NORTH EASTERN ELECTRICITY SUPPLY COMPANY OF …This specification covers the manufacture, testing and works supply and delivery of 11 ... C orrespo nd i gh ghest system V lta e c)

NORTH EASTERN ELECTRICITY SUPPLY COMPANY OF ODISHA LIMITED

NESCO :

- 1 -

SECTION - IV

TECHNICAL SPECIFICATION

OF

ELECTRICAL

MATERIALS

Insulators & Lightening Arrestor

“ GROUP – D ”


NESCO :

2. 33 Kv Post Insulator

Quantity

200 Nos

3. 11 Kv Pin Insulator

Quantity

4000 Nos

4. 11 Kv Post Insulator

Quantity

500 Nos

5. 33 Kv Lightening Arrestor

Quantity

50 Sets

1. 33 Kv Pin Insulator Quantity

1000 Nos


NESCO :

6( i) 11 KV Disc insulator 45 KN (T&C

Type)

Quantity

4500 Nos.

(ii) 11 KV Disc insulator 70 KN (B&S

Type)

Quantity

1000 Nos.

Type Test: - Certificate for the following type tests conducted (within five years proceeding to the date of opening of the tender)on same rating or higher rating in a NABL approved test house/CPRI shall have to be submitted along with offer

TECHNICAL SPECIFICATION FOR 11 KV 45 KN / 70 KN DISC

INSULATORS

1. SCOPE :

This specification covers the manufacture, testing and works supply and delivery of 11

KV Disc insulators. The Porcelain insulators shall conform to IS:731-1971ammended upto

date. Insulators shall be of Ball & Socket type.

2. SERVICE CONDITIONS :

The insulators to be supplied against this specification shall be suitable for satisfactory

continuous operation under the following tropical conditions.

2.1.1 Maximum ambient temperature (Degree C) … 50

2.1.2 Minimum ambient temperature (Degree C) … 3.5

2.1.3 Relative Humidity (%) … 10 to 100

2.1.4 Maximum Annual Rainfall (mm) … 1450

2.1.5. Maximum Wind pressure (kg/m.sq.) … 150

2.1.6 Maximum wind velocity (km/hour) … 45

2.1.7 Maximum altitude above mean sea level (meter) … 1000

2.1.8 Isoceraunic level (days/year) … 50

2.1.9 Seismic level (Horizontal acceleration) … 0.3 g

2.1.10 Moderately hot and humid tropical climate

conductive to rust and fungus growth


NESCO :

- 23 -

3. System Particulars :

a) Nominal System Voltage

11 KV

b) Corresponding highest system Voltage

c) Frequency

d) Number of phase

e) Neutral earthing

f) Min. Impulse withstand voltage

12 KV

50 Hz with 3% tolerance

3

effectively grounded.

75 KV

4. Standards :

Unless otherwise specified elsewhere in the specifications insulators shall confirm to the latest

revisions of all relevant standards available at the time of placement of the order. The

standards are as listed in annexure „D‟.

5. General Requirements

i) The Porcelain insulators shall generally conform to IS:731-1971 and any amendments up to

date to the same .

ii) Conductors :

The Disc Insulators will be used on lines on which the conductors will be A.A.A.

Conductor of size up to 200 sq. mm. and ACSR of any size up to Panther (0.2 sq. inch copper

equivalent). The insulators should withstand the conductor tension, the reversible wind

load as well as the high frequency vibrations due to wind.

iii) Type

a) Insulator shall be suitable for both the suspension and strain type of load & shall be of ball and

socket type. The insulators shall conform to Type „B‟ of IS:731-1971.

b) Diameter of porcelain disc insulator shall be 255mm except for 70KN Anti fog type Disc

Insulators . Diameter of 70 KN Anti fog type Disc. Insulators shall be 280 mm. The center to

center distance between ball & socket shall be 145mm.

c) Insulator Ends.

Disc Insulators shall have `Ball and Socket‟ ends/ Tongue and Cleave ends. The security

clips will have to be provided as per fig. 25 of I.S. 2486 (Part-2) 1989 ( amended up to date).

d) The colour of the units shall be brown for 45 KN Disc Insulators & Greenish for 70 KN Disc

Insulators for identification .


NESCO :

- 24 -

e) The number of units to be used both on suspension and tension strings shall be as given below :

Voltage Class Suspension Strings Tension Strings.

