HomeMy WebLinkAboutBID - 5992 LP TRANSFORMERS 25KVA 50KVA 100KVA PAD-MOUNTED (2)THE CITY OF FORT COLLINS
Light and Power Department
P.O. Box 580
Fort Collins, CO 80522
SPECIFICATION NO: 368-120
TITLE: PAD -MOUNTED COMPARTMENTAL -TYPE, SINGLE-PHASE
DISTRIBUTION TRANSFORMERS
WITH SEPARABLE
INSULATED LOAD BREAK HIGH -VOLTAGE CONNECTORS
r
APPROVED BY:
Kraig E. badef
Standards Engineering Manager
ORIGINATED: 09/14/72
LAST REVISED: 7/21/2004
ITEMS COVERED BY THIS SPECIFICATION
DESCRIPTION
STOCK NO.
SPECIFICATION
NO.
SERIAL
25 KVA, 120/240 ANSI Type 1 Transformer.
368-120
-130
50 KVA, 120/240 ANSI Type 1 Transformer.
368-120
-150
50 KVA, 120/240 ANSI Type 2 Transformer.
368-120
- 155
100 KVA, 120/240 ANSI Type 1 Transformer.
368-120
-170
167 KVA, 120/240 ANSI Type 1 Transformer.
368-120
-180
250 KVA, 1201240 ANSI Type 1 Transformer.
368-120
-190
REV. SYM: FF
Units shall be packaged on four-way universal pallets with 34 inches minimum opening and loaded on the truck for
side removal. The Supplier shall give 24 hour notice prior to delivery for any shipments where an individual
transformer weighs over 5,000 pounds. In addition to these requirements, the Supplier shall comply with any
additional requirements or modifications shown on the purchase order and/or supplemental instructions.
6 DEFINITIONS AND ABBREVIATIONS
Vendor or Supplier - The manufacturer and/or manufacturer's agent supplying or quoting on the specified article.
Article, Unit, Assembly - All refer to the equipment defined by this Specification.
• DC or d.c. - Direct Current.
• AC or a.c. - Alternating Current.
• °C - Degree Celsius (Centigrade)
• 'F - Degree Fahrenheit
kV -1000 volts.
CPS or Hz - Cycles per second.
psig - Pounds per square inch gauge.
V or v - Volts.
KVA - 1000 Volt-amperes.
10
368-120
REV. SYM: FF
APPENDIX A — Transformer Stock Number Coding
Below are examples that demonstrate the coding method used by City of Fort Collins to establish
transformer stock numbers.
I. SINGLE PHASE
Example #1 R--
Transformer
Single Phase
00 = 13.2Y/7620 &
7620/13.2Y x
2400/4160 outside
pole
05 = 13.2Y7620 ESNA pole
20 = 13.2Y/7620 ESNA pad
H. THREE PHASE
Example #2 368 -
Transformer
3 Phase
Pad
-XYZ
Other
KVA
0 = 5
5=50
1=10
6=75
2=15
7=100
3=25
8=167
4=37.5
9=250
1 = single voltage
2 = dual voltage
KVA
006 = 75 075 = 750
015 = 150 100 = 1000
030 = 300 150 = 1500
050 = 500
All suffixes indicate 208Y/120 sec.
For 480YI277 sec., add 1 to XYZ
(ie. 007 would indicate a 75kVA with
480Y/277 sec.)
11
368-120
APPENDIX B — DIMENSIONAL DRAWINGS
40* MAX
28" MIN
REV. SYM: FF
A
IIN
NO
3k," 5" I_ 5"Sk" 3Y•" 3K" 4� MIN
4!4 MIN MIN MIN ` MIN MIN MIN MIN M!N
HIA HIB X3 XI
CA6l-E ACCESSORY 1 32"max
PARKING STAND r I
X2
GROUND PAD 18'*2"
MAX.
