SPECIFICATION
FOR
INTERCONNECTING
POWER AUTO-TRANSFORMERS

TABLE OF CONTENTS
Page
PART I - GENERAL 2
1.1 SCOPE 2
1.2 QUALITY CONTROL 2
1.3 SUBMITTALS 3
PART 2 - PRODUCT 3
2.1 SERVICE REQUIREMENTS 3
2.2 RATINGS 3
2.3 DESIGN REQUIREMENTS 3
2.4 ACCESSORIES 6
PART 3 - EXECUTION 8
3.1 INSPECTION AND TESTING 8
3.2 SHIPPING AND HANDLING 9
3.3 PERFORMANCE 9
APPENDICES
A Deleted
B Form of Proposal for Interconnecting Power Auto-Transformers (5 sheets)
C Interconnecting Power Auto-Transformers Data Sheets (5 sheets)
D Transformer Nameplate No. 31017 of Transformer to be replaced
1

SPECIFICATION
FOR
INTERCONNECTING POWER AUTO-TRANSFORMERS
PART I - GENERAL
1.1 SCOPE
1.1.1 Items Included
1.1.1.1 Design, fabricate, test, furnish and deliver an Interconnecting Power Auto-
Transformer, including insulating oil and accessories as completely
assembled as possible within shipping and handling limitations in
accordance with this specification including all data sheets.
1.1.1.2 ONAN/ONAF 65°C rise, 2 winding Interconnecting Power Auto-Transformers.
Transformer configuration YNa0[d11] with high side voltages of 132 kV
and 154 kV, and low side voltage of 33 kV. Transformer ONAF MVA
ratings are 100/100/50 MVA. %Z is 0.395/9.51. Refer to appendix D for
equivalent requested nameplate.
1.2 QUALITY CONTROL
1.2.1 Items and Services
1.2.1.1 Control the quality of items and services to meet the requirements of this
specification, the applicable sections of the codes and standards listed in
Section 1.2.2, and all other contract documents.
1.2.2 Applicable Codes and Standards
1.2.2.1 Design, manufacture and test the specified equipment in accordance with
the applicable sections of the following standards, or alternatively
equivalent applicable internationally recognized standards, including
standards referenced in them, which are in effect at the time of
CONTRACT award.
IEC 60076 Distribution, Power & Regulating Transformers
ANSI/ASTM Specifications for Mineral Insulating Oil used in
D3487 Electrical Apparatus
NEMA ICS6 Enclosures for Industrial Controls and Systems
2

1.2.2.2 1.2.2.3 Identify in writing any conflicts between the referenced documents for
resolution. In general, when resolving conflicts, the following order of
precedence shall apply:
Transformer nameplate (Appendix D)
Transformer Data Sheets (Appendix C)
This Specification
Referenced Standards
CONTRACTOR shall have a Quality Management System that complies
with the applicable requirements of ISO 9002:1994 or equivalent National
or International Standard (e.g. - BS 5750 Part 2, EN 29002 or ANSI/ASQC
Q9002). Quality management shall include subcontractors and suppliers.
1.3 SUBMITTALS
1.3.1 Complete design drawings are required to be submitted with delivery of
transformer.
PART 2 - PRODUCT
2.1 SERVICE REQUIREMENTS
2.1.1 The transformer shall be suitable for outdoor installation.
2.1.2 The transformer shall be suitable for use as stated in Appendix C and D.
2.2 RATINGS
2.2.1 The transformer ratings, technical and engineering data shall be as listed in
Appendix C and D.
2.3 DESIGN REQUIREMENTS
2.3.1 Tank and Base
2.3.1.1 Furnish tanks with welded construction with continuous welding on tank
supports.
2.3.1.2 Furnish each transformer base with seismic rated anchor.
2.3.2 Lifting, Moving and Jacking Facilities
2.3.2.1 Furnish lifting, moving and jacking facilities in accordance with IEC
standards.
3

