8210 - Technical SpecificationsRFP 8210 Page 1 of 8
RFP # 8210
Technical Specifications
Supply of Electric Utility Instrument Transformers
A. PURPOSE
The City of Denton is providing information that will allow prospective suppliers to prepare
submissions to supply completely assembled and tested instrument transformers for use on the
69kV, 138kV, and 345kV transmission system. The instrument transformers are to be priced FOB
to the Spencer Utility Site, 1701C Spencer Road, in Denton, Texas or to other substation sites in
or near Denton as directed at the time of shipment.
B. SERVICE CONDITIONS
Site Location: The service location for these transformers will be in substations in the Denton,
Texas area.
Service Elevation: Approximately 640 feet above sea level.
Temperature: -20o F to 120o F.
Fault Current Available at the High Voltage Terminals: 35,000 amps symmetrical (maximum
available at the high voltage bushings).
Other Considerations: Moderately humid climate with 10 to 30 inches of rain per year; wind up
to 90 mph; thunderstorms with severe lightning occurring in all months of the year with the
greatest frequency during the warmer months.
C. QUALITY CONTROL
The manufacturer shall be responsible for the quality control of the manufacturing processes to
assure that all requirements of these specifications are met. However, the City reserves the right
to observe, to inspect and to require additional quality control investigations, either by its personnel
or an independently employed quality control investigator, at any or all stages of fabrication at the
manufacturer’s facilities. Failure to adequately maintain fabrication and quality of fabrication until
completion shall be grounds for cancellation of the order or any part thereof.
Field failure or field repairs required due to quality control failures or manufacturing procedures
shall be the responsibility of the manufacturer.
D. WRITTEN WARRANTY and GUARANTEES
Written guarantees shall include any limitations as to the nature of failure or time limitations. The
guarantee shall begin upon receipt of the accepted units, not on the date of manufacture.
Guarantees shall indicate whether or not it is made on a full replacement basis or a prorated basis
and if prorated then what are the terms. Manufacturer/supplier guarantees that the goods furnished
under this specification are of high quality and agrees to replace any goods found to be defective
RFP 8210 Page 2 of 8
during inspection, installation, or service for a minimum period of 12 months from the date first
energized in a substation. With the exception of units accepted for early shipment, instrument
transformers will be first energized no later than six months after delivery. For any units accepted
for early shipment, the manufacturer shall extend the warranty period such that the warranty as
specified in in this paragraph shall begin on the date the transformer is first energized in its
permanent location.
All replacements by the manufacturer/supplier shall be free of charge F.O.B. at the same delivery
point called for in the original order. Replacements must be handled in a professional and timely
manner and in no case shall a replacement unit take longer than 60 days to arrive in Denton after
first being submitted for replacement.
Respondent guarantees that all products quoted and furnished under this agreement will be
accepted at any normally used United States approved repair and warranty shop should one be
available for the manufacturer’s product quoted. The City of Denton will not accept a
manufacturer’s product that was rejected or substandard and then sold to a broker for either resale
or scrap that would not be fully warranted by the original manufacturer.
The respondent must be an approved distributor by the manufacturer of these products, and is
authorized to sell the products to the City of Denton. The respondent also guarantees that the City
will be represented by the Manufacturer, should an issue arise, and that all manufacturer’s
warranties will be in effect for the life of the contract.
E. SPECIAL DELIVERY REQUIREMENTS
1. Shipment by open flatbed truck: Instrument transformers purchased under this
agreement shall be shipped FOB Destination by open flatbed truck fully assembled and
ready for installation. The owner will provide unloading and installation.
2. Delivery location: Switches shall be delivered to the Spencer Utility Site, 1701C
Spencer Road, Denton, Texas, 76205 or to other DME substations.
3. Notice of factory shipments: The supplier shall provide notice when the products are
shipped. The owner only has a forklift to unload the products. Contact Sam Bridges at
(940) 390-6279 for notices of shipment. Secondary contact is Brian Walding at (940)-
390-3146. Delivery of the products will be accepted only between the hours of 8:00
am and 3:00 pm Monday through Friday, excluding holidays.
