ifb 18-06 transformer addendum 2 - huntsville utilities...modified by this specification, shall be...

Huntsville Utilities IFB 18-06 Transformer BidAddendum 2

A. Reminder for bid extension.1. The new bid due date is March 27, 2018 at 2:00 CDT PM.

B. Updated Specifications1. EED 105.39.7_2_22_18 (name correction-not attached)2. EED 105.39.8_2_22_18 (name correction-not attached)3. EED 105.39.9_2_22_18 (name correction-not attached)4. EED 105.15.4_12_20_175. EED 105.39.10_12_20_176. EED 105.39.11_12_20_17

C. Questions/Exceptions from Specifications

Please note Addendum(s) on proposal packets.

H u ntsville Utilities IFB 18 -06 TransformerB idA d d end u m 2

1. Stand ard warrantywillbe in effect.Stand ard warrantyis acceptable provid ed itmeets orexceed s warrantyprovid ed in H u ntsville Utilities bid package.

2. Stand ard packinglistwillbe provid ed .Stand ard packinglistis acceptable provid ed itmeets ou rspec whichcalls foraweatherproof tagind icatingH u ntsville's commod ity nu mberand P O to beattached to the transformer.

3. M ay we no qu ote anyitems whichexceed ou rcapability/capacity,ormu stwe qu ote everyitemin agrou p? The blanketwillbe award ed in grou ps i.e.overhead ,single phase pad mou nt,threephase pad mou nt.If there are anyline items in agrou pthatare no bid byavend or,H u ntsvilleUtilities reserves the rightto award thatgrou pminu s those line items to the respective vend or.

4. N o ind ication thathighvoltage taps are requ ired .Is thatcorrect?Y es.Transformers withhighvoltage taps willbe specialord eritems.

5. M ay we provid e ou rstand ard pressu re relief valve ratherthan qu alitrol?H u ntsville Utilities willrequ ire the specified qu alitrolvalve.

6. W hatis H u ntsville Utilities’d rawingrequ irements? Stand ard approvald rawings are generallyacceptable.If you thinkthere is somethingwe may requ ire thatyou d o notprovid e pleaseprovid e asample d rawingforevalu ation.

H u ntsville Utilities E lectricalE ngineeringD epartmentS ingle-P hase,O verhead,D istribu tion TransformerS pecificationsS ingle V oltage and D u alV oltage S pecifications D ated S eptember2012

1.Section 9.3,Item # 9,requ ires the externald imensions to be provid ed on C TR.H owardInd u stries onlyprovid es exteriord imensions on sales & approvald rawings.W e d o notpu td imensions on C TR.W illthis be acceptable to H u ntsville Utilities?This is acceptable.

2.Section 17 .1 (single voltage)& Section 16.1 (D u alvoltage)requ ire eachtransformerto besecu red to the palletwithtwo steelband s.W e u ses plastic band inginstead of steelband ing.P leaseconfirm if this is acceptable.H ighstrengthnylon orsimilarmaterialis acceptable.(per2007 response)

H u ntsville Utilities E lectricalE ngineeringD epartmentS ingle-P hase,P ad-mou nted,D istribu tion TransformerS pecificationsS ingle V oltage and D u alV oltage S pecifications D ated S eptember2012

1.Sections 13.3and 13.7 (single voltage)& Section 13.2 and 13.6 (d u alvoltage)W e wou ld likeapprovalto u se H oward Ind u stries highvoltage and low voltage bu shings forthis bid .H u ntsvilleUtilities granted approvalforthe 200 8 bid forH oward bu shings bu ttheyd id notgetinclu d ed intheirlatestspecs.The H Ibu shingwelland low voltage bu shingsu bmitted forapprovalareacceptable.(per200 7 response)

2.Sections 16.4 (single voltage and d u alvoltage)B othsingle phase pad specs callforstainlesssteelsecu ritybolts.H oward Ind u stries wou ld need to take exception to this requ irement.Ithasbeen ou rexperience thatstainless steelsecu ritybolts willnotpreventgalling.H oward Ind u stries


provid es silicon bronze secu ritybolts to preventgalling.These have been u sed on allsingle phasepad s bu iltbyH oward Ind u stries since year2000.This is acceptable.

(The above qu estions also applyto the Three P hase P ad -mou nted Transformers as wellas theSingle-P hase P ad -mou nted Transformers)

H u ntsville Utilities E lectricalE ngineeringD epartmentThree-P hase,P ad-mou nted,D istribu tion TransformerS pecificationsS ingle V oltage and D u alV oltage S pecifications D ated S eptember2012

1.Sections 19.1 (single voltage and d u alvoltage)The C ooperC L Fs requ ired bythe specs willsoonbe obsolete.C ooperhas new C L Fs thatwillreplace these.H oward Ind u stries has provid ed theC oopertechnicald atafortheirnew C L Fs (see attached )Und erevalu ation.

2.Sections 14.2 B u shingd esignations,kV A ,P rimaryvoltage,and second ary voltage are requ iredto be stenciled on the u nits.W illH u ntsville Utilities acceptd ecals? This wou ld allow u s to u sescannable barcod es whichhelps withqu alityassu rance.The exteriorKV A ,P rimaryvoltage,andsecond aryvoltage mu stbe stenciled .A scanable barcod e maybe u sed as well.Interiorbu shingscan be d esignated withd ecals.

3.Spec d ated Sept2012 shows primaryvoltage of 1247 0Y /7 200 in three phase pad specification.EED 105.39/6 revised N ovember16,2004 withprimaryvoltage of 1247 0 D eltais shown on theinqu iryforitems are 32-52.These bases are on the cu rrentspread sheetwiththe primaryvoltagebeing1247 0 D elta.N eed confirmation thatthe primaryvoltage is 1247 0 D elta.These are the sameas the lastbid ,ithas notchanged .Theyare 1247 0 D eltau nits.System voltage is 1247 0Y /7 200.

P olemou nttransformers:

1. Shellform u nits willnothave interlaced second aries.Shelltype non-interlaced d esigns are notacceptable.

2. N ameplates willbe laseretched anod ized alu minu m.H u ntsville Utilities willnotacceptanod ized A lu minu m.

3. O u r100 KV A and 167 KV A transformers willbe shelltype non-interlaced coild esigns.Shelltype non-interlaced d esigns are notacceptable.(H u ntsville Utilities reserves the righttoevalu ate those u nits separately.)

4. Is thermosetpolyestermaterialacceptable forlow voltage bu shinghou sing(H U has been u singforfive years)?Y es.

P ad mou nttransformers:

1. P entahead boltwillnothave arollpin bu tratheracompression washer.H u ntsville Utilities willrequ ire the rollpin.

2. P entahead boltwillnotbe stainless steelbu trathersilicon bronze.This is acceptable.

3. Stand ard non P C B labeland nameplate willbe provid ed .


P C B labelis acceptable provid ed itd oes state less than 1P P M in ad d ition to nonP C Bid entification on the nameplate.N ameplate mu stmeetH U specifications.

4. Stand ard testreport(withou texteriord imensions)willbe provid ed .This is acceptable provid edthe d imensions are provid ed on the sales and approvald rawings.

5. Stand ard pallets willbe provid ed .W e willrequ ire 4”x 4”minimu m forthe pallets.

6. W illbe lagbolted to the palletinstead of band ed .This is acceptable.

7 . W e can provid e athree-legged core foryou rD eltau nits instead of a5-legged core.Is a3-leggedC ore acceptable?N o.W e requ ire a5-legged core.

8 . C an we provid e L V porcelain bu shings where appropriate instead of A L L u nits withepox ybu shings?N o.W e willrequ ire epoxy.

9. D u alvoltage d rawings shows amaximu m wid thof 7 7 ”bu tnotsingle voltage,maywe exceed7 7 ”on the D u alvoltage and mu stwe meet7 7 ”on the single voltage? W e willallow u pto 95”wid e on large KV A u nits.

10.D istance between L V bu shings,spec requ ests 6”d esign is 6.5”.6”is aminimu m requ irement6.5”is okprovid ed you d o notexceed overallwid threqu irements.

11.Eachmanu factu rershallfu rnishH u ntsville Utilities withcertified proof,by serialnu mber,thateachtransformerd esign conforms to the shortcircu itrequ irements covered in A N SI/IEEEStand ard C 57 .12.00,Section 7 ,latestrevision,and A N SI/IEEE Stand ard C 57 .12.90,Section 12,latestrevision.C an we provid e certification on u nitd esigns notbyserialnu mber? Thatisacceptable provid ed this information is from an exactd u plicate of the requ ested serialnu mber.

12.C larification:Exteriord imensions willbe provid ed on ou tline d rawings whichaccompanytestresu lts (para10.6.1).D imensions can be provid ed on ou tline d rawings orsimilard ocu ments,bu ttheyshallbe su bmitted withtestreports.

