CITY OF LEESBURG

LEESBURG, FLORIDA

TECHNICAL SPECIFICATIONS

FOR

67 TO 13,090 KV POWER TRANSFORMER

TECHNICAL SPECIFICATIONS

FOR

67 TO 13,090 KV POWER TRANSFORMER

Contents

1.0 Scope

2.0 General Conditions

3.0 Special Conditions

4.0 Standards

5.0 Drawings

6.0 Shipping of Transformer

7.0 Manufacturer's Field Representative

8.0 Transformer

9.0 Additional Features

10.0 Transformer Monitor / Control Equipment

11.0 Tests

12.0 Guarantees

13.0 Transformer Bid Evaluation

CITY OF LEESBURG

LEESBURG, FLORIDA

SPECIFICATIONS AND BID DOCUMENTS

FOR

67 TO 15 KV POWER TRANSFORMER

TECHNICAL SPECIFICATIONS

1.0 Scope

The work shall include furnishing all equipment and materials, as set forth in the Request for Proposal and as specified herein.

Bids will be received on one (1) schedule for a power transformer. The Owner intends to purchase one (1), three-phase, 67,000 to 13,090 / 7,560 volt, LTC, power transformer for the Electric Distribution system equipped as evaluated with any or all deducts. The transformer is to be rated 18/24/30/36.6 KNAN/ KNAF/ KNAF (55C) KNAF (65C). The Owner reserves the right to reject any or all Proposals and to select any or all schedules or combinations or portions thereof listed in the Cost Proposal.

Schedule 1 North Substation Transformer #1 Fall 2028

2.0 General Conditions

2.1 All materials and equipment shall be new and shall be manufactured in the continental United States. Manufacturers must be approved by the Owner or Owner's Engineer.

2.2 These Specifications describe the type, size, and characteristics of the various materials and equipment required to be furnished, and the Drawings indicate general arrangement, equipment location, and spacing.

2.3 Strict adherence to these Specifications and Drawings is requested to facilitate review and consideration of the Proposal.

2.4 Proposals shall include the following:

2.4.1 For all equipment not directly specified, Catalog numbers, manufacturer, ratings, characteristics, types, sizes, etc., of all materials and equipment included. A simple statement that all necessary materials and equipment will be provided is not satisfactory.

2.4.2 Performance data for the several items as set forth in the Technical Specifications.

2.4.3 The Bidder shall state in his Proposal the manner in which the transformers will be shipped--namely, truck or rail; whether units shall be oil-filled or dry-air-filled; and whether bushings will be installed or removed.

2.4.4 Prices shall include line-item costs of delivery to the substation site, unloading, assembly, liquid filling, and testing as per these Specifications.

2.4.5 Delivery of the power transformer(s) will be made in (1) schedule. Delivery time and location are as follows.

Schedule 1 - North Substation 2435 Marcella Way, Leesburg, Florida 34748

- Fall of 2028

2.5 It is the intent of these Specifications that each transformer shall be complete and fully operable, once re-assembled. Any details not mentioned in the Specifications but required for satisfactory operation shall be furnished and installed by the Manufacturer.

2.6 Station power available at the Owner's substation will be 120/240 volts ac, 60 Hz, single-phase. Control voltage at the substation site will be 125 volts dc. The equipment on the transformer shall coordinate with these voltages as appropriate.

3.0 Special Conditions

Indemnity Provisions

The Bidder shall hold harmless and indemnify the Owner, its agents, and employees from any and all claims, suits, and proceedings for infringement of any patent or patents covering materials and equipment purchased hereunder. The Bidder shall defend any suit or proceeding brought against the Owner, its agents, or employees based upon a claim that the materials and equipment or any part thereof constitute an infringement of any patent, or if the Bidder shall fail to defend such suit or proceeding, the Owner may do so and the Bidder shall make reimbursement for the expense of such litigation. If the materials and equipment or any part thereof are held to constitute infringement and the use thereof is enjoined, the Bidder shall, at its own expense, either procure for the Owner the right to continue to use the materials and equipment, or such part thereof, or shall replace the materials and equipment, or such part thereof, with non-infringing materials and equipment.

3.1 Defective Materials, Equipment, and Workmanship

3.1.1 All materials and equipment furnished hereunder shall be subject to the inspection, tests, and approval of the Owner and the Bidder shall furnish all information required concerning the nature or source of any materials and equipment and provide adequate facilities for testing and inspecting the materials and equipment at the plant of the Bidder.

3.1.2 The materials and equipment furnished hereunder shall become the property of the Owner when delivered (in the case of the transformer ownership is established after delivery, assembly and testing) at the point to which shipment is to be made, provided, however, that the Owner may reject any such materials and equipment that do not comply with the Specifications for materials and equipment and warranties of the Bidder and manufacturers.

Recognition and subsequent rejection of any defective materials and equipment may occur either before or after incorporation of such materials and equipment into the facilities, provided such rejection is made within one year of date of delivery of the materials and equipment. Upon any such rejection, the Bidder shall replace the rejected materials and equipment with materials and equipment complying with the materials and equipment and warranties, FOB truck at suitable destination. The Owner shall return the rejected materials FOB truck at the same destination. In the event of the failure of the Bidder to so replace rejected materials and equipment, the Owner may make such replacement, and the cost and expense thereof shall be paid by and recoverable from the Bidder.

3.2 Warranty

The transformer(s) to be provided herein shall include a full five (5) year warranty on the complete transformer(s) together with all parts. This warranty shall extend for five (5) years from the date of energization [or sixty-six (66) months from delivery]. If the manufacturer's standard warranty is less than five (5) years, the manufacturer shall state the warranty period and provide an optional price adder for an extended five-year warranty. Warranty period and price adder (if applicable) shall be stated at the bid stage.

