Padmounted Tamper-Resistant Single Phase Distributions Transformer

SPECIFICATION

FOR

PADMOUNTED TAMPER-RESISTANT SINGLE PHASE DISTRIBUTIONS TRANSFORMER

1.0 SCOPE

1.1The ABB Inc. Padmounted Tamper-Resistant transformer design is the basis for this specification

1.2This specification together with the applicable Transformer Data Sheet provides the technical requirements for the design, manufacture and testing of padmounted tamper-resistant transformers.

1.3This specification covers only the general requirements of the transformer.

1.4The preferred electrical characteristics and mechanical features of single-phase dead front, mineral-oil immersed, self-cooled, pad-mounted, compartmental-type distributions transformers have the following ranges:

10 through 167 kVA

65 degree C average winding rise

60 hertz

HV: 4160GY/2400 through 34500GY/19920V

HV Bil: 60, 75, 95, 125, 150 kV

LV: 240/120, 480/240, 277 V.

1.5The specific requirements are stated in detail on the Transformer Data Sheet.

2.0 CODES AND STANDARDS

2.1All codes and standards referenced in this specification shall be those in effect at the time of Purchase Order award. Deviations from this specification and referenced codes and standards shall be obtained in writing from Buyer.

2.1.1Institute of Electrical and Electronic Engineers (IEEE)

C57.12.00

C57.12.25

C57.12.28

C57.12.29

C57.12.70

C57.12.80

C57.12.90

C57.12.91

2.1.2National Electrical Manufacturers Association (NEMA)

2.1.3American Society of Testing and Materials (ASTM)

3.0QUALITY ASSURANCE

3.1The manufacturer shall have specialized in the design, manufacture and assembly of liquid filled padmounted tamper-resistant transformers for a minimum of 10 years.

3.2The manufacturer shall have a well documented quality assurance program, which includes procedures for all activities in order entry, design, material procurement, manufacturing processes, testing, shipping and post shipment product follow.

3.3The manufacturer’s test floor shall have a documented calibration program. All equipment shall receive regular calibrations. Calibration standards shall be traceable to National Bureau of Standards.

3.4The transformers shall be manufactured by a company which is certified to ISO 9001: 2000. A copy of the certificate of Compliance shall be made available to the Buyer upon request.

4.0TRANSFORMER TECHNICAL REQUIREMENT

4.1Winding Characteristics

4.1.1All windings and internal connections shall be copper or aluminum. The coil insulating paper shall be thermally upgraded and shall have a thermosetting adhesive on both sides to assure coil bonding.

4.1.2The windings shall be tightly wound utilizing tension devices to place the conductor into the coils.

4.1.3For optimum dielectric and mechanical strength, epoxy coated insulation shall be placed between each layer in the winding.

4.1.4Sheet conductor shall be used in secondary winding to minimize vertical short circuit forces.

4.1.5The transformer shall be designed and constructed to withstand the external short-circuits, as defined by IEEE C57. 12.00.

4.1.6Evidence of compliance to these short-circuit requirements as required in C57.12.00 and C57.12.90 shall be submitted to the Buyer upon request.

4.1.7The transformer design shall be capable of operating aboverated voltage or below rated frequency in accordance with IEEE C57.12.00.

4.1.8The impedance shall be as specified on the Transformer Data Sheet. IEEE tolerance shall apply.

4.2Sound Level

4.2.1The padmounted tamper-resistant transformer shall be designed and constructed to minimize the audible noise generated with the transformer energized at rated voltage.

4.3HV Compartment

4.3.1The transformer shall be furnished with a high voltage compartment located on the left. The high voltage compartment shall be furnished with universal bushing wells. The HV bushing wells shall be externally clamped and removable. A parking stand between the bushing wells shall be provided for attachment of bushing accessories.

4.4LV Compartment

4.4.1The transformer shall be furnished with a low voltage compartment and shall house the LV connections in the form of copper studs with contact nuts. Rotatable spades are optional.

4.5Cabinet

4.5.1Tamper resistance shall be enhanced by continuous steel baffling on all edges of the hood and sill without the use of welded or bolted on parts.

