MADRAS ATOMC POWER STATION TENDER · PDF fileconnected to Zebra type ACSR conductor, the supply shall include 7 set of clamps and hardware suitable for Moose conductor and 7 set of

NUCLEAR POWER CORPORATION OF INDIA LIMITED(A Government of India Enterprise)

MADRAS ATOMC POWER STATION

TENDER DOCUMENT

TECHNICAL SPECIFICATION FOR245kV WALL BUSHING WITH CURRENT TRANSFORMER FOR MAPS

AIR INSULATED INDOOR SWITCHYARD

November, 2014

NPCIL PROPRITORY

This document is the property of Nuclear Power Corporation of India Limited. No exploitation or transfer of any information contained herein is permitted in the absence of an agreement with NPCIL and neither the document nor any such information may be released without the written consent of NPCIL

Nuclear Power Corporation of India Limited

Madras Atomic Power Station Section: CPage 4 of 69Rev-1Technical Specification for 245KV Wall Bushings with Current Transformer

SPECIFICATION NO.: PC-E-NOT FOR PUBLICATION / PRESENTATION OUTSIDE NPCIL

November, 2014

SECTION-C

1.0 SCOPE OF SUPPLY / WORKS / SERVICES.

1.1 This specification establishes the technical requirements of High Voltage Class OIP insulated condenser type 245kV Wall bushings with Current transformer for Line protection, bus bar differential protection, overall differential protection back up protection and metering requirement suitable for air insulated indoor switchyard of Madras Atomic Power Station

1.2 This specification covers design, engineering, material, construction, manufacture, conducting all the required tests, inspection at works by NPCIL QA engineers, packing, transportation and delivery to site, dismantling and removal of existing Brush Make wall bushing, installation and commissioning of OIP insulated condenser type 245kV Wall bushings, guaranteeing and submission of complete documents in soft and hard copy format for Madras Atomic Power Station. During tender stage Type tested equipment will be given preference hence tenderer shall submit complete valid type test reports along with offer. In case if valid type test report is not available, after placing PO, all type tests shall be conducted by the contractor in the presence of NPCIL QA engineer at his own cost..

1.3 It is not the intent to specify completely herein, all details of design and construction of the equipment. However, the equipment shall conform in all respects to high standards of engineering, design and workmanship and be capable of performing continuous commercial operation up to the CONTRACTOR'S guarantees in a manner acceptable to the PURCHASER, who will interpret the meaning of drawings and specifications and shall be entitled to reject any work or material which, in his judgement, is not in full accordance therewith.

1.4 The scope also includes but not limited to the following items / services described herein and elsewhere in the tender package.

1.5 Scope of main supply consists of the OIP insulated condenser type 245kV Wall bushings with CTs as listed below:

SL No

CT description Unit Qty Remark

1245kV Wall Bushing CT Type 1 (For GT-1 & 2)

Nos 6 At East side wall

2245kV Wall Bushing CT Type 2 (For Line-1, 2 )

Nos 6 At West side wall




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1.6 One spare bushing with CT on each type and essential spare parts as indicated in Clause No. 4.5 shall be included in the scope of supply.

1.7 Supply includes deep galvanized high tensile bolts, nut, washer and other hardware required for installation of wall bushing on the existing wall embedded frame structure at site.

1.8 Maintenance tools and tackles as described in clause 9.0 of this specification shall be supplied by the CONTRACTOR.

1.9 Whether called for specifically or not all accessories required for normal operation of equipment are deemed to be considered as a part of the CONTRACTOR'S scope of supply.

1.10 As the supplied bushing has to be mounted on the already existing wall embedded flange / wall frame assembly, the mounting flange on the bushing shall be so designed and manufactured that it will suit for the existing wall frame assembly whose dimensional details are furnished along with this specification. No modification on existing wall mounted frame is allowed. Any fine tuning required on the supplied bushing or its flange if demanded shall be done at site so that the erection, installation and commissioning can be done within the permitted time. Hence the bidder shall visit the site and collect all engineering inputs required for manufacturing of bushing and current transformer to suit site requirements, work out factory modifications and to ensure retrofitting as per site requirement.

1.11 These bushing will act as an interconnecting device between MAPS 230KV switchyard to 230KV line feeder and Station Generator Transformer (GT) through an over head conductor. As the bushing used for GT feeder will be connected to Moose type ACSR conductor and the bushing used for 230KV Line will be connected to Zebra type ACSR conductor, the supply shall include 7 set of clamps and hardware suitable for Moose conductor and 7 set of clamps and hardware suitable for Zebra conductor. In addition the design shall ensure the required mechanical, tensile and cantilever strength to sustain mechanical and electrical forces acting on the bushing throughout its life span.

1.12 The quality assurance inspection and testing as per clause 6.0 and 7.0 shall be carried out..

1.13 The scope of tender also includes submission of various end documents covered in subsequent sections, analysis, calculation reports and design review in consultation with PURCHASER. The documentation shall include all the technical information as called in the referred IS / IEC / IEEE standards regarding the




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Bushings and current transformer. The documentation and drawings shall be updated for “As built” information and shall be matched with field details. O&M manuals, calculations, procedures and test reports shall be part of “End Documentation”. The firm shall supply the complete assembly drawing giving detailed internal view of all the components in soft and hard form. Over all general arrangement drawing alone is not acceptable.

1.14 Any deviation to technical specification and tender condition shall be brought out clearly and bidder shall not submit offer with modified scope, deviating from specification. All the pages of tender document shall be signed meaning that the bidder is accepting all the tender commercial and technical specifications.

1.15 All accessories required for manufacturing the bushing and current transformer shall be purchased only from the approved vendor. The firm shall submit the vendors list along with Quality Assurance Plan for approval. NPCIL / MAPS registered vendors list is given in Annexure-B for reference.

1.16 The bushing and its accessories shall be qualified by calculations for Seismic requirement for Codal duty as per IS-1893 or IEC/IEEE. The terminal boxes, porcelain part of bushing and other critical components shall meet seismic duty requirement and all bolts sizes and hardware shall be selected and finalized accordingly.

1.17 Details, if any required will be provided by PURCHASER during detailed engineering. Similarly details required for terminating Zebra and Moose type over head conductors on terminal bushings like connector dimensions etc, shall be submitted by the supplier.

1.18 The time frame for completion of activities shall be as follows:

SL No

Activity Max. Completion time frame from date of PO/LOI

1 Submission of list of bought out accessories and the names of sub-suppliers selected from those furnished along with offer.

Submission of Quality assurance plan (QAP) with hold points for purchaser’s inspection.

Submission of drawing with detailed dimension and internal details and current transformer details.

One month




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Submission of valid type test report for main supply if already done and accepted as part of tender document

2 Design, engineering, material, construction, manufacture and complete assembly of OIP insulated condenser type 245kV Wall bushings and Current transformers as per the technical specification

Six months

3 Conducting routine / acceptance and all other tests as per the IS/IEC standard

one months

4 Indicate the duration required for type test if required5 Packing and delivery of the items 15 days6 Dismantling of existing Wall bushing, erection installation

and commissioning of new bushings at MAPS site4 days per feeder

PO: Purchase Order, LOI: Letter of Indent

1.19 For stage inspection testing or final testing as per QAP, Contractor has to give inspection call a minimum 7 days in advance for Purchaser’s inspection / witnessing of tests.

1.20 PROJECT DATA AND CONDITIONS

a. Following are the climatic conditions and protect data.1 Project title : Madras Atomic Power Station 2 Location : Kalpakkam, 70 km from South of Chennai

on the coast of Bay of Bengal.3 Nearest Rail head : Chengalpattu (32 km from Kalpakkam)4 Nearest NH : NH-45 passing thorough Chengalpattu5 Nearest Port : Chennai, 80 km from Kalpakkam6 Ambient temperature minimum : 26 deg C7 Ambient temperature maximum : Refer Clause 4.2 (13) 8 Atmospheric pressure : 1020mb

9 Wind speed : 52 kM/hr to 55kM/hr at 50m height maximum

10 Relative Humidity : 55 % to 95%11 Air Quality : Atmospheric air is sand and salt laden12 Altitude from Sea Level : 4 meters above mean sea level

The Supplier may note the severe climatic condition existing in the region with co-incident humidity, salt and sand laden atmosphere and the temperature conducive to rust and fungus growth.

b.Following are the system condition.SL No. Particulars Data

1 Nominal system voltage (kV) 220




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2 Highest system voltage (kV) 245 3 No. of phases 34 Frequency (Hz) 50 ± 3%5 Method of grounding Solidly earthed




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2.0 CONTENT

SL No Title Clause1 Scope of supply Works and Service 12 Applicable Codes and Standards 33 Specification of Main Equipment and Accessories 44 Equipment Construction & Design Details 55 Inspection & Testing 66 Quality Surveillance 77 Bushing erection, installation, site test and

commissioning checks at site8

8 Special Tools & Tackles for Erection & Maintenance 9Annexure

Ann-A Existing Bushing and CT specification detailsAnn-B List of approved vendorsAnn-C Packing and dispatchAnn-D Scope of work on transportationAnn-E Existing Bushing flange dimensional drawingAnn-F Un-Inhibited Naphthenic based EHV grade

Transformer Oil




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3.0 CODES AND STANDARDS

3.1 The design, material, construction, manufacture, inspection, testing and performance of bushing, Current transformer and their accessories shall comply with the latest editions (including amendments thereto) of all currently applicable standards, statutes, regulations and safety codes in the locality where the equipment will be installed. Nothing in this specification shall be construed to relieve the CONTRACTOR of this responsibility. This specification may contain references to older versions of IEC / IEEE / IS, but since all standards are subject to revision, bidder shall offer equipment applying the latest revision of IEC / IEEE / IS standards.

3.2 In the event of any conflict between the requirements of the codes / standards and this specification, the more stringent of the two shall govern.

3.3 Other national standards are acceptable if they are established to be equal to or superior to the listed standards. In all such cases, however, copies of English translation of such national standards shall be attached to the tender. The tenders not complying with this requirement are liable for rejection.

3.4 Prior approval shall be obtained by the CONTRACTOR from the PURCHASER regarding make and type of items as well as make and type of components, instruments and subcontracted items (if any) included in this scope but not covered in the Bushing specification data sheets under Clause 4.0.

3.5 The list of applicable codes and standards are given below.

Sl No Standard Description of the Standards

A Indian Standards

1 IS 5 Colours for ready mixed paints and enamels

2 IS-513 Cold rolled carbon steel sheets and strips.

3 IS 613 Copper Rods and Bars for Electrical Purposes

4 IS 1573 Zinc Plating for ferrous metallic part

5 IS 1893 Criteria for earthquake resistant design of structures

6 IS 2099 Bushings for alternating voltages above 1000 V

7 IS-2544 Porcelain Post insulators for systems with nominal




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voltages greater than 1000V8 IS-2629 Recommended practice for hot dip galvanising on iron

and steel9 IS-2633 Methods of testing uniformity of coating of zinc coated

articles.10 IS 2705 Current transformers - specification

11 IS 2932 Enamel, Synthetic, Exterior: (a) Undercoating (b) Finishing

12 IS 3202 Code of practice for climate proofing of electrical equipments

13 IS 3203 Code of practice for climatic proofing of electrical equipment.

14 IS 4253 Specification for Cork composition sheets

15IS 4759

Hot-dip zinc coatings on structural steel and other allied products — specification

16 IS 5621 Requirement of Porcelain (Ceramic) insulation

17 IS 6005 Code of practice for phosphating iron and steel

18 IS 6202 Specification for Flat Glass Oil Level Gauges for Oil Storage Tanks

19 IS-8263 Methods for radio interference test on high voltage insulators

20 IS 11353 Guide for uniform system of marking & identification of conductors & apparatus terminals

21 IS 12063 Degree of Protection

22 IS-13134 Guide for selection of insulators in respect of pollution conditions

23 IS-13305 Permissible limits of Visual defects for insulating porcelain for electrical Circuits.

24 IS 13508 Tan delta and capacitance Measurement test

25 IS 13730 Specification for Dual coat enamelled copper wire

26 IS 14222 Impulse Withstand voltage test

B Other relevant standard

27 IEC 60044-1 Instrument Transformer – Part 1: Current Transformer

28IEC 60044-6

Requirement of protective current transformer for transient performance




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29 IEC 60071 Insulation co-ordination.

