Vol.II Part-I/Section-II

SECTION II

2.1.4 - TECHNICAL SPECIFICATION FOR

LIGHTNING ARRESTERS

1.0 SCOPE :

The scope of this specification covers design, manufacturing and supply of equipment as per Section-I, Volume-II. The bidder mentioned in the Section of the Technical Specification means Original Equipment Manufacturer (OEM). The Purchaser means the MPPTCL.

In case bidder is not OEM, sole responsibility of offering equipment/material of manufacturer as per this specification requirement shall rest on the bidder.

2.0 STANDARDS :

Applicable Standards for the offered equipments / items shall be as per SectionI.

3.0 CLIMATIC CONDITIONS : Applicable climatic conditions shall be as per Section - I.

4.0 SYSTEM PARTICULARS : Applicable System Particulars shall be as per Section - I.5.0 GENERAL TECHNICAL REQUIREMENT :5.1The 400 KV, 220 KV, 132 KV, 36 KV and 33 KV Lightning Arresters covered under this specification shall meet the technical requirement indicated in Annexure-I enclosed with the specification.

5.2 The materials and components not specifically stated in this specification but which are necessary for satisfactory operation of the equipment are deemed to be included in the scope of supply unless specifically excluded.

5.3 The supplier should offer nearest rating of surge arresters & maximum residual voltage shall comply with the requirement indicated in Appendix-A.5.4 The transformer, which is to be protected, has BIL 1300 KVp, 900 KVp, 550 KVp & 170 KVp for 400 KV, 220 KV, 132 KV & 33 KV system respectively. Considering 20% safe margin as per IEC the impulse voltage of more than 1040 KVp, 720 KVp, 440 KVp & 136 KVp respectively for 400 KV, 220 KV, 132 KV & 33 KV systems, should not appear across the transformer. The Lightning Arresters will be installed at a distance of 5/10 metres from transformer (another 5 metres be added towards height of Lightning Arresters lead length and bushing of transformers). It should be explained with suitable graphs and calculations that the voltage more that specified above will not appear on transformer.

5.5 The graph for Temporary Over Voltage (TOV) capability should be submitted along with the bid.

5.6 ENERGY HANDLING CAPABILITY :

Calculation for energy handling capability should essentially be submitted along with the bid. The calculations should be as per latest version of IEC-99-4. The energy handling capability for single shot of wave and multiple shots of wave as per IEC should be submitted alongwith the bid.

5.7 SEPARATING DISTANCE : The minimum permissible separation between the surge arresters and any earthed object shall be indicated in the bid.

5.8 SEALING :

Each and every individual unit of surge arrester shall be hermetically sealed and fully protected against ingress of moisture. The hermetic seal shall be effective for entire lifetime of arresters and under the service conditions specified. The bidder shall furnish sectional view showing details of sealing employed. Complete details of sealing arrangement may please be furnished.

5.9 GRADING RING : The grading ring on each complete arrester may be provided for proper stress distribution for attaining relevant technical particulars in case of 400 KV, 220 KV & 132 KV Lightning Arresters.

5.10 PRESSURE RELIEF DEVICE : The surge arresters shall be fitted with pressure relief devices and arc diverting ports and shall be tested as per the requirements of IEC specification for minimum prospective symmetrical fault current as specified in clause 4(e) above.

5.11 INTERCHANGEABILITY : All the units of arresters of same rating shall be interchangeable without adversely affecting the performance.

5.12 MOUNTING :

a) The lightning (surge) arresters shall be suitable for pedestal type mounting which will be arranged by the purchaser. The drawing of mounting structure for Lightning Arresters is enclosed in Appendix-B.

b) All necessary bolts, nuts, clamps etc., required for mounting of LAs on support structure to be supplied by the purchaser shall be included in the scope of supply.5.13 TERMINAL CONNECTORS :

