipment with long life, liberal factors of safety, and suitable operating characteristics for the intended use. All materials, components, and equipment not manufactured by the Contractor shall be products of other recognized reputable manufacturers. Product Data consisting of Descriptive Literature of the circuit breakers and assessories shall be submitted for approval. The products of manufacturers

SECTION 33 75 19.00 26 Page 8 other than those specified herein will be accepted when it is proved to the satisfaction of the Contracting Officer that such products are adequate and suitable for the intended use. Upon request, the Contractor shall furnish to the Contracting Officer for his approval the names of all such other manufacturers, together with complete pertinent information regarding all such products which he proposes to incorporate in the work. Samples of materials and equipment shall be submitted for approval when so directed.

Insofar as practicable, devices and equipment used for the same or similar services shall be of the same make and type, and shall be interchangeable when of the same rating.

2.2 CIRCUIT BREAKER RATING

The circuit breakers shall be rated on a symmetrical current basis.

Ratings shall be as defined in IEEE C37.04, Part 5, and as supplemented below.

2.2.1 Basic Ratings 115 kV Breaker

Basic ratings shall be as follows:

a. Rated maximum voltage, kV, rms

b. Rated frequency, Hz

c. Rated continuous current, amperes, rms ...... 1,200

d. Rated short circuit current, kA, rms

2.2.2 Additional Ratings

Additional circuit breaker ratings shall be in accordance with the values stated on the lines corresponding to the above ratings, in the following tables:

a. NEMA C37.06, Tables 3, 3A (for general purpose breakers), 4, 6, 8, 9, and 10, and applicable notes.

b. IEEE C37.24, Table 1

2.2.3 Supplementary Ratings

These supplementary ratings are as defined by IEEE C37.06.1 and IEEE C37.04 and IEEE C37.09, and as additionally required below.

2.2.3.1 Rated Dielectric Strength

The circuit breaker shall comply with the values stated in Table 4 of ANSI C37.06, for rated maximum voltage of 123 kV, as well as the following minimum dielectric withstand test voltages, either at the SF6 gas density alarm point which blocks tripping of the breaker, or as otherwise noted:

a. Dry low frequency withstand voltage, kV rms

(1) Phase-to-ground, 1-minute

(2) Phase-to-ground, five minutes minimum, at zero gauge SF6 pressure

SECTION 33 75 19.00 26 Page 9

(3) Across open contacts, five minutes minimum, at zero gauge SF6 pressure

b. Wet low frequency withstand voltage, 10-second, phase-to-ground, external bushings only, kV rms

c. Impulse withstand voltage, full-wave, phase-to-ground, positive or negative, whichever gives the lower dielectric strength, minimum crest kV (BIL)

d. Chopped wave impulse withstand voltage, with 2 microseconds to flashover, crest kV

e. Chopped wave, phase-to-ground, with 3 microseconds minimum time to flashover, crest kV

The contacts and the insulating structures shall remain undamaged when rated impulse voltages are applied across open contacts.

2.2.3.2 Rated Transient Recovery Voltage

Each circuit breaker shall meet the related required transient voltage withstand capabilities (including short line faults) as described by paragraph 5.11.4 of IEEE C37.04. The short line fault test shall be done at 90 percent. Demonstration of compliance shall be by design test in accordance with paragraph 4.6.5.4 of IEEE C37.09, with M=0.70, and with M=0.90.

2.2.3.3 Required Load Switching Capability

Required load switching capability and life shall be in accordance with IEEE C37.04, Paragraph 5.12, and with the following:

a. Each breaker shall be capable of performing without maintenance or adjustment, 2,000 no-load operations during time periods (between scheduled breaker maintenance) of up to 6 years, when operated under the specified service conditions

b. Each breaker shall be capable of performing without maintenance, five (Co) operations at full rated interrupting currents. Procedures shall be in accordance with IEEE C37.09 (Table 2, test duty 7).

c. Each breaker shall be capable of interrupting without maintenance, at least 200 amperes for the number of operations in which the cumulative sum of the currents interrupted equals (or exceeds) 400 percent of the required asymmetrical interrupting capability of the breaker. Procedures and conditions after testing shall be in accordance with IEEE C37.04, Paragraph 5.10.3.