30 IEC 60296 Unused mineral insulating oils for transformers and switchgear

31 IEC 60137 Bushings for alternating voltages above 1000 V

32IEC 60587

Electrical insulating materials used under severe ambient conditions – Test methods for evaluating resistance to tracking and erosion

33IEC 60815

Guide for selection and dimensioning of high-voltage insulators intended for use in polluted conditions

34IEC 61462

Composite hollow insulators - Pressurized and unpressurized insulators for use in electrical equipment with rated voltage greater than 1 000 V

35IEC 61819

Test parameters in simulating lightning protection system components

36IEC 61869-1&2

General requirement of Instrument transformers and additional requirement of current transformer

37IEC 62155

Insulators ceramic or glass Hollow pressurized and unpressurized for voltages greater than 1000V

38IEC 62073

Guidance on the measurement of wettability of insulator surfaces

39 ANSI /ASME B 16.34

Valves - Flanged, threaded and welding end.

40 A105 / A105M-05 Standard specification for carbon steel forgings for piping applications.

41 IEEE 693-2005 Seismic qualification requirement

42 IEEE-62-11-2005 Pollution test requirements




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4.0 SPECIFICATION FOR MAIN EQUIPMENT AND ACCESSORIES

4.1 The contractor shall supply Bushings along CT and accessories complete in all respects as described in clause 1.0. This section covers data sheets for the bushings and Current Transformers to be supplied along with it.

4.2 SPECIFICATION FOR BUSHING

SL No

Description Unit Requirement

1 Bushing typeOutdoor - Indoor wall bushing with OIP (Oil impregnated paper insulation)Insulators made of Porcelain material.

2 Installation / Angle of mountingHorizontal mounting on a vertical flange embedded on a wall (Refer enclosed drawing M1/51300/6020/GA)

3 Conductor MaterialCopper having surface of external termination with silver plating

4 Terminal with connector Suitable for moose and zebra conductor5 Rated highest voltage kV 2456 Rated current A ≥800

7 Rated thermal short-time currentkA

(rms)40KA for 1s

8 Rated dynamic currentkA, peak

2.5 times rated short time current

9 Rated Frequency Hz 5010 Load type as per IEC 60137 Type 2 (Heavy load)

11 Minimum withstand value of cantilever load

N ≥2500

12 Creepage distance

12.1Minimum nominal creepage distance

for indoor endmm/kV

31mm/kV considering rated highest voltage of 245KV

12.2Minimum nominal creepage distance

for outdoor endmm/kV

Greater than 1.1*31mm/kV considering rated highest voltage of 245KV

13 Ambient temperature

13.1 Maximum °C 50

13.2 Maximum daily mean °C 40

13.3 Maximum yearly mean °C 32

13.4 Minimum air temperature °C -5




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14Rated lightning impulse withstand voltage (BIL)

kV 1050

15 Wet power-frequency voltage withstand test

kV rms 506

16 Height above sea level m < 1000

17 Type and colour of housing / Insulator Porcelain, colour - Brown

18 Test tap Required

19Temporary Over Voltage (phase-to-earth voltage)

kV 216

20Visual corona discharge power frequency voltage level w r to ground

kV >216

21 Mounting Flange Dimension mm As per the drawing enclosed

22 Corrosion protection of metallic parts Required

23 Thickness of the wall mmRefer enclosed drawing M1/51300/6020/GA

24 Dielectric dissipation factor ( tan δ ) ≤ 0.001 at power-frequency.

25 capacitance with respect to earth pF ≤ 5000

26Limits on maximum temperature raise and maximum temperature under normal operating condition

Consider temperature raise = maximum temperature – maximum ambient temperature

26.1 For spring or screwed contact

a Maximum temperature raise °C 60

b Maximum temperature limit °C 90

26.2Terminals to be connected to exterior conductor by screw or bolt



26.3Metallic part in contact with insulation material under normal operating condition






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4.3 SPECIFICATION DATA FOR CURRENT TRANSFORMERS

a. Current Transformer of 245kV Wall Bushing CT Type 1 (For Generator Transformer)

CORE 1 S. No Description Unit Requirement /Details

1 Ratio 1200 - 800 - 600 / 1 A2 Accuracy Class PS

3Minimum Knee PointVoltage of CT (Vk)

V 2030 - 1360 - 1050 Volts

4Maximum Secondary Resistance at 75°C

Ω 7.3 - 4.85 - 3.55 Ohms

5Maximum ExcitationCurrent at Vk/2

mA 30

6 Purpose Bus bar differential Protection

CORE 2S. No Description Unit Requirement /Details



V2030 at 1200 A1360 at 800 A1015 at 600 A


Ω7.3 at 1200 A4.85 at 800 A3.55 at 600 A


mA15 at 1200A22 at 800A30 at 600A

6 Purpose GT Overall diff Protection


1 Ratio 1200 - 800 - 600 / 1 A2 Accuracy Class 5P203 Rated Burden VA 20


Ω 1

5 Purpose Breaker Back up O/C and E/F protection




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b. Current Transformer of 245kV Wall Bushing CT Type 2 (for Line Protection)


1 Ratio1200 - 800 - 600 / 1 A - adopted 1200 / 1A

2 Accuracy Class PS


V 2030 - 1360 - 1050 Volts


Ω 7.3 - 4.85 - 3.55 Ohms


mA 30

6 Purpose Bus bar differential protection

CORE 2 & 3S. No Description Unit Requirement /Details



V 2030 - 1360 - 1050 Volts


Ω 7.3 - 4.85 - 3.55 Ohms


mA 30

6 Purpose Main –I and Main II distance Protection


1 Ratio1200 - 800 - 600 / 1 A - adopted 600 / 1A

2 Accuracy Class0.2s As per CEA regulation metering core accuracy shall be 0.2s

3 Rated Burden VA 20 4 Instrument security factor ≤ 55 Purpose Metering




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4.4 COMMON PARTICULARS / DETAILS

SL. No

Description Unit Requirement /Details

1Rated lightning impulse withstand voltage

kV, peak

1050

3Dry / Wet power-frequency voltage withstand test

kV rms

506

4Rated continuous thermal secondary current

A 2

5Rated thermal short-time current

kA 40 for 1s

6 Rated dynamic current kA2.5 times rated thermal short time current

7 Partial discharge level pC As per relevant IEC 60137 standards.

8Chopped lightning impulse

kV, peak

115 % of the full lightning impulse voltage as per IS 60044-1 SL No. 5.1.2.3

9Between-section insulation requirements

kV, rms

3

10Insulation requirements for secondary windings

kV, rms

3

11Inter-turn insulation requirements

kV, rms

4.5

12 CT mounting side Indoor side13 CT type Toroidal, bushing mounting type 14 Rated Frequency Hz 50

15Minimum withstand value of cantilever load

N 2500

16Maximum ambient temperature

°C 50

17 Earthing provision M12 bolt on the flange

18Surge protection form secondary winding

With surge suppressor




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4.5 LIST FOR ESSENTIAL SPARES FOR BUSHING AND CT

The supplier shall recommend a list of spares required for 5 years of operation to be stocked for maintenance purpose. However as a minimum, supplier shall furnish prices for the following in his offer.

1. One complete spare 245kV Wall Bushing with CT Type 12. One complete spare 245kV Wall Bushing with CT Type 23. Set of Surge arresters along with micro Switch provided for each CTs on one

bushing. (5 sets)4. Set of site replaceable O’ rings and sealing rings if any (4 sets)5. Any other item supplier feels important and be available with customer (2 sets)




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5.0 EQUIPMENT CONSTRUCTION AND DESIGN DETAILS

5.1 Bushing and Current Transformer shall be designed, manufactured with equipments and accessories in accordance with this specification and applicable standards indicated in clause No. 3.0. Material and components not specifically stated in this specification and which are necessary for meeting requirements of this specification shall be included in the scope of supply

5.2 The design and workmanship shall be in accordance with the best engineering practice to ensure satisfactory performance and service life as specified herein. Theintent of the specification is that the vendor supplying the equipment shall provide bushing with current transformer which shall be suitable for effectively working continuously throughout its life time in the air insulated indoor 220KV switchyard satisfactorily under different operating condition and environment specified in the specifications

5.3 All material used shall be of best quality and of the class most suitable for working under the conditions specified and shall withstand the variations of temperature and atmospheric conditions without distortion or deterioration or the setting up of undue stresses in any part, and also without affecting the strength and suitability of the various parts for the work which they have to perform.

5.4 Pipes and pipe fittings, screws, studs, nuts and bolts used for external connections shall be as per the relevant standards. Steel bolts and nuts exposed to atmosphere shall be high tensile type, galvanized or Cadmium plated and passivated.

5.5 Labels, indelibly marked, shall be provided for all identifiable accessories like test tap, Level indicator, earth connection pad etc. All label plates shall be of non-corrosive material.

5.6 Terminal bushing base plate, gland plates etc. in high current exposed zones shall be of non-magnetic material.

5.7 Design Requirement for Bushing

5.7.1 Wall bushing shall be of condenser type. Bushings shall be manufactured and tested in accordance with IS 2099 / IEC 60137 while hollow column insulators shall be manufactured and tested in accordance with IEC 62155 / IS 5621. The insulators shall also conform to IEC 60815 as applicable. The composite hollow insulators if used shall conform to IEC 61462.




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5.7.2 The design of the bushing shall be such that stresses due to expansion and contraction in any part of the bushing shall not lead to deterioration.

5.7.3 Porcelain used shall not engage directly with hard metal. Cement if used in the construction of a bushing shall not cause fracture by expansion or loosening by contraction. Cement thickness shall be as small and even as practicable. Cemented surface shall be fins and smooth shall not cause any type of discharge

5.7.4 The surface finish for ferrous parts shall be hot-dip galvanizing according to IS 4759 or zinc plating according to IS 1573. They shall be made of good commercial malleable iron or open hearth or electric furnace steel.

5.7.5 The surface finish for non-ferrous parts shall be electro-tinning according to IS 1359 or equivalent standard subject to agreement between the supplier and the purchaser.

5.7.6 Bushings and hollow column insulators shall be manufactured from high quality Porcelain insulator. Porcelain insulator used shall be homogeneous, free from laminations, cavities and other flaws or imperfections that might affect the mechanical or dielectric quality and shall be impervious to moisture with glaze & smooth finish.

5.7.7 Being exposed to salt laden atmosphere, the surface of the porcelain insulator shall be high class glaze so that no deposit is possible due to harsh environment. The porcelain glaze shall be unaffected by sudden changes in temperature and by atmospheric pollution by salt deposit, dust, ozone, acid and alkalis. The glaze of porcelain insulation shall have uniform brown translucent finish. The porcelain shall be sound, free from defects, thoroughly vitrified and evenly glazed.

5.7.8 The bushing shall be uniform in colour, free from blisters, burrs and similar other defects.

5.7.9 The bushings shall be of condenser type and class E or better Oil Impregnated Paper (OIP) type. External insulation material including sheds shall be manufactured from proven quality of Ceramic / Porcelain material.

5.7.10 The bushings to be supplied shall conform to the requirements of, and be type and routine tested to, the latest edition of IEC 60137

5.7.11 The flange must be made from material that is weatherproof and corrosion resisting. The flange of all bushings must be provided with a power factor testing tap rated for at least 2kV rms for 1 minute.




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5.7.12 Bushings / hollow column insulators shall be designed to have ample insulation, mechanical and electrical strength and rigidity for the conditions under which they will be used and subjected to.

5.7.13 When operating at normal rated voltage there shall be no electric discharge between the conductors and bushing which would cause corrosion or injury to conductors, insulators or supports by the formation of substances produced by chemical action. No radio interference shall be caused by the insulators / bushings when operating at the normal rated voltage.