The terminal connectors required for connection of lightning arresters to the bus bar, shall be in the bidders scope. The design of Terminal connectors shall be to Purchasers approval. Terminal connectors shall be manufactured and tested as per latest version of IS: 5561 or equivalent International Standard and should be type tested. In respect of terminal connectors following should be ensured:-

a) All casting shall be free from blowholes, surface blisters, crakes and cavities. All sharp edges and corners shall be blurred and rounded off.

b/ All current carrying parts shall be designed and manufactured to have minimum contact resistance.

c/ The contact surface must be machined smooth to obviate excessive current density.

d/ The terminal connectors for connection of conductor should be suitable for Moose / Zebra ACSR conductor with vertical as well as horizontal take off arrangement and should have adequate current carrying capacity.

e/ The terminal connectors shall be manufactured out of aluminum alloy grade A6 as per latest version of IS 5561 or equivalent grade specified in relevant International Standard and by gravity die casting process only.

f/ Terminal connector should have six bolts to hold the conductors. The conductor hold length shall not be less than 100 mm. All nuts, bolts, washers etc. shall be made of HDG mild steel.

g/ The minimum thickness of any part of clamps body should not be less than 12 mm.

h/ The surface of clamps to be tightened by six bolts should be flat in shape so that it may be possible to open the nuts and bolts by normal spanners. Therefore, any type of groove in the clamp body for fixing of nuts should be avoided.

i/The portion of clamp to hold the conductor should be flat and straight and not zig-zag in construction, at both the sides, so that holding of clamp by throttling action of current may be avoided.

j/Spacer of at least 50% of diameter of nuts should be available after the hole at both the sides of conductor holding portion for better mechanical strength.

5.14 PORCELAIN BUSHING :

a/ All porcelain housing shall be free from lamination cavities and other flaws affecting the maximum level of mechanical and electrical strength.

b/ The porcelain shall be well vitrified and non -porous.

c/ The creepage distance of the arrester housing shall comply with the requirement indicated in Annexure-I.

d/ The porcelain petticoats shall be preferably of self-cleaning type (Aerofoil design). The details of the porcelain housing such as height, angle of inclination, shape of petticoats, gap between the petticoats, diameter (ID and OD) etc., shall be indicated by the bidder in the form of a detailed drawing.

e/ The arrester housing shall conform to the requirements of IEC specification.

5.15 Galvanisation, Nickel Plating etc :

i/ All ferrous parts exposed to atmosphere shall be hot dip galvanised as per latest version of IS:2629 or equivalent International Standard. Tinned copper/brass lugs shall be used for internal wiring of discharge counter. Screws used for electrical connections shall be either made of brass or nickel-plated.

ii/ Ground terminal pads and name plate brackets shall be hot dip galvanised.

iii/ The material shall be galvanised only after completing all shop operations.5.16 SURGE COUNTER :

a) The surge discharge counter shall be provided only with each 400 KV, 220 KV & 132 KV lightning arrester. The discharge counter shall be provided with milli-ammeter for measuring the leakage current and shall not require any DC or AC Auxiliary supply. It shall be suitable for outdoor use. The installation of discharge counter shall not adversely affect the arrester performance.

b) The discharge counter shall register operation whenever lightning or any other type of surge strikes the surge arrester.

c) All necessary accessories and earthing connection leads between the bottom of the Arrester and the discharge counter shall be in the supplier's scope of supply. The discharge counter shall be so designed that the readings of discharges recorded by the counter and the readings of milli-ammeter shall be clearly visible through an inspection window to a person standing on ground. The minimum height of Purchaser's support shall be 2.5 metres.

d) Each surge counters shall have terminals of robust construction for connection to earthing lead and these shall be suitably arranged so as to enable the incoming and outgoing connections to be made with minimum bends.