Single Double Single Double

33 3 3x2 3 3x2 22 2 2x2 2 2x2

11 1 1x2 1 1x2

iv). Electromechanical & Mechanical Strength :

The mechanical and electromechanical strength of the individual and the complete Disc shall be

as specified below :

The ball and socket will generally conform to IS:2486 - Part-II /1989. For

ready reference major are reproduced below :

Failing Load Pin Balls(mm) Socket(mm)

45 KN 16 16

70 KN 16 16


NESCO :

- 25 -

The accuracy and Alternative `B‟ of these shall be checked with the corresponding `GO‟ and

`NO GO‟ gauge.

v) Creepage Distances :

The minimum creepage distance for each disc Insulator shall as mentioned below. Voltage

Creepage Distance Creepage Distance

45 KN 70 KN

11 kv 320 mm 320 mm

vi) Interchangeability :

The insulator together with the ball and sockets fittings shall be of standard design suitable

for use with the hardware of any other indigenous make conforming to relevant standards

referred above.

6.0 Tests :

Suitable number of individual units and complete string shall be subject to the

following tests in accordance with IS:731/1971 with its latest amendments.

i) Type Tests :

Following Type test shall be carried out on porcelain insulators as specified in IS: 731 /

1971 amended up to date.

1. Visual Examination.

2. Verification of dimensions.

3. Visible Discharge Test.

4. Impulse voltage withstand test.

5. Impulse voltage flashover test.

6. Wet one Minute Power Frequency withstand test and West Flashover test. 7. Temperature Cycle test.

8. Electromechanical failing load test.

9. Power frequency puncture withstand test.

10. Porosity test.

11. Galvanizing test.

ii) Acceptance Tests :

The test samples after having withstood the routine test shall be subject to the following

acceptance tests in order indicated below:

1. Verification of dimensions.

2. Temperature Cycle test. 3. Twenty four hour mechanical test.

4. Electromechanical failing load test.

5. Power Frequency puncture withstand test.

6. Porosity test.

7. Galvanizing test.

iii) Routine Tests:

1.Visual Examination

2. Mechanical test

3. Electrical test

4. Twenty four hours mechanical test

5. Electro mechanical failing load test

7 Test Certificate :

The tenderer shall furnish detailed type test reports of the offered Disc Insulators as per

clause 6.1 of the Technical Specifications at the NABL approved laboratories to prove

that the Disc Insulators offered meet the requirements of the specification. These Type

Tests should have been carried out within five years prior to the date of opening of this

tender.

i) Their offered Disc Insulators are already fully type tested at

approved Laboratory within five years prior to the date of opening of this tender.

ii) There is no change in the design of type tested Disc Insulators and those

offers against this tender.

iii) Such tenderers complying (i) and (ii) above shall furnish an undertaking in

the format schedule.

The purchaser reserves right to demand repetition of some or all the Type

Test in presence of purchaser‟s representative at purchaser‟s cost. For this purpose,

the tenderer shall quote unit rates for carrying out each Type Test. However, such unit

rates will not be considered for evaluation of the offer. In case the unit fails in the

Type Tests, the complete supply shall be rejected.

8. Testing Facilities :

The tenderer must clearly indicate what testing facilities are available in the works of

the manufacturer and whether facilities are adequate to carry out all Routine &

acceptance Tests. These facilities should be available to Board's Engineers if deputed

or carry out or witness the tests in the manufacturer works. If any test cannot be carried

out at the manufacturer's work, the reasons should be clearly stated in the tender. The insulators shall be tested in accordance with the procedure detailed in IS-731/1971

amended up to date.

9. Material Quality and Workmanship :

The quality of porcelain and hardware in case of porcelain insulators and core &

housing in case of polymeric insulators shall be of the highest grade and

best workmanship such as is suitable and customary for extra high tension lines and

shall conform to current IS or IEC (only in absence of the relevant I.S.S.).

The porcelain shall be sound, free from defect, thoroughly vitrified and smoothly

glazed and brown in colour.

Unless otherwise specified the glaze shall cover all exposed porcelain parts of the

insulator.

Glazing shall be uniform and free from defects. Small and isolated defects

in the insulator glaze of a total surface less than 0.5 sq.cm. will however be

ignored. Deviation on this account may be supported by relevant IS.

