SECTION IV OF ELECTRICAL MATERIALS GROUP -A. Tender Notice No. NESCO Utility/ MR Materials/ 18/13138 Dt

SECTION IV TECHNICAL SPECIFICATION OF ELECTRICAL MATERIALS GROUP -A Tender Notice No. NESCO Utility/ MR Materials/ 18/13138 Dt.26.11.16 Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 1

GROUP A : Sl. No. Name of the materials Unit Quantity 1 33 KV. "V' Cross Arms (GI) No. 2000 2 11 KV "V" Cross-Arms(G.I) No 3000 3 33 KV. 3 Pole 400 A.B.Switch (H) Set 80 4 33 KV. Post Insulator. No. 300 5 11KV PIN Insulator No 5000 6 33KV Stay Insulator. No 1500 7 33 KV. Pole Top Bracket. No. 500 8 33 KV. G.I. Pin. No. 500 9 40 mm G.I. Earthing Device No 1000 10 20 mm H.T. Stay Set. Set 1500 11 16 mm L.T. Stay Set. Set 2000 12 7/12 SWG G.I. Stay Wire Kg 15000 13 7/8 SWG G.I. Stay Wire Kg 15000 14 300Amp Kitkat Fuse No. 1000 15 400Amp Kitkat Fuse No. 1000 16 33KV AB Switch Male Contact(H) No 170 17 33KV AB Switch Female Contact(H) No 170 18 6 SWG GI wire Kg 1000 19 8 SWG GI wire Kg 1000 NB: 1. Bidders should put their authorized signature with office seal on each page of the documents. 2. Bidders should put their offer in the Guaranteed particulars column furnished in the tender documents. 3. Bidders should submit samples of their quoted items for item sl. no. 1 to 3, 7 to 11 & 14 to 17 at NESCO Utility Store, Balasore and furnished store receipt copy along with bid documents for verification. 4. Purchaser reserves the right to increase or decrease the above quantities during placement of purchase order or may cancel any item/items without assigning any reason thereof. General Manager (C&P) NESCOUtility, Balasore, Odisha Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 2

33KV V Cross arm (GI) TECHNICAL SPECIFICATION 33 KV V cross arm made out of 100x50x6 mm M.S Channel as per REC Standard M-1. The cross arm shall be fabricated out of 100x50x6 mm size channel having 9.2 Kg/Mtr. After fabrication the cross arm shall be Galvanized as per IS-2633/1972.(Latest Amendment), IS :2629/1985 (1 st. Revision)conforming to REC construction standard & drawi Guaranteed Technical Particulars of 33 KV 'V' Cross Arm Sl. No. Description Specified Bidders Offer 1 Type of Cross Arm ISMC 100x50 2 Channel Weight 9.2 Kg/mtr 3 Grade of Steel FY 250 4 Steel Standard IS:2062-1992 5 Fabrication Standard IS:802 (part - 2) - 1978 6 Dimension (100x50x6)mm 7 Size of M S Flat welded at both ends 50x8mm 8 Steel Tensile Strength 1500kgf/cm² 9 Hot dip, as per IS-2633/1972, Galvanisation IS :2629/1985 (latest revision) 10 Working Load 400/ 450/ 550/600Kg 11 Total Weight 19.7 Kg (approx.) 12 Drawing enclosed Name & Signature of Bidder with seal Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 3

11 KV V Cross Arm (GI) : The Cross arm is to be made out of ISMC 75x40 with 50mmx6mm flat packing on top & bottom flange of the channel where the insulator pin is to be mounted conforming to REC construction standard & drawing. Galvanized the V cross arm as per IS-2633/1972.(Latest Amendment), IS :2629/1985 (1 st. Revision). Guaranteed Technical Particulars of 11KV 'V' Cross Arm Sl. No. Description Specified Bidders Offer 1 Type of Cross Arm ISMC 75x40 2 Channel Weight 7.14 Kg/mtr 3 Grade of Steel FY 250 4 Steel Standard IS:2062-1992 5 Fabrication Standard IS:802 (part - 2) - 1978 6 Dimension (75x40x4.8)mm 7 Size of M S Flat welded at both ends 50x8mm 8 Steel Tensile Strength 1500kgf/cm² 9 Galvanisation Hot dip, as per IS-2633/1972, IS :2629/1985 (latest revision) 10 Working Load 200/300/350/400Kg 11 Total Weight (with tolerance per meter + 4%) 11.2 Kg (approx.) Name & Signature of Bidder with seal Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 4