4.0 Standards

All equipment and materials covered by these Specifications and all tests applied thereto shall, unless otherwise stated herein, be in accordance with the applicable provisions of the latest editions of the Standards and Guides of the ASTM, ANSI, AEIC, NEMA, OSHA, IEEE, and the latest revision in the National Electrical Safety Code.

Where the term "Standards" is used in the Specifications, it shall be understood to refer to the above Standards.

5.0 Drawings

5.1 Preliminary

5.1.1 Before proceeding with fabrication, the Manufacturer shall submit for approval sufficient Drawings to demonstrate that all parts conform to the requirements and intent of these Specifications. The Drawings shall include four (4) copies each of Outline, Nameplate, Control, and Elementary and Control Wiring Drawings, relay panel front view, bushing and bushing terminal connectors and arresters. Approval Drawings shall be submitted directly to the Owner, Substation Department, City of Leesburg, 2010 Griffin Rd., Leesburg, Florida 34748.

5.1.2 Each sheet of each set of Drawings shall be labeled: "City of Leesburg" in addition to other identifying information, such as substation name and transformer number.

5.1.3 The Outline Drawings shall show dimensions of equipment, including bushings, radiators and cooling equipment, base, and all other important external features. These Drawings shall show weights, volumes, bushings, catalog numbers, and ampere ratings, description of top bushing terminals, and arrangement of all external accessory devices. All dimensions shall be stated in inches or feet and inches.

5.1.4 Approval of Drawings shall not be held to relieve the Manufacturer of obligations to meet all requirements of the Specifications, of responsibility for correctness of the Drawings, or responsibility to meet original shipping promise on basis of customer's being allowed two weeks for approval.

Receipt of Approval Drawings by the Manufacturer constitutes authorization for manufacture only, based upon corrections found thereon.

5.2 Final Drawings

Contingent upon Approval Drawing review and product manufacture, the Manufacturer shall issue final documentation for the transformer as follows:

5.2.1 One (1) complete set of all Drawings, revised to "as-built" status, released on paper media.

5.2.2 Two (2) complete sets of all Drawings, revised to "as-built" status, released on two (2) separate CD-ROMs, compatible with AutoCAD, Release 2018.

5.2.3 Two (2) copies of applicable instruction books, including one (1) print each of all Drawings representing physical and electric details as furnished per paragraph 5.2.1.

5.2.4 Two (2) copies of certified test reports corresponding to functional performance measurements after final assembly.

All Drawings are to be certified correct and supplied within a reasonable length of time prior to shipment of the equipment. Each set of Drawings and documentation shall include the following information:

5.3 Outline and Assembly Drawings showing size and location of major components and all principal dimensions.

5.4 Control and relay panel front view.

5.5 Details of bushing and bushing terminal connectors.

5.6 Diagram of bushing current transformers, connection, accuracy class, polarity marking, ratios, and bushing orientation.

5.7 Current transformer performance characteristic curves and data for all relay accuracy CTs.

5.8 Details of control housing.

5.9 Panel connection diagram showing exact connection for all components furnished.

5.10 AC and DC elementary circuit diagrams for all relay and control equipment furnished.

5.11 Wiring control and schematic diagrams.

5.12 Instruction books.

5.13 Renewal parts catalog.

5.14 Two (2) copies of certified test reports bound in a binder and an electronic copy.

5.15 In addition to the above, all drawings, manuals, outlines, curves, details, schematics, and assembly pictures shall be loaded on one (1) TB portable hard drive and shipped to owner.

6.0 Shipping of Transformer

6.1 Transformer shall be shipped to the Substation according to the schedule and installed on the concrete pad (or temporary timbers) by the Bidder. The Bidder will be responsible for the supervision of reassembly, including field-testing of the unit.

6.2 The Bidder may choose to use a third-party Contractor to provide equipment and labor to perform dress-out, vacuum oil filling, and field testing of the transformer.

Only qualified and experienced Contractors may be so employed. The Bidder will remain responsible for the outcome and quality of the Contractor’s work. Field work performed by the Contractor shall be performed under the supervision of the Bidder’s Field Service Engineer.

6.3 The prices quoted shall include delivery of the equipment FOB Point of Delivery to the substation site and unloading onto a permanent concrete pad (or temporary arrangement of timbers supplied by the Bidder). The Manufacturer shall include the cost of each unit, complete rigging, and setting in place, utilizing a hydraulic crane of a least twice the capacity of the weight of the transformer. High-voltage bushings, oil, radiators, etc., not installed prior to shipping will be installed by the Manufacturer, subsequent to delivery. The Manufacturer shall provide a Field Service Engineer to supervise the dress-out of removed parts and field testing as outlined in the Specifications. The Bidder shall assume all work will be performed in an active energized station, but on de-energized equipment.

6.4 Coordinated shipment shall be made to reduce storage by the Owner and to facilitate the accumulation of component parts. Small partial shipments at scattered times will not be acceptable. In the event that delays occur, the Manufacturer shall be responsible for all shipping demurrage unless such delays are caused solely by the City.

6.5 Delivery of all items of equipment shall be made at such time as to permit unloading between the hours of 9:00 a.m. and 3:00 p.m., Monday through Thursday, holidays excluded. Ultimate delivery shall be at the discretion of the Owner. All components for the transformer shall be delivered at one time.

6.6 Before shipment, transformer shall be completely assembled to determine that all parts fit properly. Parts removed for shipment shall be marked so as to permit easy identification when reassembling.

