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HomeMy WebLinkAboutCORRESPONDENCE - GENERAL CORRESPONDENCE - 3305525 STANDARDTHE CITY OF FORT COLLINS Light and Power Department P.O. Box 580 Fort Collins, CO 80522 SPECIFICATION NO: 368-300 TITLE: PAD -MOUNTED COMPARTMENTAL-TYPE.THREE-PHASE DISTRIBUTION TRANSFORMERS WITH SEPARABLE INSULATED LOAD BREAK HIGH -VOLTAGE CONNECTORS APPROVED BY:L Tim M. Sagen Standards Engineering Division Manager DATE: 8/12/83 REVISED: 9111/01 1 of 26 368-300 REV. SYM: KK 3.2.2.14 PAINT 3.2.2.14.1 Surfaces to be painted shall be blast cleaned (commercial blast) to provide a clean dry surface free of dirt, dust, chalk, loose paint, rust, grease and any other contaminants. 3.2.2.14.2 EEI "Finishing Guidelines" specification shall apply. Finish coat shall be Desert Tan, Munsell #10YR6.0l3.0, glossy. 3.2.2.15 SAFETY LABELS The manufacturer shall not apply NEMA 260 Safety Labels. The Purchaser will apply custom "Mr. Ouch" labels after delivery. 3.2.2.16 ANGULAR DISPLACEMENT: Per Fig. 10(b) of ANSI C57.12.26-1992. 10 368-300 6.s 6.5 4.0 AA 4 113F..❑W CL 4.5 MIN _ —-- MIN + 4. + � A 50 _ 55�A�'�TI + �,Ir 65 t HIE L� + �"" IJH2 IH _ H3A + H3B ""+"" �CL XO X2 _ 27.0 �45�4.5 li 6.5 6.5 4.5 6.5 I 38.0 MIN* — __ —A FLANGE 3/4" MIN 1 V2° WX MIA H2A II3A H3B_H2B T / U �� �� �ulf X3 v 45 MIN � (L COMPARTMENT DIMENSIONS BUSHING (MINIMUM) KVA RATINGS LOW VOLTAGE .HEIGHT RATINGS A' B ALL 23,25 27 75-150 225-500 AI_l 28 ' 31 750-1000 480Y/277,208W120 28 46 I 1500-2500 48JY/227 28 46 NOTE: ' Denotes inside dimensions. ^ See Fig All dimensions in (inches). Maximum dimensions shall allow one inch clearance from edge of pad (Fig. 6), MIN' Figure 1 - Accessory compartment & Bushing Dimensions (Config. 1) REV. SYM: KK 11 368-300 Fes--- i 6 5 M I N- ty 1r- TANK sk}HACE 77- TANK SUR FACE IR - €2 tS DE Eagle Acm"QrY IVaa ciroj Stand Figure 1A — Cable Accessory Parking Stand Detail Figure 2 (Config. 2) - DELETED 7/92 Figures 3 & 4 - DELETED 11/00 Ref. now to: ANSI C57.12.26 - 1992 figures 9(a) & 9(b) REV. SYM: KK 12 368-300 4.0" A A A 4.0" MIN MIN X 1 --J A \ XC3 XO X2 REV. SYM: KK 6" RADIUS TYPICAL 3 PLACES KVA RATINGS 75-150 LOW VOLTAGE RATINGS ALL ALL 480/277, 208Y/120 Low - Voltage Bushing minimum inches). A B 4.75 8 225-500 750-2500 Figure 5 - Staggered (all dimensions 6 8 6 10 Arrangement NOTE: An area having a 6 inch radius around each bushing shall remain clear of obstructions such as gauges, etc. 13 368-300 r B REV.SYM: KK KVA SERIAL PAD DIMENSIONS (inches) A B C D E F 75 -006 thru —009 75 55 40 21 15 61 150 -015 75 55 40 21 15 61 150 -016 75 55 40 21 15 61 300 -030 75 55 40 21 15 61 300 -031 75 55 40 21 15 61 500 -050 75 55 40 21 15 61 500 -051 75 55 40 21 15 61 750 -076, -075 85 72 49 23 15 67 1000 -101,-100 85 72 49 23 15 67 1500 -151 101 87 51 23 15 76 2000 -201 107 88 51 23 15 79 2500 -251 107 88 51 23 15 79 Fig. 6 — Pad Dimensions 14 368-300 REV.SYM: KK TABLE 1A ACCESSORY EQUIPMENT ACCESSORY "A 75-150 300 500-2500 Tap changer handle in HV compartment X X X Instruction nameplate in LV compartment X X X Jacking provisions X X X Provisions for rolling in two directions X X X Lifting lugs X X X Provisions for mounting on pad X X X Arrester mounting provisions Grounding provisions in both compartments X X X 1" oil drain plug X 1"oil drain valve with sampling device X X Upper filter press and filling plug (or cap) (1") X X X Provisions for oil gauge X Provisions for pressure -vacuum gauge X X Oil gauge X Thermometer X X X Secondary CT mounting holes (4 holes on 4 3/8" x 5 5/8" centers) X X X Manual/automatic pressure relief valve X X X 15 368-300 REV. SYM: KK 3.3 SPECIFIC REQUIREMENTS FOR DESIGN OF RADIAL -FEED Units 3.3.1 FUNCTIONAL DESCRIPTION The transformer shall be a three phase, pad mounted, radial feed safe break, "deadfront" type for use on a 13.8 W grounded "Y" distribution system. 