5.7.14 Bushing shall be robust and capable of withstanding the internal pressures likely to occur in service. The design and location of clamps and the shape and the strength of the flange securing the bushing to the wall shall be such that there is no risk of fracture. All portions of the assembled enclosures and supports other than gaskets, which may in any way be exposed to the atmosphere shall be composed of completely non hygroscopic.

5.7.15 Suitable connectors shall be provided for connecting wall bushing CT terminal and 245kV conductor. (Refer clause 1.11)

5.7.16 Suitable hot dip galvanized hardware shall be provided for fixing the wall bushing CT on to the wall flange. Stainless steel hardware shall be provided for connecting current carrying parts.

5.7.17 The conductor used from one end to other end shall not have any joint in between, it may be solid or hollow as per the design requirement

5.7.18 The cross section area / current density of the conductor so chosen shall be such that it shall be able to carry normal rated current and short circuit / ground fault current without exceeding the temperature limits as specified in the specification.

5.7.19 The cross section and shape of the conductor so chosen shall be such that it shall be able to withstand all type of mechanical and electrical forces developed due to fault current, loading effect of overhead conductor and its hardware, effect of wind force on overhead conductor, thermal expansion due to change in ambient temperature and temperature raise on load current / fault current and sound generated within the indoor switchyard during operation of the breakers.

5.7.20 The terminal pad of main conductor at both the end where the connector for Moose / zebra conductor gets connected shall be provided with silver plating of Thickness between 15 to 25microns




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5.7.21 Sealing components such as gaskets, O’ rings, sealing compounds used shall be compatible with the materials it comes in contact with, shall with stand the temperature generated within the bushing and lost long throughout its life time.

5.7.22 The insulating materials, sealing rings and metallic components used within the bushing shall be so chosen that they will be compatible with the insulating oil used in the bushing.

5.7.23 Both indoor and outdoor end of the bushing shall be hermitically sealed so that the external environment will not have any impact on the internal components and insulating material of the bushings.

5.7.24 Buffer springs if used shall be aligned and tightened such that no distortion or movement will be experienced by any internal and external component of the bushing and Current transformer while bushing conductor carries normal and fault current.

5.7.25 Oil level indication shall be available and the level shall be visible when viewed from floor level

5.7.26 The test tap shall be connected to the aluminum foil using suitable internal cable and suitable technique shall be adopted for termination so that the termination lost long throughout the life time of the bushing

5.7.27 The measuring lead from aluminium foil shall be connected to a suitable test tap by suitable means

5.7.28 The test lead shall be designed with sealing arrangement so that no oil leak exists through the test tap lead.

5.7.29 The test tap lead shall be suitably designed with a facility to get it connected to earth rigidly and it shall not get opened on any reason when the bushing is in service. It shall be designed with built in safety such that unless its terminal cap is removed it shall not get dislodged from earth connection.

5.7.30 The insulation between CT and Main conductor shall be sufficient enough for meeting the performance of CT as well as Bushing

5.8 DESIGN REQUIREMENT OF CURRENT TRANSFORMER

5.8.1 The design and construction of CTs shall be sufficient to withstand the thermal and mechanical stress resulting from the specified short circuit currents.




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5.8.2 Current transformer shall be mounted on the indoor side of the bushing flange. The bushing shall preferably be so constructed that the CT cores can be removed if required.

5.8.3 The instrument current transformers shall be complete with its terminal box for each wall bushing CT.

5.8.4 The location / orientation of the terminal box on the CT shall be in line with what is available on the existing Bushings.

5.8.5 The external surface of instrument transformer or its housing shall be hot dip galvanized and poly urethane painted as given in Clause No. 5.12.

5.8.6 The instrument transformers shall be designed for use in geographic and meteorological conditions as given in Clause 1.0.

5.8.7 Different ratios specified shall be achieved by secondary taps only and primary reconnection is not acceptable.

5.8.8 Core lamination shall be of cold rolled grain oriented silicon steel or other equivalent alloys. The cores used for protection shall produce undistorted secondary current under normal and transient conditions at all ratios with specified CT parameters.

5.8.9 The excitation current shall be as low as possible and the current transformer shall be capable of maintaining its rated accuracy for burden and saturation factors as indicated through this specification

5.8.10 Current transformer’s guaranteed burdens and accuracy class are to be intended as simultaneous for all cores.

5.8.11 Current transformers shall have single primary toroidal type and suitably designed for bringing out the secondary terminals in a weather proof (IP 55) terminal box. These secondary terminals shall be terminated to stud type non disconnecting terminal blocks inside the terminal box.

5.8.12 The CT shall be so designed as to achieve the minimum risks of explosion in service. Contractor / Manufacturer shall bring out in his offer, the measures taken to achieve this.

5.8.13 The current transformer and bushing shall be suitable for horizontal transportation. It shall be ensured that the CT and wall bushing is able to withstand all the stresses imposed on it while transporting and there shall be no




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damage in transit. The supplier shall submit the details of packing design to the purchaser for review.

5.8.14 The current transformer, characteristics shall be such as to provide satisfactory performance of burdens ranging from 25% to 100% of rated burden over a range of 5% to 150% of rated current in case of metering CTs and up to the accuracy limit factor / knee point voltage in case of relaying CTs.

5.8.15 CT as a whole shall be suitable for fixing on to wall bushing in the indoor side, this arrangement shall suitably performed in cohesion.

5.8.16 Polarity marks shall indelibly be marked on each instrument transformer and at the lead terminals at the associated terminal block.

5.8.17 CT terminals shall be brought out to a terminal box; The CT terminals (terminal box) shall be accessible via the indoor side of the bushing. Polarity marks shall be indelibly marked on each CT and at the head terminations a the associated terminal block.

5.8.18 Current transformer shall comply with the requirements in IEC 61869-1&2, IEC 60044 and other applicable standards.

5.8.19 Each CT shall be equipped with an over voltage protective device to limit the voltage developed across secondary winding terminal to a safe value. The protective device shall not require attention after they have operated and shall not interfere with proper operation of relays or instruments connected to the secondary winding. Operation of this protective device shall be sensed using suitable micro switch to give remote alarm.

5.8.20 The surge diverter shall be suitable mounted / fixed within the CT compartment / terminal box and it shall be easy to replace in the event of requirement along with its micro switch

5.8.21 Introduction of surge diverter and its associated limit micro switch shall not affect the performance of CTs function during normal and system fault condition.

5.8.22 The surge diverter operation sensing micro switch terminal leads shall be brought out to terminal box so that it can be wired for remote annunciation for alerting operator.

5.8.23 Weight of the bushing with CT and all accessories shall be clearly indicated and verified for mechanical suitability for wall mounting with Over head connection

5.9 INSULATING OIL




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5.9.1 Un-inhibited Naphthenic based EHV grade transformer oil shall used for

impregnation and filling.

5.9.2 The characteristics of EHV grade transformer oil shall be as per Annexure-F of Section C.

5.9.3 Entire quantity of oil shall be from one manufacturer only.

5.9.4 Being hermitically sealing bushing, the basic price shall include the required oil also.

5.9.5 No inhibitors shall be used in the oil.

5.9.6 Electrical and physical properties of oil used in the bushing shall confirm to the following specification and as given in Annexure F

1. BDV (kV rms) > 70 kV (min.)2. Moisture content < 3 ppm (max.)3. Tan-delta at 90degC 0.01 max4. Interfacial Tension 0.035 N/m (min.)5. Resistivity at 90degC 6 x 1012 ohm-cm (min.)

5.9.7 The oil test results shall form part of equipment test report.

5.9.8 Moisture content in the solid insulation

After final drying and impregnation moisture will be brought down less than 1% by paper volume. In the absence of direct measurement of moisture level in paper insulation, vacuum level of degassing chamber not more than 0.15 torr / 0.2 mbar at rated flow and at final stage shall be maintained for sufficient time to ensure the moisture content in paper insulation is well below 1% of total volume

5.9.9 The Ultra High Vacuum type oil treatment plant of suitable capacity) suitable for treatment of EHV oil shall be used in order to achieve properties of treated oil.

Purchaser will make stage inspection for carrying out the purification of unused oil. Purification of oil shall be carried out as per plant standards & specifications. Oil parameters shall be as per IEC 60296 after completion of purification of oil. Supplier will be allowed to pour the oil into the wall bushing only after clearance from the purchaser.

5.10 TERMINAL BOXES AND ITS BUSHING




November, 2014

5.10.1 Independent terminal boxes shall be provided for the following

Current Transformer and micro switch leadsDielectric loss angle (Tan-delta) and capacitance Test Tap

5.10.2 The terminal box shall be fabricated from cast iron. The CT leads shall be brought out into the terminal box as an insulated cable through a suitable barrier and terminated in clamp or compression type terminals with bushings.

5.10.3 Terminal box shall be suitable for side entry of cables with gland plate and shall be provided with EPDM rubber gaskets on all the bolted joints to make it moisture proof and to meet specific requirement under harsh environment. The terminal of stator leads shall be of detachable type.

5.10.4 The CT terminal box shall be suitable for termination of the purchaser’s cable

5.10.5 Special care shall be taken in designing the power terminal box for purchases power cable so as to allow sufficient space for bending of cables and adequate electrical clearance.

5.10.6 Terminal bushing shall be rated for 1100V grade and be mounted on non-magnetic base plate suitable for connecting the power cables

5.10.7 The electrical and mechanical characteristics of terminal bushings shall be in accordance with IS-2099

5.10.8 All porcelain used in bushings shall be homogeneous, non-porous, uniformly glazed to brown colour and free from blisters, burns and other defects.

5.11 GROUNDING

5.11.1 Provision shall be made on the Bushing Mounting flange body and terminal boxes for connecting two numbers of purchasers grounding conductor

5.11.2 Threaded holes of M12 size shall be provided at two locations with suitable bolts, nuts, plain and spring washers. This provision is for grounding the Bushing purchasers grounding conductors of 90sqmm size terminated in Lugs. The depth of the threaded hole shall be sufficient to ensure adequate electrical contact between bolt and Bushing body.

5.12 SURFACE TREATMENT & PAINTING FOR CT COMPARTMENT AND FLANGE

5.12.1 SURFACE TREATMENT:




November, 2014

Supplier shall follow seven tank processes for surface treatment.

I. Degreasing: All sheet steel components shall be first degreased in a 5% alkaline solution

at 55 to 70 C for 10 to 12 minutes. After completion of this process, the components shall be rinsed, first in cold agitated water and then in cold water whereby all the alkali are to be removed.

II. Pickling: After degreasing, the components shall be pickled in a 20 to 25% solution of phosphoric acid based chemical called Protosolve – F at ambient temperature. Here adequate quantities of inhibitors shall be added to the bath to limit the action of acid on the metal. Thus, loss of tensile strength and the base metal itself, which can be caused by pickling, is to be avoided. The components shall be rinsed in two stages, first in cold agitated water for one minute and then in cold water. The water is then processed through a de-mineralising plant to eliminate any salt in water while rinsing.

III. Activation: In this stage the components shall be dipped in a relatively basic solution of PH 8 –10 so as to remove any trace of acid on the surface. This readies the component for phosphating in the next stage.

IV. Phosphating: In this stage the component is to be phosphatised to prevent the surface from corrosion and rusting and to ensure better paint adhesion. A 30 to 40 pointage (approx.3 – 4%) solution of H3 PO4 is used as phosphating agent. The components are dipped in a bath where the temperature is maintained at 40 to 50 C for period of 5 to 7 minutes. A microfine zinc phosphate film is then deposited on the work piece.

The components are then rinsed in cold agitated water so as to remove all precipitates, which may affect the paint coating.

V. Passivation: The components are then dipped in a deoxylite solution (chromic acid of

0.05 to 0.1% concentrations) at a temperature of 60 to 85 C. The treatment serves to fill the porosity of the phosphate coating and also removes all water contaminants, which may affect the corrosion resistance of the component.

