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St. Marys 5kV Switchgear SSM5KV20

SECTION 26 12 16.00 26

DRY-TYPE TRANSFORMERS

09/17

PART 1 GENERAL

1.1 GENERAL INFORMATION

This SECTION covers the supply, installation and testing requirements for outdoor, dry-type transformers. The equipment shall be designed to satisfy the requirements contained in each of the following sections:

13 48 00.00 26 SEISMIC RESTRAINT FOR MECHANICAL AND ELECTRICAL EQUIPMENT,

26 05 00.00 26 BASIC ELECTRICAL MATERIALS AND METHODS, 26 05 13.00 26

MEDIUM-VOLTAGE CABLE, 26 05 13.00 26 MEDIUM VOLTAGE CABLE, 26 05 19.00 26

INSULATED WIRE AND CABLE, 26 05 26.00 26 GROUNDING, AND 26 08 01.00 26

SYSTEMS TESTING AND COMMISSIONING..

1.2 REFERENCES

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

ASME INTERNATIONAL (ASME)

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

INTERNATIONAL ELECTROTECHNICAL COMMISSION (IEC)

IEC 60076-11 Power Transformers - Dry-type transformers

IEC 60529 Degrees of Protection Provided by Enclosures (IP Code)

INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS (IEEE)

IEEE C37.20.3 (2013) Metal-Enclosed Interrupter Switchgear

IEEE C57.12.01 (2015) General Requirements for Dry-Type Distribution and Power Transformers Including Those with Solid-Cast and/or Resin-Encapsulated Windings

IEEE C57.12.51 (2008) Standard for Ventilated Dry-Type Power Transformers, 501 kVA and Larger, Three-Phase, with High-Voltage 601 to 34,500 Volts, Low-voltage 208Y/120 to 4160 Volts - General Requirement

IEEE C57.12.91 (2011) Standard Test Code for Dry-Type Distribution and Power Transformers

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INTERNATIONAL ELECTRICAL TESTING ASSOCIATION (NETA)

NETA ATS (2017; Errata 2017) Standard for Acceptance Testing Specifications for Electrical Power Equipment and Systems

NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION (NEMA)

NEMA 250 (2018) Enclosures for Electrical Equipment (1000 Volts Maximum)

1.3 SUBMITTALS

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

submittals having an "I" designation are for information only. When used, a designation following the "G" or "I" designation identifies the office that will review the submittal for the Government. The following shall be submitted in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:

SD-02 Shop Drawings

Submit within 90 days after receipt of Notice to Proceed

Electrical Equipment Drawings ; G, HDC

SD-03 Product Data

Submit within 75 days after receipt of Notice to Proceed

Transformer ; G, HDC

Nameplates ; G, HDC

Surge Protection ; G HDC

Temperature Monitor ; G HDC

Unfused Disconnect Switch ; G, HDC

SD-06 Test Reports

Factory Acceptance Test Report ; G, HDC

The official factory acceptance test report for the transformer shall be submitted within 30 days of completion of all tests.

Field Test Report ; G, HDC

The field test reports shall be submitted within 30 days of completion of all field acceptance tests.

SD-08 Manufacturer's Instructions

Factory Test Procedure ; G, HDC

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The manufacturer's factory test procedures shall be submitted for review and approval 60 days prior to the scheduled date of factory acceptance testing.

Field Test Procedure ; G, HDC

The manufacturer's field test procedures shall be submitted for review and approval 60 days prior to the scheduled date of field testing after delivery.

Transformer Shipping Plan ; G, HDC

SD-10 Operation and Maintenance Data

Submit no later than 60 days prior to completion of work.

Operation and Maintenance Data ; G, HDC

1.4 PRODUCT DATA

Manufacturer's catalog cuts shall be composed of catalog cuts, brochures, circulars, specifications, product data, and printed information in sufficient detail and scope to verify compliance with the requirements of the contract documents. Catalog data shall be submitted not later than 45 calendar days after date of receipt of written Notice to Proceed.

1.5 ELECTRICAL EQUIPMENT DRAWINGS

Detailed electrical drawings shall show physical arrangement, construction details, connections, wiring diagrams, materials used in fabrication, access requirements for installation and maintenance, physical size, electrical characteristics, mounting and support details, and equipment weight. Drawings shall be drawn to scale and/or dimensioned. Optional items shall be clearly identified as included or excluded.