TECHNICAL SPECIFICATION OF 33 KV 3 POLE, 400 AMP, HORIZONTAL TYPE AB SWITCH 1.0 SCOPE:- This specification covers manufacturing testing and supply of 3 Pole, 400 AMP, 50 Hz, Single break, 33 KV class Air Break switches for outdoor installations to be used at 33/11 KV Sub-stations and for incoming & outgoing Lines suitable for operation under off load conditions. 1.1 DESCRIPTION OF THE MATERIALS:-The A.B. Switch sets shall confirm to the following parameters:- Sl. No. Description Parameters of AB Switch 33 KV i) No. of poles 3 ii) Number of Post insulator per pole 4 nos. 22/24 KV class iii) Nominal system voltage (KV) 33 iv) Highest System Voltage (KV) 36 v) Rated frequency 50HZ vi) System earthing Effectively earthed. vii) Rated nominal current Amp. viii) Altitude of installation Not exceeding 1000 M Sl. No. The post insulators used in the A.B. Switches shall have the following ratings Description Parameters P.I. of AB Switches for 33 KV i) Power frequency withstand voltage 95 ii) Power frequency withstand voltage (wet) 75 KV (RMS) iii) Impulse withstand voltage (dry) KV 170 KV (peak) iv) Power frequency puncture 1.3 times the actual dry flashover voltage of the unit Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 5

1.2 STANDARDS:- The AB Switch Set shall conform to the following standards:- i) IS-9920 (Part-I to V.) ii) IS-2544/1973 ( for porcelain post insulators iii) IS-2633 (for galvanization of ferrous parts.) or its latest amendments if any. 1.3 INSULATORS:- 22 KV / 24 KV class Post Insulators complete with pedestal cap duly cemented to be used in the AB Switch Set conforming to IS-2544/1973 The bidder shall furnish the type test certificate of the post insulators from their manufacturer for reference. The bidder shall mention make, type of insulation materials, metal fittings, Creep age distance, protected Creep age distance, tensile strength, compression strength, torsion strength and cantilever strength. 1.4 CLIMATIC CONDITIONS:- The A.B. Switch set shall be suitable for operation under the following climatic Conditions 1. Maximum ambient air temperature. 45 0 C 2. Maximum daily average air temperature 35 0 C 3. Maximum yearly average ambient air temperature 30 0 C 4. Maximum temperature attainable by a body exposed to the sun. 5. Minimum ambient air temperature 50 0 C 0 0 C 6. Maximum relative humidity. 100% 7. Minimum number of rainy days per annum 70 8. Average number of rainy days per annum 120 9. Average annual rain fall. 150 cm. 10. Number of months of tropical monsoon conditions 4 11. Maximum wind pressure. 260 Kg./ mm 2 12. Degree of exposure to atmospheric pollution. Normally polluted atmosphere. 1.5 TECHNICAL DETAILS:- 1.5.1 The 33 KV A.B. Switch Set shall be gang operated (with double tandem pipe) single air break outdoor type horizontal mounting having 4 nos. 22/24 KV post insulator per phase. The Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 6