4. Damaged or defective material or equipment: Freight that is obviously damaged on
arrival will be refused. Any necessary action regarding replacement of materials or
equipment delivered in unacceptable condition shall be the responsibility of the supplier.
This includes concealed freight damage as well as items originally defective from the
manufacturer. The supplier shall be fully responsible for detecting shipping damage as a
part of field services and assembly and for initiating all action necessary for replacement
or repair of such damage in a timely manner.
RFP 8210 Page 3 of 8
F. TECHNICAL RESPONSIBILITIES AND REQUIREMENTS
1. Detail Design: Detailed structural and electrical design is the responsibility of the
supplier. All clearances and spacings must conform to ANSI standards, and the
National Electrical Safety Code, whichever is more stringent. Greater clearances shall
apply where specified.
2. Omissions: It is the intent of this specification to require the supplier to provide
complete and fully functional instrument transformers that are equipped and featured
appropriately to perform and operate as described herein. Further it is the intent of this
specification to require that the instrument transformers be constructed, as a minimum,
in accordance with all US standards that apply to instrument transformer manufacture
and testing. Omission of any minor details from this specification, minor mistakes or
typographical errors in text, or mistakes in attempting to reference standards or data in
the standards shall not relieve the supplier from the responsibility to furnish complete
and fully functional instrument transformers that comply with accepted national
standards and meet the intents communicated herein.
3. Delivery Schedule: The supplier shall submit a schedule with the proposal indicating
the expected time (ARO) when final drawings and test reports will be provided for each
instrument transformer ordered and the time (ARO) when the instrument transformers
will be delivered assuming a reasonable time for shipping.
4. Drawing Identification: All drawings shall be identified with unique drawing
numbers, the date, and the manufacturer’s shop order number. If standard drawings or
manuals, covering a range of equipment, are supplied, such drawings and manuals shall
be clearly annotated to identify the information pertaining to the equipment supplied.
5. Approval of Design: The owner shall have an opportunity to approve the design and
features of the instrument transformers prior to manufacture. Approval drawings shall
contain sufficient information to confirm all data that was included in the bid proposal
and fully describe each unit. It is the intent of this specification to require only standard
units normally constructed by the manufacturer and identified by standard catalog
numbers. As such the information included with the bid proposal if sufficient, may be
considered as approval drawings if the successful bidder wishes. After the approval
submittal is accepted, the manufacturer shall not make any design changes that affect
mounting dimensions or electrical performance of any instrument transformer unless
approved in writing by the owner.
Review of drawings by the owner will be with respect to general design and
functionality, but shall not be construed to relieve the supplier from any responsibility
or liability for proper design, fabrication, compliance with the specifications,
compliance with standards, or for any errors that may have been contained in the shop
drawings.
The approval submittal shall provide information in sufficient detail to describe
equipment function including at least nameplate data; dimensions; space needs for
installation; mounting means; weights; shipping dimensions and weights; the locations
of interconnection points for attachment of the customer’s wiring; etc. sufficient to
RFP 8210 Page 4 of 8
allow verification of all ratings and specifications. This information will be used to
complete the design of station components.
6. Final Drawings, Instruction Books, and test Reports: No later than the scheduled first
shipment, the supplier shall furnish final drawings and certified test reports for each
type of instrument transformer being purchased and sent electronically to the owner.
Drawings shall be provided in AUTOCAD “dwg” format along with a listing of all
drawing titles and file names. Two copies of the certified test report will be furnished
for each device manufactured. One copy of drawings, instruction books, and test
reports shall be shipped with each instrument transformer to be retained at the service
site.
7. Materials and Workmanship: Only new materials shall be used in fabrication of these
instrument transformers. Damaged or defective materials shall not be repaired and
used. No peening, caulking, or filling shall be permitted in repairing cracks, pinholes,
or other types of defects. Such defects in fabricated members shall be repaired by
replacement.
G. DESIGN STANDARDS
All instrument transformers shall be manufactured to meet or exceed the requirements in the
latest revision of all USA standards that are applicable to instrument transformer construction.