2.2.3.4 Rated Control Voltage Ranges

Rated control voltage ranges shall be 90-140-volts dc for the close control circuit, and 70-140-volts dc for the trip control circuit. Further, operation of the closing and tripping control circuits shall not produce transient overvoltages exceeding 1500 volts crest.

SECTION 33 75 19.00 26 Page 10

2.2.4 Basic Ratings 230 kV Breaker

Basic ratings shall be as follows:

a. Rated maximum voltage, kV, rms

b. Rated frequency, Hz

c. Rated continuous current, amperes, rms .......... 2,000

d. Rated short circuit current, kA, rms

2.2.5 Additional Ratings

Additional circuit breaker ratings shall be in accordance with the values stated on the lines corresponding to the above ratings, in the following tables:

a. NEMA C37.06, Tables 3, 3A (for general purpose breakers), 4, 6, 8, 9, and 10, and applicable notes.

b. IEEE C37.24, Table 1

2.2.6 Supplementary Ratings

These supplementary ratings are as defined by IEEE C37.06.1 and IEEE C37.04 and C37.09, and as additionally required below.

2.2.6.1 Rated Dielectric Strength

The circuit breaker shall comply with the values stated in Table 4 of ANSI C37.06, for rated maximum voltage of 245 kV, as well as the following minimum dielectric withstand test voltages, either at the SF6 gas density alarm point which blocks tripping of the breaker, or as otherwise noted:

a. Dry low frequency withstand voltage, kV rms

(1) Phase-to-ground, 1-minute

(2) Phase-to-ground, five minutes minimum, at zero gauge SF6 pressure

(3) Across open contacts, five minutes minimum, at zero gauge SF6 pressure

b. Wet low frequency withstand voltage, 10-second, phase-to-ground, external bushings only, kV rms

c. Impulse withstand voltage, full-wave, phase-to-ground, positive or negative, whichever gives the lower dielectric strength, minimum crest kV (BIL)

d. Chopped wave impulse withstand voltage, with 2 microseconds to flashover, crest kV ......................... 1,160

SECTION 33 75 19.00 26 Page 11

e. Chopped wave, phase-to-ground, with 3 microseconds to flashover, crest kV ......... 1,040

The contacts and the insulating structures shall remain undamaged when rated impulse voltages are applied across open contacts.

2.2.6.2 Rated Transient Recovery Voltage

Each circuit breaker shall meet the related required transient voltage withstand capabilities (including short line faults) as described by paragraph 5.11.4 of IEEE C37.04. The short line fault test shall be done at 90 percent. Demonstration of compliance shall be by design test in accordance with paragraph 4.6.5.4 of IEEE C37.09, with M=0.70, and with M=0.90.

2.2.6.3 Required Load Switching Capability

Required load switching capability and life shall be in accordance with IEEE C37.04, Paragraph 5.12, and with the following:

a. Each breaker shall be capable of performing without maintenance or adjustment, 2,000 no-load operations during time periods (between scheduled breaker maintenance) of up to 6 years, when operated under the specified service conditions.

b. Each breaker shall be capable of performing without maintenance, five (CO) operations at full rated interrupting currents. Procedures shall be in accordance with IEEE C37.09 (Table 2, test duty 7).

c. Each breaker shall be capable of interrupting without maintenance, at least 200 amperes for the number of operations in which the cumulative sum of the currents interrupted equals (or exceeds) 400 percent of the required asymmetrical interrupting capability of the breaker. Procedures and conditions after testing shall be in accordance with IEEE C37.04, Paragraph 5.10.3.

2.2.6.4 Rated Control Voltage Ranges

Rated control voltage ranges shall be 90-140-volts dc for the close control circuit, and 70-140-volts dc for the trip control circuit. Further, operation of the closing and tripping control circuits shall not produce transient overvoltages exceeding 1500 volts crest.