6.7 Method of packing and loading shall be such as to protect all parts from dampness, corrosion, breakage, or vibration injury that might reasonably be encountered in transportation, storage, and handling.

6.8 All Loose Shipped Items are to be sent directly to the Owner via Fed-EX or UPS. The shipment of this equipment does not have to coordinate with the shipment or delivery of the transformer itself.

6.9 Release for shipment is to be granted by either the Owner or the Owner's Engineer based upon the manufacturer's compliance with the following:

6.9.1 Three (3) weeks notification of tests, so the Owner may have a representative present for witness of the tests for the transformer.

6.9.2 Furnishing of the requisite number of copies of the Final Drawings as called for in the Specifications. Furnishing of the requisite number of copies of the test reports as called for in the Specifications.

6.9.3 Thirty (30) days notification of tentative shipping schedule and three (3) days notification prior to delivery.

6.9.4 The Manufacturer will also disclose to the Owner, thirty (30) days in advance, the local crane service company selected for off-loading, so the Owner may contract with this same company for removal of the existing transformer at the Substation. A lift plan must be submitted for the transformer according to the schedule. Details of the substation location and existing conditions can be obtained at the mandatory pre-bid meeting. Any M.O.T. permits needed will be included in this bid.

6.10 Impact recorders.

6.10.1 One or more 3-axis impact recorder(s) shall be installed on the transformer for shipment and shall remain on the unit until it is unloaded on the transformer pad. The impact recorder shall be read prior to unloading, at the rail siding prior to unloading if applicable, on the trailer prior to transportation to the site, and after arrival at the site. The information for accessing recorder data and GPS location during transit must be supplied before the transformer leaves the factory.

6.10.2 All impact recorders shall be set for a minimum of 0.5g sensitivity. At least one shall provide GPS location, time, speed of travel, impacts in 3-axis between 10 and 250 Hz (minimum) response. A Shock Log 298 meets these criteria.

6.10.3 Impact recorders shall be shielded to prevent damage during transit and maintained in a fully functional state for the duration of shipment.

6.10.4 The Manufacturer shall state the designed impact limits in the O&M manual or the transportation drawing. In any case, logged impacts over 5g warrant internal inspection and possible return to the factory for repair.

6.11 Transformer shall be shipped by rail or truck, oil-filled (if possible) with the low-voltage bushings installed. Manufacturer shall state method of shipment, if other than specified, and this shall be evaluated when awarding the Contract. The Owner prefers that the transformer be shipped oil-filled with the low-voltage bushings installed. The main tank may be over-filled to account for the volume of oil required for radiators. If shipped by rail, Hydra-Cushion rail car shall be utilized.

If the transformer is not shipped oil-filled, it shall be shipped dry-air-filled and equipped with proper pipe connections for checking and filling under vacuum. The oil shall be shipped by tanker with the unloading facility (pump) furnished. The unloading facility shall have been flushed free of undesirable contaminants by flushing with the same type of oil provided for the transformer. The Manufacturer shall furnish all equipment, labor and supervision required for oil filling, and the Manufacturer shall coordinate timing and arrangements.

6.12 Type of shipment (oil-filled or dry-air-filled) shall be specified in the Proposal.

7.0 Manufacturer's Field Representative

The Manufacturer shall provide (and include in his base quotation) the services of a Field Service Engineer from the time the transformer arrives until assembly and testing at the site is complete. The manufacturer is responsible for all travel time. The duties of the Field Service Engineer shall include supervising installation of component parts removed for shipment, which may include but not be limited to bushings, radiators, lightning arresters, and oil. They shall perform field tests after assembly including (but not limited to) (1.) insulation test, (2.) turns ratio test for all taps, (3.) dielectric tests, (4.) functional testing of alarms and controls, (5.) PCB Oil Testing (before and after site oil filling, if applicable), and (6.) SFRA. The Manufacturer's representative will draw oil sample(s) from the unit and will be responsible for conducting (1.)

ASTM dielectric test and (2.) dissolved gas tests, to establish initial benchmark controls for future transformer maintenance. This oil sample will be drawn after oil is processed in the transformer and settled 24 hours. Reports shall be mailed in duplicate to the Owner and the Owner's Engineer for reference. Additional time required (or credit for time not worked) shall be provided at the per-day rate quoted in the Manufacturer's Proposal. Exceptions taken to the testing performed, as outlined above, may result in rejection of the Bidder's quotation.

8.0 Transformer

The following requirements shall apply to all Bid Schedules except where explicitly noted otherwise.

8.1 Type and Rating

8.1.1 The transformers shall be 60 Hertz, suitable for outdoor service at an altitude less than one kilometer (3300 feet) above sea level.

8.1.2 The transformer shall be considered a Class II, comply with design, and testing requirements for Class II transformers according to the latest IEEE standards.

8.1.3 For all Schedules, the transformer high voltage shall be 67,000 volts delta at 350 kV BIL. The transformer low voltage shall be 13,090/7,560 volts wye, 110 kV BIL. High voltage shall lead low voltage by 30° phase angle. The transformer will be operated with the neutral tied solidly to ground. All windings shall be copper. Windings shall be cylindrical (no exceptions).

8.1.4 The transformers shall be oil-immersed for continuous self-cooled/forced air/forced air cooled operation KNAN/KNAF/KNAF with two (2) stages of fan cooling and shall be furnished complete with oil. Fans shall be included with the transformer; operating voltage for fans shall be 230 volts, single-phase, and shall be thermally protected against overload failure.