2.3.3 Finish
2.3.3.1 Clean, prime and finish paint the equipment in accordance with
CONTRACTOR'S standard procedure for outdoor service. Exterior finish
color shall be CONTRACTOR'S standard.
2.3.4 Bushings and Terminations
2.3.4.1 Provide standard bushing and terminal markings unless otherwise
specified in Appendix C and D.
2.3.4.2 Furnish bushings to meet the applicable requirements of IEC, extra high
creepage.
2.3.4.3 Furnish low and high voltage terminals suitable for terminations as
specified in Appendix C and D.
2.3.5 Oil
2.3.5.1 Furnish transformer with oil in accordance with ANSI/ASTM - D3487 Type I
unless.
2.3.5.2 If possible, transformer shall be factory filled with insulating liquid and
sealed prior to shipment provided the jobsite and transportation facilities
can handle the additional weight of the insulating liquid. For transformers
which will be field filled, 110% of the required oil volume will be supplied in
drums. The transformer shall be certified and labeled as not containing
polychlorinated biphenyl (PCB) in accordance with EPA guidelines (less
than 1 PPM).
2.3.6 Oil Preservation System
2.3.6.1 Furnish CONTRACTOR'S standard sealed tank, inert gas pressure, or
conservator/diaphragm oil preservation system with all accessories for
rating and voltage class specified in the Appendix C.
2.3.7 Cooling System
2.3.7.1 Furnish the type of cooling as specified in the Appendix C.
2.3.7.2 Furnish standard control logic for operating fans and pumps.
2.3.8 Tap Changers
2.3.8.1 Furnish transformer with on-load tap changers in accordance with IEC as
specified in Appendix C and D.
4

2.3.9 Control Cabinet
2.3.9.1 Furnish a control cabinet for housing all the control and power supply
equipment located in either segment one, two, or four as designated by
IEC Figure 1, unless otherwise specified in Appendix C.
2.3.9.2 Construct control cabinet that meets the requirements of NEMA Standard
ICS6 with blank bottom removable, gasketed plate for conduit entrances.
Provide padlocking facilities.
2.3.9.3 Furnish cabinet requiring ventilation with dust filters over each intake and
exhaust opening.
2.3.9.4 Furnish NEMA 4 type enclosure designed to prevent accumulation of
contaminants along and above closed access door, unless otherwise
specified in Appendix C.
2.3.9.5 Furnish thermostatically controlled space heaters rated for use on a 220V
ac single phase circuit. Provide adequate lighting and a GFI protected 20
amp receptacle.
2.3.10 Auxiliary Power and Control Supply
2.3.10.1 Furnish equipment including automatic transfer capability from a primary to
a backup source suitable for use with CONTRACTOR’S 400V three-phase
50Hz power supply unless otherwise specified in Appendix C.
2.3.10.2 Furnish dc equipment and relays suitable for use with CONTRACTOR’S
nominally rated 110V dc system. All devices must be suitable for
continuous operation within a range of 90V to 130V dc.
2.3.10.3 Furnish ac equipment nominally rated 220Vac suitable for continuous
operation within a range of 90 to 110 percent of rated voltage. Furnish
suitable 400-220V control power transformers as required.
2.3.11 Alarms
2.3.11.1 As a minimum, furnish the following:
a. Oil low level
b. Top oil high temperature
c. Winding hot spot high temperature
d. Pressure relief device operation
e. Sudden or fault pressure relay trip
f. Primary to backup power supply transfer
5

2.3.11.2 Furnish 250V dc rated single pole double throw alarm switches.
2.3.11.3 Furnish all switch contact terminals wired to control cabinet terminal blocks.
2.3.12 Wiring
2.3.12.1 Completely wire all control, auxiliary power, and alarm circuits using
stranded copper conductors with fire retardant type SIS conductors.
2.3.12.2 Use single-conductor No. 14 AWG minimum, 600V wire for control circuits,
single-conductor No. 10 AWG minimum, 600V wire for current transformer
(CT) secondary leads, and shielded No. 16 AWG minimum, for low-level
signals. Metric equivalent cable sizes may be used.
2.3.12.3 Provide extra flexible wiring over door hinges or other locations where
leads may be subjected to flexing.
2.3.12.4 Route wiring so that devices may be removed or serviced without
disturbing wiring. Form wire bundles without sharp bends and provide
adequate support.
2.3.12.5 Wire all shields and every contact of each device, including spare contacts,
to terminal blocks for external connections.
2.3.12.6 Do not connect more than two wires to any single terminal point. Splicing
of conductor is not allowed.
2.3.12.7 Terminate all wiring on one side of terminal blocks, leaving the other side
entirely free for field cable connections. External wiring shall be arranged
for one wire to each terminal point. Use shorting type terminal blocks for
CT wiring.
2.3.12.8 Identify internal wiring with CONTRACTOR'S wire number at each end of
each wire by a plastic sleeve or similar permanent-type marker.
2.3.12.9 Run wiring from accessory devices in rigid metallic raceway, except for
short lengths of cable from fans, pumps, etc. which may be in flexible steel
conduit to connect to the rigid conduit system. Provide suitable ground
conductor.
2.3.12.10 As an option to the above requirements, CONTRACTOR may propose use
of multi-conductor armored cable in lieu of single conductor wire in conduit.
2.4 ACCESSORIES
6