Applicable standards shall include at least those of EEI, NEMA, IEEE, and ANSI. In the event
that the owner, in this specification, has incorrectly referenced a standard or a requirement, test,
or test value contained in a standard, such an error shall not relieve the manufacturer of the
requirement to comply with the standard or to perform tests properly and in the manner
prescribed in the applicable standards. The latest revisions of the following ANSI/IEEE and
NEMA standards/specifications are incorporated herein by reference:
ANSI C93.1,
ANSI C93.2,
IEEE C57.13
H. INSTRUMENT TRANSFORMER DETAILED SPECIFICATIONS
1. General Features and Requirements:
a) Metallic parts: All exposed or exposable surfaces of all instrument transformers
shall be maintenance free, not be painted, and shall not require painting for
maintenance in the future. All metallic parts shall be constructed of corrosion
resistant material, such as cast aluminum, hot dipped galvanized steel, or stainless
steel.
b) Electrical insulators: All electrical insulators shall be glazed porcelain, ANSI 70
sky gray in color.
c) Nameplates: Each instrument transformer shall have a stainless steel nameplate
that shows as a minimum: model number, BIL, serial number, year manufactured,
all ratings, voltage information, accuracy, thermal burden, accuracy burden, weight,
RFP 8210 Page 5 of 8
gallons of oil, electrical arrangement of all windings and their voltage information,
and ANSI/IEEE compliance.
d) Secondary windings for PT’s & CCVT’s: All PT’s and CCVT’s shall have at least
two isolated secondary windings each capable of producing both 115 volts and 67
volts for use in metering or relaying.
e) Accuracy: CT’s and PT’s shall be 0.3% or 0.15 with a minimum burden capability
as shown in the tabulation later in this specification. CCVT’s shall have an
accuracy of at least 0.3% for at least the main secondary winding with a minimum
burden capability as shown in the tabulation later in this specification.
f) Sealed Units: All instrument transformers shall be hermetically sealed and have
provision for accommodating thermal expansion without compromising the sealed
system.
g) Mechanical Strength: All instrument transformers shall conform to IEEE
C57.13.5 pull strength.
h) Oil level indicators: All oil filled instrument transformers shall have an oil level
indicator. For CCVT’s, oil level indicators need only be on the base tank
i) Primary voltage terminals: Primary voltage terminals for PT’s and CCVT’s shall
be NEMA 4-hole single tang flat pads suitable for connection to either copper or
aluminum fittings. Terminals for CT’s shall be NEMA 4-hole single tang flat pads
suitable for connection to either copper or aluminum fittings.
j) Grounding terminals: Each instrument transformer shall have at least one NEMA
2-hole grounding connection. The grounding connection shall be capable of
grounding both the case of PT’s and CCVT’s and providing the ground for the H2
primary winding with the owner supplying only one grounding conductor. NEMA 2-
hole compression copper lug for 19 strand 4/0 Soft Drawn Bare Copper (SDBC) and
stainless steel bolts shall be provided and securely attached to each grounding
terminal. The NEMA 2-hole compression copper grounding lug for 4/0 SDBC shall
be similar to a Burndy YA28A5 or an Anderson VACL4012BN
k) CT secondary terminal boards: The secondary terminal board in the CT secondary
compartment shall be a shorting type terminal board or block such that the CT
secondary winding can be shorted and the ratio changed without having to take the
CT off line. A ground terminal must be included on the secondary terminal board
that is permanently attached to the CT ground.
l) Secondary connection compartments: Secondary connection compartments shall
be sealed with gaskets to be weather tight. A gasketed plate in the bottom of the
compartment that can be punched by the owner or threaded watertight entrances
shall be provided for installation of field conduits.
m) Factory Testing: The proposal must include a summary of the testing that the
manufacturer will do to verify performance. At least all testing required by the
ANSI/IEEE standards shall be done.
n) CCVT protection: CCVT’s shall contain circuitry to operate to prevent overvoltage
across the series reactance in the event that the thermal burden is exceeded.
RFP 8210 Page 6 of 8
o) Frequency ratings: The frequency rating for all instrument transformers shall be 60
Hz.
p) Oil sampling valves: All oil-filled instrument transformers shall have plugged and
sealed oil-sampling valves.