PART 2 PRODUCTS

2.1 GENERAL

Transformers supplied as part of this Contract shall meet all applicable industry standards and requirements as listed in IEEE C57.12.01 and

IEEE C57.12.51 .

2.2 SERVICE CONDITIONS

2.2.1 General

Unless specified below, units shall be built for operation in outdoor, non-ventilated enclosures or with means to prevent intrusion of foreign objects in a non-hazardous environment meeting the usual service conditions outlined in Paragraph 4.1 of IEEE C57.12.01 .

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2.3 TRANSFORMER

2.3.1 Type and Rating

Transformer shall be cast resin or cast-coil sealed design,dry-type, self-cooled, NEMA Class AA, with 180 degrees C insulation and shall conform to the applicable requirements of IEEE C57.12.0l, IEEE C57.12.91, and NEMA TR 1. The transformer shall be rated 3000kVA, 3-phase, 60-Hz, 13,600 "primary"-4160 "secondary" volts nominal, and the windings shall be connected delta primary, grounded wye secondary. The transformer shall be designed to carry rated load continuously without exceeding 140 degrees C (Class 180 degrees C) temperature rise above 40 degrees C ambient temperature when installed in its TENV enclosure.

2.3.2 Winding taps

Transformers shall be supplied with de-energized, high-voltage full-capacity taps. Taps shall be four total, with two at +2.5% each above nominal voltage and two at -2.5% each below nominal voltage.

2.3.3 Impedance

The transformer impedance shall be 5.75 percent subject to ANSI standard tolerance.

2.3.4 Basic Lightning Impulse Insulation Level

The transformer's high voltage winding shall have a basic lightning impulse insulation level (BIL) of at least 95 kV. The transformer's low voltage winding shall have a basic lightning impulse insulation level (BIL) of at least 60 kV.

2.3.5 Short-Circuit Characteristics

All transformers supplied shall be built to Category II short circuit requirements as defined in IEEE C57.12.01 .

2.3.6 Sound Level

Sound levels shall not exceed the class AA, three-phase ratings listed in Table 8 of IEEE C57.12.01 .

2.3.7 Environmental

Class E2: Frequent condensation or heavy polution or combination of both in accordance with IEC 60076-11 .

2.4 Unfused Disconnect Switch

Type: Three-pole gang operated with quick-make, quick-break spring mechanism.

Enclosure: Close-coupled with transformer type NEMA 4 in accordance with

NEMA 250.

Maximum voltage: 4.76 kV low-side, 15 kV high-side.

BIL: 60 kV peak low-side, 95 kV BIL high-side.

Continuous current: 600 amperes.

Speed of opening and closing independent of switch operator.

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Separate main and break contacts to provide maximum endurance for fault close and load interrupting duty.

Provide insulating barriers between each phase.

Operating mechanism: Chain drive with two position handle.

Provide provisions for padlocking switch in the OPEN position.

Provide OPEN and CLOSED switch position indicators.

Provide inspection window in switch compartment door.

Blade position: Visible through door.

Conform to IEEE C37.20.3 Accessory: Ground pad, with two bolted-type connectors, suitable for connecting No. 4 AWG stranded bare-copper cable.

2.5 CONSTRUCTION

2.5.1 Insulation System

Transformer coils shall be Cast Resin that employs a fiber-reinforced epoxy insulation system.. Maintenance-free, moisture-resistant, tropicalized, flame-retardant and self extinguishing insulation.

2.5.2 Windings

Windings shall be copper.

2.5.3 Bus Connections

The bus connections shall be tinned or silver-plated.

2.5.4 Core and Coils

The core, coils and metal enclosure of the transformer shall be rigidly attached to a structural steel base suitable for moving the complete transformer by the use of rollers. The core shall be constructed with step-lap mitered joints. Jacking facilities and removable lifting eyes shall be provided on the core and coil assembly. The core laminations shall be free from burrs which may puncture the insulation between laminations and shall be securely fastened to prevent excessive vibration in normal service or displacement under short-circuit conditions. Provide anti-vibration mountings or isolation pads between core and coil and enclosure to reduce structre-borne noise.Four full-capacity taps, 2 above rated voltage and 2 below rated voltage, shall be provided in the high-voltage windings, and suitable means shall be provided for changing the taps while the transformer is de-energized. The terminal board shall be accessible through a door or removable panel in the enclosure. All transformer leads and taps shall be securely braced to prevent displacement or injury during transit or installation and under short-circuit condition.