8.1.5 Transformer ratings, when loaded in accordance with the latest IEEE Std.

C57.91 "Guide for Loading Oil-Immersed Transformers," shall be as follows:

Cooling Schedule No. 1

Rating (kVA)

55°C rise, KNAN 18,000

55°C rise, KNAN/KNAF 24,000

55°C rise, KNAN/KNAF/KNAF 30,000

65°C rise, KNAN/KNAF/KNAF 33,600

8.1.6 The transformer shall be capable of carrying rated current continuously at five percent (5%) above rated secondary voltage without exceeding an average winding temperature rise of 55°C above a 40°C maximum ambient and 30°C average ambient over twenty-four hours.

8.1.7 The transformer shall be 55/65°C construction where at 55°C rating the average winding temperature rise by resistance shall not exceed 55°C;

hottest-spot winding temperature rise shall not exceed 65°C; suitable for loading in accordance with latest edition IEEE C57.91 "Guide for Loading Oil- Immersed Transformers."

8.1.8 The average winding temperature rise by resistance shall not exceed 65°C;

hottest-spot winding temperature rise shall not exceed 80°C; suitable for loading in accordance with the latest revision of IEEE C57.91 “Guide for Loading Oil-Immersed Transformers.”

8.1.9 The transformer to be provided shall have full capacity, high voltage taps, at rated kVA, and shall be provided as follows:

Schedule No 1

67,000 rated volts

70,350 volts

68,675 volts

67,000 volts

65,325 volts

63,650 volts

8.1.10 A weatherproof external hand-operated tap-changing mechanism shall be provided, suitable for de-energized operation, with one (1) external handle that may be operated from the transformer base level and have provision for locking in any position. An external indicator shall clearly display the tap position that is set.

8.2 Case and Cover

8.2.1 The transformer tank design shall meet the following criteria for location of external equipment and accessory hardware:

a On Schedule 1 the control cabinet housing all low voltage wiring associated with current transformer secondary’s, automatic fan control, alarms, LTC control, etc. shall be located on the side of the tank in Segment 1 as identified by IEEE Std. C57.12.10.

b On Schedule 1 Transformer the LTC compartment shall be located on Segment 2 as identified by IEEE Std. C57.12.10.

c The control cabinet arrangement must provide any substation operator a clear and unobstructed view of the LTC position while standing at the control cabinet operating panel. If the mechanical LTC position indicator does not afford this, it may be accomplished by a remote LTC position indicator, including the indication provided on the display of the voltage regulator controller.

d On Schedule 1 Auxiliary cooling equipment including radiators, fans, and pumps, shall be located on the side of the tank in either Segment 3 or Segment 4 as identified by IEEE Std. C57.12.10. Placement of radiators shall not obstruct the operator's view of any indicating dial or gauge located within Segment 1 of the transformer.

e Final placement of the control cabinetry, LTC compartment, LTC position indicator, radiators, and all other external auxiliary equipment shall be subject to the approval of the Owner or the Owner’s Engineer. Relocation of these components will be required only as necessary to physically comply with standard facilities design for foundations, oil containment systems, and surrounding substation structures.

8.2.2 The main tank and LTC compartment shall be designed and braced for full vacuum and shall be suitable for filling with oil under a vacuum of twenty-eight inches (28") of mercury in the field.

8.2.3 Containing cases shall not leak oil. Welded joints and seams shall be employed wherever practicable.

8.2.4 Main transformer cover shall be welded. Gasketed joints for manhole covers, bushings, and other bolted attachments shall be sealed with a durable and reusable gasket material (ordinary cork or corkprene not approved) and shall be designed to permit their being made oil-tight in reassembly. Mechanical stops shall be provided to prevent crushing (controlled compression).

Machined gasket grooves are preferred; other methods require Owner or Owner’s Engineer approval.

8.2.5 Transformer base shall be suitable for skidding the transformer in a direction parallel to either center line of the tank and shall be capable of supporting the transformer on two (2) pier foundations.

8.2.6 All surfaces of case and covers, both exterior and interior, shall be thoroughly cleaned by means of shot-blasting or by any other equally effective method.

Primer and at least three (3) coats of exterior paint are to be applied. Total paint thickness on the transformer tank and control box shall be 5 mils, minimum. Radiators shall be galvanized; no painted radiators shall be allowed. Interior of tank shall be painted white.

8.2.7 The exterior bolts, nuts, and washers shall be stainless steel bolts with silicon bronze nuts or galvanized. No exposed cadmium-plated or zinc chromate-plated parts will be allowed.

8.2.8 Paint shall be standard light gray epoxy, Munsell 5BG 7.0/0.4 (ANSI No. 70), and certified leadfree.

8.2.9 The bottom of the transformer tank shall not bear on the concrete pad in the finished installation. The bottom shall be primed and painted as described above. Flat-bottom transformers shall be furnished with supporting spacer beams welded to the tank. The dimensions and locations of these beams shall be shown in the manufacturer's Drawings.

8.2.10 Mounting brackets shall be supplied along the transformer tank as necessary to support 4/0 AWG copper grounding conductor from the base of all high-side and low-side surge arresters. The supports must provide for attachment of the grounding conductor from the arresters to the 1/4-inch x 4-inch copper ground bus and to the tank grounding pads located on the front and rear corners of the tank. The grounding conductor shall be 4/0 AWG copper conductor and Hubbell Type "TLS" connectors for attachment of the conductor to the support brackets. All areas of the busbar not in use shall be painted ANSI 70 gray.

8.2.11 The transformer tank shall provide two grounding pads suitable for attachment of NEMA two-hole bronze connectors. The pads shall be located diagonally opposite front and rear corners of the tank and shall be located approximately twelve (12) inches above the transformer base.