4.6Core

4.6.1The core shall be clamped and braced to resist distortion caused by short-circuit stresses or transportation handling and to prevent the shifting of core laminations.

4.6.2The core shall be constructed of high-grade, grain oriented, silicon steel laminations, with high magnetic permeability. Core construction shall include step-lap mitered joints to keep core losses, excitation current and noise level at a minimum.

4.7Insulating Fluid And Preservation System

4.7.1The fluid preservation system shall be a sealed tank type.

4.7.2The insulating fluid shall be as specified on the Transformer Data Sheet.

4.7.3The transformer insulating fluid shall be certified to contain no detectable PCB’s (<1 PPM) at the time of shipment and the nameplate shall be so labeled. Certification shall also beprovided that the transformer and components have not been contaminated with PCB’s prior to shipment.

4.7.4The transformer insulating fluid shall meet or exceed the requirements of the appropriate IEEE and ASTM fluid Standards. The transformer fluid shall be tested for dielectric breakdown and moisture content during manufacturing.

4.8Tank Design

4.8.1The transformer tank shall be designed to withstand, without permanent deformation, with operating pressures per IEEE C57.12-25.

4.8.2Tanks shall be constructed of heavy gauge steel with welded seams.

4.8.3Tank design shall include sufficient expansion volume to allow operation under specified load conditions.

4.8.4The main cover shall be welded onto the tank.

4.8.5The transformer baseshall be suitable for rolling or skidding in the direction of either tank base centerline.

4.8.6Stainless steel 5/8” –11 lifting bosses shall be provided at two or four points on the tank depending on size and designed to provide a minimum safety factor of 5.

4.8.7Most oil restraining welds shall be robotically applied to severely limit the incidence of oil leaks and corrosion.

4.8.8Tanks shall have rounded corners on the back side to limit possible injuries.

4.8.9Tank tops shall be domed to augment water drainage and limit possible corrosion.

4.9Gaskets

4.9.1The gaskets shall be compatible for the insulating fluid in the transformer tank.

4.9.2Metal surfaces to which gaskets are applied shall be smooth, and shall have sufficient rigidity to assure proper compression of the gaskets.

4.10Cooling System

4.10.1The transformer shall be self-cooled.

4.10.2Coolers (when required) shall be rigidly welded to the tank wall.

4.11Grounding Provisions

4.11.1All non-energized metallic components of the transformer shall be grounded.

4.11.2Tank grounding provisions shall consist of two ground pads, ½” –13 NC tapped hole, 7/16” deep welded to the tank wall.

4.11.3Ground pads shall be per IEEE standards.

4.12Nameplates

4.12.1Transformer shall be furnished with a non-corrosive diagrammatic nameplate, permanently attached with non-corrosive hardware. The diagrammatic nameplate shall include the name of the manufacturer of the equipment as well as the location where the transformer was manufactured and tested. In addition, the transformer manufacturer and location of manufacture is to be supplied at the time of quotation.

4.12.2The nameplate shall contain all connection and rating information in accordance with IEEE C57.12.00 nameplate A, plus the type and quantity of fluid, and the date of manufacture.

4.12.3A non-corrosive dial plate located under the operating handle of the de-energized tap changer, when required, shall be provided which states the following: “De-energized operation only.”

4.13Exterior Finish

The transformer painting system shall be in compliance with IEEE C57.12.28. The finish shall be Bell Telephone Green, Munsell No. 7GY/3.2/1.5.

5.0TEST

5.1Testing

5.1.1Each transformer shall receive all standard routine tests as required by IEEE C57.12.00 and performed as specified by IEEE C57.12.90.

5.1.2Short Circuit withstand capability shall be verified by full short circuit tests on similar or larger units in accordance with the latest revision of IEEE C57.12.00 and IEEE C57.12.90. Short Circuit withstand verification shall be submitted to the purchaser, upon request, prior to shipment of the transformers.

5.1.3The test facility used to perform loss tests shall utilize test equipment with calibration traceable to NIST or an approved equal 3rd party laboratory.