2.3 ASSEMBLY AND MOUNTING

2.3.1 General

All three interrupter units, with the operating mechanism and all interconnecting components, shall be installed at the factory, on a permanent steel base fabricated from standard rolled shapes. The individual tank or tanks shall be mounted securely to the base by welding or by bolting and doweling. The individual interrupters' tank mounting and mechanism linkage design shall permit individual field replacement of entire pole units if necessary. With the base supported at four or more points as designated by the manufacturer, it shall be sufficiently rugged to withstand the shock of the most severe rated operating condition, and to maintain the correct alignment of the interrupter tanks and operating mechanism. The circuit breaker, including interupter tanks, operating

SECTION 33 75 19.00 26 Page 12 mechanism, mounting base, bushings, terminals, adapters, and other appurtenances, shall be contained in size to the restrictions shown on the reference drawings, with appropriate clearances for insulation and access.

The arrangement of high-voltage terminals and low-voltage conduit entrances shall be compatible with the design and locations shown on the reference drawings. The design of the mounting base, including the manufacturer's standard mounting base geometry if used, shall include all adapters necessary for secure leveling and mounting to the existing foundation, which is shown on the reference drawings. Anchor bolts and all other hardware shall be furnished by the Contractor. Lifting eyes shall be provided at locations suitable for lifting the entire circuit breaker. Shop drawings meeting the requirement of paragraph 1.3 shall be supplied by the contractor for the circuit breakers.

2.3.2 Connections

Materials for all interconnections between breaker components, such as wireways, conduit, wire, linkages, gas or air lines, shall be cut to length, formed, and assembled before shipment. Routing of raceways and fluid lines shall be in unobtrusive, protected locations.

2.3.3 Grounding

The circuit breaker interrupter tanks, operating mechanism, and other major components shall be electrically bonded together, to a common conducting path, with electrical connections not subject to deterioration by environmental or operating conditions. Two grounding pads shall be provided, one at each end of the circuit breaker. Each shall have a minimum of two tapped holes with a matching copper or bronze, two-bolt minimum, clamp-type terminal for a stranded 500 kcmil copper conductor.

Grounding pads and terminals shall comply with NEMA CC 1.

2.4 INTERRUPTERS

2.4.1 Interrupter Tanks and Fittings

2.4.1.1 Interrupter Tanks

Each interrupter tank shall be designed to be strong enough to withstand any operating stresses which may be imposed upon it when operating within its ratings. Each tank shall also be provided with the following features in addition to the interrupters:

a. Access openings of sufficient size to permit inspection of the interrupters installed inside the tank and to permit the removal or insertion of all internal parts.

b. Bushings with minimum of two bushing-type current transformers, and one power factor test terminal as described in paragraph 2.5.5, per bushing.

c. Suitable gastight seals to prevent passage of SF6 gas at each pole unit's mechanical operating penetration.

d. Gas service connection fittings.

e. Desiccant bag or molecular sieves inside the tank to absorb moisture and decomposed corrosive gases.

SECTION 33 75 19.00 26 Page 13

2.4.1.2 Interrupter Tank Connections And Tank Access Covers

All bolted interrupter tank connections and tank access covers shall be adequately gasketed with a material that will not deteriorate and the entire assembly shall be gastight and weatherproof. Ferrous bolts, nuts, and screws used in the field assembly of the breaker, such as access cover bolts and bushing flange bolts, shall be stainless or galvanized.

Provisions shall be made for removing bushings, current transformers, and interrupters, as well as entire pole assemblies, without removing other parts of the circuit breakers. Suitable eyes, bolts or lugs shall be provided for lifting each tank and equipment housing.

2.4.2 Interrupter Units

The interrupter units shall be equipped with modern and effective arc-extinguishing devices which use the puffer principle to quench the arc after current zero by the rapid flow of compressed SF6 gas across the contact surfaces of the interrupters. Contacts of interrupter units shall be easily replaceable and shall be adjustable or designed to allow for wear and minor misadjustment, so that the contacts on all phases will open and close simultaneously.