10 Mechanical Design :

The design shall be such that stresses due to expansion and contraction in any part of

insulator shall not lead to deterioration.

Cement used in manufacture of the insulators shall not cause fracture due to expansion

or loosening due to contraction.

11. Drawings :

The tender shall be accompanied with the detailed drawings showing the dimensions

of the individual Disc, Ball & Socket, complete strings giving all the design dimensions

of various component parts. The drawing for Insulators should clearly show

the method of cementing the porcelain to the metal caps and balls. Generally it shall

be as per IS.

12. Markings:

12.1 Each insulator shall be legibly and indelibly marked to show the following :

a) Name or trade mark of the manufacturer.

b) Voltage Type

c) Month and year of manufacturing.

d) Electromechanical strength in KN

e) Property of NESCO.

12.2 The “W” clip shall be marked with/punched with the ball and socket sizes for which it

is meant e.g.16B,20 etc.

12.3 Marking on porcelain shall be printed and shall be applied before firing.

13 Packing :

All insulators shall be packed in crates or boxes suitable for rough handling. Packing

shall be marked with the strength and KV rating.

14 Guaranteed Technical Particulars :

The bidders are required to furnish the guaranteed technical particulars duly filed

in the proforma along with the bid.

GUARANTEED TECHNICAL PARTICULARS FOR 45 KN

DISC. INSULATOR ( T&C TYPE)

Sl.

No

Particulars

Requirement

Bidders offer

1. Name of Manufacturer. & Address To be specified by the bidder

2. Location of type testing To be specified by the

bidder

3 Applicable standard IS-731/1971 with latest

amendment

4 Type of insulator T&C type Disc insulator

5 Nominal System Voltage 11 KV

6 Highest System voltage 12 KV

7 Visible discharge Test voltage (Minimum) 9 KV

8 Dry Impulse withstand voltage +(1.2/50 microsecond wave) 75 KV

9 Dry Impulse flashover voltage+(1.2/50 microsecond wave) 90 KV

10. Dry 1 min. power frequency withstand Voltage kV. 60 KV

11 Wet 1 min. power frequency withstand Voltage . 35 KV

12 1 min. power frequency flashover Voltage kV. (Dry) 65 KV

13. 1 min. power frequency flashover Voltage kV.(Wet) 45KV

14 Power frequency puncture voltage 105 KV

15 Mechanical Routine test load 18 KN

16 Mechanical impact strength 45 KN

17 Shattered strengths (Glass) .. KV

18 Electromechanical Failing Load 45 KN

19 Safe working load 18 KN

20 Minimum Failing Load 45 KN

21 Creepage Distance 320 CD

22 Protected creepage distance 160 CD

23 Type and Grade of Materials :

i) Insulators Porcelain

ii) Cap Malleable Casting or S.G

iii) Pin Forged pin

iv) Locking Split pin

v) Cement Portland

24 Type of semi conducting Glaze Ceramic

25 Colour of Insulators Dark Brown

26 Weight of single disc. kg. 4 Kg(Approx.)

27 Number of Insulators per crate 4 nos./ 6 nos.

28 Cross weight of Loaded crate 20 – 30 Kg

29 Whether drawing showing dimensional details have been

furnished along with bid.

To be enclosed by bidder

Name & Signature of tenderer with seal

GUARANTEED TECHNICAL PARTICULARS FOR 70 KN

DISC. INSULATOR ( B&S TYPE)

Sl.