5.1.4A certified test report shall be submitted and shall contain the test data for each transformer serial number manufactured. The certified test report shall as a minimum contain the data as specified in IEEE C57.12.90.

6.0FEATURES

6.1The transformer shall beequipped with a complete set of standard features, including.

6.1.1A flip-top hood with heavy duty 3/8” removable stainless steel hinge pins

6.1.2A recessed locking assembly with padlock provisions and penta-head locking bolt for tamper-resistant operation. (A hex-head bolt is available.)

6.1.3Oil level/fill plug.

6.1.4Self-actuating pressure relief device.

6.1.5Oil drain plug.

6.1.6A removable front sill that latches with the hood and is bolted to the front of the tank.

6.1.7Cabinet compartment security shall comply with the locking and tamper test provisions of IEEE C57.12.28.

6.1.8NEMA safety labels

6.1.9High voltage universal well bushings

6.1.10Low voltage stud bushings

6.2Optional features, which can be indicated under “other special instructions” on the Transformer Data Sheet:

6.2.1Overcurrent protection

Internal Protective Link to remove the transformer from the system in the event of an internal fault.

Oil-immersed bayonet-type fuse (fault or current sensing) in series with an isolation link. A drip device shall be provided if this means of protection is used.

Partial range current limiting fuse mounted under oil to the tank. Can be supplied in conjunction with a bayonet expulsion fuse or weak link fuse.

6.2.2Switching

Externally operated tap changer

Externally operated dual voltage switch

Externally operated loadbreak oil rotary (LBOR) switch.

6.2.3Primary Connections

Universal bushing wells (with removable studs)

Inserts

Integral (one-piece) loadbreak bushings

6.2.4Secondary Connections

Four, six or eight-hole NEMA type, tin-plated copper alloy spades.

Four-hole or seven-hole in line, tin-plated copper alloy spades.

6.2.5Other options

Cleats for anchoring sill to pad.

Stainless steel (304L or 400 CB) tank and/or cabinet

Stainless steel (400 CB) mini-skirt welded to the base of the carbon steel tank.

Conduit hole (not available with the composite hood).

Bayonet drip cup.

7.0DOCUMENTATION

7.1Nameplate drawing

7.1.1A nameplate drawing showing required IEEE information shall be provided.

7.2Installation, Operating, and Maintenance Instructions

7.2.1The seller shall provide an instruction, operating and maintenance manual covering all equipment furnished.

8.0PARTS

8.1The Seller shall provide a renewal parts list to the Buyer upon request.

Single Phase

Padmount Transformer Data Sheet: (Circled items are specific to this project.)

Customer Name: ______Project/Quote Number: ______Item No.___

1 Phase KVA Rating:10 15 25 37.5 50 100 167 OTHER (______)

Frequency:60 HZ (std.)50 HZ (optional)

Impedance Range:Min.______Max.______

Temperature Rise (Over 30°C ambient): 65C (Std.)55C (optional)

Primary (coil) Voltage: (kV)______

Primary Connection:Grounded WyeDelta

Feed:LoopRadial

Primary Taps:None (Std.) 2-2 ½ -4 BN+4 AN OTHER(______)

Primary BIL: (kV)607595125150OTHER (______)

Primary Termination:Dead Front-Wells onlyWells w/removable studsInserts

Secondary Voltage: 240/120 (3-wire)120/240 (4-wire)277 (2-wire)

480/240 (3-wire)240/480 (4-wire)

Secondary Connection: DeltaWye

Secondary Termination: Studs only (Std.)4-hole NEMA spades4-hole in line spades

6-hole NEMA spades7-hole in-line spades8-hole NEMA spades

Stainless Steel:400 series304L

HoodSillTankTank front/bottomTank Mini-skirt (400 series only)

Composite HoodYesNo

Insulating Fluid:Mineral oilBIOTEMPBeta

Application Location:Outdoor OTHER (______)

Sound Level: Special ______

Other Special Instructions:______

______

______

______1LUJ000001-SPE

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