25 k 50 32.5' --
100 _ 42'.,
167 42' 53'
2so 44' 55"
r MINIMUM OPENING
IN BOTTOM OF COMPARTMENT
FOR CABLE ENTRANCE
Figure 1 —Type 1 Transformer Dimensions and bushing Designations (not to scale)
12
368-120
StACE
DETAIL A
CABLE ACCESSORY
PARKING STAND
SEE
DETAIL A
Too
r
fA
i.- o-vi
FLTX0
FLANGE r yi
MIN
1. MAX - 18MINOPENING-
QNOTE 2)
HIGHNOLTA+IE COINNECTOAS
Ij GABLE ACCE500AY I
PARKING STAND "" 2 MIN
' 1/2 64°"150
C 61f21'118
0
REV. SYM: FF
A
WN
ARBITRARY POWT
241
�A 2
32I/IN
4 ss MIN
A" 29•1t2 t 1 5: 1
9 (NOTE 6)
„Ia
6WN 9 8:1
BASE -
BASE
SILL PLANE
ed?ouNDPAD
IO AReITRARv
POINT
Stock Number
Dimension A
Dimension B
Dimension C
Dimension D
Dimension E
368-120-155
13"
5"
4"
0"
31/'"
Figure 2 — Type 2 Transformer Dimensions and bushing Designations (not to scale)
13
368-120
REV. SYM: FF
Pad Dimensions
This drawing is not intended to dictate requirements for items purchased under Specification 368-120 but is included as
an aid to those users desiring a minimum of pad designs for the transformers covered by Specification 368-120.
The dimensions in inches of Figure 3 will fit the minimum compartments on transformers covered by this Specification as
well as the maximum transformer envelope.
48" ----'_1 JL
I I I —[3"
48"
3"
T
12" PRIMARY SECONDARY
4 1/2" FRONT T2„
15 — 8 12 15
FOURk3EBAR
18" LENGTH AND WIDTH
7 1/2"
—T T
Notes on Pad Material -
1. Concrete must be 3,000 psi minimum.
2. Maximum coarse aggregate size 1 1/2 inches.
Space requirements for pad and primary switching cabinet will generally
be G' X 12'. Factors to be considered in locating the pad include -
1. Accessibility - The transformer pad shall be accessible to
line boom bucks equipped for the installation and removal of
heavy transformers. Such accessibility shall not require
intrusion on adjacent property.
2. Proximity of Buildings, Walls, Banners, and/or Overhangs -
In addition to the clearances required for installation and
removal, the minimum clearance in front of the transformer pad
shall be eight (8) feet and the minimum clearance from all
other sides shall be two (21 feet. If the building has an
overhang, clearance to the edge of the transformer pad shall
be measured horizontally from the outer edge of the overhang.
Transformers through 300 INA may be installed under the
overhang if the vertical clearance between the pad and the
overhang is at least 25 feet and the location is accessible to
line boom trucks.
3. Codes and Standards - In addition to the above, the
installation shall conform to the National Electric Code and
federal, slate and city codes and standards.
Figure 3 — Pad Dimensions
14
368-120
REV. SYM: FF
APPENDIX C — Approved Manufacturers
Transformers purchased under this Specification shall be of the make shown below. Manufacturers not listed below may
submit written proposals demonstrating compliance with these Specifications for consideration of addition to the accepted
manufacturers list prior to the next request for bids. In addition to inclusion on the list below, manufacturer's equipment
must also satisfy all requirements of this Specification to be acceptable.
MANUFACTURER SERIAL NO.
ABB
All
Cooper Power Systems All
General Electric All
Howard Industries All
The manufacturers in the following list have been conditionally approved and may bid as an alternate. The definition and
intent of "Conditional Approval' of a manufacturer is to allow the City to gain some experience with the manufacturer's
product. Should a conditionally approved manufacturer be the evaluated low bidder, the City reserves the right to award
all, part, or none of the order to them, dependant upon the current needs of the City for that item or items.
15
368-120
TRANSFORMER LOSS EVALUATION - AVERAGE LOSSES
City Order No. S/N
Manufacturer Invoice No.
KVA/Unit
LINE
DESCRIPTION
(1)
No. of units
(2)
Average core losses
(3)
Quoted core losses
(4)
Excess average core losses:
line (2) less line (3)
(5)
Penal �r for excess average core losses:
line (1) x line (4) x $
(6)
Average copper losses
(7)
Quoted copper losses
(8)
Excess average coppper losses:
line (6) less Mine (7)
(9)
Penalty for excess average copper losses:
line (1) x line (8) x $
(10)
Penalty to be assessed manufacturer:
line (5) plus line (9) but not less
than zero
Date Prepared By:
Design Engineering
AMOUNT
REV. SYM: FF
NOTE: If any unit(s) exceeds the loss tolerances of ANSI C57.12.00, Light & Power will either reject it,
include it on these averages, or calculate losses using the Individual Transformer Losses Evaluation
Form, whichever is most favorable to Light and Power.