2.5 BUSHINGS

2.5.1 High Voltage Terminal Bushings

The high voltage terminal bushings shall be of a type conforming to the requirements of IEEE C57.19.00 and IEEE C57.19.01, except requirements not applicable to gas-filled bushings. They shall be of recent manufacture, polymer and shall be of a type and style being currently produced by the bushing manufacturer. The design of the circuit breaker shall be coordinated with the standard bushing dimension tables, such that the circuit breaker shall accommodate the entire range of tolerances shown in the tables. The circuit breaker and bushing design shall also be such that any voltage flashover will occur on the outside of the bushing before flashover occurs inside the breaker. Bushings shall be arranged to accommodate standard multi-ratio bushing type current transformers as required in these specifications.

2.5.2 Gas-Filled Type Bushings

The bushings shall be of the gas-tight and gas-filled type. The seals shall be sufficiently tight to hold pressure incident to temperature changes resulting from normal operation and changes in ambient temperature without leakage or breathing of moisture or oxygen. The bushings' gas systems may be separate or integral with those of the interrupter tanks.

If the gas systems are separate, each bushing shall have a valved connection for gas sampling, draining and filling, and a gas pressure gauge.

2.5.3 External Top And Bottom Grading Rings

Each bushing shall be provided with external top and bottom grading rings or internal shielding means as needed for shaping the electrical fields.

The radio influence voltage of the completed breakers shall not exceed the limiting values specified in NEMA Pub. No. SG4. The bushings shall be so designed that, when they are operating at normal rated voltage, there will be no electrical discharge between conductors and bushings of a nature which will cause corrosion or injury of the conductors, insulators, or supports, due directly or indirectly to the formation of chemically active

SECTION 33 75 19.00 26 Page 14 substances.

2.5.4 Manufacturer's Standard Terminals

Each bushing may be equipped with the manufacturer's standard terminals.

Each bushing terminal shall have ample capacity to carry continuously, without overheating, the rated current of the bushing to which it is connected. All contact surfaces of external terminals shall be silver-plated.

2.5.5 Standard Test Voltages

Bushings shall be designed to withstand the following standard test voltages, under the gas density conditions described in 2.2.3:

Bushing Impulse Test Insul. Class, Full Wave Low Frequency Tests - RMS kV kV Crest, kV 10-sec Wet 1-min Dry 115 550 230 260 230 900 350 425

2.6 INSTRUMENT TRANSFORMERS

2.6.1 Bushing Current-Transformers

The circuit breakers shall be equipped with bushing-type current transformers mounted on each bushing. The current transformers shall be multi-ratio types conforming to IEEE C57.13 and NEMA SG 4.

The maximum ratio for each current transformer shall be 1200:5 for the 115 kV breakers, 2000:5 for the 230 kV breakers, both with taps for the multiple ratios in accordance with IEEE Standard C57.13, Table 8. The quantity and ratios of the current transformers shall be as shown on the reference drawings. Each current transformer shall have a relaying accuracy classification of C800 and metering accuracy class of 0.3B-0.5.

The specified accuracy shall be met with rated burden applied to all secondaries simultaneously. Minimum thermal rating factor shall be 1.33.

Current transformers shall be fully enclosed and shall be adequately supported to withstand short-circuit stresses within the capacity of the circuit breaker and shall have sufficient thermal capacity and mechanical strength to comply with the circuit breaker's rated short-time current requirements. Minimum wire size for current transformer leads shall be No.

10 AWG. All current transformer leads shall be brought out through suitable seals to accessible shorting terminal blocks. Design of the current transformer installation shall be coordinated with that of the bushing and circuit breaker, such that the completely assembled circuit breaker shall retain its full-rated insulation characteristics when all current transformer leads are grounded. Each current transformer shall be checked for polarity, ratio, including all taps, and accuracy classification prior to installation on the circuit breaker.