VI. Drying: After the above process, all components are dried in a drying chamber at a

temperature of 100 to 110 C for approximately 10 minutes. This helps to remove all traces of moisture before the component is painted.




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*indicates Sa 2 ½ as per Swedish Standard SIS 055900 of ISO 8501 Part-1.

Metal parts not accessible for painting shall be made of corrosion-resistant material.

5.12.2 All the process parameters are continuously monitored for uniform finish and proper quality output.

5.12.3 The powder-coated sample is to be tested for the finish, shade, and gloss, scratch hardness, mar resistance, crosses cut adhesion, flexibility test & resistance to over baking.

5.12.4 A small quantity of finishing paint shall be supplied for minor touch-up required at site after the installation of wall bushing.

5.12.5 The supplier shall indicate the details of painting procedure in the offer for review and approval.

5.12.6 Metal parts not accessible for painting shall be made of corrosion-resistant material.

5.12.7 All the metal surfaces like CT compartments / flanges and any other metal surface (except current carrying conductors) shall be hot dip galvanized and as well as painted with one coat of primer suitable for poly urethane and two coats of final poly uratene (mat finish) with air craft grey colour shade. The minimum Dry Film Thickness (DFT) achieved shall be 155 microns.

PART’S NAME SURFACE

PREPARA

TION

PRIMER

COAT

INTERMEDI

ATE

UNDERCOA

T

FINISH

COAT

TOTAL

DRY FILM

THICKNESS

COLO

UR

SHADE

Main bushing metallic body, CT housing, etc. (external surfaces)

Shot blast cleaning Sa 2 ½ *

Epoxy base zinc primer (30-40 µm)

Epoxy high build Micaceous iron oxide (HBMIO) (75 µm)

Aliphatic polyurethane (PU) (Minimum 50 µm)

Minimum 155 µm

Shade 631 of IS-5

Main bushing metallic body, CT housing, etc. (external surfaces)

Shot blast cleaning Sa 2 ½ *

Hot oil resistant, non-corrosive varnish orpaint or epoxy

- - Minimum 30 µm

WhiteFor paint only

Terminal boxes Seven tank process as per IS 3618 & IS 6005

Zinc chromate primer (two coats)

- Epoxy paint with PU top coat

Minimum 80 µm

Shade 631 of IS-5




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5.13 NAME PLATES AND MARKINGS

5.13.1 Name plate marking shall as per IEC 60137 and IEC 61819 & 60044-1.

5.13.2 Name Plates / label shall be made of non-rusting metal or 3 ply lamicoid. Name plates shall be black with white engraving lettering

5.13.3 Name plate details bushing should include the following details

a) Supplier's name or trade mark

b) Year of manufacture and serial number

c) Supplier’s type designation

d) Highest voltage for equipment or rated phase-to-earth voltage and rated frequency

e) Rated current

f) Lightning impulse (BIL) and switching impulse (SIL) and power-frequency withstand test voltages (AC)

g) Bushing capacitance with respect to test tape and earth and dielectric dissipation factor

h) Weight of the unit with and without CT and oil

i) Maximum angle of mounting from vertical

j) Type or minimum nominal creepage distance

k) the rated insulation level

l) In addition, the following information shall be marked whenever space is available:

m) The rated short-time thermal current and the rated dynamic current if it differs from 2.5 times the rated short-time thermal current.

n) The class of insulation.

o) The rated continuous thermal current.

p) Quantity of Oil

5.13.4 Name plate details of CT Should include the following details

a) Manufacturer name and country

b) Year of Manufacture




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c) Sl No and type designation

d) Rated primary current and secondary current

e) Rated output and corresponding accuracy class

f) Highest system voltage

g) Rated insulation level

h) Rated short time thermal current and short time factor

i) Rated dynamic current

j) Secondary winding resistance (Rct)

k) Knee Point voltages (Vk)

l) Rated secondary exciting current (Ie)

m) Rated frequency

n) Reference standard

Name plate of CT shall very clearly indicate connection diagram with polarity of each core along with Surge diverter and its associated micro switch

5.14 LIFTING FACILITY:

Bushing as a whole along with CT shall be provided with adequately designed eye bolts, lugs or other devices to facilitate safe lifting and handling operations

5.15 DRAIN PLUGS:

Even though requirement is for hermitically sealing bushing, there shall be a drain opening with plug to permit removal of oil if design demands

5.16 DIMENSION AND THREADS

All the bushing dimension shall be in millimeters and shall be subject to tolerance specified in IS 1231, IS 2223 or IS 2254. All the nuts and bolts shall be fabricated in metric units.

5.17 ELECTRICAL AND PERFORMANCE REQUIREMENTS

5.17.1 Supply Voltage, frequency variation and seismic factor




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Unless otherwise noted, the bushing shall be suitable for continuous operation under the following conditions in supply voltage and frequency without exceeding the specified temperature limits

Sl No Parameter Variation limits

a Sustained variation in frequency ± 5%

b Sustained variation in Voltage ± 10%

c Sustained variation in frequency and voltage (arithmetic addition)

10%

d Bushing and CTs shall be designed for seismic acceleration and responsespectrum as specified in IS 1893 for Zone III

5.17.2 Temperature rise:

Under normal operating conditions and under severe fault conditions, the temperature raise of the bushing surface shall not exceed 20 deg C above an ambient temperature of 50 deg C. The temperature raise can exceed the above limits by 5 deg C only under the extreme voltage variation conditions indicated below

a. Full load operation at voltage greater than 110% of rated voltageb. Full load operation at voltage less than 90% of rated voltagec. Full load operation at frequency higher than 105% of rated frequency

5.18 DESIGN REVIEW:

5.18.1 The bushing and CTs shall be designed, manufactured and tested in accordance with the best international engineering practices under strict quality control to meet the requirement stipulated in the technical specification. Adequate safety margin with respect to thermal, mechanical, dielectric stress etc. shall be maintained during design, selection of raw material, manufacturing process etc so that the bushing provide long life with least maintenance. Design reviews shall be conducted by Owner or an appointed Consultant at different stages for all bushing covered under this specification; however the entire responsibility of design shall be with the manufacturer.




November, 2014

5.18.2 The design review will commence after placement of award with successful bidder and shall be finalised before commencement of manufacturing activity. These design reviews shall be carried out in detail to the specific design with reference of the bushing under scope of this specification. Purchaser may visit to the manufacturer’s works to inspect design, manufacturing and test facilities and manufacturer shall arrange for photographs of bushing and CTs under various stages of manufacturing

5.18.3 The manufacturer will be required to demonstrate the use of adequate safety margin for thermal, mechanical, dielectric and vibration design etc. to take into account the uncertainties of his design and manufacturing processes.

5.18.4 The scope of such a design review shall at least include the following:

1. Core and magnetic circuit design of CT2. Secondary Winding design4. Short-circuit withstand capability5. Thermal design including review of localised potentially hot areas.6. Cooling design for various operating conditions.7. Overload capability8. Seismic design calculations & requirement fulfilment9. Insulation co-ordination11. Corrosion protection13. Earthing 14. Processing and assembly15. Testing capabilities16. Inspection and test plan17. Transport and storage18. Sensitivity of design to specified parameters19. Vibration and Acoustic Noise20. Spares, inter-changeability and standardization21. Maintainability

5.18.5 Design analysis for bushing shall be submitted for review and approval of PURCHASER. For enabling proper review by PURCHASER, CONTRACTOR shall submit a detailed write- up on the design and operation of the bushing under normal operation and abnormal conditions etc as indicating set points for surge voltage set point for the surge arrester provided across secondary winding of CT.

5.18.6 All rated quantities subject to the Contractor’s guarantees shall be within the tolerances given in applicable standards / as modified in this specification.

5.19 SEISMIC QUALIFICATION




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5.19.1 The unit shall be designed to safely withstand the seismic forces as per IS 1893. The supplier shall specifically confirm that the design of equipment meets the specified seismic requirements by analysis.

5.19.2 Bidders should furnish test certificates to prove seismic withstand capability. If test certificates are not available, supplier has to furnish design calculation for with-standability.

5.20 DRAWING AND LITERATURE

5.20.1 TO BE FURNISHED ALONG WITH THE BID

a) Duly filled GTP as per section D and copy of specification with date stamp / sign on each page.

b) Clause No. wise deviations if any from this specification/drawings/documents in the format given in clause 28.0.

c) Tentative GA / Cross Sectional drawing and technical data sheet.

d) Type Test Reports as per the standards listed in clause 3.4 with detailed drawings submitted to type test laboratory

e) Reference list of customers with units of similar design / rating

f) Complete product catalogue

g) Manufacturer’s quality assurance standards and program (QAP), copy of ISO 9000 series or equivalent national certification.

5.20.2 In the event of an order, supplier shall submit three copies of each set of the following literatures shall be supplied with two weeks form date of purchase order.

a) Drawing (GA and Literature of wall bushing CT containing GA drawings), data sheet, illustrative pamphlet, literature, installation, and operation and maintenance instructions.

b) Calculation for sizing of various components.

c) Rating and diagram plates for Bushing and CT

d) Quality assurance plan

e) Manufacturing flow chart mentioning time duration for oil treatment, vacuum drying of paper, oil impregnation, assembling, stage inspection, inspection of hollow bushings, current transformer cores at vendor’s place and final inspection.

f) List of recommended spare parts

g) Packing and transportation procedure.




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h) Shall submit seismic evaluation report by calculation for review and approval

i) Any other drawing / document considered necessary including all manufacturers technical literature for all equipment and accessories

j) Engineering schedule giving a list of all drawings, documents, data, performance curves, test certificates, manuals, etc. to be submitted by the supplier together with dates of submissions and category of approval, ie., for approval or for reference

Supplier shall submit 3 sets soft copy of the above drawing and literature in rewriteable CD.

5.21 End Documents

The following end documents shall be submitted in hard copy (6 sets) and soft copy (3 CDs) along with delivery of the Bushing with CTs

a) Seismic evaluation report (By calculation)

b) Short circuit withstand ability of the bushing (By calculation)

c) Design review report

d) Type test reports on Wall Bushing with CTs as per IEC

e) Routine test reports on wall bushing with CTs as per IEC

f) Special test reports on wall bushing with CTs as per IEC

g) All the material certificates of bought out items.

h) All the catalogues and instruction manual for bought out items

i) Operation, Installation and Maintenance Instruction Manual for Bushing and CTs

j) Final set of as built complete drawings

k) Any other document which are essential for the bushing and CTs for future reference

5.22 Instruction Manuals

5.22.1 The supplier shall furnish two (2) draft copies of the manual for Purchaser’s review one (1) month before dispatch of the equipment. After the Purchaser’s clearance, the manuals shall be furnished along with equipment.

5.22.2 The supplier shall furnish 6 Nos. of copies of the instruction manuals which would contain detailed instructions for all erection, testing, commissioning, operation and maintenance requirements. The manual shall be furnished at the time of dispatch of the equipment and shall include the following aspects




November, 2014

a) Outline dimensional drawings showing relevant cross sectional views, earthing details and constructional features.

b) Detailed views of the core and conductor assembly, test tap connection flange dimension, etc.

c) Full technical information which may be necessary for the erection, testing, commissioning, safe operation and maintenance of the Bushing with CTs.

d) Catalogues of all the components which are liable to be replaced during the life of the Bushing and CTs and all the component parts.

e) Unpacking.

f) Handling at site.

g) Erection drawings with written assembly instructions that would enable the PURCHASER to carry out erection with his own personnel.

h) Detailed instructions for the operation and maintenance of the Bushing, CTs and its accessories.

i) Pre-commissioning tests and test procedures.

j) Procedures for removal and replacement of any faulty component with the spare one.

k) Precautions to be taken during operation and maintenance work.

l) Complete set of all type, routine and special test reports.

6.0 INSPECTION AND TESTING

6.1 General

6.1.1 The overall requirements for stage inspection and testing, material tests etc. in respect of equipment covered in this contract shall be as per Clause 7.0. The routine tests, acceptance tests, special tests and type tests are covered in this section. Inspections and tests at raw material stage, semi finished or module level are detailed in the typical QAP given in section clause 7.