16
368-120
City Order No.
Manufacturer
KVA/Unit
LINE
(1)
(2)
(3)
INDIVIDUAL TRANSFORMER LOSS EVALUATION
S/N
Invoice No.
DESCRIPTION
Tested core losses
Quoted core losses
Excess core losses
line (1) less line (2) but not less
than zero
(4) Percent difference
line (3) 1 line (2) x 100
(5) Tested total losses
(6) Quoted total losses
(7) Excess total losses
line (5) less line (6) but not less
than zero
(8) Percent difference
line (7) -j line (6) x 100
(9) Tested copper losses
(10) Quoted copper losses
(11)Excess copper losses
(12) line (9) less line (10) but not less
than zero
(12) Penalty for excess core losses
line (3) x $
(13) Penalty for excess copper losses
line (11) x $
(14) Penalty to be assessed manufacturer
line (12) plus line (13)
Date Prepared By:
Design Engineering
AMOUNT
REV. SYM: FF
17
368-120
Issued: 8/17/72
Revised: 1 /21 /94
Special Conditions and
Supplemental Instructions to Bidders
Applicable to
Specification 368-120
A. Data to be Supplied with Bidder's Proposal
The following data shall be supplied with the bidder's proposal in addition to that
information required by the "Invitation to Bid" and the "Purchase Requisition".
1. A typical list of users of 1 phase padmounted distribution class
transformers manufactured by the bidder during the past five years.
2. A typical drawing of the transformers showing that they will meet the
critical dimensions required by the Specification.
3. Impedance volts in % at full load, high voltage to low voltage at 850C.
4. No load and total losses at 850C.
5. Delivery in weeks.
6. A statement indicating compliance with our Specification without
exception or a detailed list of exceptions.
7. Escalation is _ is not _applicable for the transformers bid. If escalation
applies, the Bidder shall indicate in his bid the specific items or materials
subject to escalation, and shall give the method and indices to be used in
computing the amount thereof. Escalation occurring after the quoted
delivery date. will not be paid unless delays are the result of actions by the
City. Escalation occurring after acceptance, if Purchaser exercises the
option to delay shipment after manufacturing is completed, will not be
paid.
If the above information and compliance statement are not supplied, the proposal will not
be evaluated.
An alternate bid for the total order may be submitted in addition to the unit bids.
B. Loss Evaluations
Loss penalties and loss evaluations will be based on the
following values:
1. No load or excitation losses at $3.90/watt.
2. Load losses at $1.50/watt.
C. Shipping Terms
Ship F.O.B. point of destination, freight prepaid.
D. Terms of Payment
If escalation applies, the City of Fort Collins shall not be billed for
escalation occurring after the promised delivery date.
Test reports shall accompany the invoice. If test reports do not accompany the
invoice, late payment penalty charges incurred due to delays in obtaining the test
reports will not be paid. Certified copies of test reports shall be sent to the Design
Section, Fort Collins Light and Power Utility.
Loss penalty credits and escalation charges shall be itemized on the
invoice.
REV. SYM: FF
PREVIOUS REVISION DESCRIPTIONS ON FILE
REVISION DESCRIPTION
APPROVED
REVISION DD:
Sagen
• Paragraph 3.2.2.7.5: Editorial
10/21/94
• Add paragraph 3.2.2.9.4 requiring pentahead locking bolts
• Paragraph 3.2.2.13 add glossy to paint requirement
• Paragraph 4.2.2: Clarify impedance requirement
REVISION EE:
Sagen
. Paragraph 5.0: revised pallet size from 28 to 34 inches
2/25/98
REVISION FF
Kraig Bader
Added 50kVA ANSI Type 2 Transformer (368-120-155) to Specification
7/21/2004
Changed paint color to standard Munsell Green
Reorganized to consolidate impedance and fusing requirements into one table.