2.7 OPERATING MECHANISM, CONTROLS AND AUXILIARIES

2.7.1 General

The three poles of each circuit breaker shall be operated simultaneously by a single operating mechanism from a common shaft. The operating mechanisms shall be nonpumping and electrically trip-free, in all positions of the closing stroke. The operating system capacity shall be sufficient to

SECTION 33 75 19.00 26 Page 15 perform repeated operating cycles, using a combination of initially stored energy and recharged stored energy, as required below, without misoperation or thermal or mechanical damage. Each circuit breaker shall be capable of reclosing within 20 cycles after main contacts have fully opened. The circuit breaker, operating mechanism and control design shall permit any close or trip switches to remain closed for any length of time without causing damage. Components, circuitry and connections for local controls, for remote control and monitoring, and for external power sources for operating, controls and heaters, as well as instrument transformer connections, shall be provided as described below. A common SF6 gas system shall be provided to monitor, sample, remove and refill the gas from the interrupter tanks. The system shall normally interconnect all three poles in a common gas reservoir, yet shall allow isolating any single or pair of interrupter poles while monitoring, sampling or processing the remaining pole(s). All operating mechanisms, controls, indications and alarms, and auxiliary equipment, shall be enclosed in a weatherproof, dustproof housing. Any interior component which can be damaged or misoperate due to dust exposure shall have its own dusttight housing.

2.7.2 Operating Mechanisms

2.7.2.1 General

The operating mechanism shall be designed to provide continuous operating force through the entire range of motion, in either breaker close or open direction. The mechanism shall be designed and manufactured to withstand all operating stresses, and bearings, pins, bolts, nuts and other connections shall be locked and pinned in a manner to prevent loosening or change of adjustment. The operating mechanism shall not require critical adjustments, and failure of any spring (other than the operating energy storage spring, where applicable) shall not prevent tripping nor cause tripping or closing of the circuit breaker. All bearings that require periodic applications of grease shall be equipped with pressure-type grease fittings unless otherwise approved by the Government. A time-travel recorder transducer shall be mounted on the mechanism, such as that for Programma or Doble Engineering Company's Circuit Breaker Motion Analyzer.

2.7.2.2 Capacity

The operating mechanism shall be capable of performing the following operating sequences without thermal or mechanical damage, while the circuit breaker is operating at rated short circuit current and related required capabilities:

a. The standard ANSI duty cycle of CO, 15 seconds, CO.

b. Each pneumatic or hydraulically operated breaker shall be able to repeat indefinitely: C, 10 seconds, OCO, 20 seconds, CO, 30 seconds, CO, 30 minutes. At the end of this cycle, the energy system shall be fully charged, ready to repeat more cycles.

c. Each motor-charged spring operated mechanism shall meet the duty cycle of OCO, 30 seconds, CO. At least 5 successive CO operations shall be possible without overloading the spring charging motor. The mechanism shall have provisions for manually charging the springs.

2.7.2.3 Energy Supply and Storage Means

The pump unit or air compressor or spring charging system, including motor

SECTION 33 75 19.00 26 Page 16 shall be in a weatherproof cabinet, with or separate from that for the operating mechanism. Air compressors for pneumatic systems, and hydraulic pumps for hydraulic systems if used, shall be air cooled. OSHA type guards shall be provided on operating mechanisms, belts, and pulleys, adequate for personnel and equipment protection during both operation and maintenance.

A suitable means shall be provided to prevent operation of the mechanism when maintenance work is being done. All filters furnished shall be of types for which replacement and renewal parts are commercially available in the United States. Fluid lines shall have sufficient fittings for easy removal of valves and disconnection of lines from all major mechanism and breaker parts. Pressure relief valves shall be provided for all pressurized systems.

2.7.2.4 Special Requirements for Pneumatic Mechanisms Only

The pneumatic type of operating mechanism shall consist of a self-contained air supply system and the necessary accessories to meet the inherent and the specified performance requirements. The circuit breaker shall be opened by pneumatic operation and shall be closed by either pneumatic operation or compression springs. Means shall be provided at the mechanism housing for opening the breaker pneumatically by manual operation of the air valve, and for manually closing the breaker. Each mechanism shall be provided with its own compressor equipment consisting of an air compressor, air filter, air receiver, pressure relief valves, pressure gauges, necessary control, piping, and valves. An accessible tap, with isolation valve and plugged fitting, shall be provided in the air line to permit attachment of an external air connection. Manual valves shall be provided to allow compressor removal without discharging the system, and to isolate each pressure gauge and switch independently. Manual valves shall be provided to isolate the operator from the air supply, or means shall be provided to prevent manual operation of the operator unless the receiver is drained of air. An air filter shall be installed in the air compressor intake to prevent entrance of dirt and dust. Where the intake is inside the steel housing, the housing shall also be provided with a suitable filter to prevent the entrance of dust. Where the air intake is not inside the housing, the intake shall be not less than 6 feet above the ground, and the intake and filter shall be of a design and type suitable for outdoor, all-weather use including dusty locations, without requiring frequent maintenance. Where any air exhaust is inside the housing, filtered housing openings shall be provided, ample to prevent damaging shock to housed equipment or bulging of the housing during air discharge. All operating valves subject to moisture in the compressed air, which could freeze the moisture during operation, shall be provided with low-temperature protection to assure reliable operation of the breaker.