13.W e willprovid e highvoltage bu shingC ooperpart# B W 150F,is thatacceptable? Y es.

14.C an we provid e 12 hole spad e bu shingin lieu of 10 hole? This is acceptable provid ed thespacinghorizontallybetween the holes is notd ecreased .

15.A bove 150 KV A replacementof the low bu shingwillrequ ire openingof the bolton covertoaccess.This is acceptable provid ed access is possible.

16.Is atype A N SItype B nameplate acceptable forallKV A sizes?Y es.

17 .A re two bolts (one 6”from the topand one 6”from the bottom)foraccess to the highvoltagecompartmentacceptable?Y es.


18 .W e u se a¾”non slotted hole forH V compartmentd oors,is this acceptable? Y es.

19.O n the H V d oorwe u se a1”d iameterstainless flatwasherbetween the d oorand hold ingd evice,is this acceptable? Y es.

20.O n the H V d oorthe washerbetween the springis brass notstainless steel,Is this acceptable?Y es.

21.A re 2 ½”hinges acceptable? N o,they mu stmeetou rspecification of aminimu m of 3”.

22.C an we boltthe transformerto the palletinstead of band ing? N o.

23.H u ntsville Utilities fu singspecifications chartin the three phase pad mou nted transformerspecifications appears to be ou tof d ate.The C ooperchartfortheirreplacementfu ses is attached .

240-98 .pd f

24.W e can onlysu pplyan u ngrou nd ed H V neu tralon 1247 0Y x 24940Y with240 d elta.Shou ld weprovid e aseparate H 0 bu shing(N otgrou nd ed )foorthese particu laritems,orleave the H Vneu tralinternallyisolated and floating? Grou nd ed -W ye primaryis notavailable withthe D eltasecond ary.O n stand ard 240 voltd eltasecond ary this is notacceptable.

25.In reviewingd esigns we bu iltH u ntsville some years ago,Inote the tanks are largerthananticipated .The reason forthe extraheightis thatH u nstville d rawings show the on-off switch6”minimu m above the highestbu shing,on the same line as the B ayonets.Since B ayonets are atthe oillevelline,bu tthe switchmu stbe u nd eroil,6”minimu m on the switchforces atallertankthan 6”minimu m forthe B ayonets.P age 2 d rawingsays the switchmaybe located perthemanu factu rers d iscretion,“within the d imensionalrestrictions”of page 3.W e cou ld red u ce tanksize bylocatingthe switchtoward the centerof the highvoltage,d own in the “V ”of thebu shings.M u stthe switchbe 6”minimu m above the highestbu shing,orwas the d ashed line inthe d rawingforthe B ayonets only? N o.Use manu factu rers d iscretion,makingsu re thattheswitchis operable withallcables in place.

26.This exception applies onlyto those items withd eltaconnected second aries.SpecificallyitemsSeq.54,Seq.57 ,Seq.60,Seq.63,and Seq.66 of B lanketInqu iry13-05.The requ ested bayonetorbayonet/EL SP fu singforthese transformers is notavailable,d u e to the Y -D eltaconnection.The possible recoveryvoltage d u ringfu se operation can reach24940 volts,exceed ingtheclearingcapability (23000 volts)of the requ ested fu singscheme. A n internalcartrid ge fu sewithaP artialRange C u rrentlimitingfu se willbe provid ed on D u alV oltage u nits havingaD eltaSecond ary.The cartrid ge fu se is manu factu red by A B B and the partialrange cu rrent-limitingfu se is manu factu red by H i-Tech.L iteratu re coveringbothfu ses is attached .This is acceptable.

REVISED R. GRIGG _ DATE 12/20/17 ELECTRIC ENGINEERING

112 SPRAGINS STREET HUNTSVILLE, AL 35801

APPROVED ___________ DATE _______

SINGLE-PHASE, SUBMERSIBLE, DUAL VOLTAGE DISTRIBUTION TRANSFORMER SPECIFICATION EED105.15.4 APPROVED K. HENSLEY_____

DATE 12/20/17

PAGE 1 OF 14 GENERAL SPECIFICATIONS FOR UTILITY MATERIAL

HUNTSVILLE UTILITIES ELECTRICAL ENGINEERING

SINGLE-PHASE, SUBMERSIBLE, DISTRIBUTION TRANSFORMER SPECIFICATIONS

PRIMARY VOLTAGE – 7200 X 14400 (DUAL VOLTAGE)

SECONDARY VOLTAGE – AS SPECIFIED BY HUNTSVILLE UTILITIES

1.0 SCOPE

1.1 This specification covers the electrical characteristics and mechanical features of single-phase, 60

Hertz, conventional, mineral oil-immersed, self-cooled, dual voltage, submersiable type,

padmounted, dual voltage, distribution transformers with separable insulated high voltage

connectors.

2.0 STANDARDS

2.1 All characteristics, definitions, terminology, etc., except those that are specifically outlined and/or

modified by this specification, shall be in accordance with ANSI/IEEE Standards C57.12.00,

C57.12.80, and C57.12.90, latest revisions, and ANSI Standards C57.12.23 and C57.12.70, latest

revision.

3.0 SIZES COVERED

3.1 Transformer sizes covered under this specification include 1 kVA through 500 kVA.

4.0 PRIMARY VOLTAGE

4.1 Transformer primary voltage shall be as follows:

Rated Primary Voltage (Dual Voltage)

12470GRDY/7200 x 24940GRDY/14400

5.0 SECONDARY VOLTAGE

5.1 Transformer secondary voltage shall be as specified and/or requested by Huntsville Utilities.

Rated Secondary Voltage (Volts)



APPROVED ___________ DATE _______


DATE 12/20/17


1. 240/120

2. 480/240

3. 277

6.0 INSULATION LEVEL

6.1 The high voltage insulation shall be as follows:

Rated High Voltage (Volts) BIL (kV) Insulation Class (kV)

12470GRDY/7200 x 24940GRDY/14400 125 18

6.2 The low voltage insulation shall have a BIL rating of 30 kV and be of the 1.2 kV insulation class.

7.0 TEMPERATURE RISE LIMITS

7.1 Temperature rise and loading conditions shall conform to ANSI/IEEE Standard C57.12.90,

Section 11, latest revision, and ANSI/IEEE Standard C57.12.00, Section 5.11, latest revision.

8.0 REFERENCE TEMPERATURE

8.1 The reference temperature to which losses, impedance, regulation, and efficiency are corrected

shall be 85C.

9.0 TESTING

9.1 Each transformer shipped to Huntsville Utilities shall pass each and every test specified herein.

9.2 Routine tests shall be conducted on each transformer, and, except as specified in ANSI Standard

C57.12.23, Section 5.2, latest revision, all testing procedures shall follow and/or comply with

ANSI/IEEE Standard C57.12.00 and ANSI/IEEE Standard C57.12.90, latest revisions.

9.3 Each transformer manufacturer shall perform a production line full-wave voltage impulse test of

each unit prior to shipment. Each respective transformer manufacturer shall furnish Huntsville

Utilities with a detailed description of the procedure(s) and test method(s) used during the

execution of each production line impulse test.

9.4 Each manufacturer shall furnish Huntsville Utilities with certified proof, by serial number, that

each transformer design conforms to the short circuit requirements covered in ANSI/IEEE



APPROVED ___________ DATE _______


DATE 12/20/17


Standard C57.12.00, latest revision, Section 7, latest revision, and ANSI/IEEE Standard

C57.12.90, Section 12, latest revision.

9.5 Each manufacturer shall furnish Huntsville Utilities with a certified test report, by serial number,

for each transformer. Each certified test report shall include the following information:

A. Percent impedance; (85° C)

B. Load loss (quoted and actual);

C. No load loss (quoted and actual);

D. Total loss (quoted and actual);

E. Percent excitation current; (@100% Voltage)

F. High and low voltage ratings;

G. Serial number of unit;

H. kVA size;

I. Exterior dimensions;

J. Huntsville Utilities purchase order number.

9.6 Each manufacturer shall ship to Huntsville Utilities one (1) copy of each certified test report for

each transformer. Receipt of one (1) copy of each certified test report for each transformer is

a requirement for payment. Certified test reports shall be shipped within thirty (30) days of

transformer shipment to the following address:

Huntsville Utilities

Purchasing Department

P.O. Box 2048

Huntsville, AL 35804

10.0 CONSTRUCTION AND DESIGN

10.1 Each transformer shall be constructed and/or designed to meet or exceed construction standards

set forth by ANSI Standard C57.12.23, Section 6, latest revision.



APPROVED ___________ DATE _______


DATE 12/20/17


10.2 Dual primary voltage transformers shall be designed such that under normal operating conditions,

no electrical or mechanical damage will occur when the dual voltage switch is set in any possible

setting.

10.3 Each transformer shall be of the sealed tank design suitable for continuous operation while

completely submerged.