2.4.1 Standard Accessories
2.4.1.1 Furnish all standard accessories in accordance with IEC. Provide all
accessory devices that have a monitoring function with contacts for
alarming (see also section 2.3.10). As a minimum, the following
accessories should be included:
a. Neutral ground resistors, when shown on the data sheets, are to have
stainless steel grid material.
b. Winding (hottest spot) temperature RTD-100 ohm platinum and
temperature indicator with alarm contacts.
c. Load tap changers, when shown on the data sheets, shall be equipped
with automatic and local/remote manual control and a remote tap
indication.
d. Oil level and top oil temperature indicator.
e. Shorting type terminal blocks on current transformer.
2.4.2 Pressure Devices
2.4.2.1 Furnish a sudden pressure or Buchholz protective relay with contacts wired
to terminal blocks for alarm and trip functions (see also paragraph
2.3.12.1).
2.4.2.2 Furnish a pressure relief device with contacts wired to terminal blocks for
alarming.
2.4.3 Tools
2.4.3.1 Furnish a complete set of special tools necessary for installation and
maintenance of the transformer and auxiliary apparatus mounted on it.
7

PART 3 - EXECUTION
3.1 INSPECTION AND TESTING
3.1.1 General:
Routine and design tests will be conducted in accordance with ANSI
C57.12 or IEC 76.1
3.1.1.1 BUYER will have the option of witnessing tests. CONTRACTOR shall
advise BUYER ten (10) working days in advance of tests. Failure to do so
may result in re-performing the tests at CONTRACTOR'S expense.
3.1.1.2 Provide certified test reports for all tests performed.
3.1.1.3 Perform transformer tests with the transformer having its own bushings
installed.
3.1.1.4 Perform thermal tests (heat run and loss tests) for each transformer in
accordance with ANSI C57.12.00-2000 Table 19.
3.1.2 Required Tests
3.1.2.1 Perform routine transformer tests as identified in Section 8 of ANSI
C57.12.00 in accordance with ANSI C57.12.90.
3.1.2.2 Perform routine terminal bushing tests in accordance with ANSI C57.19.00
or supply certified routine test reports from identical units.
3.1.2.3 Perform design transformer tests as identified in table 16 of ANSI
C57.12.00 in accordance with ANSI C57.12.90 or supply certified design
test reports for duplicate or essentially duplicate transformers.
3.1.2.4 Perform the following other transformer tests in accordance with ANSI
C57.12.90 as required by Appendix C.
a. Perform insulation power factor tests for the full windings. Conduct test
between windings and between each winding separately and ground.
b. Perform Partial Discharge Test during the induced voltage test of the
high-voltage windings at a number of test voltage levels in accordance
with ANSI C57.12.90 Sections 10.6 and 10.7.
Submit the level of Partial Discharge considered to be damaging and
the maximum level of discharge expected at 100 percent induced test
voltage. Investigate partial discharge determined to be damaging by
test or found to be in excess of the expected maximum level take the
necessary corrective action. Retest the transformer for partial
discharge following any correction action.
c. Perform front-of-wave impulse tests.
8

d. Perform switching impulse tests using a unidirectional wave of negative
polarity.
3.1.1.5 Functionally test all alarm contacts, sudden pressure sensors, current
transformers, fans and other auxiliary equipment that form part of the
transformer unit.
3.2 SHIPPING AND HANDLING
3.2.1 Preparation for Shipment and Handling
3.2.1.1 Prepare the equipment for shipment so as to protect the case, radiators,
core and coils, bushings and all other parts and auxiliary devices or
accessories from corrosion, dampness, breakage, or vibration injury that
might be encountered in transportation and handling. Manner of packaging
shall be such as to prevent tampering or pilfering.
3.2.1.2 Deliver transformer as complete as practicable consistent with shipping
limitations and protection requirements for the equipment.
3.2.1.3 Ship transformer in dry nitrogen or dry air in accordance with transformer
CONTRACTOR’S standard procedure, with adequate positive pressure
and dewpoint of minus 200F or lower if transformer is required to be
shipped without oil.
3.2.1.4 When oil is to be shipped separately, ship in containers or tanks specially
designed and used for this service.
3.2.1.5 Mark the shipping center of gravity on four sides of the tank to aid riggers
in handling.
3.2.2 Shipment
3.2.2.1 Coordinate shipping arrangements, as required, to ensure that
transformers arrive onsite with the proper field orientation.
3.2.2.2 Ensure that dimensions meet shipping clearance from the factory to the
railroad siding specified as the destination and determine any special
routing necessary for the shipment.
3.2.2.3 Monitor any rail shipments by calibrated and certified accelerometers. If
the transformer being furnished has been subjected to acceleration and/or
deceleration greater than that stated in the design data as the maximum
allowable during delivery, CONTRACTOR shall inspect, repair and test the
equipment as necessary to meet this specification.
3.3 PERFORMANCE
9