2.7.2.5 Special Requirements for Hydraulic Mechanisms Only

The circuit breaker shall be closed and opened by hydraulic operation of the mechanism. Means shall be provided at the mechanism housing which will permit manual operation of the hydraulic valves for hydraulically opening or closing the breaker at normal speeds. Each mechanism shall be provided with its own pump equipment, consisting of an oil reservoir, oil pump, suitable oil filter, accumulator, pressure gage, necessary controls, piping, and valves. The accumulator may be located in the housing or adjacent to it. Each hydraulic mechanism shall have provisions to permit adjustment of the accumulator precharge pressure with a standard hose and gage assembly. Each hydraulic mechanism shall include a shutoff valve between the main reservoir and pump, or other provisions to permit the removal of the motor and pump for maintenance without draining the oil from

SECTION 33 75 19.00 26 Page 17 the main reservoir. At least one reservoir on each system shall be located to provide a positive head on all points of the system, to prevent the entrance of air, or the system shall be designed to function with air present, without misoperating at any time, while either running or idle.

2.7.2.6 Special Requirements for Electric Motor Driven Spring Mechanisms Only

The state of charge shall be clearly visible by spring position indicators. Spring charge shall occur only after a close operation, or, an adjustable delay (0 to 2s) may be provided to allow staggered recharge between multiple breakers at a given site.

2.7.3 Gas Monitoring and Service System

All gas compartments shall be monitored in normal operation. The monitoring system shall consist of temperature compensated pressure switches (density relays) with adjustable contact operation settings, pressure gauges, gas sample valves, and other devices necessary to verify and maintain the system's integrity. Pressure gauges shall be legible from the ground, and shall be either temperature compensated or provided with a weatherproof temperature compensating chart and thermometers, mounted near the pressure gauges. Gauges and sample valves shall be readily accessible for ease of maintenance while the circuit breaker is energized. Each circuit breaker shall have means of connecting to the Government's portable gas handling equipment. The Contractor's standard fitting may be provided at this point, and two fittings capable of mating with it shall be furnished with the accessories for each circuit breaker, for the Government's use in construction of adapters to the portable equipment.

2.7.4 Controls, Indication and Alarms

2.7.4.1 General

a. The control scheme shall be as shown on the reference drawings and described herein, and shall be complete with all features necessary to perform local and remote closing, tripping, and testing, as well as to automatically provide for safety, and remote indication and alarms, except where indicated otherwise below. The required controls shall be conveniently grouped for operation from an accessible location in a central housing.

b. A "Local-Remote" transfer switch and a breaker control switch shall be provided and mounted in the mechanism housing. Circuit breakers shall be designed to initiate normal closing or opening by remote contacts, only when the transfer switch is in the "Remote" position. The breaker control switch shall control local electrical closing and opening of the circuit breaker only when the transfer switch is in the "Local" position.

c. The circuit breaker may be operated for high-speed reclosing (O, 0 seconds, C, 0 seconds, O), within 20 60-Hz cycles (or later, at Government choice) after main contacts reach fully open. If needed, the Government will furnish the remote reclosing relay. A "b" auxiliary switch contact shall be provided to permit immediate reclosing. Any time delay prior to reclose required by the circuit breaker design, must be provided by the Contractor, and shall not cause the total delay to exceed 20 cycles. Circuit breaker condition and performance shall not be degraded if reclosing occurs in less than 20

SECTION 33 75 19.00 26 Page 18 cycles.