6.1.2 This section covers the tests to be carried out on the bushing and current transformer and its major components at works before final dispatch of equipment to site.

6.1.3 The equipments (Bushing and CTs) offered should have been successfully type tested as per the relevant standards, amended up to date. In case the equipment of the type and design offered has already been type tested, bidder shall furnish type test reports along with the offer for review and acceptance. Type tests must not have been conducted earlier than five years from the date of opening of bids.




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6.1.4 In the absence of valid type test report, one bushing / CT (of each core) shall be subjected to all type test specified in this tender and as per relevant standards after it undergoes routine test. All type tests shall be conducted by the firm in the presence of NPCIL QA engineer on his own cost. The bushing underwent type test will not be accepted as part of main supply. Only after successful type test and its acceptance, bushing / CT manufacturing shall be commenced for supply to NPCIL.

6.1.5 The purchaser reserves the right to demand repetition of some or all the type tests in the presence of his representative. No extra payment can be demanded for repetition of any test.

6.1.6 If the bushing / CT underwent type test fails, again the bushing / CT shall be manufactured with required corrective measure and again subjected to type test, and until it passed in the test they will not be accepted. No extra charges shall be demanded in such cases.

6.1.7 Based on the success of the bushing / CT undergoes type test, clearance for commencement of manufacturing of the bushing / CT will be given by the purchaser.

6.1.8 If there are changes in the components or in the design / type already type tested and the design / type offered against this specification, the purchaser reserves the right to demand repetition of tests without any extra cost before commencement of supply. The bidder shall bring out in his offer all such changes made in components, materials, design etc. as the case may be and likely affects of such changes on type qualification.

6.1.9 The test certificate for the materials used for all the bushing and CT shall be submitted for verification to NPCIL QA Engineers as per QA plan. All the bushings / CTs shall undergo Routine test, as per Clause No. 6.0 and whatever test / inspection indicated in the QA Plan.

6.1.10 All routine, type test if required and acceptance tests if any shall be conducted in the presence of the purchaser’s representatives. No material shall be dispatched unless the purchaser communicates his written approval to these test certificates

6.1.11 Short circuit withstand ability of the bushing by calculation shall be submitted for review and acceptance

6.2 Routine tests on CTs

6.2.1 Each individual CT shall be tested in manufacturer site. The following tests shall be conducted as per IEC 61869 & 60044 and other relevant standards.




November, 2014

a) Verification of terminal markings, polarity and oil leakage

b) Power frequency dry withstand voltage test on secondary winding

c) Power frequency dry withstand voltage test between sections

d) Overvoltage Inter-turn test (4.5KV)

e) Determination of errors

a. Ratio and phase angle error at 20% and 120% rated current for 25% and 100% rated burden for metering CT core

b. Ratio and phase angle error at rated burden and rated current for relaying CT cores

c. Composite error at rated accuracy limit of primary current by excitation current test for relaying CT cores

d. Instrument security factor test for measuring CT core

f) Secondary winding resistance, Insulation resistance

g) Winding ratio and Knee point voltage

h) Magnetizing current

i) Between-section insulation requirements: 3KV

j) Insulation requirements for secondary windings: 3KV

k) Partial discharge test

l) Measurement of dielectric dissipation factor

6.3 Routine tests on Bushing

6.3.1 Each individual bushing shall be tested in manufacturer site. The following tests according to IEC 60137- 2008 - clause 9.1, 9.3 and 9.4 shall be conducted.

a) Measurement of dielectric dissipation factor (tan ) and capacitance at ambient temperature

b) Dry lightning impulse voltage withstand test (BIL)

c) Dry power frequency voltage withstand test 506kV - 50 Hz for 1 min.

d) Tests of tap insulation

e) Measurement of the partial discharge level

Partial discharge values: Highest partial discharge values at 1.05 Um/√3 shall be ≤ 5 pC




November, 2014

Highest partial discharge values at 1.50 Um/√3 shall be ≤ 10 pC

f) Visual inspection and dimensional check

g) Tightness Pressure test on oil filled bushing

h) Each bushing shall be subjected to routine electrical tests performed at standard room temperature to measure C1 and C2 power factor and capacitance. The test shall be carried out at 10kV for C1 measurement and at least 1kV for the C2 measurement.

i) Chopped lightning impulse: 115% of full lightning impulse voltage as per IS 60044-1 SL No. 5.1.2.3.

6.4 Type tests on CTs

6.4.1 Following Type Tests shall be done for Current transformers as per the latest IEC 61869 / 60044

a) Short time current test b) Temperature rise testc) Lightning impulse testd) High voltage power frequency wet withstand teste) Determination of errors and accuracy classf) Radio interference voltage measurement (RIV)g) Instrument security factor to prove the instrument security current does not

exceed the rated value for measuring CTsh) Partial discharge testi) Measurement of dielectric dissipation factor

6.5 Type tests on Bushings

6.5.1 Following Type Tests shall be done for Wall Bushings as per the latest IEC 60137

a) Cantilever Load withstand Test

b) Temperature rise, porosity, galvanizing, temperature cycling

c) Thermal stability test

d) Dry lightning impulse voltage withstand test (BIL)

e) Wet power-frequency voltage withstand test (506Kv)

f) Thermal short time current withstand test

g) Dynamic current withstand test

h) Electromagnetic compatibility tests (EMC)




November, 2014

i) Tightness test on liquid filled bushing

j) Verification of dimensions

k) Artificial Pollution test as per IEEE-62-11-2005

6.6 Auxiliary Equipment (Surge diverter and micro switches)

All other auxiliary shall be tested as per the relevant standards. Test certificates shall be submitted for bought out items. High voltage withstand test shall be performed on auxiliary equipment and wiring after complete assembly.

6.7 Rejection

Purchaser may reject bushings during testing if any of the following conditions arise:

6.7.1 Partial discharge not as per the limiting value indicated in the standards

6.7.2 Dielectric loss factor (Tan delta) value not meeting the specification.

6.7.3 Bushing / CT is proved at any stage to have been manufactured not in accordance with the agreed technical specifications and approved quality control plan and approved drawings.

6.8 Inspection:

Bushing and CTs will be inspected at every stage of manufacturing and testing by NPCIL QA engineers / Engineers MAPS as per the approved Quality Assurance plan as detailed in Clause NO. 7.0 of this specification. At every stage, the inspection call shall be made at least one week in advance so that the inspector will be able to come with preplanning. During inspection if any values found deviated from the limiting values, they will be rejected.




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7.0 QUALITY SURVEILLANCE

7.1 The general requirements regarding quality assurance, organizational set up for quality surveillance, qualification and experience details of personnel of quality Assurance department, QA Manual, Mock up test procedures etc. are covered in this section.

7.2 This document indicates the requirements expected from the contractor / manufacturer of the above equipment. Subsequent to the placement of Purchase order contractor / manufacturer shall submit for purchaser's approval a quality assurance plan in line with this document incorporating specific document numbers for "format of records", "acceptance norms" and "reference documents".

7.3 The supplier shall invariably furnish the following information along with his offer failing which his offer shall be liable for rejection.

a) Names of sub-suppliers of individual accessories (like liquid silicone rubber, current transformer, current transformer core, copper and winding, Aluminium conductor, connector clamps, wires, CT terminal box etc).

b) Information and copies of test certificates in respect of bought out accessories.

c) List of manufacturing facilities available.

d) List of areas in manufacturing process where stage inspections are carried out for quality assurance and details of such tests and inspection.

e) Type test certificates not older than five years as on the previous date of tender opening.

7.4 The supplier shall submit the type and routine test certificates of bought out items, at the time of routine testing of the fully assembled wall Bushing.

7.5 The supplier shall within 30 days of placement of order, submit following information to the purchaser.

a) List of bought out accessories and the names of sub-suppliers selected from those furnished along with offer.

b) Type test certificates of the bought out accessories.

c) Quality assurance plan (QAP) with hold points for purchaser’s inspection. The quality assurance plan and hold points shall be discussed between the purchaser and supplier before the QAP is finalised.

d) Dimensional drawing for Bushing, its internal and current transformer details




November, 2014

7.6 PROGRESS REPORTING

7.6.1 Outline document to be submitted for Purchaser approval for outline of production, testing, inspection, packing, dispatch, documentation program.

7.6.2 Detailed Progress Report

To be submitted to Purchaser once a month containing:

a) Progress on material procurement

b) Progress on fabrication (As applicable)

c) Progress on assembly (As applicable)

d) Progress on internal stage inspection

e) Reason for any delay in total program

f) Details of test failures if any in manufacturing stages

g) Progress on final box up

h) Routine and type test program

i) Constraints / forward path

7.7 Deviations from this specification (if any) shall be stated in writing (in the format mentioned in section D 2.7) with the tender by reference to the Specification Clause / GTP / Inspection / Drawing and a description of the alternative offer. In the absence of such a statement, it will be assumed by the Purchaser that the Manufacturer / Supplier comply fully with this specification.

7.8 Quality control plan

This indicates the requirements expected from the contractor/manufacturer of the 230 kV wall bushing current transformers. Subsequent to the placement of Purchase Order supplier shall submit for purchaser’s approval a quality assurance plan in line with this document incorporating specific document numbers for “format of records”, “acceptance norms” and “reference documents”.

Abbreviations

V : Verified byP : Performed by




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W : Witnessed by (After lapse of due notice to NPCIL, manufacturer may proceed with manufacturing)

H : Hold (Unless a written clearance is obtained from NPCIL, manufacturer shall not proceed to next stage)

1 : NPCIL QS / Inspection engineer from Site2 : Prime Supplier 3 : Approved External Laboratory or Sub Vendor QC (if vendor

QC / facility not available.)AD : Approved Document such as Tender Document, Purchase

order, Drawings & Test ProceduresTR : Test ReportPS : Plant StandardCHP : Customer Hold Point IS : Indian StandardsIEC : International Electro-technical Commission standardsIEEE : Institute of Electronics and Electrical Engineers standardsNote:

1. Photos shall be furnished to NPCIL during manufacturing and testing of bushings

2. Wherever V & W are both indicated, NPCIL QS to witness test or review TRs.

3. All the important tests will be witnessed by NPCIL Engineering & Procurement Group & Clearance will be given

4. Continuous surveillance check will be done by NPCIL engineer during manufacturing and testing of Bushing

5. TRs not more than five year old from date of opening of Part-I of tender shall be reviewed for acceptance. Otherwise test shall be carried out.

6. Minor: The characteristic of a component, process or operation whose failure neither materially reduce the usability of the product in operation, nor does it affect the aesthetic aspects.

7. Major: The characteristic of a component, process or operation whose failure may cause operation failure which cannot be readily corrected at site or cause substandard performance, increased erection and maintenance cost, reduced life or seriously affect aesthetics or ergonomics.

8. Critical: The characteristics of a component, process or operation failure of which will surely cause operating failure or intermittent troubles which is difficult to rectify at site or render the unit unfit for use or safety hazards.




November, 2014

9. ‘‘Failure “of a characteristic means failure to meet the ‘acceptance norms ‘.

10. Sampling: Generally in accordance with IS: 2500. Sampling will be used as under.

11. If 100% “witness” is carried out by “Prime supplier”, NPCIL will witness on sample basis, or if 100% “witness” of tests is carried out by “sub-supplier”, “Prime supplier” will witness on sample basis.

12. Wherever more than one standard is specified for acceptance norms, the standard which gives the better value will be the considered for acceptance.