8.2.12 A grounding bus (loop configuration) shall be supplied by the manufacturer for each three-phase transformer including attachment to the neutral bushing, the base of all surge arresters and to two tank ground pads.

8.2.13 The tank shall include a 1/4-inch x 4-inch minimum copper ground bus to connect on each diagonal corner to the grounding pads located at the base of the transformer. The ground bus shall be supported along the surfaces of the tank by the necessary quantity of 5 kV style insulators. The ground bus shall be connected to the neutral bushing using a 1200-ampere flexible copper shunt to a 4-hole NEMA bushing terminal pad. The ground bus shall be connected to the NEMA 2-hole grounding pad at the base of the transformer using a 600-ampere flexible copper shunt. The copper ground bus shall provide four-hole NEMA drilling at the lower end for attachment of the substation ground grid. The bus shall also provide two-hole NEMA drilling located appropriately for attachment of bonding conductors from the bases of the transformer-mounted surge arresters. Any part of the busbar not in use shall be painted ANSI 70 gray.

8.2.14 The tank shall be designed such that the base will fit on a foundation nine feet by fourteen feet (9’ x 14’). Bidder shall provide an outline drawing and base dimensions at the bid stage.

8.2.15 High voltage and low voltage bushings shall be on the same centerline (H2 and X2 in line). The outline drawing shall clearly indicate the distance from the tank centerline. The Bidder shall provide the centerline dimensions at the bid stage.

8.3 Impedance

For Schedule1 the transformer impedance at normal base rating shall be 8.5% with IEEE standard tolerances at 67,000 volts to 13,090/7,560 volts.

8.4 Sound Level

The transformer will be designed so that the average sound level will be in accordance with the latest revision of NEMA TP 80050.

8.5 Bushings and Terminals

8.5.1 The three-phase transformer shall be provided with three (3) primary and four (4) secondary cover-type bushings constructed of high strength wet process porcelain.

8.5.2 All high-voltage bushings shall be oil-filled and dimensionally interchangeable between circuit breakers and transformers according to latest revisions of IEEE Std. C57.19.01. The high-voltage bushings shall be condenser type and have provisions for power factor testing. Bushings for all schedules shall be draw lead type, rated as follows:

HV Bushings XV & X0 Bushings

Schedule No. kV Rated kV BIL Amps kV Rated kV BIL Amps

1 69 350 600 15 110 2000

8.5.3 High-voltage bushings shall be PCORE or equivalent, provided with an electro tin-plated bronze terminal connector suitable for flat spade connection with NEMA four-hole drilling, either built into the bushing or furnished as a separate item.

8.5.4 Low-voltage bushings shall be PCORE or equivalent, provided with an electro tin-plated terminal connector for flat spade connection with NEMA four-hole drilling. Low-voltage neutral bushing shall be identical to the corresponding phase bushings.

8.5.5 Low-voltage neutral bushing shall be provided with a connection for flat spade connections with NEMA four-hole drilling and connected to a 1/4" x 4" (minimum) copper bus extending from the terminal to a tank ground pad for direct connection to the station ground system.

8.5.6 The bushings shall be spaced to comply with, or exceed, minimum phase-to-phase and phase-to-ground external clearances between live parts in accordance with IEEE Std. C57.12.00. External phase-to-phase clearances shall not be less than twelve inches (12”). All external bushing mounting hardware shall be stainless steel. All connections shall be suitable for either copper or aluminum connectors.

8.6 Auxiliary Cooling

8.6.1 Cooling equipment shall be furnished in accordance with IEEE standards for transformer self-cooled and forced air-cooled ratings of KNAN/KNAF/KNAF.

8.6.2 Provisions shall be made for cooling radiators to be mounted independently of one another on the transformer, and individually removable from the transformer tank and provided with valves on the transformer tank side so that one cooler may be removed from operation or replaced while the transformer is in service without interfering with the operation of the other coolers (radiators). Radiators shall be designed and braced to withstand all vibration and operating forces. Radiators shall be galvanized. No painted radiators will be allowed.

8.6.3 Radiator mounting flanges on the transformer tank shall each be equipped with valves to permit the removal or replacement of an individual cooling radiator or bank of radiators without loss of either oil or gas above oil, in the transformer tank.

8.6.4 Each cooling radiator shall be equipped with a plug at the top and a drain valve at the bottom of the unit. The quantity of oil in each radiator shall be included on the transformer nameplate.

8.6.5 The cooling fans shall be controlled through the transformer monitor. The transformer monitor shall provide automatic control for the operation of all cooling stages based on the sensing of transformer oil and winding temperature. Each fan shall be driven by an enclosed, waterproof induction motor rated 230 volts ac, single-phase, 60-Hertz. Each motor shall be equipped with thermal overload protection. Each fan shall be dynamically balanced for vibration-free operation. All fan guards shall be galvanized steel and meet OSHA Safety Standards.

8.6.6 The fans shall be mounted independently of each other so that only one fan may be removed from operation or replaced while the transformer is in service without interfering with the operation of the other fans. Control of the fans shall be arranged for automatic control through the transformer monitor.

Complete control and starting equipment shall be provided for each fan.

Means of indication shall be provided to indicate failure of fan power supply fans with indication by the transformer monitor. Fans will be operated by Owner power supply.

8.6.7 All switching equipment shall be enclosed in the transformer control cabinet, complete with all conduit and inner wiring.