3.3.2 DESIGN AND CONSTRUCT ION The requirements for radial -feed transformers shall be the same as those of loop -feed with the following exceptions: 3.3.2.1 RATINGS Table 2 - Radial -Feed Transformer Ratinos Stock No. kVA Low Voltage Impedance Bushing T e/Confi . Hi h Voltage Low Voltage 368-300- 006 75 208Y/120 1.9% O ®© 368-300- 007 75 480Y/277 1.9% O OO Per Figures 5A, & 7 of ANSI C57.12.26-1992 (In -Line) EXCEPTION: high voltage bushings shall be 32 - 36 inches above the base of the transformer ® Figures 9(a) & 9(d) of ANSI C57.12.26 - 1992 (stud with 4-hole pad) © Figure 8(a) of ANSI C57.12.26-1992 (Staggered) 3.3.2.2 ACCESSORY CABINET The accessory cabinet shall be dimensioned in accordance with Fig. 7 of ANSI C57.12.26-1992. 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 all 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 defined in Section 4.6 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 850 C. 4.2.2 TOLERANCE ON IMPEDANCE VOLTAGE Tolerance shall be as specified in ANSI C57.12.00. 16 368-300 REV. SYM: KK 4.2.3 TOLERANCE ON IMPEDAN CE 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 FUNCTIONAL TESTS Functional tests shall consist of those tests and related requirements as cross referenced in Table 2A and shall be performed on each unit, except Temperature and Noise Tests which shall be performed on one unit of each design (KVA) per order. Table 2A - Functional Tests TEST TEST PARAGRAPH REQUIREMENT OR REFERENCE Examination Of Product 4.6 3.0, 3.1, 3.2, 3.3 This specification) Ratio 4.6 ANSI C57.12.00 Section 8 Polarity And Phase Relation 4.6 ANSI C57.12.00 Section 8 Excitation Loss 4.6 ANSI C57.12.00 Section 8 Excitation Current 4.6 ANSI C57.12.00 Section 8 Impedance & Load Loss 4.6 ANSI C57.12.00 Section 8 Temperature Tests' 4.6 ANSI C57.12.00 Section 8 Dielectric Tests 4.6.1 3.2.2.2 This specification) Impulse Tests 4.6.2 3.2.2.2 This specification) Leak Testing 4.6.3 3.2.2.8 & 3.2.2.9 This specification) Noise Testing* 4.6.4 3.2.2.12 This specification) "One unit per design per order. 4.4 TEST METHODS -- FUNCTIONAL TESTS Each completed unit shall be inspected to determine compliance with respect to dimensions, material, workmanship, construction and marking, and routine tests on all units shall be made as specified in Section 8 of ANSI Standard C57.12.00, and in ANSI Standard C57.12.90. In addition to routine tests, the following test requirements and/or modifications shall apply. 4.4.1 DIELECTRIC TESTS Induced and applied potential Dielectric Tests shall be performed in accordance with ANSI C57.12.00 and C57.12.90. The low voltage windings shall have a test potential to ground of 10,000 volts for one minute. The test potential between high voltage windings shall be 34,000 volts for one minute. 4.4.2 IMPULSE TESTS ANSI Standard Impulse Tests shall be performed. Full Wave Impulse Test shall use a 1.5 x 50 microsecond wave. 4.4.3 LEAK TESTING The transformer tank shall be filled with oil and tested for air and oil leaks under (1) 4 psig vacuum for '/z hour, (2) 7 psig pressure for 24 hours in the sequence indicated. An alternate method of leak testing may be performed by injecting halogen gas under 10 psig and detecting leaks through the use of a halogen detector. (Note, the automatic/manual pressure relief device must be removed for this test). 4.4.4 NOISE TESTING Noise testing shall be conducted in accordance with applicable NEMA Standards. 5. PREPARATION FOR DELIVERY Transformers shall be prefilled 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. Units shall be fully palletized in four-way universal pallets with 28" minimum openings to facilitate handling from any side. Pallets shall be independent of the transformer. The Supplier shall give 24-hour notice prior to delivery for any shipments where an individual transformer weighs over 4,000 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. 