operating mechanism shall be suitable for manual operation from the ground level and shall be so designed that all the three phases shall open or close simultaneously. The Switches shall be robust in construction, easy in operation and shall be protected against over travel or straining that might adversely affect any of its parts. The required base M.S. Channel, phase coupling rod, operating rod with intermediate guide braided with flexible electrolytic copper, tail piece of required current carrying capacity and operating mechanism with ON & OFF positions shall be provided. The operating rod shall be medium gauge of 32mm diameter nominal bore G.I. pipe single piece 6 meters. The phase coupling rod for gang operation shall medium gauge 25mm dia nominal bore G.I. Pipe. Rotating post insulators shall be provided with suitable bearing mounted on a base channel with 6 mm thick thrust collar and 6mm split pin made out of stainless steel. The operating down rod shall be coupled to the spindle (minimum dia - 32mm) for gang operation through another suitable bearing by two numbers 10mm dia through stainless steel bolts with double nuts. The post insulators should be fixed with the base channel using Galvanized Nuts and Bolts. All the bearings shall be provided with grease nipple. All ferrous parts shall be galvanized and polished. The pipes shall be galvanized in accordance with IS-4736/1968. 1.5.2 Mounting: - The A.B. Switches shall be suitable for horizontal mounting in all type of substation structures. 1.5.3 Switching Blades: - It shall be made out of electrolytic copper with silver plated. The approximate size shall be 250mm x 50 x 8mm. The switch shall have such a spring mechanism so as to ensure that the speed of the opening of contact is independent of speed of manual operation. 1.5.4 Fixed Contacts:- The fixed jaw type female contracts (50x8x95 )mm shall be made of electrolytic copper ( minimum 95 % copper composition) duly electroplated controlled by Phosphor bronze high pressure spring housed in robust G.I. Cover. It is essential that provision shall be made in fixed female contracts to take the shock arising from the closing of moving contract blade without the same being transmitted to the post insulator. The arrangement made in this regard shall be specifically shown in the drawing. 1.5.5 Arcing Horn:- As the switches are generally meant for isolating transmission line and distribution transformers, suitable arcing horns shall be provided for breaking the charging current horn shall be made of 10 mm dia G.I. Rod with spring assisted operation. Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 7

1.5.6 Terminal Connectors:- Terminal connectors shall be robust in design. The size of fixed connector shall be ( 80 x 50 x8 mm) and size of movable connector shall be of ( 80 x50) x ( 80 x 50) x 8 mm of copper casting with uniform machine finishing duly silver plated made out of minimum 95 % copper composition with 2 nos. 12 mm dia holes provided with suitable brass bolts and double nuts, flat washers & 2 nos. bimetallic solderless sockets suitable up to ACSR Panther or AAAC 232 mm 2 conductor. 1.5.7 Spacing:- The minimum clearance between phase to the switch shall be 1200 mm. The operating down rod shall be at a transverse distance of 300 mm from the outer limb of the switch. The centre spacing between two post insulators of the same phase shall be 560 mm. In the open position of the A.B. Switches the moving blade shall rotate through anangle of 90 0. This shall be exhibited in the drawing. 1.5.8 Drawing & Literatures:- Drawings of 33 KV 400 amp, 3 Pole, single break A.B. Switch shall be furnished along with the tender. The details of construction and materials of different parts of the A.B. Switches shall clearly be indicated in the tender and illustrative pamphlet / literature for the same shall be submitted along with the tender. 1.6 TESTS & TEST CERTIFICATE 1.6.1 Type Test:- Certificates for the following type tests conducted within five years proceeding to the date of opening of tender on prototype set of A.B Switch in a Govt. Approved Testing Laboratory preferably at CPRI, Bhopal/ Bangalore shall have to be submitted for reference and scrutiny. i. Impulse voltage dry test ii. iii. iv. Power frequency voltage dry test Power frequency voltage wet test Temperature of resistance. v. Measurement of resistance. vi. vii. viii. ix. Test to prove the capability of carrying the rated peak short circuit current and the rated short time current. Mainly active load breaking capacity test. Transformer off-load breaking test. Line charging breaking capacity test. x. Operation tests. Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 8