8.7 Current Transformers

8.7.1 Each transformer shall be equipped with bushing type current transformers mounted inside the main case on terminals H1, H2, H3, X1, X2, X3, and X0 with all secondary leads brought to identified terminals in a control cabinet mounted for nominal working height from ground level. Terminal blocks shall have short circuiting devices, which will maintain a continuous CT secondary circuit while tap positions are being changed. Each CT shall be connected to a separate six-point terminal block and shall comply with the CT Drawing included with these Specifications.

8.7.2 All bushing type current transformers shall be standard multi-ratio, 5 leads, C800 relaying accuracy, in compliance with IEEE Std. C57.13 except when specified otherwise.

8.7.3 In addition to any CT’s needed for the operation and monitoring described elsewhere in this specification, bushing type current transformers shall be furnished on terminals as follows:

8.7.4 High Voltage Bushings

Provide 2 each (6 total per power transformer) - 600/5 ampere BCT, 2.0 TRF on H1, H2 and H3 bushing with taps for 50, 100, 150, 200, 250, 300, 400, 450, 500, and 600 to 5 ampere ratios.

8.7.5 Low Voltage Bushings

Provide 2 each (6 total per power transformer) - 2000/5 ampere BCT, 2.0 RTF on X1, X2 and X3 bushing with taps for 300, 400, 500, 800, 1100, 1200, 1500, 1600, and 2000 to 5 ampere ratios.

Provide 2 each (2 per power transformer) - 2000/5 ampere BCT, 2.0 TRF, with C800 relaying accuracy in the neutral of the secondary (X0) with taps for 300, 400, 500, 800, 1100, 1200, 1500, 1600, and 2000 to 5 ampere ratios.

8.7.6 If the current transformers are mounted in a removable current transformer adapter, the current transformer shall be shipped in the main transformer mounted in the adapters. The current transformer secondary leads shall be permanently connected to the terminal blocks in the Control Cabinet. No splicing of secondary current transformer leads shall be required after delivery to the Owner. Marking of leads and locations of shorting-type terminal boards control panel shall be in accordance with the attachment in the Appendices.

8.7.7 A CT metal diagram instruction plate shall be provided. Ratios, accuracy class, and thermal rating factor of the bushing current transformer shall be shown on the nameplate.

8.8 Lightning Arresters

Lightning arresters shall be of the station class type, transformer mounted for the high- and low-voltage side on each phase of the three-phase transformer and shall be rated:

Arrester Ratings

System Voltage Duty Cycle (RMS) Metal Oxide (MCOV)

69 kV, 350 kV BIL 72kV 57kV

13.09/7.56 kV, 110 kV BIL 10 kV 8.40 kV

8.8.1 Metal oxide lightning arresters are rated either in terms of maximum continuous operating voltage (MCOV) or by the conventional arrester rating (duty cycle), which they replace. MCOV ratings are assumed here for metal oxide arresters. However, metal oxide arresters, which are given conventional ratings (duty cycle), may be furnished if the MCOV equivalent ratings are as specified here.

8.8.2 The lightning arresters shall be located with relation to one another and the bushings to comply with, or exceed, minimum phase-to-phase and phase-to-ground clearances between live parts in accordance with the latest version of IEEE Std. C57.12.00.

8.8.3 The lightning arresters shall be provided with connections to the line-side bushing terminals with connections equivalent to the full capacity of the transformer. Ground conductors equivalent at minimum to 1/4" x 4" copper bus shall also be furnished and carried to the transformer ground pads with loop configuration as shown in the Appendices.

8.8.4 The body of the lightning arresters shall be polymer, light gray, ANSI No. 70.

8.8.5 The lightning arresters shall comply with IEEE Std. C62.11.

8.9 Control Cabinet

8.9.1 A weatherproof NEMA 3R control cabinet shall be furnished enclosing control circuits, signal circuits, protective relays, individual transformer alarm indicators, a 120-volt AC convenience duplex receptacle, a 40-watt equivalent

LED light with guard, dual door switches, and a suitable 230-volt, 60 Hertz heater with double pole terminal circuit breaker.

8.9.2 The control cabinet and internal wiring shall comply with IEEE Std. C57.148.

8.9.3 The cabinet shall be furnished with swing door(s) complete weather stripping, handle, three-point latching mechanism and provisions for padlocking. The door(s) shall be equipped with provisions to fix the swing in the open position. A collapsible laptop shelf shall be located on the inside of either door such as a Hoffman Shelf AASHLF-1818. Mount shelf so that working height is no greater than 4’ from bottom of the transformer.

8.9.4 All wire into the control cabinet shall have 600-volt flame-resistant, moisture-proof insulation and shall be enclosed in rigid metallic conduit. All conductors into the control cabinet shall terminate on a clearly marked and properly identified terminal board. Terminal boards for CT leads shall be shorting type, all terminal boards shall be equipped with non-magnetic split type lock washers and ring type compression lugs.

8.9.5 All cabinets attached to the transformer shall be solidly grounded to the transformer tank.

8.9.6 The control cabinet heater shall be equipped with guards and thermostatically controlled through the transformer monitor, so that the guard temperature cannot exceed 120°F. The 240-volt electric terminals at the heater shall be covered.

8.9.7 All IED’s need to be accessible for viewing and operation without the use of stepladders. All IED viewing components (e.g., displays and targets) and control components (e.g., pushbuttons) shall be located between 3’-11” and 5’-0” from the bottom of the transformer.