17 368-300 REV. SYM: KK 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 refers to the equipment defined by this specification. • DC or d.c. - Direct Current. • AC or a.c. - Alternating Current. • °C - Degree Celsius (Centigrade) • OF - 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. REV.SYM: KK APPENDIX A Typical pad designs are shown in Figures 1A through 3A. The dimensions in inches of Figures 1A through 3A will fit the minimum compartments on transformers covered by this Specification as well as the maximum transformer envelope. 19 368-300 REV. SYM: KK ITEMS COVERED BY THIS SPECIFICATION DESCRIPTION STOCK NO. SPECIFICATION NO. SERIAL 75 KVA, 208Y/120 RADIAL 368-300 -006 75 KVA, 408Y/277 RADIAL 368-300 -007 75 KVA, 208Y/120 LOOP 368-300 -008 75 KVA, 480Y/277 LOOP 368-300 -009 150 KVA, 208Y/120 LOOP 368-300 -015 150 KVA, 480Y/277 LOOP 368-300 -016 300 KVA, 208Y/120 LOOP 368-300 -030 300 KVA, 480Y/277 LOOP 368-300 -031 500 KVA, 208Y/120 LOOP 368-300 -050 500 KVA, 480Y/277 LOOP 368-300 -051 750 KVA, 208Y/120 LOOP 368-300 -075 750 KVA, 480Y/277 LOOP 368-300 -076 1000 KVA, 208Y/120 LOOP 368-300 -100 1000 KVA, 480Y/277 LOOP 368-300 -101 1500 KVA, 480Y/277 LOOP 368-300 -151 2000 KVA, 480Y/277 LOOP 368-300 -201 2500 KVA, 480YI277 LOOP 368-300 -251 368-300 551 - J-3., 1S" PRIMARY SEC - FRnN- L Imo— 213" —f 1 )' FOUR 43 REBAR LENGTH AND WIDTH 0 40' 3" 3" i — Notes on Pad Ii 1. Corcrete must be 3,000 psi minimc-n. 2__ Veximurr coarse aggregate size ' 1/2 inches. Space requirements for pad one primary swltcring cabinet will gererally be 9X 12'_ Facto-,, to be conside-ed n ocating tie pod Include - Accessibl i[y - The transformer pad shall be accessible to ine boom tracks equipped for toe Installation one removal of ,eavy trahsform ers. Suce accessibility shall not requi,e intrusion on ad,ecent property. 2. Proximity of Bcildings, Walls, Barriers, and/or Overhangs - n addition to the clearances required for irstallation and -emoval, the min mum clearance In front of the transformer pad stall be eight (8) fee: arc the minimuri cleerarce from al' nfher sides shobe three (3j feet_ f the bulding has an cverhang, clearance to '.he edge of t'ne transformer pod shall be measures horizontally from the outer edge of the overharq_ ransform ers through 300 KVA may be nstol ed under the overharg if the vertical clearance between the pad and the overharg is or least 25 feet and the location is accessible to I'ne boom trucks. Codes and Standards - In ocditiion to tie above, the 'nstailation shall conform to the Notarial Electric Code and federo, stele and cry codes arc standards. L S ! 93 R V Nam.---DAT- - nr a' rwr cauxe LIONT end POWER REV. SYM: KK I DwNLD.E. A P P DSNG. ENC APP DIST. APP COLLINS DWG 3PHASCI -IGH I AND POWER LiLPARTMEN` TRANSEORMER PAD DESIGN 5 — 500 KVA 3 PHASE Figure 1 A - Pad Design (75 - 500 KVA) li JOO-OUV REV. SYM: KK 85" II -- j - - 15" PRIMARY SE: ❑NCARv �T 72' 18' 2c" 23- - — 18' ---� - IIWR 43 REBAR LENGTH AN' WIBTII 7 C,6" 1 - - -- T Nolcs on Pad Materici - 1 Concrete must 'oe 3,000 psi minimum. 2_ vlax'mum coarse aggregcte size 1 1/2 inches. Sacce requirements for pad and primary switchirq cabinet will generally be 9' x 12. Factors to be considered in locating the poc include - 1. Accessbillty - ]he transformer pad shell be accessible to line boom trucks egHippec for the instollalien cnd removal of heavy transformers. Such accessbillty shall not require intrusion on adjacent proaer;y_ 2. Proxim'ty of Buildings, Walls, Barriers. and/or Overhangs - In cddition to the clearances required for installation and removal, the min,mum clearance in front of the transformer pea shall be eight (8) feet and the minlmum clegronce `-om at other sides shall be four (4) feel. If the building nos an overhang, clearance to the edge of the transformer odd shot be meosurec hodzontaily from the outer edge of the overhang. frons`ormers tarougl' 3-0 KVA mcy be installed uncer the overharg I' the vertical clearance between the peal end the overharg is at least 25 feet and the location is accessible to line boom trucks. S. Codes acd Standards - In addition to the dbcve, the instalrotion shall conform to the National Electric Coce and fecerel, state and city cases and scancards. 