2. CCVT Electrical Requirements:
Rating Description 345kV
Maximum System Voltage 362kV
1 Minute Dry Withstand 785kV
Short Time Overvoltage – One Minute 1.4
Performance Reference Voltage 207,000 V
Minimum Creepage Distance 361 in.
Minimum Strike Distance 111 in.
BIL 1550kV
Minimum Accuracy (two secondary windings) 0.3%
Burden (for above accuracy) W,X,Y,Z
Ratios (each secondary) 1800/3000:1
Maximum Thermal Burden 1000 VA
Ferroresonance Suppression
Less than 10% of
peak within 10
cycles at 150% of
max rated voltage
Normal Capacitance 2,150 pF
RFP 8210 Page 7 of 8
3. PT Electrical Requirements:
Rating Description 69kV 138kV 345kV
Maximum System Voltage 72.5kV 145kV 362kV
Continuous Overvoltage Rating 1.2 1.2 1.2
Short time Overvoltage – One Minute 1.73 1.73 1.5
Rated Primary Voltage 40,250 80,500 207,000
Minimum Creepage Distance 63 138 361
Minimum Strike Distance 22 43 104
BIL 350 650 1300
Minimum Accuracy 0.3% 0.3% 0.3%
Burden (for above accuracy) W, X, Y, Z, ZZ* W, X, Y, Z, ZZ* W, X, Y, Z,
ZZ*
Ratios (each secondary) 350/600:1 700/1200:1 1800/3000:1
Minimum Thermal Burden: Oil-filled
(each secondary) 3250 VA 3250 VA 3000 VA
Minimum Thermal Burden: Dry Type 2000 VA - -
*See Page 10: IEEE C57.13 Table 15 – Standard PT Burdens
4. CT Electrical Requirements
Rating Description 69kV
(Extended Range)138kV 138kV
(Extended Range)
Maximum System Voltage 72.5kV 145kV 145kV
Rated Primary Voltage 40,250 80,500 80,500
Minimum Creepage Distance 63 138 138
BIL 350 650 650
Minimum Accuracy 0.15% 0.3% 0.15%
Minimum Burden B1.8 B1.8 B1.8
Accuracy Range 0.5% 0.5% 0.5%
Ratios 1000:5 150/300:5 150:5
Thermal Rating, 1 Second 63kA 22.5kA 22.5kA
Rating Factor 3.2 1.5 4
RFP 8210 Page 8 of 8
5. Insulating Oil
The insulating oil may be new inhibited or new uninhibited mineral oil, refined from
predominantly napthenic base crude, as long as it complies with Doble TOPS. The supplier
shall provide information with the proposal describing the type and quality of oil and the
tests performed to verify the properties. All oil filled devices shall be certified as free of all
polychlorinated biphenyl compounds. Equipment shall be so marked and shall be certified to
the owner in writing referencing devices by description and serial number. The owner, at his
expense, may test any oil supplied. If the oil is discovered to contain PCB's, or to be
unacceptable in any way, required disposal and replacement actions will be at the supplier's
expense. Certification of the quality of the oil used or of the factory quality assurance
measures shall be provided.
6. Alternative Submission for “Dry-Type” 69kV PT’s and CT’s:
The owner desires an alternate dry-type submission for 69kV PT’s. These devices will be
evaluated on the same basis as the oil filled unit and shall meet the same technical
requirements, or equivalent, as the oil filled units unless specified otherwise. The supplier
shall include complete descriptive information with the bid.
7. Factory Tests
All tests listed in current version of the ANSI standards shall be performed. The proposal
shall include a listing prepared by the manufacturer giving the manufacturer’s interpretation
of the specific tests required by all standards. The listing shall include the test values that are
to be used. Certified copies of the test reports are required. The test reports shall include the
results of all tests. The owner shall have the option of observing tests on any factory visit.
8. Standard PT Burden Definitions
IEEE C57.13 TABLE 15 – STANDARD PT BURDENS
Designation Volt Ampere (VA) Rating Burden Power Factor
W 12.5 0.1
X 25 0.7
M 35 0.2
Y 75 0.85
Z 200 0.85
ZZ 400 0.85
These burden designations have no significance except at 60 Hz.