d. The circuit breaker controls shall be provided to close contacts for remote alarms, and to prevent breaker closing, and to either initiate or prevent tripping, when system pressures (operating or dielectric) progressively decrease to abnormal values.

e. A capacitor trip device shall be provided for emergency tripping of the breaker in the event of failure of the trip circuit 125-volt dc control source. The capacitor trip device shall consist of a suitable size, long life, energy storage capacitor which is charged by the normal trip circuit dc control source. The capacitor shall be capable of being recharged within 10 seconds and shall hold sufficient charge to trip the breaker after the charging potential is completely removed.

f. All controls and indicators used by an operator shall be adequately insulated or protected to prevent inadvertent human contact with the energized circuit.

g. The trip circuit shall be capable of isolation from all other circuits. All external connections for the trip circuit, including power, shall be terminated on terminal block points separate from those of other circuitry. Any interconnections with other control circuits shall be made from those terminal points only rather than within the trip circuit.

2.7.4.2 Indication, Monitoring, and Alarms

a. Switch contacts. Contacts for internal circuit breaker controls shall be conservatively rated for the duty they will experience.

Contacts for connection to remote circuits shall be rated for service on a 125 volt dc ungrounded system, and on a 120 or 240-volt single phase ac grounded or ungrounded system. Continuous current rating shall be 15 amperes minimum. Minimum inductive interrupting ratings shall be 0.5 ampere for 125-Volt dc duty, and 10 amperes for 120 or 240-Volt ac duty. All specified contacts, including spare contacts, shall be terminated on separate points on terminal blocks located together in a common accessible area within the control cabinet.

b. Indication. The following mechanical indication shall be provided. Unless noted otherwise, the indicators shall be easily readable from the outside front of the operating cabinet.

(1) Circuit breaker position. These indicators shall give positive information of the position of the contacts, whether closed, open, or in an intermediate position.

(2) Operation counter. The counter shall be directly operated by the mechanism when the circuit breaker opens, and shall not be affected by cycling power to control circuits.

(3) Spring charge indicator for any springs used to store operating energy. This may be located within a housing, but shall be otherwise easily readable when the housing door is open.

(4) A pressure gauge for each operating pressure system.

c. Auxiliary Switches. Each circuit breaker mechanism shall be equipped with one or more auxiliary switches which operate as the

SECTION 33 75 19.00 26 Page 19 breaker closes and opens. Contacts shall be electrically independent, silver plated or of silver alloy, self-aligning and shall close with a wiping action. The auxiliary switch shall have at least 12 independent contacts in addition to those specified elsewhere or required for normal circuit breaker control. Each of these additional contacts shall be of a type which can be changed between form "a" and form "b", with respect to circuit breaker position, or optionally, at least 8 "a" and 8 "b" non-interchangeable contacts may be substituted for the specified 12 contacts.

d. Automatic Controls and Alarms. Automatic controls and alarms shall not respond to momentary conditions during normal operation of the breaker, such as brief pressure changes. Contacts for remote alarm indication shall each be electrically isolated from all other contacts, and shall respond to alarm conditions by closing. The following functions shall be provided for response to:

(1) Reduction of gas density in the SF6 gas insulating system.

At least two independent adjustable density monitor switch stages shall be provided. The first stage shall contain a contact to alarm remotely when the gas density decreases to a safe but abnormally low value. The second stage shall contain one or more electrically independent contacts as required which operate just before gas density becomes too low for safe closing or tripping.

These second stage contacts shall prevent closing, prevent tripping, and alarm remotely. The second stage shall be capable of reconfiguration by wire changes and readjustment only, to trip the breaker, prevent closure, and alarm remotely when the density closely approaches a value too low for safe interruption of rated short circuit current.