11 /02/90 RI V NG DATE DWN D.E. APF DSNG. ENG APP DIST_ APP -- CI AY OF FORT COLLINSIDWG 3PHASE2 LIGHT AND F'0'�IER D�PARfz IMENT TRANSFORVER PAD DESIGN 500 — '000 KVA LwMr mina POWER 3 PHASE Figure 2A - Pad Design (500 - 1000 KVA) 21 368-300 - 8 - f p"gor 15' WINDOW SECONDARY ff• �, II - FRLiNr� - --1I' � -� , t[VF 45 RFBAR LENGTH AND WIDTH Kates on fad `Sateriol Concrete must be 3,000 psi minimum_ 2. Maximum coarse aggregate size 1 '12 inches Space requirements for pad and primary switching cabinet witeenerolly be 9' X 12'. Factors to be consiaered Ic Iocatirg the pad Include — 1. Accessibility — The transformer pod shall be accesslbla to ine boom trucks equipped for the inslalla Lion and removal of reavy transformers. Such accessibility sha'.I not regcire iitrus'or on adjacent property. 2. proximity of du ldings, Walls, panniers, andFor Overhangs — In addition to tie ceorcnces roqulred for installation and removal, the mirtmum cleararce Ir -ont of the tronsfo^ner pod shall be eight (8) feet and the minimum clearance from ail other side shall be four (/ feet_ If :he building has an overhang, clearancc to the edge of the transformer pad shal be rncasured horizontally from the outer edge of the overhang. Transformers through 3K KVA may be '.nstallec urder the overhanc if the vertical clearnnce between the pad erd tnc overecne is of least 25 feet and the Inaction Is accessible co lire boom trucks. S. Codes and Standards n additlor tc tie above, the installation shall co,forne to tie Nai,onol Electric f:odc and federal, state and city codes one standards. RCV NO_ DATE CITY 4 •OAT CpllfY LIGHT end POWCR REV. SYM: KK DWV � DDJAPP CSNG ENG APP DIST APP CITY 0 EORT : 01 � INS DWG 3PHASC3 LICH AND `0'1,NER DEFT,-� IMEN- _ IN/ N E F 0 R M I N-PAD DESIGN 1000 - 2G00 KVA 7-PHASE Figure 3A - Pad Design (1000-2500 KVA) 22 368-300 REV. SYM: KK APPENDIX B 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 manufacturer 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. TABLE 3B MANUFACTURER SERIAL NO. Cooper Power Systems All ASEA Brown-Bovari All Howard Industries All Pauwels Transformers 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. 23 368-300 APPENDIX C The following forms for Individual and Average Transformer Losses are used by the City of Fort Collins to determine loss penalties. 1) Transformer Loss Evaluation Average Losses Form 2) Individual Transformer Loss Evaluation Form 94 1500-SUu TRANSFORMER LOSS EVALUATION - AVERAGE LOSSES City Order No. Manufacturer KVA/U LINE DESCRIPTION (1) No. of units (2) Average core losses (3) Quoted core losses S/N Invoice No. (4) Excess average core losses: line (2) less line (3) (5) Penalty for excess average core losses: line (1) x line (4) x $ (6) Average copper losses (7) Quoted copper losses (8) Excess average copper losses: line (6) less line (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: KK 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. City Order No. Manufacturer KVA/Unit LINE (1) (2) (3) (4) (5) (6) (7) (8) 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 Percent difference Line (3)- line (2) x 100 Tested total losses Quoted total losses Excess total losses Line (5) less line (6) but not less than zero. Percent difference Line (7) - line (6) x 100 Tested copper losses Quoted copper losses Excess copper losses Line (9) less line (10) but not less than zero. Penalty for excess core losses Line (3) x $ Penalty for excess copper losses Line (11) x $ Penalty to be assessed manufacturer Line (12) plus line (13) Bv: Design Engineering AMOUNT REV. SYM: KK 368-300 REV. SYM: KK REVISION DESCRIPTIONS REVISION DESCRIPTION Previous on file APPROVED REVISION FF: Tim Sagen • Add Paragraph 5.2.2.9.3: pentahead locking bolts Susan Coram • Paragraph 3.2.2.13.1: add glossy requirement. 