8.10 Wiring

8.10.1 All power wiring shall be made with #10 AWG stranded tinned copper wire or larger sized wire. The primary insulation jacket of all wiring shall be 600-volt, 90°C, water, oil, and flame resistant. Control wiring shall be 45 or 65 mil stranded cable and not smaller in size than #14 AWG tinned copper wire, with the exception that wiring to alarm auxiliary relays and indicate lights may be smaller in size. SIS control wire is recommended. All current transformer leads are to be #10 AWG stranded tinned copper or larger.

a Power wiring shall be sized as required in accordance with the National Electrical Code.

b All connections for wiring shall be made using silicon bronze, split-type lock washers.

c All wires shall be identified at each end with legible permanent labels.

d Wiring connections between fixed and hinged sections shall be minimum 41-stranded wire.

e Seven-stranded control wire is not acceptable.

f All terminal connections for conductor sizes #10 AWG in size and smaller shall be made with full-ring tongue compression-type lungs. Lugs shall be Burndy Type YAV, or approved equivalent. Spade-type terminals or slip-on connectors are not acceptable.

g All terminal connections for conductors sizes #2 AWG through #9 AWG shall be made with Burndy Type YAV or approved equivalent.

h All terminal connections for conductor sizes larger than #2 AWG shall be made with two-hole, long-barrel, double-indent, crimp-type lugs: Burndy Hylug Type YA or approved equivalent. (Single-hole lugs may be used only where necessary).

8.10.2 Grommets shall be provided for all openings in metal barriers used for wiring.

8.10.3 Uninsulated exposed conductor or terminal lug shall not extend beyond the sides of the terminal block or its insulating barriers.

8.10.4 All leads for multi-ratio current transformers shall be wired to terminal blocks in the control cabinet. If junction boxes are required in wiring between the current transformers and control cabinet, terminal blocks shall be used for wiring connections. In-line-type disconnecting terminals such as American Petroleum Institute (API). No. 32488 or Burndy No. YZ10 will not be acceptable.

8.10.5 If accidental short circuiting of certain wires can result in malfunction of equipment, these wires shall not be terminated on adjacent terminal block points.

8.10.6 No more than two (2) wires per terminal point is allowed.

8.11 Terminal Blocks and Fuse holders

8.11.1 Molded-type terminal blocks, rated 600 volts and 30 amperes, for all external control connections, shall be provided. Terminal blocks with self-contained pressure-type connectors are not acceptable.

8.11.2 Marathon 1600 DJ Series or General Electric Type EB-25 terminal blocks or equivalent shall be provided furnished with white marking strips for identification of terminal wires for all connections except current transformers. The terminals shall be identified with legible permanent markings.

8.11.3 Marathon 1600 SC or General Electric Type EB-27 terminal blocks or equivalent shall be provided for current transformer leads with at least three

(3) shorting screws per terminal block. A separate short-circuit-type terminal block shall be provided for each set of current transformer leads. A States terminal block is not an acceptable substitution.

8.11.4 No covers blocking visible connection points of terminal blocks will be allowed.

8.11.5 One three-pole terminal block sized for #6 to #2/0 AWG wire for Owner's single-phase, three-wire, 120/240 volt, control power leads shall be furnished.

8.11.6 A minimum of 15 percent spare (but not less than 12 points) terminal points shall be provided in the control cabinet. These terminal points shall be furnished with all screws and lock washers.

8.11.7 Fuse holders shall be finger safe fuse holders, Ferraz Shawmut, US3J Series for 30A and US6J series for 60A, Mersen Ultra-safe modular 600 V for class J fuses.

8.12 Alarm Annunciator and Relays

See Section 10.0 for Transformer Monitor specifics.

8.12.1 The transformer shall be equipped with various alarms and an alarm annunciator to provide visual indication of abnormal conditions as designated herein. Each alarm shall be in the form of a normally open contact wired to terminal blocks in the transformer control cabinet via paired wire leads. The alarm annunciator shall be flush-mounted on the control panel within the transformer control cabinet at a height no higher than 4’-5” from transformer bottom and shall be wired to the designated alarms brought to the terminal blocks.

8.12.2 The annunciator shall provide an HMI for alarm and information interrogation. The annunciator shall latch in the "on" state for each alarm detected until manually reset.

8.12.3 The annunciator shall provide dry, normally open contacts so that summary alarms may be remotely annunciated on alarm equipment within the Owner's substation. The auxiliary contacts shall be wired to terminal blocks in the transformer control cabinet for use by the Owner. The annunciator shall provide a minimum of fourteen (14) alarm input points and be for use at 125 Vdc. The annunciator shall be a SEL-2533 manufactured by Schweitzer Engineering Laboratories, model 253301233A0A2X1

8.12.4 The following alarms are to be wired to the Annunciator.

a Transformer High Oil Temperature from gauge (26Q) b Transformer High Winding Temperature from gauge (49T) c Transformer Liquid Low/Alarm Level (71Q) d LTC Liquid Low/Alarm Level (71Q-LTC) e Transformer Pressure Relief (63PR) f Transformer Undervoltage (auxiliary power) (27-1) g Transformer Gas System - High Tank Pressure (63G-HI) h Transformer Gas System - Low Tank Pressure (63G-LO) i Transformer Gas System - Low Supply (63G) j Transformer Gas System - Temperature Alarm (63T) k LTC Raise Limit (16R) l LTC Lower Limit (16L) m LTC Trouble (e.g., vacuum switch failure)

8.13 Fault Pressure Relay

8.13.1 A fault pressure relay shall be provided on the transformer tank for the detection of rapid rates of positive increase in transformer tank pressure. The fault pressure relay circuit to be provided shall include the necessary auxiliary relays and circuitry that will provide a visual indication (relay target) at the transformer upon fault pressure detection. The fault pressure relaying shall also provide tripping contacts for the remote initiation of transformer lockout to the Owner. The fault pressure relaying shall also provide contacts for the transformer monitor.