13. Any deviation to this QAP shall be brought out by vendor in his offer failing which this QAP shall be complied with fully


Madras Atomic Power Station Section: CPage 44 of 69Rev-1

Technical Specification for 245KV Wall Bushings with Current Transformer


November, 2014

SL. NO COMPONENTCHARACTERISTICS

CHECKEDCATEGORY

METHOD OF CHECK

EXTEND OF CHECK

REFER-ENCE

DOCU-MENT

ACCEPTANCENORM

FORMAT OF

RECORD

AGENCY REMARK

V P W H

1.0 Raw Materials1.1 Kraft Paper insulating materials

a Electric strength of paper (Proof strength of paper)

Major test 1 sample from each consignment

IEC 60554 IEC 60554 TC 1,2 3

b Tensile or Bursting strength of paper

Major Verification of records

1 sample from each consignment

IEC 60554 IEC 60554 TC 1,2 3

c Thickness of paper Major Measurement 1 sample from each consignment

IEC 60554 IEC 60554 TC 1,2 3

d Aging test (Heat stability test)

Major test Random IEC 60554 IEC 60554 TC 1,2 3

e Reaction on hot oil Major test 1 sample from each consignment

IS 335 and PS

Acidity comparable to blank oil

TR 1,2 2, 3

f Physical condition and cleanliness of paper

Major Visual check 1 sample from each consignment

PS Free from damages and dent marks

TR/TC 1,2 2

g Water absorption Major test Random IEC 60554 IEC 60554 TC 1,2 3

h pH of aquesious extract of paper

Major test Random IEC 60554 IEC 60554 TC 1,2 3

1.2 Copper conductor

a Dimensional and visual control

Major Measurement Sample from each consignment

PS PS TC 1,2 3





November, 2014

b Tensile strength and elongation

Major test Sample from each consignment

PS PS TC 1,2 3

c Electrical resistivity Major test Sample from each consignment

PS PS TC 1,2 3

d Conductor finish Major Visual Sample from each consignment

PS Bright finish without scratchy and dent

TC 1,2 3

e Chemical analysis / composition

Major Verification of records

Sample from each consignment

PS PS TC 1,2 3

1.3 Sheet steela Chemical and

mechanical properties(tensile strength and Percentage of elongation)

Minor Verification of suppliers certificate

100% Heat Number

IS 2062 IS 2062 TC 1,2 3

b Dimensions Minor Measurement 100% PS PS TC 1,2 3c Identification of

certified raw materialsMinor Verification

of 100% RV Number on plate / section

100% PS PS TC 1,2 3

1.4 CRGO steela Specific loss after and

before ageing testCritical Epstein test One sample

from each consignment

IEC 60404 IEC 60404 TC 1,2 3

b Stacking factor Major Measurement Random IEC 60404 IEC 60404 TC 1,2 3c Magnetization

characteristic / Induction

Major Test One sample from each consignment

IEC 60404 IEC 60404 TC 1,2 3





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d Ductility, surface insulation resistivity

Major Test Random IEC 60404 IEC 60404 TC 1,2 3

e Thickness Minor Measurement Random PS PS TC 1,2 3f Ageing test Major test Random IS 249 IS 249 TC 1,2 3g Chemical analysis Major Verification

of recordsOne sample from each consignment

IEC 60404 IEC 60404 TC 1,2 3

h Edge, burr, bow, waviness & Insulation (To be checked after de-burring)

Critical Measurement Random PS IEC 60404 TC 1,2 3

i Dimension of lamination

Minor Measurement During setting for each size of lamination

PS As per mgf drawing

TC 1,2 3

1.5 Aluminium foil material ASTM B373

a Mechanical properties Major Test One sample from each consignment

As per ASTM standard

As per ASTM standard

TC 1,2 3

b Dimensional and visual control

Major Measurement One sample from each consignment

PS PS TC 1,2 3

c Electrical resistivity Major Measurement One sample from each consignment

PS PS TC 1,2 3

d Conductor finish Major One sample from each consignment

PS PS TC 1,2 3

e Chemical analysis / composition

Major Test One sample from each consignment

PS PS TC 1,2 3

2.0 Aluminium Casting





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a Visual Major Physical Sample PS PS TR 1,2 3

b Dimensional Major Physical Sample PS PS TR 1,2 2

3.0 Insulator (Porcelain)

a Visual, Dimensional, Conformity.

Major Physical 100% IS 5621 / IEC

IS 5621 / IEC TR 1,2 3

b Surface Finish Minor Chemical Sampling PS PS TR 1,2 3 2

c Creepage distance measurement

Major Measurement 100% IS 5621 / IEC

IS 5621 / IEC TR 1,2 3 1,2

d Electrical test Major HV Test 100% IS 5621 / IEC

IS 5621 / IEC TR 3 1,2

e Temperature cycle test Major Measurement 100% PS PS TR 3 1,2

f Pressure test Major Measurement 100% PS PS TR 3 1,2

g Porosity test Major Measurement sample IS 5621 / IEC

IS 5621 / IEC TR 3 1,2

h Internal flaw Major Ultrasonic 100% PS PS TR 3 1,2

i Bending strength at 70% on all four direction

Major Mechanical 100% PS PS TR 3 1,2

j Parallelism & eccentricity

Major Mechanical 100% PS PS TR 3 1,2

k Dielectric strength Major Electrical 100% PS PS TR 3 1,2

4.0 End fitting with porcelain

Visual Major Physical Sample IEC 617 IEC 617 TR 1,2 3

5.0 Welding electrodes and Welding procedure

a Welding procedure and welder Qualification

Major Mechanical 100% PS PS TR 3 1,2 1 WPS shall be approved by NPCIL





November, 2014

b Chemical and mechanical properties of welding electrodes

Major Verification of suppliers certificates

100% IS 814 IS 814 TC 1,2 3

c Visual checks on weld properties and weld

Minor Visual 100% IS/PS IS/PS TR 3 1,2 1

d Test on welding Major NDT Sampling PS PS TR 1,2 3 2

6.0 Paining of all metallic structures

a Seven Tank process(Phospating)

Major Physical 100% PS PS TR 1,2 3 2

b Primer & painting Major Thickness,Sampling,MeasurementVisual,Adhesion

Sampling PS PS TR 1,2 3 2

7.0 Galvanizing of structures

a Uniformity of Zinc coating

Chemical Physical 1 sample per lot IEC 60099-4

IEC 60099-4 TR 3 1,2

b Weight of Zinc coating

Chemical Physical 1 sample per lot IEC 60099-4

IEC 60099-4 TR 3 1,2

c Salt spray Test beyond 500 hours and shall exhibit excellent corrosion resistance.

Major Chemical Sampling PS PS TR 1,2 3

8.0 Gasket and O’ Rings

a Visual Major Physical / Measurement

100% PS PS TR 1,2 3

b Dimensional Major Physical / Measurement

100% PS PS TR 1,2 3

9.0 End terminal connector





November, 2014


100% PS PS TR 1,2 3


100% Approved drg

PS TR 1,2 3

10.0 Assembly CT and wall bushing Unit


100% PS PS TR 1,2 3


100% PS PS TR 1,2 3

c Verification of BOM and components type, rating etc

Major Physical 100% PS PS TR 1,2 3

d Wire routing Major Physical Sampling PS PS TR 1,2 3

e Wire Dressing Major Physical Sampling PS PS TR 1,2 3

f Schematic Checks Major Electrical 100% AD AD TR 1,2 3 1,2

11.0 Uninhibited naphthalene based transformer oil

a All test as per Annexure-F of this section at source. Check for drum quality and oil leakage

Major Test Sample of all batches

As per Annexure F of this section

As per Annexure F

TR 3 2,1 1 Continuous surveillance check by NPCIL QS engineer at source point

12.0 Cable glands Visual Checks MAJOR Observation 100% PS PS TR 1,2 3

Dimensional Checks MAJOR Measurement 100% PS PS TR 1,2 3

13.0 FINAL INSPECTION

13.1 Current Transformer

13.1.1 Routine test





November, 2014

a Verification of terminal markings

Major Visual 100% IEC 61869 & 60044

IEC 61869 & 60044

TR 1,2 3

b HV Insulation test on CT Secondary winding

Major Measurement 100% IEC 61869 & 60044

IEC 61869 & 60044

TR 1,2 3 1,2 1

c Inter-turn over voltage test for Secondary winding


IEC 61869 & 60044

TR 1,2 3 1,2 1

d Determination of errors (Metering and Relaying CTs)


IEC 61869 & 60044

TR 1,2 3 1,2 1

e Secondary winding resistance, IR value Knee point voltage, CT ratio, Magnetizing characteristics,


IEC 61869 & 60044

TR 1,2 3 1,2 1

f Between-section insulation requirements: 3KV

Major Measurement Sampling IEC 60044-1 SL No. 5.1.3

IEC 60044-1 SL No. 5.1.3

TR 1,2 3 1,2 1

g Insulation requirements for secondary windings: 3KV

Major Measurement Sampling IEC 60044-1 SL No. 5.1.4

IEC 60044-1 SL No. 5.1.4

TR 1,2 3 1,2 1

13.1.2 Type Test

a Mechanical test Major Electrical Sampling IEC 61869 & 60044

IEC 61869 & 60044

TR 1,2 3 1,2 1

b Determination of errors

Major Measurement Sampling IEC 61869 & 60044

IEC 61869 & 60044

TR 1,2 3 1,2 1

c Radio interference voltage measurement (RIV)


IEC 61869 & 60044

TR 1,2 3 1,2 1





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d Instrument security current test for metering CT


IEC 61869 & 60044

TR 1,2 3 1,2 1

13.2 Assembled Wall Bushings with CT13.2.1 Routine test

a Measurement of dielectric dissipation factor (tan δ) and capacitance at ambientTemperature up to rated voltage (For both increasing and decreasing voltage)

Major Electrical 100% IEC 60137 IEC 60137 TR 1,2 3 1,2 1

b Dry lightning impulse voltage withstand test


c Dry power frequency voltage withstand test

Major Electrical 100% IEC 60137 (at 506KV)

IEC 60137 TR 1,2 3 1,2 1

d Measurement of partial discharge quantity


e Test of tape insulation Major Electrical 100% IEC 60137 IEC 60137 TR 1,2 3 1,2 1

f Tightness Pressure test on liquid filled bushing

Major Mechanical 100% IEC 60137 IEC 60137 TR 1,2 3 1,2 1

g Visual inspection and dimensional checks

Major Measurement 100% IEC 60137 IEC 60137 TR 1,2 3 1,2 1





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h Chopped lightning impulse at 115% of full lightning impulse voltage.

Major Measurement 100% IEC 60044-1 SL No. 5.1.2.3

IEC 60044-1 SL No. 5.1.2.3

TR 1,2 3 1,2 1

13.2.2 Type test - Bushing which undergo type test will not be considered as part of supplya Cantilever load

withstand TestMajor Physical 1 No IEC 60137 IEC 60137 TR 1,2 3 1,2 1

b Thermal stability test Major Electrical 1 No IEC 60137 IEC 60137 TR 1,2 3 1,2 1

c Temperature rise test Major By calculation to demonstrate temperature rise limit

IEC 60137 IEC 60137 TR 1,2 3 1,2 1

d Wet power frequency voltage withstand

Major Electrical 1 No IEC 60137 (at 506KV)

IEC 60137 TR 1,2 3 1,2 1

e Dry lightning impulse voltage withstand test (BIL)

Major Electrical 1 No IEC 60137 IEC 60137 TR 1,2 3 1,2 1

f Thermal short time current withstand test


g Dynamic current withstand test


h Electromagnetic compatibility tests (EMC)

Major Measurement 1 No AD AD TR 1,2 3 1,2 1

i Verification of dimensions

Major Measurement 1 No IEC 60137 IEC 60137 TR 1,2 3 1,2 1





November, 2014

j Artificial Pollution test

Major Measurement 1 No IEEE-62-11-2005

IEEE-62-11-2005

TR 1,2 3 1,2 1

14.0 Documentation Visual Critical Physical 100% PP PO – Tender specification

TR 1,2 3 1,2 1

15.0 Packing and dispatch

Checking of completeness of theequipment and accessories per contractChecking of proper Packing. Check for supply of operation manual, packing list and reports

Major Physical 100% PS PS 1,2 3 2





November, 2014

8.0 BUSHING ERECTION INSTALLATION AND COMMISSIONIG CHECKS AT SITE

8.1 GENERAL

8.1.1 The scope of this section covers the details for Receipt & Storage, Erection, Pre-commissioning checks and tests to be done at site.