2.5.5 Ground Bus

A continuous ground bus shall be installed inside the transformer enclosure including the transition and termination compartments. It shall be copper not less than 2 inch by 1/4 inch. The ground bus shall be mechanically connected to the core, frame and enclosure. The use of ground cables in lieu of bus is not allowed. The ground bus shall be bonded to the bus within the switchgear. Ground connections to surge protection equipment shall be by adequately sized bus. In the high voltage compartment the bus shall be installed up the wall to allow close connection of the medium voltage cable shields. A burndy type YA lug shall

SECTION 26 12 16.00 26 Page 5 be provided to connect a 1/0 AWG copper cable to the powerhouse ground bus.

2.5.6 Temperature Rise

The average winding temperature rise, as measured by resistance, shall be 115 degrees Celsius maximum.

2.5.7 Enclosures and Mounting

2.5.7.1 General

Enclosures shall be of a Totally-Enclosed Non-Ventilated (TENV) or IP 55 with corrosion-resistant finish per IEC 60529 dead-front, freestanding (i.e. no mechanial connections to the transformer) construction. All enclosures shall be constructed to prevent inadvertent access to energized parts and the ingress of solid foreign objects. The enclosure shall be constructed such that all points are solidly bonded to the cubicle ground connection. All bolts, studs, machine screws, nuts, and tapped holes shall be in accordance with ASME B1.1 . Interior and exterior surfaces shall receive not less than one coat of corrosion-resisting paint in accordance with the manufacturer's standard practice. The enclosures shall be painted ANSI 61 Light Gray color. Enclosure shall prevent ingress of bugs and vermin.

2.5.7.2 Incoming Sections

A metal-clad high voltage transition compartment shall be provided for terminating the incoming medium voltage shielded cables. Ground bus and support for cable bracing shall be included in this section. Access to the interior of the compartment shall be through removable bolted panels or bolted hinged doors. Connections between the terminals of the incoming cables and the high-voltage winding terminals of the adjacent transformer shall be by means of copper bus with not less than 600 amps continuous current-carrying capacity and 22kA asymmetrical amperes momentary current rating. Heavy-duty clamp type terminal lugs shall be provided for connecting the high-voltage cables to the transformer high-voltage bus.

The design shall allow adequate space for bending and bracing of medium voltage shielded cable. The termination point for the medium voltage cable shall be no less than 3 feet from where the cable enters the enclosure. Grounding studs shall be installed on all three phases for use by maintenance personnel to install safety grounds.

2.5.8 Outgoing Section

A metal-clad medium voltage transition compartment shall be provided for connecting the transformer bus to the 5kV conductors. Access to the interior of the compartment shall be through removable bolted panels or bolted hinged doors. The connections shall be made of copper bus with not less than 1200amps continuous current-carrying capacity and 25kA symmetrical amperes momentary current rating.

2.5.9 Structural Design Criteria and Seismic Calculations

See Section 13 48 00.00 26 , SEISMIC RESTRAINT FOR MECHANICAL AND

ELECTRICAL EQUIPMENT

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2.6 SURGE PROTECTION

2.6.1 Surge Arresters

Surge Arresters for each phase shall be mounted in the low voltage terminal compartments, respectively. Surge arresters shall be metal-oxide, station class, with a MCOV of 5.1 kV for 4.16 kV winding. Surge arresters shall be constructed in accordance with the requirements of IEEE C62.11.

Submit the surge arrester design test results for each type of arrester provided and the surge arrester conformance test results shall be submitted for each arrester provided. If surge arresters are not mounted near the base of the enclosure, a ground bus shall be run to close proximity of the surge arrester so that cable is not run along the equipment housing to the enclosure ground bus. All tests shall be performed in accordance with IEEE C62.11.

2.7 NAMEPLATES

The transformer shall be provided with a cast bronze, stainless steel, or anodized aluminum nameplate conforming to the requirements of IEEE C57.12.01 , Table 13. In addition to the requirements of Table 13, the nameplate shall also include the following information:

(a) Date of Manufacture

(b) Manufacturing plant location and address

(c) Government contract number

2.8 TEMPERATURE MONITOR

2.8.1 General

Each transformer shall include a temperature monitor mounted on a side panel such that it is easily read during normal operation. The same temperature monitor product shall be provided for each transformer monitored.