8.13.2 Contacts supplied for alarms and initiation of station lockout shall be dry, normally open, latching operation with manual hand reset. Contacts shall be suitable for use at 125 volts dc. Current shall be limited to 20 amperes resistive.

8.13.3 Contact leads for alarm and trip shall be brought to a terminal block for field connection by the Owner.

8.13.4 All relay coils associated with fault pressure detection shall be driven by the Owner's 125 volts dc power supply.

8.13.5 The fault pressure detection relay shall be Qualitrol 900 mounted in the oil space. The unit shall have a 2” ball valve to isolate the unit from the main tank in support of maintenance. Auxiliary target relays and latched tripping relays shall be a Qualitrol 909 series. All associated auxiliary relays shall be mounted within the transformer control cabinet.

8.14 Positive Pressure System

The transformer shall be equipped with a positive pressurizing system, utilizing nitrogen gas to protect the transformer oil in the main tank from oxidation and moisture absorption. The system shall consist of a nitrogen gas supply (cylinder) complete with supply pressure gauge, multi-stage pressure reduction assembly and associated piping and valves to control the flow of gas to and from the tank. The system shall provide alarms for low gas supply, high tank pressure, and low tank pressure conditions. The nitrogen supply cylinder, supply pressure gauge, and multi-stage pressure reduction assembly shall be housed in a weatherproof enclosure, mounted on the transformer tank, preferably on the 1 side.

The system shall maintain transformer tank pressure at 0.5-psi minimum and 5.0 psi maximum, with appropriate fill and bleed-off regulation. Gas system alarms shall actuate whenever pressure falls below 0 (zero) psi or rises above 5.5 psi or whenever supply pressure falls below 125 psi.

The gas cylinder system shall include a second supply outlet for connection to a second transformer at the Owners substation include a shut-off valve for this outlet and Inert Air System(mini).

8.15 Transformer Oil/Oil Inhibitor and UL Approved

8.15.1 Insulating oil for the main tank, oil-filled bushings, shall be non-toxic, fire-resistant, bio-based natural ester dielectric fluid. The insulating fluid shall be Factory Mutual, UL classified “Envirotemp FR3” as manufacturing by Cargill, Inc.

8.15.2 All transformer oil supplied shall have antioxidant oil inhibitor added. All performance enhancing additives shall be food-grade compatible with the insulating oil as outlined in 8.15.1. Manufacturer shall provide associated PCB certification and nameplate as per General Conditions. Manufacturer shall provide associated PCB certification and nameplate as per General

Conditions.

8.16 Load Tap Changing for Transformer

The Load Tap Changer shall be a Reinhausen RMV-II with the TAPCON 250 controller.

The transformer to be furnished shall be provided with load tap changing equipment in addition to all provisions described heretofore for all Schedules. The tap changing equipment for the transformer must be capable of parallel operation with a second LTC-equipped transformer. Method of parallel operation to be in accordance with IEEE Std. C57.153 standard circulating current method or as agreed to by the Owner. The second LTC-equipped transformer may utilize the traditional “analog” scheme.

8.16.1 The load tap changing equipment shall be furnished to provide the characteristics and features outlined herein. The equipment shall be designed to withstand full-voltage short-circuit conditions and also to initiate and complete any desired tap change under full-voltage short-circuit conditions.

The manufacturer will state in his Proposal the guaranteed minimum number of maintenance-free LTC operations of the unit. Units guaranteeing less than 500,000 operations before maintenance will be evaluated as unresponsive.

8.16.2 The load tap changing equipment covered by the Specifications and all tests applied thereto shall conform to the latest standards of the IEEE, NEMA, NESC, and ANSI.

8.16.3 The LTC circuit and components shall be arranged so that with a constant voltage held on any high voltage rated kVA tap, the tap changer will operate to provide ± voltage regulation of the low-voltage transformer terminals in sixteen (16) 5/8% steps above and below rated voltage (33 total tap positions). For voltages above rated position, the transformer will deliver rated kVA. For voltages below rated position, the transformer will deliver at its terminals a current equal to the current at rated kVA and rated voltage.

8.16.4 The LTC taps may be located wherever necessary in the windings or circuits to produce the desired result. A series transformer may be used if necessary.

The final location of the LTC compartment shall be subject to the approval of the City or the City's Engineer.

8.16.5 The main transformer tank shall include:

a Series transformer (if required by design).

b Preventive reactor. (This may be omitted if the tap changer is a resistance-bridging device).

c Current transformers for line-drop compensator and parallel operation as needed. Primary current determined by rating and design. Secondary current 0.2 amps. A secondary reduction transformer may be utilized in the control cabinet.

d Hot spot temperature indicator.

8.16.6 The separate oil-filled compartment shall utilize a free breathing Reinhausen MTRAB DB 100 unit. The compartment shall include:

a Mechanical stops at limits of switch movement.

b Gauge indicating compartment seal and/or positive pressure.

c Liquid-level gauge similar to gauge used on transformer tanks.

d Drain and filling valve: one-inch (1") screw-end globe valve.

e Resealable pressure relieve device.

f RTD for temperature monitoring.

8.16.7 The separate tap-changer motor control compartment shall include:

a Drive motor 120 volts to be supplied from station power supply.

b Provision for manual operation with electrical interlock with drive motor.

c Position indicator equipped with electrically resettable drag hands and with electrical limit switches. The position indicator shall be graduated for each step position (16L-0-16R) and shall be located for unobstructed visibility to any personnel attending the main control compartment…