10.4 Transformer shall be designed to remain sealed within temperature range limits as outlined in

ANSI Standard C57.12.23, Section 6.4.1, latest revision.

10.5 Switch handles, separable connectors, replaceable fuses, and other accessories designed for

opertation after the transformer is in place shall be located on the transformer so that they can be

operated from above with hot-line tools.

10.6 Overall transformer dimensions shall conform to ANSI Standard C57.12.23, Section 6.1.1, latest

revision.

10.7 Transformer tank, cover, and exterior appurtenances shall be constructed of stainless steel.

10.8 All insulating paper uses as layer insulation in transforme coil assembly shall be bonded type,

coated on both sides with a thermosetting adhesive and properly cured prior to impregnating with

oil, or the coils shall be wound with primary conductor containing a thermosetting adhesive that

when properly cured will form an effective bond, both turn to turn and layer to layer.

11.0 TANK FINISH

11.1 Each transformer shall have a coal-tar epoxy finish. Manufacturer’s standard overfinish of paint

will be acceptable on top of coal-tar epoxy. If paint is used, paint finish shall be

weather/oil/corrosion-resistant of such quality that it meets or exceeds Proposed EEI Finishing

Requirements, latest revision.

11.2 Tank coats on transformers rated 100 kVA and below shall be a finish capable of withstanding a

direct blow of 160 inch-pounds per ASTM D-2794-69.

12.0 BUSHINGS AND TERMINALS

12.1 The electrical characteristics of the transformer bushings and terminals shall be as follows:

60-Hertz

Insulation Class BIL Dry One-Minute Withstand

25 kV 125 kV 40 kV



APPROVED ___________ DATE _______


DATE 12/20/17


1.2 kV 30 kV 10 kV

12.2 Electrical characteristics, number, location, and physical arrangement of high voltage bushing

wells and connectors shall be as specified in ANSI Standard C57.12.20, Section 6.2, latest revision.

12.3 Two (2), high voltage, externally clamped, T&B (Blackburn), Central Moloney, T&B

(Elastimold), or Cooper (RTE) bushing wells, which will accept T&B (Blackburn), T&B

(Elastimold), or Cooper (RTE) load-break bushing inserts, shall be provided to permit the

operation of the transformer in a looped primary cable system. The bushing wells shall be marked

with the name of the manufacturer externally visible after installation. Copreme or Nitrile

gasketing material shall be provided and limiters shall be installed to prevent excessive

compression of the gaskets.

12.4 All high voltage leads shall be insulated and arranged to ensure that lead to ground contact is not

possible. Bushing wells shall be externally removable, and high voltage leads shall be of sufficient

length to permit field replacement of the bushing wells without opening the tank.

12.5 Electrical characteristics, number, location, and physical arrangement of low voltage terminal

leads shall be as specified in ANSI Standard C57.12.23, Section 6.2, latest revision.

12.6 Low-Voltage termination for units below 167 kVA shall consist of three (3) leads of underground,

insulated, stranded copper conductor six feet (6’) in length and sized per Table #1.

12.7 All low voltage leads shall be insulated and arranged to ensure that lead to ground contact is not

possible. Bushing wells shall be externally removable, and low voltage leads shall be of sufficient

length to permit field replacement of the bushing wells without opening the tank.

12.8 Internal secondary leads shall be identified with appropriate markings permanently embossed in

the leads that correspond with lead markings on the nameplate.

12.9 Terminal markings and designations shall be as specified by ANSI Standard C57.12.70, latest

revision.

12.10 All high voltage bushing wells and connectors and low voltage terminals shall be clearly marked

on the transformer tanks with weather/oil/corrosion-resistant, yellow paint or Huntsville Utilities

approved transformer markings. Gummed and/or adhesive labels and/or signs will NOT be

acceptable.

12.11 Terminal designations shall be readable with all cables in place.



APPROVED ___________ DATE _______


DATE 12/20/17


12.12 An accessory mounting parking bracket for use with the test/grounding bushing and parking

bushing for load-break terminators shall be supplied beside each high-voltage bushing well as

specified by ANSI Standard C57.12.23 Section 6.2, latest revision.



APPROVED ___________ DATE _______


DATE 12/20/17


12.13 In order to permit operation of the transformer in a looped primary cable system, transformer

components shall have minimum current-carrying capabilities of two hundred amperes (200A)

(continuous) and ten thousand amperes (10,000A) RMS symmetrical for 0.17 seconds (short-time

current rating) for transformers with or without high voltage switching.

13.0 ACCESSORIES

13.1 Each transformer shall be equipped with an externally operated, two (2) position, dual voltage

(7200 x 14400 Volts) switch. The dual voltage switch handle shall be brought out through the top

of the transformer tank for external operation. The dual voltage switch shall be clearly designated

with Huntsville Utilities approved transformer markings. Switch positions shall be indicated 7200

Volts (7.2 kV) x 14400 Volts (14.4 kV). In addition, the dual voltage switch shall: (1) clearly

indicate its purpose and switch positions; (2) be easily readable and operable with all conductors

in place; (3) be clearly marked for de-energized operation only. Transformers shall be shipped

with the dual voltage switch in the 7200 Volt position.

13.2 Each transformer shall be equipped with lifting provisions permanently attached and arranged on

the transformer tank to provide a distributed balanced lift in a vertical direction for the completely

assembled transformer as specified in ANSI Standard C57.12.23, Section 6.1.5, latest revision.

13.3 Base bars or other suitable means shall be furnished to protect the bottom of the tank while in

transit and during installation.

13.4 Each transformer shall be supplied with a durable, metal, instruction nameplate located as

specified by ANSI Standard C57.12.23, Section 6.3,latest revision. The nameplate shall be made

of stainless steel or other approved, non-corrosive metal and permanently marked with essential

operating data. The nameplate shall contain information for Nameplate A, as specified in

ANSI/IEEE Standard C57.12.00, Section 5.12, latest revision. The following information shall be

included on the transformer nameplate: (1) the BIL rating of the transformer; (2) decoded date the

transformer is manufactured (Example: MFR. DATE 10/17); (3) notation of the current limiting

and Bay-O-Net fuses in the circuit diagram. The nameplate shall be attached to the transformer

with weather/corrosion-resistant fasteners. The nameplate shall be readable with all conductors

in place.

13.5 Each transformer shall be provided with a Qualitrol, self-actuating, pressure relief device. The

pressure relief device shall automatically vent when the pressure reaches 102 PSIG and reseal

when the pressure falls to 6 PSIG. Exposed parts shall be made of weather/oil/corrosion-resistant

materials. Approved pressure relief devices must meet or exceed ANSI Standard C57.12.23,

Section 6.5, latest revision.

13.6 All external markings (kVA markings, switch indicators, bushing markings, etc.) shall be either

permanently painted on the unit using weather/oil/corrosion-resistant paint or shall be permanently



APPROVED ___________ DATE _______


DATE 12/20/17


marked on stainless steel plates riveted, welded or bolted to the unit. Any exceptions to this

specification requires prior approval from Huntsville Utilities.

13.7 No gummed labels or signs shall be attached to the exterior surface of the transformer, except:

A. Those cited in Section 15.2.

B. A label containing the manufacturer’s serial number and Huntsville Utilities’ commodity

number and purchase order number shall be affixed on the rear surface of the transformer.

13.8 No warning labels or signs shall be attached to the exterior surface of the transformer.

14.0 TANKS

14.1 Each transformer tank shall be designed in accordance with ANSI Standard C57.12.23, latest

revision.

14.2 Each transformer tank shall be of sufficient strength to withstand a pressure of seven (7) PSIG

without permanent distortion of the tank as outlined in ANSI Standard C57.12.23, Section 6.5.1,

latest revision.

14.3 Each transformer manufacturer shall furnish each transformer with tank grounding provisions.

Tank grounding provisions shall be constructed per ANSI Standard C57.12.23, Section 6.5.4,

latest revision. Tank grounding provisions shall be capped before the unit is painted.

14.4 Tank covers shall be domed or sloped to prohibit moisture accumulation.

15.0 INSULATING OIL

15.1 Each transformer shall be filled with mineral insulating oil and shall be certified to contain less

than one part per million (1ppm) Polychlorinated Biphenyls (PCB's) as measured on a dry weight

basis. A notice to this affect shall be included on the transformer nameplate.

EXAMPLE:

FILLED WITH OIL CONTAINING LESS THAN 1 PPM PCB's

or

CONTAINS LESS THAN 1 PPM PCB's 15.2 A separate, standard “Non-PCB” label, blue background with white lettering with the following

legend: “Non-PCB Mineral Oil – when manufactured contained less than 1 PPM PCB” shall be attached to the top of all submersible transformers.