2.8.2 Inputs

The transformer temperature monitor shall utilize four inputs: winding 1, winding 2, winding 3, and ambient temperature . Input RTDs or thermocouples shall be placed in the anticipated hottest spot of each winding assembly. RTDs or thermocouples shall be of the type recommended for the selected monitor. The monitor shall operate off of a 125 VDC supply.

2.8.3 Outputs

At a minimum, two (2) programmable Form C contacts, rated for operation on a 125 VDC system, shall be available for over-temperature alarms and/or trip. Set trip at high temperature and the alarm at 15 degrees lower.

Provide analog output from transformer temperature monitor for input to SCADA system.

2.9 HEATERS

Heaters shall be provided with the transformer. They shall be rated for 240VAC but the numbers of heaters to be provided shall be designed for operation at 120VAC. A thermostat shall be provided to operate the

SECTION 26 12 16.00 26 Page 7 heaters and shall have user defined setting range of no less than 60 to 105 degrees F.

2.10 WIRING

Wiring for accessories shall be adequately supported to prevent damaging the conductors due to vibration or maintenance activities and shall be connected to accessible terminal blocks. The frame members and conduit shall be utilized to protect exposed wiring from damage and all wiring on base shall be protected from stepping on during maintenance activities.

Entrance of wiring and raceways into cabinet enclosures shall be by bushings designed for the purpose and all cabinets and conduit shall be adequately bonded to ground by bonding jumpers or fitting approved for grounding. Insulation and jackets of wiring shall be non-PVC.

2.11 CONTROL CABINET

A control cabinet shall be provided with terminal blocks and control equipment as specified or required. This control cabinet shall be used for terminating the external control and power cables, temperature relay, control fuses, circuit breakers, instrumentation wires and current transformer secondary wiring. The control cabinet shall have a door to allow access from the crib dam without entering the transformer enclosure. Doors with mounted equipment shall have a minimum bonding jumper of #10 AWG across panel hinges.

2.12 OPERATION AND MAINTENANCE DATA

Operation and maintenance data shall comply with the requirements of Section 01 33 00 SUBMITTAL PROCEDURES andpackage 5 of 01 78 23 OPERATION AND MAINTENANCE DATAand shall include complete operating, maintenance, and storage data regarding the transformer and its related equipment and shall be included in the Operation & Maintenance Manual. The data shall include the manufacturer's name, model number, catalog cuts, parts list, service manual, drawings, and a brief description of all equipment and their basic operating features. The data shall list routine maintenance procedures, possible breakdowns and repairs, and a trouble-shooting guide including detailed instructions for removal, overhaul, reconditioning, and reinstallation of replaceable components. In addition, the data shall also contain recommended frequency of inspections and cleaning.

PART 3 EXECUTION

3.1 FACTORY TESTING

3.1.1 General

The unfused disconnect switch shall receive the full set of routine production tests as defined in IEEE C37.20.3 . The transformer shall receive the full set of routine tests as defined in IEEE C57.12.01 , Table

16. The requirements in this paragraph constitute minimum testing requirements and do not preclude the manufacturer from performing any standard tests as part of the manufacturing process. The factory tests, including test equipment, test methods, measurements, and computations, shall be in accordance with the applicable requirements of IEEE C57.12.01 and IEEE C57.12.91 , and shall be subject to the approval of the Contracting Officer.

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3.1.2 Additional Tests

The transformer shall receive the following additional tests:

(a) Temperature rise test. This test shall be made according to IEEE C57.12.91 Section 11. This test is required to demonstrate that the new transformers can meet the rated temperature rise when installed in the enclosure.

(b) Audible sound level test. This test will be performed according to IEEE C57.12.91 Section 13. This test is required to demonstrate that the new transformer will not exceed the maximum allowable audible sound level of 68dBA when installed in the enclosure.

(c) Impulse test. This test will be performed according to IEEE C57.12.91 Section 10.5. This test is required to demonstrate that the new transformer can meet their rated BIL when installed in the enclosure.

(d) Insulation resistance test. This test will be performed according to IEEE C57.12.91 Section 10.9. This test is required to provide a baseline for each transformer supplied under this contract and all data files shall be provided to the Government Quality Assurance Representative (GQAR).