No

Particulars

Requirement

Bidders offer

1. Name of Manufacturer. & Address To be specified by the

bidder

2. Location of type testing To be specified by the

bidder

3 Applicable standard IS-731/1971 with latest amendment

4 Type of insulator B&S type Disc insulator




8 Dry Impulse withstand voltage +(1.2/50 microsecond wave) 110 KV

9 Dry Impulse flashover voltage+(1.2/50 microsecond wave) 120 KV

10 Dry 1 min. power frequency withstand Voltage kV. 70 KV

11 Wet 1 min. power frequency withstand Voltage 45 KV

12 1 min. power frequency flashover Voltage kV. (Dry) 80 KV

13 1 min. power frequency flashover Voltage kV.(Wet) 50KV

14 Power frequency puncture voltage 110 KV

15 Mechanical Routine test load 28 KN

16 Mechanical impact strength 70 KN

17 Shattered strengths (Glass) .. KV

18 Electromechanical Failing Load 70 KN

19 Safe working load 28 KN

20 Minimum Failing Load 70 KN

21 Creepage Distance 320 CD

22 Protected creepage distance 160 CD

23 Type and Grade of Materials :

i) Insulators Porcelain

ii) Cap Malleable Casting or S.G

iii) Pin Forged pin

iv) Locking W clip

v) Cement Portland

24 Type of semi conducting Glaze Ceramic

25 Colour of Insulators Dark Brown

26 Weight of single disc. kg. 4 Kg(Approx.)

27 Number of Insulators per crate 4 nos./ 6 nos.

28 Cross weight of Loaded crate 20 – 30 Kg

29 Whether drawing showing dimensional details have been

furnished along with bid.

To be enclosed by

bidder

GUARANTEED TECHNICAL PARTICULARS 11 Kv & 33 Kv PIN INSULATOR

Sl. No.

Description 11 Kv PIN INSULATOR 33 Kv PIN INSULATOR

1 Normal working voltage 11 Kv (rms) 33 Kv (rms)

2 High system voltage. 12 Kv (rms) 36 Kv (rms)

3 Visible Discharge voltage dry PF. 9 Kv (rms) 27 Kv (rms)

4 1 Minute withstand voltage wet PF. 65 Kv (rms) 95 Kv (rms)

5 1 Minute withstand voltage................. 35 Kv (rms) 75 Kv (rms)

6 PF puncture withstand voltage. 110 Kv (rms) 180 Kv (rms)

7 Impulse withstand voltage :

(+ ve) 80 Kv peak 205 Kv peak

(- ve) 80 Kv peak 240 Kv peak

8 Impulse flashover voltage :

(+ ve) 90 Kv peak 205 Kv peak

(- ve) 120 Kv peak 240 Kv peak

9 Minimum failing load. 5 KN. 10 KN.

10 Minimum creepage distance. 240 mm. 580 mm.

11 Colour of glaze. Brown. Brown.

12 Weight per unit. 1.4 Kg. (Apprx.) 8.6 Kg. (Apprx.)

13 Size of insulator. (Height) 125 mm. 225 mm.

(Diameter) 125 mm. 285 mm.

14 Material of thimble. Lead. Lead.

15 Steel head. Small head. Large head.

16 Standard. IS : 731/1971. IS : 731/1971.

17 Tolerance. Tolerance will be allowed as per IS : 731/1971 or latest amendments if any.

18 Marking :-- Each insulator will be legibly marked to show the following :

(a) Name of the Purchaser :-- WESCO

(b) Name or trademark :--

(c) Month & year of manufactureing :--

(d) Minimum failing load.

PACKING :-- All insulators shall be packed in wooden crates suitable for easy but rough handling & acceptable for road transport. Where more than one insulator are packed in a crate, separator shall be fixed between the insulators to keep individual insulator in position without movement in the crate.

TECHNICAL SPECIFICATION 11 KV POST INSULATORS

1. Scope- This specification covers the manufacture, testing and works supply and delivery

of 1 1 KV post insulators. The Porcelain insulators shall conform to IS:731-

1971ammended upto date.Small fittings like spring washers, nuts etc may be electro-

galvanised.

2. System conditions:

Frequency : ( 50 ± 3%)Hz

Nominal System Voltage : 11 K V

Maximum System Voltage : 12 KV

No. of phases : 3

Power frequency one minute withstand(Dry) : 75 KV

Neutral Earthing arrangement System : Effectively Earthed

3. Requirements:

The post type insulators shall be suitable for outdoor use and cap & base type. Caps & base shall

have plain machined faces & zigs shall be used for drilling bolt holes on the cap & in the base for

easy & perfect assembly. Regarding Test for Mechanical strength for post Insulators, all the

necessary tests are as per 9.6.5.1, 9.6.5.2, & 9.6.5.3 of IS:2544-1973 with latest amendments are

to be carried out at the manufacturer‟ s premises.

For each of the Post Insulators / Insulator sets Bolts, Nuts, Set Screws & Washers shall be

supplied as follows :

i. Requisite numbers of set Screws & Spring Washers for assembling the Post Insulator

unit.

ii. Requisite numbers of set screws & spring washers for fixing bus-bar Support to the cap

in the top Post Insulator.

iii. One set of Bolts, Nuts & Washers or Lock nuts & plain washers for mounting the

Insulators on the support steel structures of bus support.

iv. 5% spare Nuts & Bolts with washers shall have to be supplied of no extra cost by the

purchaser with each consignment.