APPROVED ___________ DATE _______


DATE 12/20/17


16.0 FUSING

16.1 Each transformer shall be furnished with an approved, oil-immersed, Cooper (RTE) or ABB

(Westinghouse) Bay-O-Net draw-out fuse holder and an approved, current sensing, Cooper (RTE)

Bay-O-Net fuse element.

16.2 A series connected, partial-range, oil-immersed, Chance Type "TL", Hi-Tech Type "OS", or RTE

Type "ELSP" current limiting fuse, suitably sized for both voltages (see table #1), shall be installed

on the source side of each Bay-O-Net fuse.

16.3 The current limiting fuse shall be mounted in accordance with the fuse manufacturer's

recommendation in the immediate vicinity of the loop buss and ahead of the Bay-O-Net fuse

feeding the primary winding. The current limiting fuse shall be rigidly mounted to eliminate

shifting of the fuse and/or the possibility of fuse to ground contact. The dislodging of a current

limiting fuse will result in the immediate removal of the respective manufacturer from Huntsville

Utilities' list of approved manufacturers.

16.4 The Bay-O-Net fuse shall be mounted on top of the transformer and positioned so that the fuse

may be easily removed and installed by a person using a hot stick from above.

16.5 The Bay-O-Net fuse holders shall be marked so that the name of the manufacturer is externally

visible after installation.

16.6 Transformers shall be shipped with the 7200 Volt Bay-O-Net fuse installed.

16.7 Bay-O-Net fuses and current limiting fuses shall be sized per table #1.

17.0 SHIPPING

17.1 Each transformer shall be placed on a solid wood pallet for shipment. Each transformer shall be

secured to the pallet with two steel bands attached to the transformer lifting provisions in a manner

that prevents damage to the transformer paint finish. Transformers shall not be stacked.

17.2 A tag indicating Huntsville Utilities' commodity number and purchase order number shall be

attached to the transformer inside the terminating compartment.

18.0 LOSS EVALUATIONS

18.1 The following performance information is to be furnished by each transformer manufacturer with

the quotation.



APPROVED ___________ DATE _______


DATE 12/20/17


1. No load losses in watts at normal frequency and voltage.

2. Total full load losses in watts at normal frequency and voltage.

Loss evaluation is an integral factor in the final selection process. The evaluation of losses will be

based on the total cost of ownership for 30 years based on the following formula:

Cost of Ownership = $1.791 x Purchase Price

Plus $7.4206 x No load loss in watts

Plus $3.3393 x Load loss in watts

Where the load losses are computed as Total loss - No load

loss

19.0 TOLERANCES FOR LOSSES

19.1 The quoted losses shall be guaranteed by the manufacturer as specified in ANSI/IEEE C57.12.00,

Section 9.3, latest revision (IE each unit received, shall be evaluated for load losses on an

individual basis {rather than an average basis} as defined in paragraphs 20.0 through 23.2).

20.0 LOSS VERIFICATION

20.1 Each manufacturer shall furnish Huntsville Utilities with certified loss test reports, by serial

number, for each unit. Receipt of the certified loss test reports by Huntsville Utilities shall be

a requirement for payment. Each certified test report shall include loss data as specifically

required for quotation as well as size and configuration of each transformer.

20.2 Each certified test report will be reviewed by Huntsville Utilities to ensure that each transformer

conforms to ANSI/IEEE Standard C57.12.00, (latest revision).

20.3 Each shipment of distribution transformers received by Huntsville Utilities will be routinely and/or

randomly sampled and loss tested. Huntsville Utilities personnel will compare data obtained

through this loss testing procedure to the data provided by the manufacturer in the certified test

reports. The manufacturer's certified loss data must be within 2% of the data obtained by

Huntsville Utilities testing.

20.4 If the loss data obtained by Huntsville Utilities testing is not within 2% of the manufacturer's

certified loss data, Huntsville Utilities will choose one or more of the following corrective actions:

A. Conduct loss testing on the entire lot of transformers received by Huntsville Utilities with the

loss testing results being used in place of the certified loss data reported by the manufacturer.



APPROVED ___________ DATE _______


DATE 12/20/17


The cost of the loss testing shall be credited to Huntsville Utilities by the respective

manufacturer.

B. Reject the entire lot of transformers and return the transformers to the respective manufacturer

at the manufacturer's expense.

C. Return a random sampling of the lot of transformers to the respective manufacturer for

verification of the loss test data by the manufacturer.

D. Subject a random sampling of the lot of transformers to testing conducted by a mutually

agreed upon third party test laboratory.

If actions taken under Items C. and D. indicate that the manufacturer's certified loss data is

inaccurate, the respective manufacturer will bear the expense of the above action(s).

20.5 Any manufacturer whose certified test reports are found to be in error shall be subject to probation,

suspension, and/or deletion as an approved supplier. Such suspension or deletion shall not

necessarily be limited to a particular item or class of items.

21.0 LOSS ADJUSTMENT PROCEDURES

21.1 Transformer losses shall not exceed tolerances specified in ANSI/IEEE Standard C57.12.00,

Section 9.3 - Tolerances for Losses (latest revision). Each transformer that fails to conform to this

standard shall be returned to the manufacturer, freight collect, for replacement. Alternately,

Huntsville Utilities may require credit from the manufacturer equal to the present value of the

added cost of ownership for a 30-year period but not to exceed the original purchase cost of the

transformer. The credit required shall be based on the difference of the actual losses and quoted

losses using the evaluation formula costs.

Example:

Evaluation Definitions: Quoted Values: Actual Values:

PPF Purchase Price Factor = 1.791 Purchase Price = $10.00 Purchase Price = $10.00

NLF No Load Loss Factor = 7.4206 No Load Losses = 1.0 No Load Losses = 1.2

LLF Load Loss Factor = 3.3393 Load Losses = 2 Load Losses = 2.1

Quoted Values Actual Values



APPROVED ___________ DATE _______


DATE 12/20/17


Purchase Price times PPF $10.00 * 1.791 = 17.91 $10.00 * 1.791 = 17.91

Plus + +

No load losses times NLF 1.0 * 7.4206 = 7.4206 1.2 * 7.4206 = 8.90472

Plus + +

Load Losses times LLF 2.0 * 3.3393 = 6.6786 2.1 * 3.3393 = 7.01253

Equals Evaluation value = 32.0092 = 33.82725

Quoted evaluation 32.0092

Minus -

Actual evaluation 33.82725

Equals Evaluated Difference 1.81805

Evaluated Difference (1.81805)

Divided by purchase price factor 1.791

Equals Purchase Price Adjustment (1.0151)

Check: re-evaluate units with adjustment to purchase price:

Quoted Purchase Price $10.00

Plus Purchase Price Adjustment ( 1.0151)

Equals Actual Purchase Price $ 8.9849

Actual Purchase Price times PPF $ 8.9849 * 1.791 = 16.0919559

Plus +

No load losses times NLF 1.2 * 7.4206 = 8.90472

Plus +

Load Losses times LLF 2.1 * 3.3393 = 7.01253

Equals Evaluation value = 32.00092

This equals the quoted evaluated life cost.

Thus the computed adjustment is accurate.

The required credit would be the 1.0151 or 1.02 if rounded to cents (since .0051 is greater than .005).

If the adjustment above had been positive, the actual losses would have been less than quoted and no

credit would have been due from the manufacturer.

We would not issue a credit to the manufacturer for beating his loss quotation.



APPROVED ___________ DATE _______


DATE 12/20/17


Per ANSI C-57.12.00.9.3, tolerances for losses are as follows:

Number of No-load Load

Units on Basis of Losses Losses

One Order Determination (%) (%)

1 1 10 6

2 or more Each unit 10 6

2 or more Average of 0 0

all units

Therefore, each unit must be within 10% on no load losses and within 6% on load losses. If more than

one identical unit is shipped as one order in a single shipment, the average of all units must meet quoted

losses with no tolerance.

21.2 Any manufacturer who supplies Huntsville Utilities with transformers that repeatedly fail to meet

quoted losses shall be subject to probation, suspension, and/or complete deletion as an approved

supplier.

22.0 EXCEPTIONS AND DEVIATIONS

22.1 Manufacturers quoting transformers to this specification shall indicate any areas where changes

to this design and/or specification are required by their design standards. Any recommended

changes to this design and/or specification offered by the manufacturer shall be accompanied by

sufficient information to permit full evaluation of the desired changes. Any change to this design

and/or specification requires prior approval from Huntsville Utilities Electrical Engineering.

Detailed approval drawings, design criteria, test data, and prototype samples shall be submitted

with design or specification change requests.

22.2 Huntsville Utilities will routinely and/or randomly inspect and/or test each shipment of

transformers to ensure that each transformer received conforms to this specification and/or

any agreed upon deviations.