xi. xii. xiii. Mechanical endurance test. Mechanical strength test for the post insulator as per IS-2544/1973. Test for galvanization of metal (ferrous) parts as perm IS-2633/1973. Besides, mechanical endurance test will have to be conduct on one set in the presence of our authorized person who shall be deputed to carryout acceptance tests before delivery of the materials. 1.6.2 Routine Tests: - The following routine tests shall have to be conducted on each sets and results are to be furnished for consideration of deputing inspecting officer for inspection and conducting testing of the materials. 1. Power frequency voltage dry test 2. Measurement of resistance of main circuit 3. Tests to prove satisfactory operation. 4. Dimension check 5. Galvanization test. 1.7 GUARANTEED TECHNICAL PARTICULARS:- The Bidder shall furnish the guaranteed technical particulars duly filled in the format at Appendix-I along with the tender. 1.8 COMPLETENESS OF EQUIPMENT:- Any fittings, accessories for apparatus which may not have been specifically mentioned in this specification but which are usual or necessary in equipment of similar plant shall be deemed to be included in the specification and shall be supplied by the Tender without extra charge. All plant and equipment shall be completed in all details whether such details are mentioned in the specification or not. 1.9 INSPECTION:-Routine and acceptance tests shall be conducted at the place of manufacturer. The bidder are requested to furnish details of equipment which will be used for testing along with tender. The bidder of those manufacturers who do not have adequate testing facilities for conducting routine and acceptance test are liable for cancellation. The successful bidder has to furnish routine test certificate and guaranteed certificate for approval prior to offer of materials for inspection for each consignment of offer. Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 9

GUARANTEED TECHNICAL PARTICULARS FOR 33KV, 400A, 50 HZ, 3 POLE, SINGLE BREAK TYPE AB SWITCH Sl. No Particulars Desired values Bidder s 1 2 3 4 Maker s name and country To be specified by the tenderer 1. of origin 2. Type of Switch Rotating type only 3. Suitable for mounting Horizontal only Number of supporting post 4 nos.22 KV / 24 KV Post Insulators per 4. insulators per phase phase as per ISS-2544/1973. 5. No. of Breakers per phase Single Break offer 6. Post Insulator. a) Maker s name and country of origin Techno Ceramics / Allied Ceramic/JSI/Equivalent type test certificate to be provided along with bid. b) Type of cementing To be quoted for original cemented only & as per IS-2544-1973 & relevant IEC. c) One minute power frequency withstand voltage Dry 95 KV RMS. d) One minute power frequency withstand voltage Wet 75 KV RMS. e) Visible discharge voltage 27 KV RMS. f) Dry Flashover Voltage To be specified by the tenderer g) Power frequency puncture with stand voltage h) Impulse withstand voltage 1.3 times of actual dry flash over voltage 170 KV (peak) (switch in position) i) Creepage distance (mm) 450 mm minimum. (actual creepage distance for which type test have been conducted is to be specified by the tenderer 7. Impulse withstand voltage for positive and negative polarity 1.2 / 50 mircro- second wave. a) Across the isolating distance 195 KV (peak) Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 10

b) To earth & between poles 170 KV (peak) 8. One minute power frequency withstand voltage. a) Across the isolating distance 80 KV (RMS) b) To earth & between poles 70 KV (RMS) 9.a) Rated normal current and rated 400 amps. 50 Hz frequency b) Rated short time current. 16 KA ( RMS ) 10. Rated short circuit making capacity 25 KA (RMS) 11. Rated peak withstand current 40 KA ( Peak ) 12. Rated cable charging breaking capacity 13. 14. 15. a) Rated Transformer off load breaking capacity Rated line charging breaking capacity Minimum clearance between adjacent phases Switch Closed ( centre to centre) Switch Opened ( centre to edge b) of blade) 16. Temperature rise 40 KA ( RMS ) 16 Amp (RMS) 5.3 Amps ( RMS) 1200 mm 640 mm Temperature rise shall not exceed the maximum limit as specified below at an ambient temperature not exceeding in 40 0 C b) Copper contacts in air c) Terminal of switch intended to be connected to external conductor by bolts 65 0 C 50 0 C 17. Vertical Clearance from top of insulator cap to mounting channel 508 mm (minimum) Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 11