5.17 MANUFACTURE OF Zinc Oxide (ZnO) ELEMENTS :

a)It is desired that the bidder should have all modern facilities to manufacture zinc oxide discs, with special emphasis on automation of each element of processing of raw materials, mixing of ingredients employed for manufacture of discs, verification of homogeneity of powder mixture, preparation and compression of disc element and stage verification/ testing of disc elements. The bidder must confirm that the process employed for the purpose is fully automatic and should describe all critical stages of manufacture, including the following:

i. Batch Mixing

ii. Batch Grinding

iii. Batch Homogenising

iv. Spray Drying

v. Sieving or Sizing

vi. Sintering

b)The bidder should also briefly describe the methods adopted and instruments used for measurements to check the quality in following areas as also other important areas during manufacturing process:

i. The fineness of material having sub micron size of particles.

ii. To measure the particle sizes of input and process materials.

iii. Determination of trace impurities in all the metallic oxides.

iv. The determination of viscosities of the metal oxide slips during powder preparation.

v. To determine the impurity levels of Chlorides, Nitrates and Sulphates as a spot check.

vi. To check the porosity and the grain sizes of pressed metal oxide elements.

vii. Process of testing of each disc after final finishing.

5.18 EARTHING : The Lightning Arrester shall be provided with two separate earthing terminals for bolted connection to 65 x 10 and 50 x 8 mm MS flat to be provided by the Purchaser for connection to station earth-mat.

5.19 NAME PLATE :

The arresters shall be provided with non-corrosive legible nameplate indelibly marked with the following information:

i. Madhya Pradesh Power Transmission Co. Ltd.

ii. Order No. & Date

iii. Manufacturer's name or trademark, type and identification no. of the arresters being supplied.

iv. Rated voltage

v. Maximum continuous operating voltage

vi. Type

vii. Rated frequency

viii. Nominal discharge current

ix. Long duration discharge class

x. Pressure relief rated current in kA rms.

xi. B.I.L. of the equipment to be protected.

xii. Year of manufacture

xiii. Identification of the assembly positions of the unit (for multi unit arresters only).

5.20 MOUNTING STRUCTURE:

The drawing of standard mounting structure of Lightning Arresters is enclosed. The suppliers should confirm specifically the Lightning Arresters shall be suitable for mounting on our structures.

6.0 TESTS :

6.1 TYPE Test

All the equipment offered, shall be fully type tested as per relevant Indian Standards or any equivalent International Standard (as specified in clause-2) during the last five years from the date of BID opening. Copy of test reports shall be enclosed with the bid. For any change in the design / type already type tested and the design/type offered against this bid, the Purchaser reserves the right to demand repetition of same or all type tests without any extra cost. 6.2. Acceptance and Routine Tests:

6.2.1 The manufacturer shall carry out all acceptance and routine tests as stipulated in the relevant Indian Standards or equivalent International Standards in presence of Purchasers representative.

6.2.2 Immediately after finalisation of the programme of type/ acceptance/ routine testing, the manufacturer shall give sufficient advance intimation to the Purchaser, to enable him to depute his representative for witnessing the tests.

6.2.3 Acceptance tests, whenever possible shall be conducted on the complete arrester unit. The number of samples to be subjected to acceptance tests shall be decided by the purchaser at the time of actual testing.

6.2.4 The special thermal stability test shall be carried out as acceptance test. The acceptance tests shall include the galvanisation test on metal parts.

6.2.5 The functional (operational) acceptance tests shall be carried out on the surge counter by way of checking its operation at following nominal discharge currents ;

a) 100 Amps with 8/20 microsecond wave shape

b) 10 kA with 8/20 microsecond wave shape.

7.0 INSPECTION :

i. The Purchaser shall have access at all times to the works and all other places of manufacture, where the isolators are being manufactured and the Bidder shall provide all facilities for unrestricted inspection of the Bidders works, raw materials, manufacture of all the accessories and for conducting necessary tests as detailed herein.

ii. The successful Bidder shall keep the Purchaser informed in advance of the time of starting and of the progress of manufacture of equipment in its various stages, so that arrangements could be made for inspection.

iii. No material shall be dispatched from the point of manufacture unless the material has been satisfactorily inspected and tested.

iv. The acceptance of any quantity of the equipment shall in no way relieve the successful bidder of his responsibility for meeting all the requirement of this specification and shall not prevent subsequent rejection if such equipment are later found to be defective.

8.0 QUALITY ASSURANCE PLAN & STAGE INSPECTION :

QAP & stage inspection shall be as per Section I Volume II.