22.3 Bids will be awarded to manufacturers based on the manufacturer's stated compliance with this

specification in its entirety. In the event that a bid is awarded to a manufacturer, and said

manufacturer's product is discovered not to be in compliance with this specification (and/or any

agreed upon deviations) in any manner, any/all of the following actions will be required by

Huntsville Utilities:

1. Any transformers received that do not comply with this specification in its entirety will be

rejected and returned to the manufacturer at the manufacturer's expense.



APPROVED ___________ DATE _______


DATE 12/20/17


2. The respective manufacturer will be required to provide Huntsville Utilities with the number

of units initially quoted (at the initial quoted price and loss values) which do comply with this

specification in its entirety. Provision of the initial number of units quoted by the respective

manufacturer is mandatory even if said manufacturer is required to supply units manufactured

by another approved source. Units supplied by another approved source shall be delivered in

the time specified by the manufacturer winning the bid.

3. Failure to comply with this specification (and/or any agreed upon deviations) in its entirety

may result in the manufacturer's immediate suspension or removal from Huntsville Utilities'

list of approved manufacturers. Such suspension or deletion shall not necessarily be limited

to a particular item or class of items.



APPROVED ___________ DATE _______


DATE 12/20/17


TABLE #1

FUSING SPECIFICATIONS CHART FOR

SINGLE-PHASE, SUBMERSIBLE, DISTRIBUTION TRANSFORMERS

PRIMARY VOLTAGE – 7200 x 14400 VOLTS (DUAL VOLTAGE)


kVA

SIZE

RTE

7200Volt

“Bay-O-Net”

Current Sensing

Fuse Element

RTE

14400 Volt

“Bay-O-Net”

Current Sensing

Fuse Element

PARTIAL RANGE

CURRENT LIMITING

FUSE

CHANCE

TYPE “TL”

HI-TECH

TYPE “OS”

RTE

TYPE “ELSP”

CONDUCTOR

SIZE 25

4000353C06

4000353C04

C705-0797

HTDS242035

3544030M61M

2/0

37.5

4000353C06

4000353C04

C705-0797

HTDS242035

3544040M61M

2/0

50

4000353C08

4000353C06

C705-0798

HTDS242035

3544050M61M

4/0

75

4000353C10

4000353C08

-----------

HTDS242065

354480M71M

350 MCM

100

4000353C10

4000353C08

-----------

HTDS242065

354480M71M

500 MCM

167

4000353C12

4000353C10

-----------

HTDS242100

3544125M71M

500 MCM

(2 PER LEG)



APPROVED ___________ DATE _______

SINGLE-PHASE, OVERHEAD, DUAL VOLTAGE DISTRIBUTION TRANSFORMER SPECIFICATION EED105.39.10 APPROVED K. HENSLEY____

DATE 12/20/17



SINGLE-PHASE, OVERHEAD, DUAL VOLTAGE, DISTRIBUTION TRANSFORMER SPECIFICATIONS

PRIMARY VOLTAGE – 7200 X 14400 (DUAL VOLTAGE)


1.0 SCOPE


Hertz, conventional, mineral oil-immersed, self-cooled, dual voltage, overhead type, distribution

transformers.

2.0 STANDARDS


modified by these specifications, shall be in accordance with ANSI / (IEEE) Standards C57.12.00,


revisions.

3.0 SIZES COVERED


4.0 PRIMARY VOLTAGE

4.1 Transformer primary voltage shall be as specified and/or requested by Huntsville Utilities.

Rated Primary Voltage (Dual Voltage)

1) 7200/12470Y x 14400/24940Y



Rated Secondary Voltage

1) 120/240



APPROVED ___________ DATE _______


DATE 12/20/17


2) 240/480

3) 277




7200 / 12470 Y 125 25

x

14400 / 24940 Y



7.1 Temperature rise and loading conditions shall conform to ANSI/IEEE Standard C57.12.90, Section

11, latest revision, and ANSI/IEEE Standard C57.12.00, Section 5.11, latest revision.


8.1 The reference temperature to which losses, impedance, regulation, and efficiency are corrected shall

be 85C.

9.0 TESTING







Utilities with a detailed description of the procedure(s) and test method(s) used during the execution

of each production line impulse test.

9.4 Each manufacturer shall furnish Huntsville Utilities with certified proof, by serial number, that each

transformer design conforms to the short circuit requirements covered in ANSI/IEEE Standard

C57.12.00, Section 7, latest revision, and ANSI/IEEE Standard C57.12.90, Section 12, latest

revision.

9.5 Each manufacturer shall furnish Huntsville Utilities with a certified test report, by serial number, for



APPROVED ___________ DATE _______


DATE 12/20/17


each transformer. Each certified test report shall include the following information:

A. Percent impedance (85C)

B. Load loss (quoted and actual)

C. No load loss (quoted and actual)

D. Total loss (quoted and actual)

E. Percent excitation current (@ 100% Voltage)

F. High and low voltage ratings

G. Serial number of unit

H. kVA size

I. Exterior dimensions

I. Huntsville Utilities purchase order number

9.6 Each manufacturer shall ship to Huntsville Utilities one (1) copy of each certified test report for each

transformer. Receipt of one (1) copy of each certified test report for each transformer is a

requirement for payment. Certified test reports shall be shipped within thirty (30) days of

transformer shipment to the following address:

Huntsville Utilities


P. O. Box 2048



10.1 Each transformer shall be constructed and/or designed to meet or exceed construction standards set

forth by ANSI Standard C57.12.20, latest revision.

10.2 Dual primary voltage transformers shall be designed such that under normal operating conditions,

no electrical or mechanical damage will occur when the dual voltage switch is set in any possible

setting.



APPROVED ___________ DATE _______


DATE 12/20/17


10.3 All insulating paper used as layer insulation in transformer coil assembly shall be bonded type,




10.4 Transformer core-coil shall be of either shell or core type interlaced design. Shell type non-

interlaced designs are not acceptable.

11.0 TANK FINISH

11.1 Each transformer shall have a light gray (Light Gray No. 70, Munsell Notation 5BG 7.0/0.4 or

equivalent), weather/corrosion-resistant paint finish. Paint shall be of such quality that it meets or

exceeds Proposed EEI Finishing Requirements, latest revision.

11.2 Transformers one hundred (100) kVA and below shall have an insulated coating on the tank cover

capable of withstanding 12 kV at a 2000 volts/second rate of rise or 15 kV at 500 volts/second rate

of rise tested per ASTM D149 using 1/4" diameter electrodes. The results of design tests to confirm

this capability shall be submitted for approval.



11.4 For transformers rated above 100 kVA, the minimum acceptable coating shall be a thermosetting

powder 2.5-3.5 MILS thick.


12.1 Each transformer shall be provided with cover-mounted, high voltage, wet-process, porcelain

bushing(s) with eyebolt terminals.

12.2 High voltage bushings shall be gasketed and internally clamped to provide a moisture proof and/or

oil proof seal.

12.3 Color of high voltage bushing(s) shall match Light Gray No. 70, Munsell Notation 5BG 7.0/0.4.12.4

Electrical characteristics, number, location, and physical arrangement of high voltage bushing(s)

shall be as specified in ANSI Standard C57.12.20, Section 6, latest revision.

12.4 Each transformer shall be furnished with low voltage, two-piece, porcelain or glass polyester

bushings with terminals per ANSI Standard C57.12.20, Section 6.1.2, latest revisions.

12.5 Low voltage bushings shall be securely keyed and sealed to prohibit moisture and/or oil migration.

12.6 Electrical characteristics, number, location, and physical arrangement of low voltage terminals shall

be as specified in ANSI Standard C57.12.20, Section 6, latest revision.



APPROVED ___________ DATE _______


DATE 12/20/17


12.7 Internal secondary leads shall be identified with appropriate markings permanently embossed in the

leads that correspond with lead markings on the nameplate.

12.8 All terminal markings and connections shall be as specified in ANSI Standard C57.12.70, latest

revision.

12.9 All bushing markings shall be either permanently painted on the transformer with

weather/oil/corrosion-resistant paint, or shall be permanently marked on stainless steel plates

riveted, welded, or bolted to the unit. Gummed and/or adhesive labels and/or signs will NOT be

acceptable. Transformer markings other than those specified above are NOT acceptable unless

previously approved by Huntsville Utilities.

13.0 ACCESSORIES

13.1 Each transformer shall be equipped with an externally operated two (2) position, dual voltage switch.

The dual voltage switch handle shall be brought out through the side of the transformer tank for

external operation. The dual voltage switch shall be clearly designated using Huntsville Utilities

approved markings. Switch positions shall be indicated 7200 volts (7.2 kV) or 14400 volts (14.4

kV). In addition, the dual voltage switch shall: (1) clearly indicate its purpose and switch positions;

(2) be easily readable and operable with all conductors in place; (3) be clearly marked for de-

energized operation only. Transformers shall be shipped with the dual voltage switch in the 7200

volt position.