18. Type of Contact: - a) Self aligned, high pressure jaw type fixed contacts of electrolytic copper of size 50 mm x 8 mmx95 mm duly silver plated. Each contact should be revetted with three nos. Copper rivets with a bunch (minimum 3 mm thick) consisting of copper foils, each may vary from 0.15 mm to 0.25 mm. These total thickness of copper foils per jaw should be 6 mm. Jaw assemblies are to be bolted through stainless steel bolts and nuts with stainless steel flat and spring washer. b) Solid rectangular blade type moving contact of electrolytic copper size 250 mm x 50 mm x 8 mm duly silver plated ensuring a minimum deposit of 10 micron of silver on copper contacts or as may be prescribed under relevant ISS / IEC. c) Pressure spring to be used in jaw contacts shall be Stainless Steel having 8 nos of turn x 28 mm height x 14.4 mm diameter with 14 SWG wire (minimum six nos springs shall be used) 19. Connectors:- Terminal connectors for both movable and fixed should be of copper flats of same size similar to that of moving contact blades (minimum 95% copper composition). The fixed connector shall of size 80 mm x 50 x 8 mm and the size of movable connector shall be size 80 x 50 x 8 mm with machine finishing duly silver plated with 2 nos. of 3/8 stainless steel bolts, nuts, plain washers & spring washers should be provided along with 2 nos solder less bimetallic sockets for each connector suitable sockets for each connector suitable up to 232 mm² AAA conductor. 20. Moving Contacts supports:- Movable contact is to be supported by galvanized angle of 50 x 50 x 5 mm in each phase and the moving contact are to be bolted through 2 no stainless steel bolts and nuts with suitable stainless steel flat and spring washers. Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 12

21. Galvanization a) Iron parts shall be dip galvanized as per IS-2633/1972. b) b) The pipe shall be galvanized as per IS- 4736/1968. 22. Details of Phase a) Coupling Rod b) Operating Rod 25 mm nominal bore G.I. pipe medium gauge. 32 mm nominal bore G.I. pipe medium gauge single length 6 mtrs. The detailed dimension of the G. I. pipe as per IS-1239 (Pt. I) as mentioned below :- Nomin al base (mm) Outside diameter Max Min Diameter thickness (mm) 2 34.2 33.3 3.25 5 3 42.9 42 3.25 c) Arcing Horns 2 10 mm dia G.I. rod with spring assisted operation. d) Force of Fixed contact spring To be specified by the tenderer. e) Copper braided flexible tapes:- 450 mm long 2 nos. of flexible electrolytic copper tape or braided chord (with tin coated) having minimum weight 450 gms per meter and both ends shall be crimped with copper sockets through brass bolts and nuts with brass flat washers. Two nos of suitable copper sockets shall be used at both ends. The minimum no. of flexible wires should be 1536 of 36 SWG for each flexible chord. f) Quick break device Lever mechanism. g) Bearings 4 nos. self lubricated bearing to be provided with grease nipple including 4th bearing being a thrust bearing. h) Locking arrangement Pad Lock & Key arrangement at both ON & OFF position. i) Earth Terminal: To be provided at base channels. Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 13

23. Supporting Channels 100 x 50x5 mm M.S. Channel hot dip galvanized. 24. Weight of each pole complete To be specified by the tender 25. Detailed drawing To be submitted by the bidder NB- Every AB Switch should bear the marking of manufacturer s name,purchaser s name, P.O. No., Sl. No. etc. Name & Signature of Bidder with seal 33KV 400 Amp. AB Switch Male contact(h) & Female contact(h) Requirement a) Self aligned high pressure jaw type fixed contacts of electrolytic copper of size 50mm x 8 mm x95mm duly silver plated.each contact should be riveted with three nos. copper rivets with a bunch ( minimum 3 mm thick) of copper strips /foil each may vary from 0.15 mm to 0.25 mm to and total thickness of copper foil per jaw should be 6 mm. Jaw assembles are to be bolted through brass bolts and nuts with spring washer. b) Solid rectangular blade type moving contact of electrolytic copper of size 250mmx50 mm X 8 mm duly silver plated ensuring a minimum deposit of silver 10 micron on copper contacts or as may be prescribed under relevant ISS / IEC. Bidders Offer c) Pressure springs are to be used in each jaw contacts should be phosphorous bronze having 8nos. of turns x 28mm heights X14.4mm diameter with 14 SWG wire ( minimum six nos. springs shall be used). Name & Signature of Bidder with seal Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 14