8.1.2 The CONTRACTOR shall carry out a detailed inspection and testing programme for field activities covering areas right from the receipt of material stage up to commissioning stage. An indicative programme for such activities as envisaged by the Employer is given below. However, it is CONTRACTOR's responsibility to draw up and carry out such a programme duly approved by the Employer.

8.1.3 In may please be noted that being operating plant, installation of wall bushings all at a time in one stretch is not be possible. One feeder having 3 wall bushings at a time can be installed and commissioned for 230KV Line feeders depending upon availability of work permit which depends on line clearance from M/s TANTRNASCO. For generator transformer feeder, the job can be taken up only when unit is under shut down. Hence the installation work shall be done depending upon availability of feeder isolation with multiple visits. Hence minimum three to four visit will be required for completion of whole erection and commissioning activity. (Tentatively two visit for line feeders, one visit for each GT feeder)

8.1.4 As the bushing needs to be installed in the indoor switchyard and since the switchyard scheme is with section and transfer bus scheme, it is not possible to isolate the total switchyard for the purpose of erection and installation of the bushing. Only the associated feeder will be isolated and all the other feeders and buses will be live, hence all safety precautions necessary to follow to ensure personnel and equipment safety shall be strictly followed. At any stage if the station safety inspector felt, the safety practice adopted is insufficient, he has the right to stop the stop and the job can be preceded further only after making the required safety arrangements.

8.1.5 All the persons involved in the job shall undergo safety training at site as per the station practice for which no certificate will be issued from the department. It may be noted that safety shoe and helmet is mandatory requirement to enter into MAPS premises for any purpose.

8.2 Receipt and Storage Checks

8.2.1 The contractor shall furnish details procedure for storing the received items at site till it is installed and commissioned.

8.2.2 The bushing and their accessories will be received at site and stored by adopting proper preservation method as per OEM recommendation till erection work is taken-up. The CONTRACTOR shall ensure following points for safe receipt and storage of equipment:





November, 2014

8.2.3 Prior to erection work, the firm shall Check and record condition of each package, visible parts of the bushing / CT for any damage.

8.2.4 Carry out basic healthiness checks on equipment during storage.

8.3 Disconnection and removal of existing bushing

8.3.1 The firm shall submit the detail work plan with procedure and field quality plan before start of the work at site for dismantling of exiting bushing, erection and commissioning work including all the site test for review and approval

8.3.2 As the scope includes disconnection and removal of the existing bushing all the necessary tools, tackles, cranes and handling facility required for the same shall be brought by the firm.

8.3.3 Any scaffolding required shall be arranged by the firm.

8.3.4 After obtaining the valid work permit and clearance for the job, required prearrangement shall be made following all the prevailing safety practice.

8.3.5 Mark and disconnect all the CT leads at the indoor end, de-glad the cables and remove the cable from the existing terminal box and presser them safety

8.3.6 After disconnection of OH conductor and connector they shall be properly guided and preserved. If required the short bit of OH conductor at indoor side may be replaced for which the required length of conductor will be provided by the department

8.3.7 After removing the fixing hardware of the existing bushing, the bushing shall be safety handled and brought down to floor level with required crane and handling tackles and then sent to stores yard at designated / identified location.

8.3.8 The existing wall embedded flange and its holes thread shall be thoroughly cleaned so the new bushing can be erected and fixed neatly.

8.4 Erection checks

8.4.1 The new bushing / CT and their accessories shall be shifted to their designated location in 230KV switchyard. The CONTRACTOR shall ensure following points for the erection of equipment:

8.4.2 Physical inspection of equipment after transportation up to 230KV switchyard for any

shipping damage

8.4.3 Check the condition of test tap and its Insulation resistance

8.4.4 Measure Bushing IR value, capacitance and tan delta of the bushing before erection





November, 2014

8.4.5 Verify the flange dimension of the bushing with the flange dimension embedded on a wall for dimension matching

8.4.6 Conduct all the commissioning test required on CT such as resistance, IR value, ratio, magnetizing current, Knee point voltage, current ratio etc for all core and record them

8.4.7 Using crane and handling tackle, lift the bushing to the position align the flange holes and fix the bushing with existing embedded flange and secure all the fixing bolts to the required torque.

8.4.8 Establish all the earth connection as per the requirement at both indoor and outdoor end of the bushing

8.4.9 Verify the oil level before and after installation and check for any oil leak

8.5 COMMISSIONING CHECKS

8.5.1 Commissioning checks indicated below are indicative only. However the contractor shall carry out actual commissioning checks on all the equipments covered in this specification as per manufacturer’s recommendation and PURCHASER’s instructions. The original Equipment Manufacturer's engineer shall be present during performance of tests at site and manufacturer's concurrence taken before completion.

8.5.2 Approved Field Quality Plan shall be complied throughout the erection and commissioning work

8.5.3 The following pre commissioning checks and tests shall be carried out by the CONTRACTOR after completion of erection of bushing / CT at site. CONTRACTOR shall prepare detailed pre commissioning check list as per requirement of bushing CT manufacturer’s installation & commissioning instruction manual. Procedures for precommissi0oning checks shall be submitted for approval and complete instructions shall form part of the procedure. The CONTRACTOR shall ensure inclusion of following points in the pre commissioning checks:

8.5.4 Measure bushing IR value, Tan delta and capacitance before installation at location.

8.5.5 After installation on the location measure IR value, capacitance and tan delta, partial discharge before making end termination at indoor and outdoor end

8.5.6 Establish wiring for surge diverter micro switch as per the sire drawing for generating alarm

8.5.7 Establish CT connection and the existing scheme. Conduct dynamic test by injecting current from protection panel and verify the response

8.5.8 Establish end termination at both indoor and outdoor end.





November, 2014

8.5.9 Energise / Charge the bushing and measure the current through the earth lead if any record them.

8.6 PERFORMANCE GUARANTEE

8.6.1 245 kV wall bushing / current transformers supplied shall be guaranteed for satisfactory performance for a period of 24 months from the date of commissioning of all the supply of wall bushing with CT units.

8.6.2 The equipment if found defective/failed within the above guarantee period shall be replaced or repaired by the supplier free of cost within one month from receipt of intimation.

9.0 SPECIAL TOOLS AND TACKLES FOR ERECTION & MAINTENANCE

9.1 Following essential maintenance tools and tackles shall be included in the scope of the supply. The general requirements for maintenance tools and tackles are covered in clause 5 of this document. The list of items considered shall be indicated in the technical part of the bid and item wise price shall be indicated in the Price part:

9.2 The TENDERER shall supply all the necessary special tools, tackles, appliances and lifting devices for the effective maintenance and servicing of the complete equipment and components..

9.3 All the tools & tackles necessary for handling, erection, installation & commissioning of Bushing and CTs should be arranged by the CONTRACTOR and the same shall be removed from the site after use and decontamination. It includes overhead crane, chain pulley block, al type handling equipments, safety ropes etc.

9.4 All the test instruments required for commissioning the equipment is under the scope of the contractor. Power supply required for such instruments will be provided free of cost by department.





November, 2014

ANNEXURE: ASPECIFICATION OF EXISTING WALL BUSHING

230KV Wall Bushing Specification

Feeder Breakers CB 2 (Line 4), CB 3 (GT 2), CB 5 (Line 3), CB 7 (Line 2), CB 9 (GT 1) and CB 10 (Line 1)

SL No Details Unit ParameterA Wall Bushing

1 Manufacturer Name Brush Switchgear Limited, England

2 Model OVW 230/3003 Standards applicable4 Type of Bushing Condenser

graded

5 Type of insulation used Oil Impregnated paper

6 Rated voltage KV 2457 Rated frequency Hz 508 Maximum voltage at which bushing can continuously

operate (Line to Earth)KV 142

9 Manufacturer rated current A 80010 De-rating factor for site conditions %11 Rated continuous current without exceeding 70deg C

temperature in an ambient of 50deg CA

12 Dynamic current rating Peak KA 80.32513 Short time thermal current rating KA 31.514 Insulation level

a Power frequency with stand voltage dry and wet (Amplitude) for 1 minutes

KV 460

b Impulse withstand voltage 1.2 / 50micro Sec wave KV Peak

1050

c Visual discharge voltage KV 195Provision for wall thickness mm

15 Creepage distancea Outdoor mm 9000

i Total mmii Protected

b Indoori Total mm 5600ii Protected mm

16 Length of bushinga Indoor / outdoor type

i outdoor side mmii Indoor side mmiii Total mm 5820

17 Weight of bushing





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1 Indoor / Outdoor type Drg 3B-15064 Kgs A9702261/6218 Description of special glaze if offered19 Strength of bushing

a Cantilever strength (Horizontal installation) at bushing terminal

Kgs 2500N

b Tensile strength Kgsc Compressive strength Kgsd Torsion strength KGM

20 Weather capacitive tape provided21 Power factor voltage curve of bushing provided22 Insulation power factor at which bushing is considered

unsafe

23 Weather all the test as specified will be performed 24 Material and size of central conductor25 Color of porcelain

26 Material and finish of fittings27 Type of cement 28 Maximum length of inclination from horizontal at which

bushing can be installedDeg

29 Radio interference voltage micro V

30 Position of installation Horizontal31 Position during transportation 0 to 90 deg

B Bushing Current transformer

CT ratio 1200-800-600/11 Rated primary current A 12002 Rated extended primary current % 203 Rated continuous thermal current A 14404 Short time current rating

a Rated short time thermal current KA 31.5b Rated duration Sec 1c Rated dynamic current KA

Peak80.325

5 Maximum temperature raise of winding at rated continuous thermal current, Rated frequency and rated burden

Deg C

45

6 Class of insulation of winding7 Protection / metering Class of CTs

a Core 1 PSb Core 2 PSc Core 3 PSd Core 4 Metering

7 Knee point voltage of CTsa Core 1 V 2030/1360/1050b Core 2 V 2030/1360/1050c Core 3 V 2030/1360/1050d Core 4 V





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7 Maximum excitation current at Kpva Core 1b Core 2c Core 3d Core 4

8 Maximum secondary resistance at 75 deg Ca Core 1 7.3-4.85-3.65

ohm at 1200-800-600/1A

respectivelyb Core 2c Core 3d Core 4

9 Cable gland sizea Core 1b Core 2c Core 3d Core 4

10 Accuracy class for metering core 4 Class 0.211 Rated Burden for metering core 4 50VA

Annexure – A1

List of drawing as part of tender document

SL No Drawing Number Drawing description

1 M1/51300/6020/GA Support arrangement for mounting wall bushing

2 M1/51352/2501/GA Existing wall bushing GA drawing

3 M1/51300/1015/GA Line wall bushing to Tower connection

4 120-B-1390 TERMINAL CONNECTOR





November, 2014

ANNEXURE -B

LIST OF APPROVED VENDORS / SUB VENDORs / Sub Contractors

The corresponding Annexure (List of Approved Subcontractors) to the TENDER specifies major items of supply or services and a list of approved Subcontractors against such items. The Bidder shall satisfy himself regarding NPCIL approved subcontractors for their technical and financial capabilities. The bidder at the time of submission of Part-I (Technical) bid may indicate additional subcontractors for any of the given items, for evaluation by the Purchaser and if found acceptable, inclusion of such subcontractor in approved subcontractors list, before opening of Price Bid. In so far as no Subcontractors are listed against any such item or items not covered in the list, the Contractor shall prepare and submit to Purchaser a list of Subcontractors for such items for approval and inclusion in such list with the Part-1 bid. List of Approved sub-contractors / Vendors as issued with the Contract shall be strictly adhered to for procurement of goods/services from designated subcontractor(s) / Vendors.

1.0 All the bidders shall quote the prices on the basis of the approved sub-contractors/ sub-vendors indicated below. Bidders may kindly note that revision of prices will not be entertained on account of additional sub-vendor proposed by EPC contractor and subsequently approved by Purchaser, in line with GCC.

2.0 Approval by the Purchaser for any of the Subcontractors shall not relieve the Contractor from any of its obligations, duties or responsibilities under the Contract.