(2) In the operating system:

(a) Low operating pressure (or other stored energy). For hydraulic or pneumatic operating mechanisms, three switch stages shall be provided to operate when the pressure drops below the mechanism's rated operating pressure range. The first stage shall contain a contact to alarm remotely when the operating pressure is between 95 and 98 percent of rated. The second stage shall contain contacts as required to prevent circuit breaker closing, and a contact to alarm remotely, just before the pressure is insufficient to close and safely open the breaker at rated short-circuit current. The third stage shall contain contacts as required to prevent breaker tripping, and a contact to alarm remotely, just before the pressure is insufficient to safely open the circuit breaker at rated short circuit current. The third stage shall be capable of reconfiguration by wire changes and readjustment only, to trip the breaker, prevent closure, and alarm remotely when the pressure closely approaches a value too low for safe interruption of rated short circuit current.

(b) Remote alarm for loss of electrical power to the operating mechanism.

(c) Remote alarm for loss of electrical power to the control circuits.

(d) Trip, disable closing, and remote alarm for incomplete operation, when a close or open operation does not complete within

SECTION 33 75 19.00 26 Page 20 an acceptable time interval.

(e) Remote alarm for excessive run time for the energy storage system.

2.7.4.3 Key Interlocks

Each circuit breaker shall be provided with Kirk key interlock equipment, or approved equal, to prevent operation of its two existing isolating disconnecting switches when the circuit breaker is closed, and to prevent test operation of the circuit breaker unless both existing disconnecting switches are locked open. The Contractor shall furnish and install the locks on the circuit breakers. The Contractor shall also furnish Kirk type B interlocks with type S auxiliary switches for both existing disconnecting switches associated with each new circuit breaker. The circuit breaker and its existing disconnecting switches shall be keyed as a separate unit system.

2.7.5 Cabinets

2.7.5.1 General

All operating mechanisms for circuit breakers, including tripping and closing mechanisms, relays, local test and transfer switches, circuit breakers for control and supply circuits, auxiliary switches, compressors or pumps, motors, starters, heaters, gauges, terminal blocks and other necessary equipment shall be enclosed in ample size cabinets.

2.7.5.2 Access

Access to controls, the operating mechanism, or the energy storage equipment shall be through hinged doors of the housing or cabinet. The equipment layout within the cabinet shall allow easy access to wiring and to terminal blocks, easy replacement of equipment, and easy adjustments for maintenance. At least 12" of clear space shall be retained above the floor plates for training of cables.

2.7.5.3 Identification

One or more permanent, noncorroding circuit breaker nameplates in accordance with IEEE C37.04, Paragraph 7, shall be provided, mounted in a conspicuous location outside the cabinet.

2.7.5.4 Heaters

One or more metal-enclosed heaters with thermostats shall be provided, capable of continuous operation, of sufficient capacity to maintain automatically within the cabinets, both the proper temperature to prevent condensation and a temperature suitable for correct operation of all mechanisms in the housing, when the outside temperature is as low as minus 30 C. The heaters shall be installed in the lower parts of the cabinets.

Heaters shall also be provided for valve protection if needed. The heater power sources will be 208 volts, 60 Hz, single phase, 20 amperes maximum per circuit fed from 120/208 volt three-wire grounded-neutral circuits.

Heaters shall be divided into as many circuits as necessary to avoid overloading the sources. The heater circuits shall be independent from all other circuits, with separate terminals for their power sources. If tank heaters are required, their power source will be 208 volts, 60 Hz, single phase, 20 amperes maximum per circuit fed from 120/208 volt three-wire

SECTION 33 75 19.00 26 Page 21 grounded-neutral circuits as well.

2.7.5.5 Convenience Outlet

A duplex, 3-wire, 20-ampere straight-blade, grounding type GFI receptacle, suitable for use on a grounded-neutral 120 volt ac circuit, shall be provided inside the controls cabinet and breaker cabinet. Three incoming terminal block points, and a single-pole non-automatic circuit breaker for the ungrounded conductor shall be provided and connected to the receptacle.

2.7.6 Electric Supply

The circuit breaker electrical power systems shall be designed to operate properly from the supply sources. Devices shall be capable of functioning through the ranges of voltages given in Table 9 of NEMA C37.06. Maximum continuous current in each circuit shall not exceed 20 amperes. The stored operating energy charging system, if pneumatic or hydraulic, shall be designed for 208-volt ac, single phase, 60 hz, 3-wire grounded neutral, or shall be designed for 125-volt dc, ungrounded.