10-18-95 REVISION GG: Susan Coram • Title page: Remove revised date Tim Sagen • Paragraph 4.4 and Table 2A: Change Temperature Tests and Noise Test from every 9-22-95 unit to one unit of design. REVISION HH: Opal Dick • GE removed from Appendix B Tim Sagen 12-13-96 REVISION II: • Add paragraph 3.2.2.10 OVERCURRENT PROTECTION and renumber remaining paragraphs in section 3.2 Opal Dick • Revise Fig. 1 to reflect a "V" configuration for the primary bushing arrangement vs. an Tim Sagen in -line arrangement. 6/3/99 • Revise Fig. 17 to remove requirement for CT mounting studs and increase dimensions A from 5' and 5.5" to 6" on 225-2500 kVA sizes REVISION JJ Bill Bray • Reformat and converted to MS Word, delete List of Active Pages Tim Sagen 9/14/2000 REVISION KK Kraig Bader • Added drawing 1 a to describe cable accessory parking stand detail Tim Sagen • Revise to reflect current editions of national standards 9 / 11 / 2001 • Change impedance on 368-300-009 from 1.7% to 1.9%. TABLE OF CONTENTS ITEMS COVERED BY THIS SPECIFICATION........................................................ REVISION DESCRIPTIONS......................................................................................... 1. SCOPE.......................................................................................................................... 2. APPLICABLE DOCUMENTS................................................................................... 3. REQUIREMENTS....................................................................................................... 3.1 GENERAL REQUIREMENTS FOR DESIGN ....................................................... 3.2 SPECIFIC REQUIREMENTS FOR DESIGN OF LOOP -FEED UNITS .............. 3.3 SPECIFIC REQUIREMENTS FOR DESIGN OF RADIAL -FEED UNITS.......... 4. QUALITY ASSURANCE............................................................................................ 4.1 GENERAL............................................................................................................... 4.2 TEST CONDITIONS............................................................................................... 4.3 FUNCTIONAL TESTS........................................................................................... 4.4 TEST METHODS -- FUNCTIONAL TESTS......................................................... 5. PREPARATION FOR DELIVERY........................................................................... 6. DEFINITIONS AND ABBREVIATIONS................................................................. APPENDIXA................................................................................................................... APPENDIXB.................................................................................................................... APPENDIXC..................................................................................................................., TRANSFORMER LOSS EVALUATION - AVERAGE LOSSES .......................... INDIVIDUAL TRANSFORMER LOSS EVALUATION ........................................ REV. SYM: KK ............................................................... 2 ............................................................... 3 ............................................................... 