3.3.1 3.3.2 State in the proposal the transformer no-load losses at rated voltage and
the load losses at the maximum transformer MVA rating as specified in
Appendix C. No-load and load losses shall include losses for cooling
equipment required for transformer operation.
Provide actual losses of transformer in accordance with testing specified in
Section 3.1.
10

APPENDIX B
FORM OF PROPOSAL
FOR
INTERCONNECTING POWER AUTO-TRANFORMERS
ENGINEERING INFORMATION
Bidder __________________
Transformer Tag __________________
Type (shell or core) _________________
1. INSTALLATION INFORMATION
A. Weight
1) Transformer
a) Weight of complete transformer b) Shipping weight lb
c) Largest shipping section lb
lb
2) Oil
a) Net weight lb
B. Oil gal
C. Transformer dimensions complete, length x width x height
_____in in in
D. Largest shipping section, length x width x height
in in in
E. State whether the transformer will be shipped with the permanent tank covers
(with temporary covers for bushing and collar flanges) or with temporary tank
covers. Indicate extent of field assembly required.
F. State whether the transformer will be shipped in the upright or horizontal
position.
2. TRANSFORMER DATA
A. Complete technical details of the oil preservation system
B. Efficiency, including cooler losses, at rated voltage at:
1) 100 percent of maximum rated MVA %
2) 75 percent of maximum rated MVA %
B-1

3) 50 percent of maximum rated MVA %
KW
KW
KW
KW
KW
KW
KW
KW
KW
C. Losses
1) No-load losses at 75°C:
a) 100 percent of rated voltage (guarantee value) b) 105 percent of rated voltage c) 110 percent of rated voltage 2) Load losses at rated voltage at 75°C:
a) 100 percent of maximum rated MVA (guarantee value) b) 75 percent of maximum rated MVA c) 50 percent of maximum rated MVA d) Total power requirements of auxiliary cooling equipment at maximum
rated MVA (guarantee value)
3) Guaranteed total losses at maximum rated MVA. Total losses shall include
no-load loss, load loss and the loss of cooling equipment required for full load
operation at normal ratio.
4) Cooler losses at no load, if applicable D. Permissible continuous loadings at rated ambient and rated voltage without
exceed standard hot spot temperature for the following conditions:
1) With one radiator cooler unit out of service 2) With the largest separately controlled group of radiator cooler units out of
service
E. Impedance
1) Impedance at maximum rated MVA %
2) Tolerance
3) Variation of Impedance due to Load Tap Changer (LTC)
F. Guaranteed switching surge withstand strength HV winding G. Maximum expected partial discharge (corona) level, at 100 percent induced
test voltage, RIV
H. Level of corona considered to be damaging I. Guaranteed audible sound level MVA
MVA
KV
Microvolt
Microvolt
Db
B-2

H-Winding X-Winding Y-Winding
KV
A
KV
A
3. BUSHING DATA
{PR
IVA
TE }
A Line Bushing
1) rated voltage
2) rated current
3) Manufacture
4) Type
5) Catalog No.
B Neutral Bushing
1) rated voltage
2) rated current
3) Manufacture
4) Type
5) Catalog No.
KV
A
KV
A
KV
A
KV
A
4. PROTECTIVE DEVICES
A . Sudden pressure or Buchholz protective relay
1) Manufacturer
2) Type (include literature in proposal)
B. Complete description of combustible gas monitoring
C. Surge arresters KV
1) Rating (Voltage Class (MCOV))
2) Manufacturer
3) Catalog number
5. DRAWINGS
A. Preliminary outline drawings furnished with proposal (List drawing numbers.)
B. Time required after award of purchase order to furnish preliminary drawings.
1) Outline Weeks
2) Plan of base
3) Schematic or elementary diagram
4) Connection diagram
B-3