3.0 Followings are list of Approved vendors / Sub contractors / Sub vendors for this Package.

4.0 The following table gives the tentative list of item to be bought out for Bushing with CT manufacturing. Any other item if required to be included, the same shall be included with the proposed vendor name from whom it is proposed to buy for approval by NPCIL.

SL.NO. DESCRIPTION APPROVED VENDORS1 Conductor SAM DONG, KOREA

KSH INTERNATIONALPRECISION WIRESCHANDRA PROTECOASTA, AUSTRIAVIJAI ELECTRICALS

2 Copper Wire Rod / Tube BIRLA / HINDALCO / STERLITE3 CRGO (Lamination Supplier) NIPPON STEEL, JAPAN / JFE, JAPAN /

BRITISH STEEL, UK / POSCO, KOREA / AK STEEL

4 Control Wires NICCO / UNIVERSAL CABLES / FINOLEX / UNIFELX CABLES /





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HAVELS / POLYCABS CABLES5 CRGO Lamination Processors BHEL / TELK / ALSTOM / CGL /

MAHINDRA STEEL SERVICES VIJAI ELECTRICALS / DELTA

6 Porcelain Insulators BHEL / WIS / JAYSHREE / BIRLA7 Insulation Kraft Papers WEIDMANN / FIGEHOLMS / RAMAN

BOARD, MYSORE8 Valves (Gate & Globe) AUDCO / FOURESS / NITON / LEADER 9 Terminal Blocks ELEMEX / CONNECT WEL

10 Paints ASIAN / AKZO NOBEL/ JOTUN

11 MS Steel (As per IS- 2062) SAIL / TATA STEEL / RINL12 Welding Electrodes AS PER NPCIL APPROVED LIST13 Current Transformer ALSTOM / MGC MOSER-GLASER /

RHM INTERNATIONAL / TELK / SINWAVE / EMPACK

14Wall bushing

ALSTOM / MGC MOSER-GLASER / RHM INTERNATIONAL / BHEL / TELK





November, 2014

ANNEXURE-C

PACKING AND DESPATCH

1.0 The wall bushing with CTs shall be dispatched in suitable crates / container structurally strong to prevent damage while transportation.

1.1 The detailed dispatch schedule for each unit shall be supplied well in advance. In the schedule, items accompanying the wall bushing units shall be separately listed.

1.2 The packing list for each shipment shall indicate complete details of equipment being shipped to enable to consignee to identify the parts and to ensure that no equipment stated to have been shipped has either lost in transit or if damaged, to initiate replacement proceedings and also to enable the insurance claims to be preferred. If the invoice does not contain full details, if any part not specifically mentioned in the packing list is missing in transit the supplier shall be responsible for supply of such parts to the purchaser without any extra cost.

1.3 Packing shall have protection against corrosion, dampness, heavy rains, breakage and vibration. Packing for accessories and spares robust non-returnable packing case with all the above protection and identification labels

1.4 Packing identification label of each packing case shall have the following details

a) Individual serial number

b) Purchaser’s name

c) PO number (along with SAP item code if any) & date

d) Equipment Tag No.( if any)

e) Destination

f) Manufacturer / Supplier’s name

g) Address of Manufacturer / Supplier

h) Description and Quantity

i) Country of origin

j) Month and year of manufacturing

k) Case measurements

l) All necessary slinging and stacking instructions

1.5 The supplier shall be responsible for all transit damage due to improper packing.





November, 2014

ANNEXURE-D

SCOPE OF WORK FOR TRANSPORTATION

MADRAS ATOMIC POWER STATION DATA

The site of Madras Atomic Power Station ( Here in after refer to as site) is located at Kalpakkam, District Kancheepuram, Tamilnadu about 80 km by road from Chennai, 35 km by road from Chengalpattu and 18 km by road from Mamallapuram. The site is on the east coast of INDIA adjacent to Bay of Bengal , the region between Chennai and Pondichery.

1.0 Transportation Activity from Manufacture end:-

a. Packing, covering, Loading, lacing & safe transportation of Bushing with CTs and spares along with its accessories from factory premises to MAPS, Kalpakkam (Tamil Nadu) site. In case, destination location is changed, same will be communicated to bidder in advance prior to transportation of Bushing.

b. Unloading and shifting of Bushing with CTs along with its accessories to the specified location at MAPS, Kalpakkam (Tamil Nadu) site.

c. For all above transportation requirement, the necessary transit insurance shall be arranged by the contractor. Cost to be included in transportation charges.

d. Other transportation requirements are already detailed in General Contract Conditions

2.0 Transportation Terms & Conditions:-

2.1 The transportation activities shall be carried out through specialized agencies that are well equipped with necessary equipments and have the experience of similar types of jobs.

2.2 Only brief details of transportation have been given above. It is not possible to specify each & every activity in detail. For ensuring satisfactory performance, in case any additional activity is required, same is to be performed by the contractor at his own cost.

2.3 The Transport contractor shall arrange permissions from all concerned central/state govt. authorities such as CPWD/PWD, Railways, Electricity boards, R.T.O. Forest, Municipality, Home department, Police etc. for transportation of the consignment from both sides before the consignment is moved out to ensure safe and trouble free transportation up to the required destination. All the expenses incurred to obtain such permission, if any, shall be borne by the contractor. However, necessary letter for obtaining such permission, if any, from respective





November, 2014

authorities, will be issued by NPCIL. The contractor shall submit Xerox copies of all applications, which he has applied to different agencies for obtaining the permission. MAPS will retain them for record. The contractor shall be responsible for any delay/damage/loss occurred to any property en-route during the movement due to non-availability of any such permission or otherwise.

2.4 Any infrastructure development work required during the movement of consignment will be contractor’s responsibility without any additional charges.

2.5 The transportation from Manufacturer’s premises to MAPS, Kalpakkam, Tamil Nadu will be at Carrier’s risk without transshipment en-route. However, in case of any emergency or unforeseen situations consignment can be shifted from one carrier to another with approval of Bushing manufacturer (in this case Contractor). Transport contractor should be able to do all these on his own and no departmental assistance in terms of man and material will be provided by MAPS. The contractor should arrange even the lifting equipment like crane etc. No additional charges will be given.

2.6 All drivers should possess valid driving license and all documents of the vehicles such as R.T.O. passing certificate, registration book, tax book etc. shall be current and valid.

2.7 The contractor shall also adhere to the safety aspects with regard to the consignment movement as covered under relevant prevalent Motor vehicle Act.

2.8 MAPS shall not be responsible for payment of any compensation to the contractor for injuries / accident to their manpower suffered during the performance of the contract or damage to vehicle and other material under any circumstances whatsoever.

2.9. Contractor shall make all necessary arrangements to load / unload bushings during erection work. At MAPS, NPCIL will provide only Forklift required for this purpose, free of cost, if required.

2.10. The contractor shall be responsible for all losses including non-delivery, theft, pilferage, damage due to any cause whatsoever from the time he receives the consignment and during the period it is held by him till the consignment is safely delivered to the consignee.

2.11. Certification of transport equipment: The contractor shall provide all relevant documents / certificates for the equipment being used by him to transport above consignments to ensure good health of equipment and validity of equipment.

2.12 The contractor shall be in close liaison during the entire operation i.e. from the time of loading the consignment till the time of unloading and safe delivery of the consignment at above indicated destinations,

3.0 LIABILITIES OF CONTRACTOR REGARDING LOSSES / DAMAGES





November, 2014

The contractor shall abide by all the instructions that may be given to him from time to time by the Corporation or by an officer authorised to act on behalf of the Corporation and / or by the other officers authorised to operate the contract. The contractor shall be bound to act with the diligence and shall be responsible to pay due compensation towards any losses / damage that NPCIL might suffer in consequence of the negligence of his employees and /or agents.

4.0 TRANSIT INSURANCE:

Necessary transit insurance cover shall be arranged by the contractor for shipment of Bushing with CTs from manufacturer’s premises to NPCIL / MAPS, Kalpakkam, Tamilnadu. The contractor shall be fully responsible for all the losses including non- delivery, theft, pilferage, damage due to any cause whatsoever from the time he receives the consignment till delivery of the same at destination.

5.0 Desired time schedule for transportation activities:-

S.No. Description Months

1 Time required for transportation of bushings from Manufacturing premises including safe loading to MAPS, Kalpakkam (Tamil Nadu) site, safe unloading etc..

15 days

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ANNEXURE-E

EXISTING BUSHING FLANGE DIMENSIONAL DRAWING





November, 2014

ANNEXURE: F

UN-INHIBITED NAPTHENIC BASED EHV GRADE TRANSFORMER OIL

SL NO.

Characteristics Limiting values of parameter

1 Appearance Clear & transparent and free from suspended matter or sediments

2 Density at 20 Deg.C Kg/dm3, Maximum. 0.895

3 Kinematic Viscosity, mm2/S

a) at 40 deg.C, Maximum 11

b) at Minus 30 deg.C, Maximum. 1800

4 Interfacial Tension at 27 deg.C (N/m), Minimum

0.04

5 Flash Point deg.C, Minimum. 140

6 Pour Point deg.C, Minimum Minus 45

7 Neutralization Value

7-a Total Acidity, Maximum 0.03 mg KOH/g

7-b Inorganic Acidity / alkalinity Nil

8 Corrosive Sulphur ( CIGRE test method (TF

A2.32.01 Revision of tests and specifications for corrosive sulphur in Transformer Oils)

Non-Corrosive

9 Electric Strength (Break Down Voltage)

a) New Unfiltered oil, kV, Minimum 30 kV

a) After Filtration kV, Minimum > 70 kV

10 Dielectric Dissipation Factor (Tan Delta) at 90 deg.C , Maximum

0.002

11 Specific Resistance (Resistivity)

a) at 90 deg.C, Minimum 35x1012 Ohm - cm





November, 2014

b) at 27 deg.C, Minimum 1500x1012 Ohm - cm

12 Oxidation Stability after 164 Hrs. at 100 deg.C

a) Neutralization Value, Maximum 0.2 mg KOH/g

b) Total sludge % Wt., Maximum 0.05% by weight

13 Ageing characteristics after accelerated aging (Open beaker method with Copper Catalyst)

a) Specific resistance :

At 27 deg.C, Minimum 2.5 x 1012 Ohm - cm

At 90 deg.C Minimum 0.2 x 1012 Ohm - cm

b) Tan Delta at 90 deg.C, Maximum 0.20

c) Total acidity , Maximum 0.05 mg KOH/g

d) Total sludge, Maximum 0.05% by Wt.

14 Water content, mg/kg 30 in bulk delivery 40 in drum deliveryBefore filling < 3ppm

15 Presence of oxidation inhibitor, percent by weight

Not Detectable with respect to IS-335 Amendment-1997

16-a Napthenic Content 46 to 53%

16-b Paraffinic Content 36 to 46%

16-c Aromatic Content Remaining/balance

17 Health, Safety and Environment (HSE)

17.1 PCA content (BS 2000 Part 346), %, Maximum

3 %

17.2 PCB content (IEC 61619), mg/kg Less than 1

17.3 Negative Impulse Voltage testing kVp

(ASTM D-3300), Minimum

145

18 Total sulphur content (BS 2000 part 373 or ISO 14596), %

0.15 %





November, 2014

19 2-Furfural content (IEC 61198) , mg/kg, Maximum

0.1

20 Gassing (IEC 60628 A) No general requirement,however, negative gassingtendency is not acceptable

NOTE: 1

Oil samples ( One Composite and 8 individual) shall be tested at the works of transformer oil manufacturer)

NOTE: 2

Test Results of 1 (One) Composite sample shall meet test requirement as per Item Nos. 1 to 20 above.

NOTE: 3

Test Results of 8 Individual samples shall meet test requirement as per Item Nos. 9, 10 & 11 above.

NOTE: 4

In case, test facilities of any test mentioned above are not available at the works of transformer oil manufacturer, the same test shall be conducted at any third party test lab having NABL accreditation and approved by NPCIL.