5 ............................................................... 5 ............................................................... 5 ............................................................... 5 ............................................................... 7 .............................................................16 .............................................................16 ............................................................. 16 .............................................................16 .............................................................17 ............................................................. 17 .............................................................17 ............................................................18 .............................................................19 ............................................................ 23 ............................................................. 24 ............................................................ 25 ............................................................ 26 4 368-300 SPECIFICATION FOR PAD -MOUNTED COMPARTMENTAL -TYPE, THREE-PHASE DISTRIBUTION TRANSFORMERS WITH SEPARABLE INSULATED LOAD BREAK HIGH -VOLTAGE CONNECTORS 1. SCOPE REV. SYM: KK This Specification establishes the minimum electrical requirements and mechanical features of three phase, 60 HZ, mineral oil immersed, self -cooled, pad -mounted, compartmental -type distribution transformers rated 2500 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 to ANSI requirements for pad -mounted compartmental -type, self -cooled, three-phase, distribution transformers for use with separable insulated high -voltage connectors, C57.12.26. 2. APPLICABLE DOCUMENTS The following documents form a part of this Specification to the extent specified herein. The latest issue in effect on the date of invitation for bids shall form a part of this Specification, unless otherwise noted. • ANSI C57.12.00 - Distribution, power, and regulating transformers, and shunt reactors, general requirements for • ANSI C57.12.26 - Pad mounted, compartmental -type, self -cooled three phase, distribution transformers for use with separable insulated high voltage connectors, high voltage 34,500 Grd Y/19,920 volts and below, 2500 kVA and smaller, requirements for • ANSI C57.12.70 - Terminal markings and connections for distribution and power transformers • ANSI C57.12.80 - Terminology for power and distribution transformers • ANSI C57.12.90 - Distribution, power, and regulating transformers, and shunt reactors, test code for • ANSI/IEEE 386 - Separable insulated connectors for power distribution systems above 600V • NEMA STANDARD TR1 - Transformers, regulators and reactors 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) ANSI C57.12.26 c) Other applicable ANSI and NEMA Standards. 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 80°C hot spot temperature rise. The temperature rise of the insulating oil shall not exceed 650C when measured near the top of the tank. The temperature rise is based on an altitude of 3,300 feet. 3.1.3 GENERAL CONSTRUCTION 3.1.3.1 The pad -mounted compartm ental-type transformers shall consist of the transformer tank, high -voltage cable terminating compartment, and the low -voltage cable -terminating compartment. All three of these components 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, except the main cover bolts may be exposed. Where the main cover bolts are exposed, the 368-300 REV. SYM: KK corner bolts shall be welded or otherwise rendered tamperproof. 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 compartment shall be on the right. 3.1.3.3 Construction of the unit shal I be such that it can be lifted, skidded, and slid into place on the mounting pad without disturbing the entrance cables. 