Consolidated secondary terminal requirements into one table.
. Added maximum impedance requirement for 250kVA transformer (+/-7.5% from nominal for
transformers with impedance greater than 2.5%) per ANSI/IEEE C57.12.00-2000.
. Re-evaluated fusing requirements of all transformers in this specification. Went from dual
sensing bay-o-net (expulsion) fuses to current sensing bay-o-net (expulsion) fuses. Fuse sizing
was changed as follows:
• Changed 25 kVA from 8A expulsion 140 amp CL to 10A expulsion / 30A CL
• Changed 50 kVA from 15A expulsion / 80 amp CL to 15A expulsion / 40A CL
• Changed 100 kVA from 25A expulsion / 175 amp CL to 25A expulsion / 80A CL
• Changed 167 kVA from 40A expulsion / 200amp CL to 40A expulsion 1125A CL
• Changed 250 kVA from 65A expulsion / 350amp CL to 65A expulsion / 125A CL
ti:Y171 ill
REV. SYk FF
TABLE OF CONTENTS
PREVIOUSREVISION DESCRIPTIONS ON FILE..........................................................................................................................2
1 SCOPE...................................................................................................................................................................................................4
2 APPLICABLE DOCUMENTS............................................................................................................................................................4
2.1 ANSI C57.12.00 - DISTRIBUTION, POWER, AND REGULATING TRANSFORMERS, AND SHUNT REACTORS, GENERAL REQUIREMENTS
FOR.........................................................................................................................................................................................................4
2.2 ANSI C57.12.25 - PAD MOUNTED, COMPARTMENTAL -TYPE, SINGLE-PHASE, DISTRIBUTION TRANSFORMERS WITH SEPARABLE H-V
CONNECTORS, STANDARD REQUIREMENTS FOR.......................................................................................................................................4
2.3 ANSI C57.12.28 - SWITCHGEAR AND TRANSFORMERS - PAD -MOUNTED EQUIPMENT -ENCLOSURE INTEGRITY...............................4
2.4 ANSI C57.12.70 - TERMINAL MARKINGS AND CONNECTIONS FOR DISTRIBUTION AND POWER TRANSFORMERS...............................4
2.5 ANSI C57.12.80 - TERMINOLOGY FOR POWER AND DISTRIBUTION TRANSFORMERS........................................................................4
2.6 ANSI C57.12.90 - DISTRIBUTION, POWER, AND REGULATING TRANSFORMERS, AND SHUNT REACTORS, TEST CODE FOR.................4
2.7 IEEE C57.91 - GUIDE FOR LOADING MINERAL -OIL -IMMERSED OVERHEAD AND PAD -MOUNTED DISTRIBUTION TRANSFORMERS
RATED 500 KVA AND LESS WITH 650C OR 550C AVERAGE WINDING RISE..........................................................................................4
3 REQUIREMENTS................................................................................................................................................................................4
3.1 GENERAL REQUIREMENTS FOR DESIGN......................................................._......................................................................4
3.2 SPECIFIC DESIGN REQUIREMENTS..........................................................................................................................................5
4 QUALITY ASSURANCE....................................................................................................................................................................9
4.1 GENERAL.......................................................................................................................................................................................9
4.2 TEST CONDITIONS.......................................................................................................................................................................9
4.3 NOT USED.........................................................................................................................................................................................9
4.4 TESTS..............................................................................................................................................................................................9
5 PREPARATION FOR DELIVERY....................................................................................................................................................9
6 DEFINITIONS AND ABBREVIATIONS........................................................................................................................................10
APPENDIX A -TRANSFORMER STOCK NUMBER CODING...................................................................................................11
APPENDIX B - DIMENSIONAL DRAWINGS.................................................................................................................................12
PADDIMENSIONS..............................................................................................................................................................................14
APPENDIX C - APPROVED MANUFACTURERS.........................................................................................................................15
TRANSFORMER LOSS EVALUATION - AVERAGE LOSSES....................................................................................................16
INDIVIDUAL TRANSFORMER LOSS EVALUATION.................................................................................................................17
3
368-120
REV. SYM: FF
SPECIFICATION FOR
PAD -MOUNTED COMPARTMENTAL -TYPE
SINGLE-PHASE DISTRIBUTION TRANSFORMERS
WITH SEPARABLE INSULATED LOAD BREAK HIGH -VOLTAGE CONNECTORS
1 SCOPE
This Specification establishes the minimum electrical requirements and mechanical features of single phase, 60 HZ,
mineral oil immersed, self -cooled, pad -mounted, compartmental -type distribution transformers rated 250 KVA and
smaller, high voltage 13,200 Grd Y/7620 volts, with separable insulated load break high voltage connectors. These
transformers are used for step down purposes from an underground primary cable supply.