TECHNICAL SPECIFICATIONS OF 33 KV POST TYPE INSULATOR 1.Scope of Work: This Specification covers design, engineering, manufacture, assembly, stage testing, inspection & testing before supply and delivery at site of the 33 KV post type insulator 2.0 INSULATORS 2.1 General Requirements 2.1.1 The Porcelain shall be sound, free from defects, thoroughly vitrified and smoothly glazed. 2.1.2 Unless otherwise specified, the glaze shall be brown in colour. The glaze shall cover all the porcelain parts of the insulator except those areas which serve as supports during firing or are left unglazed for the purpose of assembly. 2.1.3 The design of the insulator shall be such that stresses due to expansion and contraction in any part of the insulator shall not lead to deterioration. The porcelain shall not engage directly with hard metal. 2.1.4 Cement used in the construction of the insulator shall not cause fracture by expansion or loosening by contraction and proper care shall be taken to locate the individual parts correctly during cementing. The cement shall not give rise to chemical reaction with metal fittings, and its thickness shall be as uniform as possible. 3.0 Tests: The insulators shall comply with the following tests as per IS:2544-1973 & IS: 5350(PT III)-1971. 3.1 Type tests a) Visual examination b) Verification of dimensions c) Visible discharge test d) Impulse voltage withstand test. e) Wet power-frequency voltage withstand test. f) Temperature cycle test. g) Electro-mechanical failing load test. h) Mechanical failing load test (for those of type B strin insulator units to which electro mechanical failing load test (g) is not applicable. i) Twenty four hours mechanical strength test (for string insulators only when specified by the purchaser). j) Puncture test k) Porosity test and l) Galvanising test. 3.2 Acceptance Tests The test samples after having withstood the routine tests shall be subjected to the following acceptance test in the rder indicated below: a) Verification of dimensions. b) Temperature cycle test. c) Twenty four hours mechanical strength test(for string insulator units only when specified by the purchaser) d) Electro-Mechanical failing load test. e) Puncture test Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 15

f) Porosity test and g) Galvanising test. 3.3 Routine Test a) Visual examination. b) Mechanical routine test(for string insulator units only) and c) Electrical routine test(for string insulator units only) 3.4 Marking 3.4.1 Each Insulator shall be legibly and indelibly marked to show the following. a) Name and trade mark of the manufacturer. b) Month and year of manufacture c) Minimum failing load in Newtons d) Country of the manufacturer and e) ISI Certification mark, if any. f) Specific Parameters & Layout Conditions. 3.4.2 Marking on porcelain shall be printed and shall be applied before firing. 3.5 Packing All insulators (without fittings) shall be packed in wooden crates suitable for easy but rough handling and acceptable for rail transport. Where more than one insulator are packed in a crate, wooden separators shall be fixed between the insulators to keep individual insulators in position without movement within the crate. GUARANTEED TECHNICAL PARTICULARS FOR 33 KV POST INSULATOR Slno. Description Unit Specified Bidder s UNIT STACK Offer 1 2 3 4 Manufacture Name Address of Manufacture Reference Standard (s) of Insulator To be Submitted by Bidder To be Submitted by Bidder IS: 2544-1973 & IS:5350(PT-III)-1971 Height mm 254 508 5 Insulating Part Diameter mm 192 192 6 Pitch Circle Diameter a) Top Metal Fitting mm 76 76 b) Bottom Metal Fitting mm 76 76 7 Minimum creepage Distance 8 Cantilever Strength mm 450 900 Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 16