3.1.3.4 An 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 shall be as shown in Fig. 1 of this Specification. Maximum transformer and minimum pad dimensions are shown in Fig. 6 of this Specification. 3.1.4 LOSSES The total losses of a transformer shall be the sum of the excitation losses and the load losses (12R 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 Instructions to Bidders." Transformers will be evaluated on excitation losses and 12R losses at the specified rates. If tested losses exceed quoted losses but are within the tolerances of paragraph 9.3, ANSI C57.12.00-2000, 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 paragraph 9.3, ANSI C57.12.00-2000, 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. 3.1.5 SERVICE CONDITIONS Service conditions shall be as defined in paragraph 4.1 of ANSI C57.12.00 except the ambient temperature range shall be 40°C above to 320C below zero. The transformer shall operate safely with starting temperatures as low as 32°C below zero. 368-300 REV. SYM: KK 3.2 SPECIFIC REQUIREMENTS FOR DESIGN OF LOOP -FEED Units 3.2.1 FUNCTIONAL DESCRIPTION The transformer shall be a three phase, pad mounted, loop feed -safe break, "deadfront" type for use on a 13.8 kV grounded "Y" distribution system. 3.2.2 DESIGN AND CONSTRUCT ION 3.2.2.1 RATINGS Table 1 - Loop -Feed Transformer Ratinas Stock No. WA Low Voltage Impedance Bushing T pe/Confi . Hi h Volta a Low Voltage 368-300- 008 75 208Y/120 1.9% D OO 368-300- 009 75 480Y/277 1.9% i0 OO 368-300- 015 150 208Y/120 2.1 % iD OO 368-300- 016 150 480Y/277 2.1 % i0 OO 368-300- 030 300 208Y/120 2.5% iD OO 368-300- 031 300 480Y/277 2.5% ( OO 368-300- 050 500 208Y/120 3.04% ( OO Os 368-300- 051 500 480Y/277 3.04% D OO 368-300- 075 750 208Y/120 5.75% 0 Os 368-300- 076 750 480Y/277 5.75%O Os 368-300- 100 1000 208Y/120 5.75% iD Os 368-300- 101 1000 480Y/277 5.75% D Os 368-300- 151 1500 480Y/277 5.75% O (3 368-300- 201 2000 480Y/277 5.75% D Os 368-300- 251 2500 480Y/277 5.75% iD Os OFigure 1 (V-config.) of this specification OO Low -voltage line and neutral terminals shall be stud type bushings in accordance with ANSI C57.12.26-1992, Fig. 9(d) and shall include a separate spade with NEMA standard drilling ® Figure 9(a) of ANSI C57.12.26 - 1992 (4-hole pad) (3) Figure 9(b) of ANSI C57.12.26 - 1992 (6-hole pad) 3.2.2.2 INSULATION LEVEL 3.2.2.2.1 The basic impulse level (BIL) of the completely assembled transformer, including 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 Paragraph 5.10 of ANSI C75.12.00-2000 3.2.2.2.3 The unit shall withstand test voltages in accordance with ANSI C57.12.00 and impulse tests in accordance with NEMA Standards for Transformers, Publications No. TR1. 3.2.2.3 TRANSFORMER CORE A five -legged core -coil assembly or three separate core -coil assemblies shall be employed. The use of three-legged designs is expressly prohibited. 7 368-300 REV. SYM: KK 3.2.2.4 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 operating handle shall be mounted in the primary compartment. 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 and Fig. 5 of this specification. 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 he cover. Welded bushings and wells are expressly prohibited. 3.2.2.5.2 High -voltage bushing wells s hall be 200A load -break interface 8.3/14.4 kV bushings in accordance with ANSI/IEEE Std. 386. 3.2.2.5.3 Low voltage bushing arrange ment and spacing shall be "staggered", as shown in Fig. 5 of this Specification. 3.2.2.5.4 The low -voltage neutral shal I be a fully insulated bushing. A ground pad shall be provided on the outer surface of the tank and a removable copper ground strap shall be provided and connected between the low -voltage neutral bushing and the ground pad. 3.2.2.5.5 The high -voltage neutral sha 11 be connected to the low -voltage neutral internally with provision for opening this connection for testing. 