5) HV and LV bushing flange and terminal details
C. Time required after approval of initial drawings to furnish final design
drawings
Weeks
7. ONSITE STORAGE
A. State recommendations for short-term onsite storage (six months or less).
B. State recommendations for long-term onsite storage (over six months).
8. EXCEPTIONS
A. Does the proposed equipment comply with the specifications?
B. If no, the Bidder shall indicate the page in the proposal where the exceptions
are found.
Company
Signature
Title
Reference Number
Date of Bid
B-4

APPENDIX C
INTERCONNECTING POWER AUTO-TRANFORMER
Transformer Tag per appendix D
Note: Refer to appendix D for further details.
Transformer Function
Generator Step-up Startup/Reserve
Unit Auxiliary Unit Substation
x Auto-Transformer
Service Conditions
Harmonic Load Currents
Other Service Conditions continuous duty, for 50C ambient (55C rise average)
Ratings
Vector group YNa0[d11)
Rated Voltage ratio 154/132/33 kV
Base, natural cooling, 75/75/37.5 MVA
Maximum, forced cooling, 100/100/50 MVA
Frequency 50 Hz
Phases per Transformer Tank 3
Maximum available short circuit fault current 1000 MVA at 132 kV for 2 sec.
Cooling Method ONAN OFAF
X ONAN/ONAF ONAN/OFAF
ONAN/ONAF/ONAF ONAN/ONAF/OFAF
Other
Losses
Losses including Cooling Equipment will be evaluated at the following costs:
No Load Losses N/A $/KW
Load Losses N/A $/KW at maximum rated MVA
Terminations
C-1

High Side (H) 132kV High Side (X) [154 kV] Low Side (Y) [33kV]
Open Bushing Open Bushing Open Bushing
X Air Terminal Chamber X Air Terminal Chamber X Air Terminal Chamber
Bus Duct Bus Duct Bus Duct
Cable Size Cable Size Cable Size
Cond./Phase Cond./Phase Cond./Phase
Other Other Other
Tap Changer
X On Load Tap Changer (motorized) equivalent to 3XARSG 3252/521-521/51-22 (20)/0614
Refer to Appendix D Location of Tap Changer Refer to Appendix D
Steps Refer to Appendix D X H-Winding X X-Winding Y-Winding
Range High Voltage Surge Arresters
Required X Not Required
Max. Continuous Operating Voltage KV (Line-Ground)
Insulated Base Discharge Counter Other
Sound Level
Audible Sound Level measured in accordance with ANSI/IEEE C57.12.90 at
rated voltage with all Cooling Equipment running.
Less than n/a Db at 3 feet (1 meter) (A-weighted)
Tests
All routine, design, and other transformer tests identified in IEEE C57.12.00-2000, Table 19, shall be performed
with the exception of those listed below:
Insulation Resistance
Insulation Power Factor
Partial Discharge (Corona)
Front of Wave Impulse
Switching Impulse
X Short Circuit
C-2

Auxiliary Power
The CONTRACTOR will provide the following:
AC power supply Number 2
Rating 400V, 3 ph, 4wire +/- 10%
Max. S.C. current 65 kA
DC power supply Number 1
Rating will inform
Max. S.C. current 40kA
Control Cabinet
X ANSI/IEEE Standard Location X Enclosure Type, NEMA 4
Other Location
Transformer Oil
X ANSI/ASTM Standard
Other
Other
Winding Temperature Rise by Resistance Maximum hot spot temperature rise at maximum rated MVA
65 °C
80 °C
Impedances at MVA at Reference Temperature of 85°C
Refer to Appendix D.
Design for Front-of-Wave Impulse Required
X Not-Required
C-3

H-Winding X-Winding Y-Winding
Winding Rated Voltage 154 KV 132 KV 33 KV
Winding BIL Min 650 KV Min 650 KV 250 KV
Winding Neutral BIL 250 KV
Winding Connection Earthed Wye via
earthing disconnect
switch
Delta
Neutral Grounding X Solid
Resistance
None
X Solid
Resistance
None
amps secs
Solid
Resistance
X None
Rating of Seller Provided
Neutral Ground Resister
Phase Relationship YNa0[d11]
Line Bushing BIL Min 650 KV 650 KV 250 KV
Phase to ground voltage 54 mm/kV creep 54 mm/kV creep 54 mm/kV creep
Neutral Bushing BIL 250 KV
44 mm/kV creep
Line Bushing Location X Cover
Side
Neutral Bushing Location X Cover
Side
X Cover
Side
Cover
Side
Cover
X Side
Cover
Side
Bushing Material Standard
Bushing Color Standard
Bushing Markings Standard
C-4