a) Upright Kgf 900 459 b) Inverted Kgf 700 340 9 Tensile Strength Kgf 3060 3060 10 Torsional Strength Kgfm 70 70 10 Compression Strength Kgf 4600 4600 11 Nominal System Voltage KV(rms) 22 33 12 13 14 15 a) b) Highest System Voltage Power frequency withstand voltage (Dry) Power frequency withstand voltage (Wet) Impulse-withstand test voltage(1.2x50 microsecond wave) Positive Negative KV(rms) KV(rms) KV(rms) KVP KVP 24 36 75 140 55 90 Caps Padestal 125 190 125 190 16 Material of Cap Aluminium Alloy Cap 17 Drawing & Sample To be submitted by bidder NB- Every insulator should bear the marking of manufacturer s name & Purchaser s name and ISI mark. Name & Signature of Bidder with seal 11 KV PIN INSULATOR: 1.SCOPE : The specification cover the manufacture, testing at works supply and delivery of Porcelain insulators for overhead power lines with a nominal voltage below 12KV. Both Pin and Shackle type insulators are covered. 2.APPLICABLE STANDARDS: Except when they conflict with the specific requirements of this specification, the insulators shall comply with IS : IS:731 & IS: 3188 or the latest version thereof. 3.GENERAL REQUIREMENTS: The porcelain shall be sound, free from defects, thoroughly vitrified and smoothly glazed. The design of the insulators shall be such that the stresses due to expansion and contraction in any part of the insulator shall not lead to its deterioration. The glaze shall be brown in color for insulators. The glaze Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 17

shall cover the entire porcelain surface parts except those areas that serve as supports during firing. The insulators shall be suitable for use with all Aluminum Conductor or Copper conductor or ACSR upto 100 sq.mm. The insulators should withstand the conductor tension the reversible wind load as well as the high frequency vibrations set due to wind. 4.SYSTEM CONDITIONS: Frequency : 50 Hz Nominal System Voltage Maximum System Voltage LT System Minimum LT Voltage Power frequency one minute withstand Voltage(wet) : 11KV : 12KV : 11KV : 35KV 5. TYPE OF INSULATORS: The standard Pin insulators shall be of designation Type B of IS : 731 or its latest revision. 6. TESTS: 6.1 Type tests: a) Visual examination b) Verification of dimensions c) Temperature cycle test d) Dry one minute power frequency withstand test e) Wet one minute power frequency withstand test f) Mechanical strength test g) Porosity test 6.2 Acceptance test: The insulators, after having withstood the routine test shall be subjected to the following acceptance tests in the order given below: a) Verification of Dimensions. b) Temperature cycle test c) Mechanical strength test d) Porosity test 6.3 Routine tests: ii) Visual examination 7.TESTING FACILITIES: a. The Bidder must clearly indicate what testing facilities are available in the works of the manufacturer and whether the facilities, are adequate to carry out all the routine as well as type tests. These facilities should be made available to Purchaser s Engineers if deputed to carry out or witness the tests. If any tests cannot be carried out at the manufacturer s works, the reasons should be clearly Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 18

stated in the tender. b. The Bidder shall furnish detailed type test reports of the offered 11KV Pine insulator as per clause 6.1 of this specification. All the above Type Tests shall be carried out at laboratories, which are accredited, by the National Accreditation Board of Testing and Calibration Laboratories (NABL) of Government of India to prove that the 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. c. There offered L.T. shackle Insulators & pin insulators are already fully Type Tested at Laboratories accredited by the National Accreditation Board of Testing and Calibration Laboratories (NABL) within five years prior to the date of opening of the tender. There is no change in the design of Type tested L.T. shackle Insulators and those offers against this tender. 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. MARKING: a. Each insulator shall be legibly and indelibly marked to show the following: i) Name of Purchaser- NESCO ii)name or trade mark of the manufacturer iii) Year of manufacturer iv) ISI certificate, mark, if any. b. Marking on porcelain shall be applied before firing. 10. Packing : All insulators shall be packed in crates or boxes suitable for rough handling. Packing shall be marked with the strength and voltage rating. Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 19