9.0 DOCUMENTATION :-

9.1 All drawings shall conform to latest version of international standards organization (ISO) A series of drawing sheet/ Indian Standards Specification IS-11065. All drawings shall be in ink and suitable for microfilming. All dimensions and data shall be in S.I. Units.

9.2 List of Drawings and Documents:

The Bidder shall furnish four sets of following details and drawings along with the bid:-

i. General outline drawings of complete Lightning Arrester with technical parameters.

ii. Drawings showing clearance from grounded and other live objects and between adjacent poles of Lightning Arresters required at various heights of Lightning Arresters.

iii. Drawing showing details of pressure relief device.

iv. Sectional view to explain pressure relief arrangement.

v. Detailed drawing of discharge counters along with the wiring and schematic drawing of discharge counters & meters.

vi. Details of grading rings if used.

vii. Outline drawing of insulating base.

viii. Mounting details of Lightning Arresters.

ix. Details of the line terminal connector and ground terminals.

x. Volt time characteristics of Lightning Arresters.

xi. Details of galvanising being provided on different ferrous parts.

xii. The detailed dimensional drawing of porcelain housing such as ID, OD, thickness and insulator details such as height, profile of petticoats, angle of inclination & gap between successive petticoats, total creepage distance etc.

xiii. Name plate drawing.

xiv. Sectional view of sealing arrangement and pressure relief device.

xv. Type test reports in case the equipment has already been type tested.

xvi. Test reports, literature, pamphlets of the bought out item and raw material.

9.3 The successful Bidder shall within two weeks of placement of order, submit four sets of final version of all the above drawings for Purchasers approval. The Purchaser shall communicate his comments/approval on the drawings to the Bidder within reasonable time. The Bidder shall, if necessary, modify the drawings and resubmit four copies of the modified drawings for Purchasers approval within two weeks from the date of Purchasers comments. After receipt of Purchasers approval, the Bidder shall within three weeks submit 20 prints and two good quality reproducible of the approved drawings for Purchasers use.

9.4 The Bidder before commencement of supply shall submit six sets of the type test reports, duly approved by the Purchaser. Two copies of acceptance and routine tests certificates, duly approved by the Purchaser shall accompany each dispatched consignment.

9.5 The manufacturing of the equipment shall be strictly in accordance with the approved drawings and no deviation shall be permitted without the written approval of the Purchaser. All manufacturing and fabrication work in connection with the equipment prior to the approval of the drawing shall be at the Bidders risk.

9.6 Twenty (20) copies of nicely printed and bound volumes of operation, maintenance and erection manuals in English Language, for each type and rating of equipment supplied shall be submitted by the Bidder for distribution to field officers, prior to the dispatch of the equipment. The manual shall contain all the drawings and information required for erection, operation and maintenance of the equipments. The manual shall also contain a set of all the approved drawings, type test reports etc.

9.7 Approval of drawings/work by Purchaser shall not relieve the Bidder of his responsibility and liability for ensuring correctness and correct interpretation of the latest revision of applicable standards, rules and codes of practices. The equipment shall conform in all respects to high standards of engineering, design, workmanship and latest revisions of relevant standards at the time of ordering and Purchaser shall have the power to reject any work or material, which in his judgment is not in full accordance therewith.

10. PACKING AND FORWARDING :

Bidder shall ensure that the equipment shall be packed in crates suitable for vertical/ horizontal transport, as the case may be and suitable to withstand handling during transport and outdoor storage during transit..