3.2.2.6 ACCESSORY CABINET 3.2.2.6.1 The accessory cabinet shall consist of a high -voltage and low- voltage compartment generally constructed in accordance with applicable ANSI specifications and dimensioned in accordance with Fig. 1 of this Specification. 3.2.2.6.2 Cabinet doors shall be hinged, removable, and lockable. Stainless hinge pins shall be provided. 3.2.2.7 ACCESSORY EQUIPMENT Accessory equipment shall be provided in accordance with Table 1A and the following details: 3.2.2.7.1 Suitable jack bosses or equi valent jacking facilities shall be provided on the tank. Vertical clearance for a jack shall be 1'/z inches minimum, 3'/z inches maximum. 3.2.2.7.2 The transformer base shall b e arranged for rolling in two directions: Parallel to and at right angles to the centerline of the high -voltage bushings. 3.2.2.7.3 Four lifting lugs shall be provided. These lugs shall be adequate strength and size and arranged on the tank to provide a suitable lift for the completely assembled unit. 3.2.2.7.4 The base of the assembly sh all 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. 1). 3.2.2.7.5 Terminal designations are sh own in Figure 1. The identification of terminal connections shall be shown on the instruction nameplate. Instruction nameplate shall be corrosion resistant, located in the low -voltage compartment, 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 ANSI C57.12.00-2000, paragraph 5.12. In addition, either on the nameplate or label affixed near it, the manufacturer shall indicate that the dielectric fluid is non -PCB. 368-300 REV. SYM: KK 3.2.2.7.6 An automatic pressure relief device shall be located within the compartment. This device shall meet the following requirements: • '/Z 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 force minimum. • Bug shield. • Cracking pressure of 10 t 2 psig. • Resealing pressure of 6 psig minimum. • Zero leak rate from resealing pressure to —8 psig. • Minimum flow rate of 35 SCFM at 15 psig. 3.2.2.8 OIL 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 —320C to 105°C. 3.2.2.9 TANKS The tank shall be domed or sloped to shed water and shall be of sufficient strength to support a minimum of 500 lbs. Construction of the tank shall be in accordance with ANSI C57.12.26-1992, Section 7, except bolted cover is preferred. 3.2.2.9.1 If main cover is welded, adequate handhole(s) shall be provided. Handholes shall be concealed. Bolted -on covers shall be adequately gasketed and tamperproof. Main cover bolts may be exposed; however, where cover bolts are exposed, the corner bolts shall be welded or otherwise rendered tamperproof. 3.2.2.9.2 Tank grounding provision sh all be in accordance with paragraph 7.6.4 of ANSI C52.12.26-1992. 3.2.2.9.3 Locking bolts shall be penta head style. 3.2.2.10 OVERCURRENT PROTECTION Overcurrent protection consisting of a Cooper Power Systems ELSP oil -immersed partial range current limiting fuse in series with a Cooper Power Systems oil -immersed current sensing weak link cartridge shall be provided. Fuses shall be sized to meet the following criteria • Withstand 25 times transformer rated load current for 0.01 second • Withstand 12 times transformer rated current for 0.1 second • Withstand 3 times transformer rated load current for 10 seconds • Allow not less than 140% nor more than 200% continuous overload • Clear fault at 3 to 4 times transformer rated current in 300 seconds. 3.2.2.11 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). 3.2.2.12 AUDIBLE SOUND LEVEL The audible sound level shall be in accordance with NEMA Standard TR1. 3.2.2.13 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. 6 of this specification.