3.1.3 Factory Acceptance Tests Procedure

The Contractor will provide the Government with a minimum of 14 days advanced notification of factory testing. The government needs to witness the factory testing unless waived in writing. The Contractor shall submit a transformer Factory Test Procedure . The tests procedure shall include the following information, at a minimum, for each design:

(a) an estimated schedule of testing durations

(b) descriptions of each test, including connections and equipment.

Blank or sample test sheets are acceptable assuming the equipment type and configuration matches the proposed transformer being tested.

(c) test levels for each test, where applicable

(d) manufacturer acceptance values for each test

(e) calculated values

3.1.4 Factory Acceptance Test report

Within 30 days of completing all tests, the manufacturer shall submit a factory acceptance test report . The test report shall include:

a. A list of equipment used, with calibration certifications.

b. A copy of measurements taken.

c. The dates of testing.

d. The equipment and values to be verified.

e. The conditions specified for the test.

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f. The test results, signed and dated.

g. Final measurements.

3.2 SHIPMENT

The Contractor shall submit for approval a Transformer Shipping Plan detailing the Contractors shipping method and shipping protection. The Government may reject transformers subjected to excessive moisture or contamination due to improper protection during shipment. Transformer cabinets showing visible signs of impact or trauma upon arrival may be rejected by the Government. The Government will not be responsible for shipping costs on rejected transformers.

3.3 FIELD TESTING AND ACCEPTANCE

3.3.1 General

The Contractor shall perform field acceptance testing to verify that each transformer is undamaged from shipping and fit for service. A field test procedure shall be submitted for approval 60 days prior to field acceptance testing. The procedure shall include the required tests, listed below, at a minimum, in addition to a schedule showing expected durations, and a list of test equipment used to complete testing. The field tests, including test equipment, test methods, measurements, and computations, shall be in accordance with the applicable requirements of IEEE C37.20.3 , IEEE C57.12.01 and IEEE C57.12.91 , and shall be subject to the approval of the Contracting Officer.

3.3.2 Inspections

Perform in accordance with the manufacturer's recommendations and include the following visual and mechanical inspections and electrical tests, performed in accordance with NETA ATS, and performed by the transformer field engineering services personnel.

Visual and mechanical inspection

(a) Compare equipment nameplate information with specifications and approved shop drawings.

(b) Inspect physical and mechanical condition. Check for damaged or cracked insulators.

(c) Inspect all bolted electrical connections for high resistance using low-resistance ohmmeter, verifying tightness of accessible bolted electrical connections by calibrated torque-wrench method, or performing thermographic survey.

(d) Perform specific inspections and mechanical tests as recommended by manufacturer.

(e) Verify correct equipment grounding.

3.3.3 Required Electrical Tests and Values

The Contractor shall perform the following electrical tests, at a minimum, after installing the unit in its final location. This list shall not

SECTION 26 12 16.00 26 Page 10 preclude any field testing required for warranty purposes:

(a) Perform insulation resistance tests between windings and each winding to ground and calculate the polarization index. The polarization index shall be greater than 1.0.

(b) Perform power factor testing

(c) Perform turns-ratio tests at all tap positions, if applicable. Turns-ratio tests shall not deviate more than 0.5% from adjacent coils or the factory test results.

(d) If the core is not solidly grounded, perform a core insulation resistance test. The core insulation resistance shall be greater than 1.0 megaohm at 500 VDC test value.

The Contractor shall perform its testing activities, and coordinate and provide time in the construction schedule for this tesing. During the Government testing, the Contractor shall provide skilled craftworkers to support the Government's testing activities. Craftworkers shall be appropriate trades and skill level required for the particular tests to be performed. Craftworkers will only be required to make adjustments or changes to Contractor-installed equipment when a need is identified during performance of the Government's testing activities.

3.3.4 Test Report

A field test report for each transformer shall be submitted within 30 days of completion of tests. The test report shall contain all tests completed, with test equipment used for each test.

3.3.5 Commissioning

The Contractor shall be responsible for performing all equipment commissioning required by the equipment manufacturers and as noted in Section 26 08 01.00 26 SYSTEMS TESTING AND COMMISSIONING.

3.3.6 Field Applied Painting

The Contractor shall touch-up any paint damage caused to the enclosure paint through the course of this Contract by applying the manufacturer's recommended paint system in accordance with manufacturer's instructions.

The touch up color shall match the manufacturer's paint.

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