This standard generally conforms with ANSI requirements for pad -mounted compartmental -type, self -cooled, single-
phase, distribution transformers, C57.12.25.
2 APPLICABLE DOCUMENTS
The following documents of the issue shown form a part of this Specification to the extent specified herein. In those
cases when the document is note dated, the latest issue in effect on the date of invitation for bids shall form a part of
this Specification.
2.1 ANSI C57.12.00 - Distribution, power, and regulating transformers, and shunt reactors, general requirements for.
2.2 ANSI C57.12.25 - Pad mounted, compartmental -type, single-phase, distribution transformers with separable H-V
connectors, standard requirements for.
2.3 ANSI C57.12.28 - Switchgear and Transformers - Pad -Mounted Equipment -Enclosure Integrity.
2.4 ANSI C57.12.70 - Terminal markings and connections for distribution and power transformers.
2.5 ANSI C57.12.80 - Terminology for power and distribution transformers.
2.6 ANSI C57.12.90 - Distribution, power, and regulating transformers, and shunt reactors, test code for.
2.7 IEEE C57.91 - Guide for Loading Mineral -Oil -Immersed Overhead and Pad -Mounted Distribution Transformers
Rated 500 kVA and Less with 650C or 550C Average Winding Rise.
3 REQUIREMENTS
3.1 GENERAL REQUIREMENTS FOR DESIGN
3.1.1 BASIC DESIGN STANDARDS
Transformers purchased under these Specifications shall be new and, unless otherwise specified, meet
the requirements of the applicable ANSI Standards and the modifications and additions given in the
subsequent paragraphs. In case of conflict, the requirements of the following documents shall apply in
the priority shown:
a) This Specification
b) Applicable ANSI Standards
Approved manufacturers are listed in Appendix C.
3tit3-120
REV. SYM: FF
3.1.2 KILOVOLT -AMPERE TEMPERATURE RATINGS
Kilovolt -ampere ratings are continuous and are based on not exceeding either a 65°C average winding
temperature or an 800C hot spot temperature rise. The temperature rise of the insulating oil shall not
exceed 65°C when measured near the top of the tank. The temperature rise is based on an altitude of
3,300 feet. The transformers shall be designed for overloads based on IEEE C57.91.
3.1.3 GENERAL CONSTRUCTION
3.1.3.1 The pad -mounted compartmental -type transformers shall consist of the transformer tank and high -and -low -
voltage cable terminating compartment constructed in accordance with ANSI C57.12.25 and ANSI C57.12.28.
The terminating compartment and tank shall be assembled as an integral unit, tamperproof and weatherproof for
mounting on a pad. There shall be no exposed screws, bolts, or other fastening devices which are externally
removable. The cover shall be welded construction. There shall be no opening through which foreign objects
such as sticks, rods, or wires might be inserted to contact live parts. Suitable means for padlocking the
compartment door(s) shall be provided.
3.1.3.2 The high- and low -voltage compartment shall be located side by side on one side of the transformer tank. When
facing the compartment, the low -voltage side shall be on the right.
3.1.3.3 Construction of the unit shall be such that it can be lifted, skidded, and slid into place on the mounting pad
without disturbing the entrance cables.
3.1.3.4An undercoating over the regular finish or an equivalent treatment shall be applied to all surfaces that are in
contact with the pad to minimize corrosion.
3.1.3.5 Minimum dimensions for Type 1 transformers shall be as shown in Figure 1, Appendix B. Minimum dimensions
for Type 2 transformers shall be as shown in Figure 2, Appendix B.
3.2 SPECIFIC DESIGN REQUIREMENTS
3.2.1 FUNCTIONAL DESCRIPTION
The transformer shall be a single phase, pad mounted, loop feed -safe break, "dead -front" type for use on
a 13.8 kV grounded "Y" distribution system.