13.2 Each transformer shall be furnished with arrester mounting pads.

13.3 Transformers shall be provided with lifting lugs permanently attached and arranged on the

transformer tank to provide a distributed balanced lift in a vertical direction for the completely

assembled transformer as specified in ANSI Standard C57.12.20, Section 6.2.6.3, latest revision.

13.4 Each transformer shall be equipped with single or two position support lugs (hanger brackets) as

specified in ANSI Standard C57.12.20, Section 6.5, latest revision.

13.5 Each transformer shall be supplied with a durable, metal instruction nameplate as specified by ANSI

Standard C57.12.20, Section 6.3.4, latest revision. Nameplates shall be made of stainless steel or

other approved, non-corrosive metal and permanently marked with essential operating data. The

nameplate shall contain information for Nameplate A as specified in ANSI/IEEE Standard

C57.12.00, Section 5.12, latest revision. Voltage designations shall be in accordance with

ANSI/IEEE Standard C57.12.00, latest revision. The following information shall be included on

the transformer nameplate: (1) the BIL rating of the transformer; (2) decoded date the transformer

is manufactured (Example: MFR DATE 10/17). The nameplate shall be attached to the transformer

with weather/corrosion-resistant fasteners on or immediately adjacent to the lower support lug.

Nameplate shall be readable with all conductors in place.



APPROVED ___________ DATE _______


DATE 12/20/17


13.6 Each transformer shall be provided with a means of relieving excessive pressure as specified in

ANSI Standard C57.12.20, Section 6.2.7, latest revision. The pressure relief device shall

automatically vent when the pressure reaches 10±2 PSIG and reseal when the pressure falls to 6

PSIG. If a self-venting/resealing cover design is utilized, the assembly shall remain effectively

sealed for overloads and external secondary short circuits of the duration and magnitude allowed by

industry standards, but shall vent pressure at a minimum of 8 PSIG and reseal at a minimum of 6

PSIG. Designs which utilize a cover venting system which does not reseal are not permitted. The

completely assembled transformer shall withstand an internal static pressure of 7 PSIG without

permanent distortion. The manufacturer shall certify that design tests have been made on

representative production samples of each diameter to withstand pressure at a rate of rise of one

PSIG per second above 7 PSIG up to the cracking pressure of the pressure relief valve, as specified

in ANSI Standard C57.12.20, Section 6.2.7.1, latest revision, or the pressure at which the cover

design relieves excessive pressure, as specified in ANSI Standard C57.12.20, Section 6.2.7.2, latest

revision, without rupturing or displacing other components of the enclosure. Approved pressure

relief devices or designs must meet or exceed ANSI Standard C57.12.20, Sections 6.2.7 through

6.2.7.3, latest revisions.

13.7 All external markings (kVA markings, switch indications, bushing markings, etc.) shall be either


marked on stainless steel plates riveted, welded, or bolted to the unit.


A. Those cited in Section 15.2

B. A label containing the manufacturer’s serial number and Huntsville Utilities’ commodity

number and purchase order number shall be affixed on the top surface of the transformer.


14.0 TANKS

14.1 Transformer tanks shall be designed per ANSI Standard C57.12.20, latest revision.

14.2 Tank withstand should meet NEMA TR1-1980, Part 2, Page 6, Section D.

14.3 Tank covers shall have a minimum slope of 1.5 to prohibit moisture accumulation.

14.4 Each transformer shall be furnished with tank grounding provisions. Tank grounding provisions

shall be constructed per ANSI Standard C57.12.20, Section 6.5.4, latest revision. Tank grounding

provisions shall be capped before the unit is painted.

15.0 INSULATING OIL



APPROVED ___________ DATE _______


DATE 12/20/17


15.1 Each transformer shall be filled with mineral insulating oil and shall be certified to contain less than

one part per million (1 ppm) Polychlorinated Biphenyls (PCBs) as measured on a dry weight basis.

A notice to this affect shall be included on the transformer nameplate.

EXAMPLE:

FILLED WITH MINERAL OIL CONTAINING LESS

THAN 1 PPM PCBs AT TIME OF MANUFACTURE

or

CONTAINS LESS THAN 1 PPM PCBs

15.2 A separate standard “Non-PCB” label, blue background with white lettering with the following

legend: “Non-PCB Mineral Oil – when manufactured contained less than 1 PPM PCB” shall be

attached on the side opposite the hanger on overhead transformers.

16.0 SHIPPING




16.2 All single phase transformers must be loaded from the rear of the truck for unloading by forklift

from the rear exit of the trucks trailer.



the quotation.

1. No load losses in watts at normal frequency and range.

2. Total full load losses in watts at normal frequency and voltage.






Where the load losses are computed as

Total loss - No load loss



APPROVED ___________ DATE _______


DATE 12/20/17



18.1 The quoted losses shall be guaranteed by the manufacturer as specified in ANSI/IEEE C57.12.00,

Section 9.3, latest revision (IE each unit received, shall be evaluated for load losses on an individual

basis {rather than an average basis} as defined in Paragraphs 17.0 through 20.2.


19.1 Each manufacturer shall furnish Huntsville Utilities with certified loss test reports, by serial number,

for each unit. Receipt of the certified loss test reports by Huntsville Utilities shall be a

requirement for payment. Each certified test report shall include loss data as specifically required

for quotation as well as size and configuration of each transformer.


conforms to ANSI/IEEE Standard C57.12.00, latest revision.




reports. The manufacturer’s certified loss data must be within ±2% of the data obtained by


19.4 If the loss data obtained by Huntsville Utilities testing is not within ±2% of the manufacturer’s


a. Conduct loss testing on the entire lot of transformers received by Huntsville Utilities with the

loss testing results being used in place of the certified loss data reported by the manufacturer.

The cost of the loss testing shall be credited to Huntsville Utilities by the respective

manufacturer.

b. Reject the entire lot of transformers and return the transformers to the respective manufacturer

at the manufacturer’s expense.

c. Return a random sampling of the lot of transformers to the respective manufacturer for


d. Subject a random sampling of the lot of transformers to testing conducted by a mutually agreed

upon third party test laboratory.

If actions taken under Items c. and d. indicate that the manufacturer’s certified loss data is inaccurate,

the respective manufacturer will bear the expense of the above action(s).





APPROVED ___________ DATE _______


DATE 12/20/17




20.1 Transformer losses shall not exceed tolerances specified in ANSI/IEEE Standard C57.12.00, Section

9.3 - Tolerance for Losses (latest revision). Each transformer that fails to conform to this standard

shall be returned to the manufacturer, freight collect, for replacement. Alternately, Huntsville

Utilities may require credit from the manufacturer equal to the present value of the added cost of

ownership for a 30-year period but not to exceed the original purchase cost of the transformer. The

credit required shall be based on the difference of the actual losses and quoted losses using the

evaluation formula costs.

Example:




LLF Load Loss Factor = 3.3393 Load Losses = 2 Load Losses = 2.1



Plus + +


Plus + +




Minus -

Actual evaluation 33.82725

Equals Evaluated Difference 1.81805



Equals Purchase Price Adjustment (1.0151)



Plus Purchase Price Adjustment (1.0151)

Equals Actual Purchase Price $ 8.9849




APPROVED ___________ DATE _______


DATE 12/20/17


Plus +


Plus +





The required credit would be the 1.0151 or 1.02 if rounded to cents (Since .0051 is greater than .005).

If the adjustment above had been positive, the actual losses would have been less than quoted and no credit

would have been due from the manufacturer. We would not issue a credit to the manufacturer for beating

his loss quotation.

Per ANSI/IEEE Standard C57.12.00, Section 9.3, (latest revision) tolerances for losses are as follows:

Unless otherwise specified, each unit must be within 10% on no load losses and within 6% on load losses.


quoted losses shall be subject to probation, suspension and/or complete deletion as an approved

supplier.


21.1 Manufacturers quoting transformers to this specification shall indicate any areas where changes to

this design and/or specification are required by their design standards. Any recommended changes

to this design and/or specification offered by the manufacturer shall be accompanied by sufficient

information to permit full evaluation of the desired changes. Any change to this design and/or

specification requires prior approval of Huntsville Utilities Electrical Engineering. Detailed

approval drawings, design criteria, test data, and prototype samples shall be submitted with design

or specification change requests.

21.2 Transformers addressed by these specifications are subject to routine and/or random inspections

and/or testing conducted by Huntsville Utilities to assure that the transformers provided by the

vendor comply with this specification and/or any agreed upon deviations.