11. DISCREPANCY IN TECHNICAL PARTICULARS :

Regarding discrepancy in technical particulars, stipulation under Section-I, Volume-II shall be applicable..APPENDIX APRINCIPAL TECHNICAL PARAMETERS OF LIGHTNING ARRESTERS

S. No.Particulars400 KV220 KV132 KV36 KV33 KV

1Nominal system voltage 400 KV220 KV132 KV33 KV

2Rated arrester voltage 390 KV198 KV120 KV36 KV30 KV

3Highest system voltage 420 KV245 KV145 KV36 KV

4Maximum continuous operating voltage(KV rms)290168963024

5Temporary over voltage capability (KV Rms)

a/ 0.1 sec.

b/ 1.0 sec.

c/ 10 sec. 410

400

390237

218

198139

132

12044

42

3936

34

32

6Nominal discharge current corresponding to 8/20 micro second wave shape (KA)2010101010

7Minimum energy discharge capability (as per long duration discharge class of IEC- 99-4) in KJ/KV84.74.74.72.83

8Long duration discharge class.43332

9Maximum residual voltage at nominal discharge current of 8/20 micro sec. wave for 10 KA (KV peak)90048030011090

10Minimum prospective symmetrical fault current for pressure relief test 40 KA for one sec.26.2 KA for two sec.

11High current Impulse withstand (KA)100 100 100100 100

12Creepage distance of porcelain housing (mm)1050061253625950900

13Pressure relief device.-- Class A---

14Insulation level of housing

(Lightning Impulse withstand voltage) (KVp)1425 1050 650250 170

15Cantilever strength (Kgm)1000300

16 Terminal connector

a.Quantity1 No.1 No.1 No.1 No.1 No.

b.ConductorMooseZebra

c.Arrangement of current take offHorizontal & Vertical

APPENDIX - BThe following drawings showing mounting dimensions of structure & general requirement of surge counter are enclosed here with for guidance:

SNo.DescriptionDrawing No.

1.Mounting Details for 400 KV Lightning Arresters.JICA/MPPTCL/TR.101-107/ Mounting Details

2.Base plate details for mounting of 220 KV, 132 KV & 33 KV Lightning ArrestersJICA/MPPTCL/TR.101-107/ Base Plate Details

3.Surge monitor for Gapless Lightning ArrestersJICA/MPPTCL/TR.101-107/ Surge Monitor

4.Pad Clamp for Zebra ACSR Conductor JICA/MPPTCL/TR.101-107/ Pad Clamp ZEBRA

SCHEDULE I(A)DESCRIPTION OF EQUIPMENT FOR SCHEDULE FOR RATES AND PRICES TO BE FURNISHED IN BIDDING FORM OF SECTION-IV, VOLUME-I

SNo.Particulars of Equipment / ItemQty.

A400 KV Lightning ArrestersAs per Annexure C Section I, Volume II, Part - I

1.a. 400 KV metal oxide gapless type Lightning Arresters complete with terminal connector & grading ring etc. meeting all the technical requirements of tender specification and set of spares as per Annexure-D Section-I Vol. II, Part-I.b. Porcelain insulating base for above.

c. Surge counter for above.

B220 KV Lightning Arresters

2.a. 220 KV metal oxide gapless type Lightning Arresters complete with terminal connector & grading ring etc. meeting all the technical requirements of tender specification and set of spares as per Annexure-D Section-I Vol. II, Part-I.b. Porcelain insulating base for above.

c. Surge counter for above.

C132 KV Lightning Arresters

3.a. 132 KV metal oxide gapless type Lightning Arresters complete with terminal connector & grading ring etc. meeting all the technical requirements of tender specification and set of spares as per Annexure-D Section-I Vol. II, Part-I.b. Porcelain insulating base for above

c. Surge counter for above

D36 KV Lightning Arresters

4.36 KV metal oxide gapless type Lightning Arresters complete with terminal connector etc. meeting all the technical requirements of tender specification and set of spares as per Annexure-D Section-I Vol. II, Part-I.

E33 KV Lightning Arresters

5.33 KV metal oxide gapless type Lightning Arresters complete with terminal connector etc. meeting all the technical requirements of tender specification and set of spares as per Annexure-D Section-I Vol. II, Part-I.

NOTE :

1. The above description of the equipment is given for the purpose of offering the prices and to mention description of equipment in invoice for claiming payment. 2. The quantity of above equipments has been mentioned in Annexure-C of Section-I of Vol. II Part-I.

PAGE JICA/MPPTCL/TR-101 to 107

255 Lightning Arresters