4. Creepage Distances :

The minimum creepage distance shall 31mm/KV.

5. Tests:

Suitable number of individual units shall be subject to the following tests in accordance with

IS:731/1971 with its latest amendments

6. Test Certificate :

The Bidder shall furnish detailed type test reports of the offered post Insulators at the

NABL approved laboratories to prove that the Disc Insulators offered meet the

requirements of the specification. These Type Tests should have been carried out within

five years prior to the date of opening of this tender.

v) Their offered Insulators are already fully type tested at approved Laboratory

within five years prior to the date of opening of this tender.

vi) There is no change in the design of type tested Insulators and those offers against

this tender.

7. Testing Facilities :

The Bidder must clearly indicate what testing facilities are available in the works of the

manufacturer and whether facilities are adequate to carry out all Routine & acceptance Tests.

These facilities should be available to Purchaser‟ s Engineers if deputed or carry out or

witness the tests in the manufacturer works. If any test cannot be carried out at the

manufacturer's work, the reasons should be clearly stated in the tender. The insulators shall

be tested in accordance with the procedure detailed in IS-731/1971 amended up to date.

8. Drawings :

The tender shall be accompanied with the detailed drawings showing the dimensions of the

individual insulator, giving all the design dimensions of various component parts.

Generally it shall be as per IS.

9. Markings :

Each insulator shall be legibly and indelibly marked to show the following : a) Name or trade mark of the manufacturer.

b) Voltage Type

c) Month and year of manufacturing.

d) Country of Manufacturer

e) ISI certificate mark

10. Packing :

All insulators shall be packed in crates or boxes suitable for rough handling. Packing shall be marked with the strength and KV rating.

GUARANTEED TECHNICAL PARTICULARS FOR 11 KV POST INSULATOR

Sl.

No.

Requirement Requirement Bidder’s offer

1 Name of Manufacturer. & Address To be specified by the bidder

2 Location of type testing To be specified by

the bidder

3 Applicable standard IS-731/1971 with latest amendment




7 Impulse withstand voltage +(1.2/50 microsecond wave)

90 KVp (+ve) and

105 KVp (-ve)

8 Impulse flashover voltage+(1.2/50 microsecond wave)

95 KVp (+ve) and

120 KVp (-ve)

9 1min. power frequency flashover Voltage kV. (Dry)

70 KV

10 1min. power frequency flashover Voltage kV.(Wet)

45 KV

11 Cantilever strength

a. Upright 65 Kg(Min)

b. Inverted 400 Kg(Min)

12 Tensile strength 2050 Kg

13 Torsion strength 34 m-Kg

14 Compression strength 3600 Kg

15 Conforming standard As per IS

NB- Every insulator should bear the marking of manufacturer’s name and ISI mark

TECHNICAL SPECIFICATION FOR LIGHTNING ARRESTORS 1. SCOPE :

1.1. This Specification covers design, manufacture, testing at manufacturer's Works, packing,

supply, delivery of 42 KV & 12 KV classes of gapless Lightning Arrestors complete with fittings

and accessories.

1.2. These arrestors shall be of Heavy Duty, Station Class / Distribution Class and Gapless Zinc

Oxide type.

1.3. Arrestors shall be hermetically sealed units suitable for outdoor installation on self-supporting base or structures.

2. STANDARD :

Arrestors shall conform in general to IEC-99-4 document or its latest amendment and IS/IEC

as follows:

i) IEC-99-4 : Gapless Lightning Arrestor

ii) IS 3070 P-III : Metal Oxide Surge Arrestors without gaps for AC Systems. iii) IEC 99 P-III : Artificial Pollution Testing of Lightning Arrestor

iv) IEC 270 : Partial Discharge Measurement.

v) IS 2071 : Methods of H V Testing

vi) IS 6209 : Methods for Partial Discharge Measurement

vii) IS 5621 : Hollow Insulators for use in electrical equipment

3. DEVIATION :

Normally the offer should be as per Technical Specification without any deviation. But any

deviation felt necessary to improve performance, efficiency and utility of equipment must be

mentioned in the 'Deviation Schedule' with reasons duly supported by documentary evidences

and advantages of such deviation. Such deviations suggested may or may not be accepted.