3.2.2 DESIGN AND CONSTRUCTION
3.2.2.1 RATING
The transformer shall be rated as follows
a) High Voltage 13.200 Grd. Y/7620 volts
b) Low Voltage 240/120
c) Taps Two - 2'/% FC above and below normal
d) Polarity Additive
e) Capacity, Impedance values, and fusing for transformers in this specification shall conform to Table 1:
3156-120
REV. SYM: FF
Table 1 — Transformer Capacity. Impedance and Fuse Selection
Stock
WA
Min.
Max.
Bay-O-Net
Current Limiting Fuse(s)
Number
Capacity
Impedance
Impedance
Fuse
368-120-130
25
1.77%
2.16%
10 Amp
ELSP 354403OM61M (30 A)
4000353C06
368-120-150
50
1.77%
2.16%
15 Amp
ELSP 354304OM61M (40 A)
4000353C08
368-120-155
50
1.77%
2.16%
15 Amp
ELSP 354304OM61M (40 A)
4000353C08
368-120-170
100
1.95%
2.38%
25 Amp
ELSP 3543080M71M(80A)
4000353C10
368-120-180
167
2.28%
2.79%
40 Amp
ELSP 3543125M71M (125 A)
4000353C12
368-120-190
250
5.75%
6.61%
65 Amp
ELSP 3543125M71M (125 A)
4000353C14
*The BAY-0-NET fuse shall be located in the high voltage side of the compartment.
3.2.2.2INSULATION LEVEL
3.2.2.2.1 The basic impulse insulation level (BIL) of completely assembled high -voltage and low -voltage terminals
shall be 95 kV and 30 kV respectively.
3.2.2.2.2 Dielectric test levels shall be in accordance with the distribution levels in Section 4 of ANSI C57.12.00.
3.2.2.3 HIGH -VOLTAGE TAPS
A no-load tap changer with external operating handle shall provide two - 2'/z% full capacity taps above and
below normal. The tap changer operating handle shall be located within the high -voltage terminal side of the
terminal compartment.
3.2.2.4 NOT USED
3.2.2.5 BUSHING WELLS AND TERMINALS
3.2.2.5.1 The number, location, and arrangement of bushing wells, terminals and parking stands shall be as
shown in Fig. 1 or Fig. 2 in Appendix B. All low -voltage bushings and high -voltage wells shall be
externally clamped and shall have leads of sufficient length to allow them to be changed without
removing the cover. Welded bushings and wells are expressly prohibited.
3.2.2.5.2 High -voltage terminals shall be universal flowerpot bushing wells in accordance with Figure 3 of
ANSI/IEEE 386-1985. Two wells shall be provided and shall be connected in a feed -through
configuration. Loadbreak bushing inserts in accordance with Figure 5 of ANSI/IEEE 386-1985 will be
owner furnished.
3.2.2.5.3 Low -voltage line and neutral terminals shall be sized as shown in Table 2 in accordance with ANSI
C57.12.25. Bushing arrangement and spacing shall be shown in Fig. 1 or Fig. 2 in Appendix B.
Table 2 — Low Voltage Terminal Sizes
Stock Number
kVA Capacity
Low voltage Terminal Size
368-120-130
25
5/8" x 11" UNC-2A copper studs
368-120-150
50
5/8" x 11" UNC-2A copper studs
368-120-155
50
5/8" x 11" UNC-2A copper studs
368-120-170
100
1" x 14" UNC-2A copper studs
368-120-180
167
1" x 14" UNC - 2A copper studs
368-120-190
250
1 %d' x 12 UNF - 2A copper studs.
3.2.2.5.4 The low -voltage X2 bushing shall be a fully insulated bushing. A ground pad shall be provided on the
outer surface of the tank and an external removable cov er ground strap shall be provided and
connected between the low -voltage X2 bushing and the ground pad.
3.2.2.5.5 The high -voltage neutral shall be securely grounded internally.
356-12IJ
REV. SYM: FF
3.2.2.6ACCESSORY CABINET
3.2.2.6.1 The accessory cabinet shall consist of a compartment containing high- and low -voltage bushings
constructed in accordance with applicable ANSI specifications, including ANSI C57.12.28. Dimensions
shall be in accordance with Fig. 1 of this specification.