21.3 Bids will be awarded to manufacturers based on the manufacturer’s stated compliance with this


manufacturer’s product is discovered not to be in compliance with this specification (and/or any



a. Any transformers received that do not comply with this specification in its entirety will be



APPROVED ___________ DATE _______


DATE 12/20/17


rejected and returned to the manufacturer at the manufacturer’s expense.

b. The respective manufacturer will be required to provide Huntsville Utilities with the number

of units initially quoted (at the initial quoted price and loss values) which do comply with

this specification in its entirety. Provision of the initial number of units quoted by the

respective manufacturer is mandatory even if said manufacturer is required to supply units

manufactured by another approved source. Units supplied by another approved source shall

be delivered in the time specified by the manufacturer winning the bid.

c. Failure to comply with these specifications (and/or any agreed upon deviations) in their

entirety may result in the manufacturer’s immediate suspension or removal from Huntsville

Utilities’ list of approved manufacturers. Such suspension or deletion shall not necessarily

be limited to a particular item or class of items.



APPROVED ___________ DATE _______

SINGLE-PHASE, OVERHEAD DISTRIBUTION TRANSFORMER SPECIFICATIONS EED105.39.11 APPROVED K. HENSLEY____

DATE 12/20/17



SINGLE-PHASE, OVERHEAD, SINGLE VOLTAGE, DISTRIBUTION TRANSFORMER SPECIFICATIONS

PRIMARY VOLTAGE – 7200 OR 14400 (SINGLE VOLTAGE)


1.0 SCOPE


Hertz, conventional, mineral oil-immersed, self-cooled, single voltage, overhead type, distribution

transformers.

2.0 STANDARDS


modified by these specifications, shall be in accordance with ANSI / IEEE Standards C57.12.00,


revisions.

3.0 SIZES COVERED


4.0 PRIMARY VOLTAGE

4.1 Transformer primary voltage shall be as specified and/or requested by Huntsville Utilities.

Rated Primary Voltage (Single Voltage)

1) 7200/12470Y

2) 14400/24940Y





APPROVED ___________ DATE _______


DATE 12/20/17


Rated Secondary Voltage (Volts)

1. 120/240

2. 240/480

3. 277




7200/12470Y 95 15

14400/24940Y 125 18



7.1 Temperature rise and loading conditions shall conform to ANSI/IEEE Standard C57.12.90,

Section 11, latest revision, and ANSI/IEEE Standard C57.12.00, Section 5.11, latest revision.


8.1 The reference temperature to which losses, impedance, regulation, and efficiency are corrected

shall be 85C.

9.0 TESTING







Utilities with a detailed description of the procedure(s) and test method(s) used during the

execution of each production line impulse test.



APPROVED ___________ DATE _______


DATE 12/20/17


9.4 Each manufacturer shall furnish Huntsville Utilities with certified proof, by serial number, that

each transformer design conforms to the short circuit requirements covered in ANSI/IEEE

Standard C57.12.00, Section 7, latest revision, and ANSI/IEEE Standard C57.12.90, Section 12,

latest revision.

9.5 Each manufacturer shall furnish Huntsville Utilities with a certified test report, by serial number,

for each transformer. Each certified test report shall include the following information:

1. Percent impedance; (85 C)

2. Load loss (quoted and actual);

3. No load loss (quoted and actual);

4. Total loss (quoted and actual);

5. Percent excitation current; (@ 100% Voltage)

6. High and low voltage ratings;

7. Serial number of unit;

8. kVA size;

9. Exterior dimensions;

10. Huntsville Utilities purchase order number.

9.6 Each manufacturer shall ship to Huntsville Utilities one (1) copy of each certified test report for

each transformer. Receipt of one (1) copy of each certified test report for each transformer is

a requirement for payment. Certified test reports shall be attached to the invoice for the

transformers:

Invoice To: Huntsville Utilities


P.O. Box 2048





APPROVED ___________ DATE _______


DATE 12/20/17


10.1 Each transformer shall be constructed and/or designed to meet or exceed construction standards

set forth by ANSI Standard C57.12.20, latest revision.

10.2 All insulating paper used as layer insulation in transformer coil assembly shall be bonded type,




10.3 Transformer core-coil shall be of either shell or core type interlaced design. Shell type non-

interlaced designs are not acceptable.

11.0 TANK FINISH

11.1 Each transformer shall have a light gray (Light Gray No. 70, Munsell Notation 5BG 7.0/0.4 or

equivalent), weather/corrosion-resistant paint finish. Paint shall be of such quality that it meets or

exceeds Proposed EEI Finishing Requirements, latest revision.

11.2 Transformers one hundred (100) kVA and below shall have an insulated coating on the tank cover

capable of withstanding 12 kV at a 2000 volts/second rate of rise or 15 kV at 500 volts/second rate

of rise tested per ASTM D149 using 1/4" diameter electrodes. The results of design tests to

confirm this capability shall be submitted for approval.



11.4 For transformers rated above 100 kVA, the minimum acceptable coating shall be a thermosetting

powder 2.5-3.5 MILS thick.


12.1 Each transformer shall be provided with cover-mounted, high voltage, wet-process, porcelain

bushing(s) with eyebolt terminals.

12.2 High voltage bushings shall be gasketed and internally clamped to provide a moisture proof and/or

oil proof seal.

12.3 Color of high voltage bushing(s) shall match Light Gray No. 70, Munsell Notation 5BG 7.0/0.4.

12.4 Electrical characteristics, number, location, and physical arrangement of high voltage bushing(s)




APPROVED ___________ DATE _______


DATE 12/20/17


12.5 Each transformer shall be furnished with low voltage, two-piece, porcelain or glass polyester

bushings with terminals per ANSI Standard C57.12.20, Section 6.1.2, latest revisions.

12.6 Low voltage bushings shall be securely keyed and sealed to prohibit moisture and/or oil migration.

12.7 Electrical characteristics, number, location, and physical arrangement of low voltage terminals


12.8 Internal secondary leads shall be identified with appropriate markings permanently embossed in

the leads that correspond with lead markings on the nameplate.

12.9 All terminal markings and connections shall be as specified in ANSI Standard C57.12.70, latest

revision.

12.10 All bushing markings shall be either permanently painted on the transformer with

weather/oil/corrosion-resistant paint, or shall be permanently marked on stainless steel plates

riveted, welded, or bolted to the unit. Gummed and/or adhesive labels and/or signs will NOT be

acceptable. Transformer markings other than those specified above are NOT acceptable unless

previously approved by Huntsville Utilities.

13.0 HIGH VOLTAGE TAPS

13.1 Primary taps shall be supplied on units rated 7200/12470Y only when requested by Huntsville

Utilities.

13.2 All tap changers shall:

a. Conform to all aspects of ANSI Standard C57.12.20, Section 6.2.1, ANSI Standard

C57.12.20, Section 6.2.1.1, and ANSI Standard C57.12.20, Section 6.2.1.2, latest revisions;

b. Be two (2) - 2 ½ % above rated voltage and two (2) - 2 ½ % below rated voltage;

c. Be externally operated;

d. Have the same BIL rating of the highest voltage level when operated at each tap setting;

e. Be provided with positive stops to identify the highest and lowest tap positions;



APPROVED ___________ DATE _______


DATE 12/20/17


f. Be designed to prevent accidental operation by requiring a preliminary step such as loosening

a set screw before the tap position can be changed. This positive locking device shall be

clearly visible to field personnel operating the tap changer;

g. Have a permanent, clearly marked indicator plate showing tap positions;

h. Have all external components constructed or weather/corrosion-resistant material;

i. Be designed for operation using hot line tools;

j. Rotate in a clockwise direction from the high tap voltage to a lower tap voltage in the high

voltage winding;

k. Be clearly marked for de-energized operation only.

EXAMPLE: DE-ENERGIZE TRANSFORMER BEFORE

OPERATING TAP CHANGER

13.3 Transformers shall be shipped with the tap changer in the 100% tap position.

13.4 Approved manufacturers of tap changers include Central Moloney, G.E., ABB T&D, Cooper, and

ASP.

14.0 ACCESSORIES

14.1 Each transformer shall be furnished with arrester mounting pads.

14.2 Transformers shall be provided with lifting lugs permanently attached and arranged on the

transformer tank to provide a distributed balanced lift in a vertical direction for the completely

assembled transformer as specified in ANSI Standard C57.12.20, Section 6.2.6.3, latest revision.

14.3 Each transformer shall be equipped with single or two position support lugs (hanger brackets) as

specified in ANSI Standard C57.12.20, Section 6.5, latest revision.

14.4 Each transformer shall be supplied with a durable, metal instruction nameplate as specified by

ANSI Standard C57.12.20, Section 6.3.4, latest revision. Nameplate shall be made of stainless

steel or other approved, non-corrosive metal and permanently marked with essential operating

data. The nameplate shall contain information for Nameplate A as specified in ANSI/IEEE

Standard C57.12.00, Section 5.12, latest revision. Voltage designations shall be in accordance

with ANSI/IEEE Standard C57.12.00, latest revision. The following information shall be included



APPROVED ___________ DATE _______


DATE 12/20/17


on the transformer nameplate: (1) the BIL rating of the transformer; (2) decoded date the

transformer is manufactured (Example: MFR DATE 10/17). The nameplate shall be attached to

the transformer with weather/corrosion-resistant fasteners on or immediately adjacent to the lower

support lug. Nameplate shall be readable with all conductors in place.