But deviations not mentioned in Deviation Schedule will not be considered. 4. DUTY REQUIREMENT:

The Surge Arrestors are being provided to protect the following equipment whose insulation

levels are indicated in the table given below:

Equipment to be protected L I for 42 KV

system (KVp) L I for 12 KV

system KVp) Power Transformer

+/-170

+/-75

Instrument Transformer

+/-170

+/-75

CB/Isolator Phase to ground +/-170

+/-75

Across open poles

+/-195

-

4.1. The Lightning Arrestors shall be capable of discharging Lightning and switching surges and

temporary power frequency over voltages .The Surge Arrestor shall be capable of discharging

over voltages occurring during switching of unloaded transformers and long lines.

4.2. The Arrestors shall be capable of withstanding Maximum Continuous Operating Voltages

(M.C.O.V). 4.3. The Arrestors supplied shall be suitable for heavily polluted atmosphere.

4.4. The reference current of the Arrestors shall be high enough to eliminate the influence of

grading and stray capacitance on the measured reference voltages.

5. FITTINGS & ACCESSORIES:

5.1 Arrestor rating upto 42 KV shall be directly mounted on structure as there is no surge

counter. 5.2 Each single pole arrestor shall be provided with suitable name plate, at the base with the

following data:

i) Name of device

ii) Manufacturer's name and trade mark, type and identification iii) Year of manufacture

iv) Voltage rating & frequency rating.

v) Nominal discharge current

vi) MCOV (Maximum Continuous Operating Voltage in KV).

vii) Discharge class.

viii) Energy Discharge capability (KJ/KV rating)

ix) Purchase Order reference

x) Applicable Standard.

xi) Pressure Relief rated current in KA rms (for arrestors fitted with Pressure Relief device)

xii) Serial Number & NESCO

5.3 Clamp type terminal connector shall be suitable for either ACSR /AAAC DOG/WOLF Conductor

for 42 KV and DOG / RABBIT Conductor for 12 KV system voltage class L.A. having horizontal/

vertical take off. Detailed particulars have been indicated in the specification for Clamps and

Connector in this bid document. 5.4 Two ground terminal connectors suitable for G.I strip of required size shall be provided on

diagonally opposite sides.

5.5 Necessary hardware such as nuts, bolts, spring washers, etc. shall be supplied for different

units. 5.9 12 KV Lightning Arrestor should be of Distribution Type and should have suitable Fault

Indicator.

6 CONSTRUCTIONAL FEATURES :

6.1 The arrestor elements shall be designed in such a way as to obtain robust construction with

excellent mechanical and electrical properties even after repeated operation. The lightning

arrestors should be adequately designed to operate satisfactorily under temporary power

frequency over voltage as given in Specific Technical Parameters, after discharging two shots

of respective long duration surges. Uniform density of zinc oxide element shall be maintained

to provide uniform current distribution. 6.2 The lightning Arrestors shall be of adequate Pressure Relief Class as per IEC-99-4 , fitted with

Pressure Relief Devices and Arc diverting ports to minimise possibilities of shattering of

porcelain housing. 6.3 Sufficient creepage distance shall be provided to reduce excessive uneven voltages over the

porcelain due to contamination, for which the arrestor shall not fail.

6.4 Seals shall be provided in such a way that these are always effectively maintained even when discharging the maximum rated lightning current.

6.5 Housing of Insulators shall be of Porcelain, glazed and completely vitrified and free from blow

holes, micro-cracks or void. Porcelain, housing shall be so coordinated that external flashover

will not occur due to application of any impulse or switching surge voltage up to the maximum

design value for the arrestor. 6.6 The end fittings shall be made of non-magnetic and corrosion proof material. It is preferable

that the LAs shall be hermetically sealed with inert gas (Nitrogen).

6.7 Arrestors shall be suitable for mounting on a support structure. 6.8 12 KV Class Distribution Type Lightning Arrestor should have provision for Fault

Indicator/Disconnector.