3.2.2.6.2 Cabinet doors shall be hinged, removable, lockable, and of sufficient size to provide adequate working
space when removed or open. Unlocking the padlock shall permit access to both the high- and low -
voltage terminations. Stainless steel hinge pins shall be provided.
3.2.2.7ACCESSORY EQUIPMENT
Accessory equipment shall be provided_ in accordance with the following details:
3.2.2.7.1 Deleted
3.2.2.7.2 The transformer base shall be arranged for rolling in two directions: Parallel to and at right angles to the
center line of the high -voltage bushings.
3.2.2.7.3 Lifting lugs or bosses for screw -in lift bolts shall be provided. These lugs or bosses shall be adequate
strength and size and arranged on the tank to provide a suitable balanced lift for the completely
assembled unit.
3.2.2.7.4 The base of the assembly shall be provided with suitable means for mounting the unit on the pad. An
internal flange shall be provided at the base of the accessory compartment to provide means for
mounting the unit on the pad. (Fig. land Figure 2, Appendix B).
3.2.2.7.5 Terminal designations are shown in Figure 1 and Figure 2, Appendix B. The identification of terminal
connections shall be shown on the instruction nameplate. Instruction nameplate shall be located in the
low -voltage side and shall be readable with cables in place. Where the nameplate is mounted on a
removable part, the manufacturer's name and transformer serial number shall be permanently affixed to
a non -removable part.
Instruction nameplate shall contain the information specified in 5.12 of ANSI C57.12.00-1987, Nameplate
A. Also, on the nameplate, or label affixed near it, the manufacturer shall indicate that the dielectric fluid
contains less than 1 ppm PCB.
3.2.2.7.6 A suitable marking inside of the tank shall indicate the correct oil level at 25°C.
3.2.2.7.7 An automatic pressure relief device shall be located within the compartment. This device shall meet the
following requirements:
• ''Y4" NPT or larger male Inlet Port.
• Exposed parts of weather and corrosion resistant materials.
• Non -deteriorating gasket and o-ring material.
• Manual pull ring able to withstand 25 pound force minimum.
• Body able to withstand 100 pound shear force minimum.
• Bug shield.
• Cracking pressure of 10 t 2 psig.
• Resealing pressure of 8 t 2 psig.
• Zero leak rate from 8 t 2 psig to -8 psig.
• Minimum flow rate of 35 SCFM at 15 psig.
3.2.2.7.8 An RTE BAY-O-NET current sensing fuse and internally mounted partial range current limiting fuse shall
be furnished as shown in Table 1.
3.2.2.8O1L PRESERVATION
Transformers shall be of sealed -tank construction. Sealed -tank construction is that which seals the interior
of the tank from the atmosphere, and in which the gas plus the oil volume remains constant. The
transformer will remain effectively sealed for a top -oil temperature range of -50C to 105°C.
3.2.2.9 TANKS
The tank shall be domed or sloped to shed water. The tank shall be of sufficient strength to support a
minimum of 500 lbs. vertical load. Construction of the tank shall be in accordance with ANSI C57.12.25-
1981, paragraphs 6.1 and 6.6.
368-12U
REV. SYM: FF
3.2.2.9.1 The cover shall be welded construction.
3.2.2.9.2 Tank grounding provision shall consist of two steel pads, each with 'Y2 inch - 13 NC tapped hole, 7116
inch deep.
3.2.2.9.3 These ground pads shall be welded on the transformer base or on the tank wall near the base, one in
the high -voltage side and one in the low -voltage side. In cases where the transformer tank and
compartments are separate, provisions shall be made for electrically connecting them.
3.2.2.9.4 Locking bolts shall be pentahead.
3.2.2.10 COMPONENTS FOR LOOPED PRIMARY
The minimum current -carrying capability of components for the looped primary cable system shall be 200
amperes (continuous) and 10,000 amperes symmetrical (momentary).
3.2.2.11 AUDIBLE SOUND LEVEL
The audible sound level shall be in accordance with NEMA Standard TR1-1980.
3.2.2.12 BASE PLAN
The base plan of a completely assembled unit shall be such that it can be installed on a pad of the
dimensions shown in Fig. 1 B.