14.5 Each transformer shall be provided with a means of relieving excessive pressure as specified in

ANSI Standard C57.12.20, Section 6.2.7, latest revision. The pressure relief device shall

automatically vent when the pressure reaches 10±2 PSIG and reseal when the pressure falls to 6

PSIG. If a self-venting/resealing cover design is utilized, the assembly shall remain effectively

sealed for overloads and external secondary short circuits of the duration and magnitude allowed

by industry standards, but shall vent pressure at a minimum of 8 PSIG and reseal at a minimum of

6 PSIG. Designs which utilize a cover venting system which does not reseal are not permitted.

The completely assembled transformer shall withstand an internal static pressure of 7 PSIG

without permanent distortion. The manufacturer shall certify that design tests have been made on

representative production samples of each diameter to withstand pressure at a rate of rise of one

PSIG per second above 7 PSIG up to the cracking pressure of the pressure relief valve, as specified

in ANSI Standard C57.12.20, Section 6.2.7.1, latest revision, or the pressure at which the cover

design relieves excessive pressure, as specified in ANSI Standard C57.12.20, Section 6.2.7.2,

latest revision, without rupturing or displaying other components of the enclosure. Approved

pressure relief devices or designs must meet or exceed ANSI Standard C57.12.20, Sections 6.2.7

through 6.2.7.3, latest revisions.

14.6 All external markings (kVA markings, switch indications, bushing markings, etc.,) shall be either


marked on stainless steel plates riveted, welded, or bolted to the unit.


1. Those cited in Section 16.2

2. A label containing the manufacturer’s serial number and Huntsville Utilities’ commodity

number and purchase order number shall be affixed on the top surface of the transformer.


15.0 TANKS

15.1 Transformer tanks shall be designed per ANSI Standard C57.12.20, latest revision.

15.2 Tank withstand should meet NEMA TR1-1980, Part 2, Page 6, Section D.



APPROVED ___________ DATE _______


DATE 12/20/17


15.3 Tank covers shall have a minimum slope of 1.5 to prohibit moisture accumulation.

15.4 Each transformer shall be furnished with tank grounding provisions. Tank grounding provisions

shall be constructed per ANSI Standard C57.12.20, Section 6.5.4, latest revision. Tank grounding

provisions shall be capped before the unit is painted.

16.0 INSULATING OIL

16.1 Each transformer shall be filled with mineral insulating oil and shall be certified to contain less

than one part per million (1 ppm) Polychlorinated Biphenyls (PCBs) as measured on a dry weight

basis. A notice to this affect shall be included on the transformer nameplate.

EXAMPLE:

FILLED WITH MINERAL OIL CONTAINING LESS

THAN 1 PPM PCBs AT TIME OF MANUFACTURE

or

CONTAINS LESS THAN 1 PPM PCBs

16.2 A separate standard “Non-PCB” label, blue background with white lettering with the following

legend: “Non-PCB Mineral Oil – when manufactured contained less than 1 PPM PCB” shall be

attached on the side opposite the hanger on overhead transformers.

17.0 SHIPPING




17.2 All single phase transformers must be loaded from the rear of the truck for unloading by forklift

from the rear exit of the trucks trailer.



the quotation.



APPROVED ___________ DATE _______


DATE 12/20/17


a. No load losses in watts at normal frequency and voltage.

b. Total full load losses in watts at normal frequency and voltage.






Where the load losses are computed as

Total loss - No load loss


19.1 The quoted losses shall be guaranteed by the manufacturer as specified in ANSI/IEEE C57.12.00-

1987, Section 9.3. Average of all units is interpreted to mean all units in a single manufacturing

run delivered to Huntsville Utilities in a single shipment. Split shipments shall be evaluated

separately.


20.1 Each manufacturer shall furnish Huntsville Utilities with certified loss test reports, by serial

number, for each unit. Receipt of the certified loss test reports by Huntsville Utilities shall be a

requirement for payment. Each certified test report shall include loss data as specifically required

for quotation as well as size and configuration of each transformer.


conforms to ANSI/IEEE Standard C57.12.00, latest revision.




reports. The manufacturer’s certified loss data must be within ±2% of the data obtained by


20.4 If the loss data obtained by Huntsville Utilities testing is not within ±2% of the manufacturer’s




APPROVED ___________ DATE _______


DATE 12/20/17


a. Conduct loss testing on the entire lot of transformers received by Huntsville Utilities with

the loss testing results being used in place of the certified loss data reported by the

manufacturer. The cost of the loss testing shall be credited to Huntsville Utilities by the

respective manufacturer.

b. Reject the entire lot of transformers and return the transformers to the respective manufacturer

at the manufacturer's expense.

c. Return a random sampling of the lot of transformers to the respective manufacturer for


d. Subject a random sampling of the lot of transformers to testing conducted by a mutually

agreed upon third party test laboratory.

If actions taken under Items c. and d. indicate that the manufacturer's certified loss data is

inaccurate, the respective manufacturer will bear the expense of the above action(s).





21.1 Transformer losses shall not exceed tolerances specified in ANSI/IEEE Standard C57.12.00,

Section 9.3 - Tolerances for Losses (latest revision). Each transformer that fails to conform to this

standard shall be returned to the manufacturer, freight collect, for replacement. Alternately,

Huntsville Utilities may require credit from the manufacturer equal to the present value of the

added cost of ownership for a 30-year period but not to exceed the original purchase cost of the

transformer. The credit required shall be based on the difference of the actual losses and quoted

losses using the evaluation formula costs.

Example:




LLF Load Loss Factor = 3.3393 Load Losses = 2.0 Load Losses = 2.1




APPROVED ___________ DATE _______


DATE 12/20/17



Plus + +


Plus + +




Minus Actual evaluation -33.82725

Equals Evaluated Difference = 1.81805



Equals Purchase Price Adjustment =(1.0151)



Plus Purchase Price Adjustment +( 1.0151)

Equals Actual Purchase Price =$ 8.9849


Plus +


Plus +





The required credit would be the 1.0151 or 1.02 if rounded to cents

(since .0051 is greater than .005).

If the adjustment above had been positive, the actual losses would have been less than quoted and no credit

would have been due from the manufacturer.

We would not issue a credit to the manufacturer for beating his loss quotation.

Per ANSI/IEEE Standard C-57.12.00, Section 9.3, tolerances for losses are as follows:

Number of No-load Load



APPROVED ___________ DATE _______


DATE 12/20/17


Units on Basis of Losses Losses

One Order Determination (%) (%)

1 1 10 6

2 or more Each unit 10 6

2 or more Average of 0 0

all units

Therefore, each unit must be within 10% on no load losses and within 6% on load losses. If more than

one identical unit is shipped as one order in a single shipment, the average of all units must meet quoted

losses with no tolerance.


quoted losses shall be subject to probation, suspension, and/or complete deletion as an approved

supplier.


22.1 Manufacturers quoting transformers to this specification shall indicate any areas where changes

to this design and/or specification are required by their design standards. Any recommended

changes to this design and/or specification offered by the manufacturer shall be accompanied by

sufficient information to permit full evaluation of the desired changes. Any change to this design

and/or specification requires prior approval from Huntsville Utilities Electrical Engineering.

Detailed approval drawings, design criteria, test data, and prototype samples shall be submitted

with design or specification change requests.

22.2 Transformers addressed by these specifications are subject to routine and/or random inspections

and/or testing conducted by Huntsville Utilities to assure that the transformers provided by the

vendor comply with this specification and/or any agreed upon deviations.

22.3 Bids will be awarded to manufacturers based on the manufacturer's stated compliance with this


manufacturer's product is discovered not to be in compliance with this specification (and/or any



a. Any transformers received that do not comply with this specification in its entirety will be

rejected and returned to the manufacturer at the manufacturer's expense.



APPROVED ___________ DATE _______


DATE 12/20/17


b. The respective manufacturer will be required to provide Huntsville Utilities with the number

of units initially quoted (at the initial quoted price and loss values) which do comply with this

specification in its entirety. Provision of the initial number of units quoted by the respective

manufacturer is mandatory even if said manufacturer is required to supply units manufactured

by another approved source. Units supplied by another approved source shall be delivered in

the time specified by the manufacturer winning the bid.

c. Failure to comply with this specification (and/or any agreed upon deviations) in their entirety

may result in the manufacturer's immediate suspension or removal from Huntsville Utilities'

list of approved manufacturers. Such suspension or deletion shall not necessarily be limited

to a particular item or class of items.

ifb 18-06 transformer addendum 2 - huntsville utilities...modified by this specification, shall be...

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