7 APPLICATION :

The lightning Arrestors are used for protection of incoming and outgoing line and also of the

power transformers from lightning surge as well as from power frequency over voltage. 8 TENDER DRAWINGS, CATALOGUES AND TEST REPORTS :

Following drawings and manual/leaflet in one copy with each tender shall be submitted :

i) General outline drawing giving plan, elevation, side view and sectional view, top and

bottom connection arrangement with pitch circle diameter and other dimensions of the

complete assembly with surge counter and leakage current measuring meter where

applicable. Size of terminals and lifting lugs, shipping weight etc are to be indicated.

Name and rating plate diagram are to be furnished.

ii) The bidder shall submit complete Test Report of all tests (including Type Test) as

stipulated in the relevant IS carried out from NABL/Govt. approved Laboratories on

Lightning Arrestor unit of identical design along with their offer. The submitted Test

Report shall amply prove that the test have been carried out within 5 (five) years from

the date of submission of Tender. 9 TEST REPORTS AND TYPE TESTS :

The Bidder should submit the Complete Test Reports (including Dynamic Short

Circuit Test Report)&Reports of Type Tests as stipulated in latest relevant

IS/IEC with complete Identification, Date & Sl.No., carried out within 5(Five)

Years from Due Date of Tender, in CPRI/NABL accredited/Govt. recognized Test House or Laboratory on Tendered Item of identical design, With Tender

Documents failing which their offer may not be technically accepted.

10 TEST AT FACTORY AND TEST CERTIFICATES :

i) Each LA shall comply with the requirements of routine test as specified in the relevant

IEC:99-4 & IS:3070 (Part - III).

ii) Routine test at manufacturer's works shall be carried out in presence of representative

of NESCO.

iii) All routine & acceptance tests shall be carried out at the manufacturer's works on every

lot offered for inspection as per relevant IEC & IS. Selection of samples for acceptance test as well as rejection and retesting shall be guided by relevant IEC & IS.

iv) The Tenderer shall give at least 7 days’ advance notice intimating the actual date of

inspection and details of all tests that are to be carried out. Relevant Type & Routine

Tests’ Certificates obtained from the competent Authority(ies)for all accessories/ bought

out items shall have to be furnished.

SPECIFIC TECHNICAL PARAMETERS

TYPE OF ARRESTOR STATION CLASS HEAVY DUTY GAPLESS

DISTRIBUTION CLASS

i) Nominal system voltage (KV) 33 11

ii) Highest system voltage (KV) 36 12

iii) System Neutral Earthing NEE(Grounded Through EE Earthing Transformer)

iv) BIL of transformers (KVp) 170 75

v) System fault level (KA) 25 16

vi) Maxm. System BIL (KVp) 170 75

LA RATINGS :

i) Rated Voltage (KV) 42 12

ii) Maxm. Continuous operating voltage (KVrms)

36 10

iii) Nominal Discharge Current (KAp) 10 5 iv) Line discharge class 2 Distribution Class

v) Minimum Energy Discharge capability (KJ/KV)

[If there is any Deviation the same may be mentioned in the Deviation Sheet]

vi) Temporary over voltage withstand

capability (KVrms) for 10.0 secs

vii) Insulation Housing withstand voltages

i) Lightning Impulse(Dry)

ii) Power frequency(wet)

for 10 KA

for 5 KA

viii) Minimum creepage Distance acceptable

(mm)

5 5

42 12

Minimum values as per IEC

1100 300

i) Pressure Relief Class To be tested in accordance with IEC

ix) (Minimum) High Current Impulse withstand

(4/10) KA (peak)

x) Maxm.Lightning Impulse (8/20 micro-

second impulse) residual voltage (KVp) :

100 65

5 KA 112 34

10KA - - xi) Maxm. switching surge (30/60 micro-

second wave) protective level (KVp)

500 Amps 98 21

1000 Amps - -

2000 Amps - -

xii) Maxm. Steep Impulse (1/20 micro-seconds

impulse) residual voltage at 10 KA (KVp)

130 28

xiii) RIV/Partial Discharge (micro-volt / pico-

coulomb) when energised at 1.05 times its

continuous operating voltage shall not

exceed

250 microvolt/ less

than 50 pico-coulomb

1000 microvolt/ less

than 500 pico-

coulomb

xiv) Terminal connection ACSR Conductor (7 Strand), Dog/ Wolf

xv) Rated Frequency (Hz) 50 50

xvi) Minimum Visible Corona Discharge - -

voltage(KV rms)

ACSR Conductor (7 Strand),Dog/Rabbit