3.2.2.13 PAINT
EEI "Finishing Guidelines" specification shall apply. Finish coat shall be Munsell Green, glossy.
3.2.2.14 LOSSES
The total losses of transformer shall be the sum of the excitation losses and the load losses (I2R losses).
Load loss tests shall be performed and reported on all units regardless of whether or not a record of such
tests is available on duplicate units. Loss evaluations and loss costs will be based on the values shown in
the "Special Conditions and Supplemental Instruction to Bidders." Transformers will be evaluated on
excitation losses and I2R losses at the specified rates. If tested losses exceed quote losses but are within
the tolerances of Table 18, ANSI C57.12.00-1987, the additional cost incurred from the differential of losses
will be calculated using the following equation and the above specified rates and will be deducted from the
original Purchase Order or back charged to the manufacturer. In Table 18 and the following equation "Units"
shall mean "Transformers of the same size and design on one order ".
Excess loss $ _ [No. of units] [(No Load Loss Evaluation $) (Avg. No Load Losses - Quoted No Load
Losses) + (Load Loss Evaluation $) (Avg. Load Losses - Quoted Load Losses)]. If this equation results in a
negative number, no credit will be given the Supplier.
If any unit or units exceed the tolerances of Table 18, ANSI C57.12.00-1987, that unit or units shall not be
shipped without express permission from the City. If accepted, the deduction for excess losses will be based
on the following equation: Excess loss $ _ (No Load Loss Evaluation $) (No Load Losses - Quoted No Load
Losses) But Not Less Than Zero + (Load Loss Evaluation $) (Load Losses - Quoted Losses) But Not Less
Than Zero.
3.2.2.15 SAFETY LABELS
NEMA 1260 Safety Labels shall not be applied by the manufacturer: Purchaser will apply customer warning
labels after delivery.
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4 QUALITY ASSURANCE
4.1 GENERAL
4.1.1 RESPONSIBILITY FOR INSPECTION
Unless otherwise specified, the vendor is responsible for the performance of all inspection requirements
as specified herein. Except as otherwise specified, the vendor may utilize his own facilities or any
commercial laboratory acceptable to the City of Fort Collins. The City reserves the right to perform or
witness any of the inspections set forth in this Specification where such inspections are deemed
necessary.
4.1.2 TEST REPORT
The manufacturer shall furnish to the purchaser certified copies of the results of loss tests prior to
payment. Copies shall be sent to the Design Section as well as with the invoice. Unsigned copies are
not acceptable even if accompanied by a signed cover letter. The Quality Control Manager shall review
and sign each test report.
4.2 TEST CONDITIONS
Unless otherwise specified, testing required by Section 4.4 shall be conducted under the following
conditions:
4.2.1 REFERENCE TEMPERATURE
The reference temperature to which losses, impedance, regulation, and efficiency are corrected shall be
85°C.
4.2.2 TOLERANCE ON IMPEDANCE VOLTAGE
Impedance on completed units shall fall within the range specified herein.
4.2.3 TOLERANCE ON IMPEDANCE VOLTAGE ON A TAP
The percent departure of tested impedance voltage on any tap from tested impedance voltage at rated
voltage shall not be greater than the total tap voltage range expressed as a percentage of the rated
voltage.
4.3 Not used.
4.4 TESTS
The kinds of tests to be performed and the test procedures shall be as specified in ANSI C57.12.20, ANSI
C57.12.00, and C57.12.90 except as specified herein.
4.4.1 DIELECTRIC TESTS
No applied potential test shall be made. The induced -potential test shall be made by applying between
the terminals of one winding a voltage which will develop from high -voltage line terminals to ground a
voltage of 1000 volts plus 3.46 times the rated transformer winding voltage.
4.4.2 IMPEDANCE AND LOAD -LOSS TESTS
Impedance and load -loss tests shall be made on each unit and may not be omitted even if a record of
such tests made on a duplicate unit is available.
6 PREPARATION FOR DELIVERY
Transformers shall be prefilied with the appropriate amount of transformer oil and shall be shipped by open -bed truck.
Units shall be packaged in such a way as to provide for ease of handling and to protect units from shipping damage.
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