GUARANTEED TECHNICAL PARTICULARS 11 KV PIN INSULATOR Sl. No. Description Specific Requirement Bidders offer Name of Manufacturer. & Address Location of type testing Applicable standard To be specified by the bidder To be specified by the bidder IS: 731,IS 3188 or the latest version 1 Normal working voltage 11 Kv (rms) 2 High system voltage. 12 Kv (rms) 3 Visible Discharge voltage dry PF. 9 Kv (rms) 4 1 Minute withstand voltage wet PF. 65 Kv (rms) 5 1 Minute withstand voltage... 35 Kv (rms) 6 PF puncture withstand voltage. 110 Kv (rms) 7 Impulse withstand voltage : 8 Impulse flashover voltage : (+ ve) 80 Kv peak (- ve) 80 Kv peak (+ ve) 90 Kv peak (- ve) 120 Kv peak 9 Minimum failing load. 5 KN. 10 Minimum creepage distance. 240 mm. 11 Colour of glaze. Brown. 12 Weight per unit. 1.4 Kg. (Apprx.) 13 Size of insulator. (Height) 125 mm. (Diameter) 125 mm. 14 Material of thimble. Lead. 15 Steel head. Small head. 16 Standard. IS : 731/1971. 17 Tolerance. Tolerance will be allowed as per IS : 731/1971 or latest amendments if any. 18 Drawing To be submitted 19 Conforming standard As per IS NB- Every insulator should bear the marking of manufacturer s name & Purchaser s name and ISI mark. Name & Signature of Bidder with seal Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 20

TECHNICAL SPECIFICATION OF 33KV STAY INSULATOR TECHNICAL SPECIFICATION OF HT GUY STRAIN INSULATORS (STAY INSULATORS) 1. SCOPE: The specification covers porcelain guy strain insulators for use in HT distribution system. 1. APPLICABLE STANDARDS: Except when they conflict with the specific requirements of this specification, the insulators shall comply with IS: 5300-1969 or the latest version thereof. 3.GENERAL REQUIREMENTS: The porcelain shall be sound, free from defects, thoroughly vitrified and smoothly glazed. The design of the insulators shall be such that the stresses due to expansion and contraction in any part of the insulator shall not lead to its deterioration. The glaze shall be brown in color for insulators. The glaze shall cover the entire porcelain surface parts except those areas that serve as supports during firing. 4. SYSTEM CONDITIONS: HT Frequency : 50 Hz Nominal System Voltage : 33 KV Maximum System Voltage HT System : 36 KV Power frequency one minute withstand (Dry) : 75KV (rms) Power frequency one minute withstand (wet) : 45KV(rms) Neutral Earthing arrangement LT System 5. TYPE OF INSULATORS: : Solidly Earthed Solidly Earthed The standard guy strain insulators shall be of designation as per IS: 5300/1969 or its latest revision. The recommended type of guy strain insulators for use on guy wires of 33KV overhead line. 6. TESTS: 6.1 Type tests: a) Visual examination b) Verification of dimensions c) Temperature cycle test d) Dry one minute power frequency withstand test e) Wet one minute power frequency withstand test f) Mechanical strength test g) Porosity test 6.2 Acceptance test: The insulators, after having withstood the routine test shall be subjected to the Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 21

following acceptance tests in the order given below: a) Verification of Dimensions. b) Temperature cycle test c) Mechanical strength test d) Porosity test 6.3 Routine tests: i) Visual examination 7. TESTING FACILITIES: a. The Bidder must clearly indicate what testing facilities are available in the works of the manufacturer and whether the facilities, are adequate to carry out all the routine as well as type tests. These facilities should be made available to Purchaser s Engineers if deputed to carry out or witness the tests. If any tests cannot be carried out at the manufacturer s works, the reasons should be clearly stated in the tender. b. The Bidder shall furnish detailed type test reports of the offered HT Stay Insulators as per clause 6.1 of this specification. All the above TypeTests shall be carried out at laboratories, which are accredited, by the National Accreditation Board of Testing and Calibration Laboratories(NABL) of Government of India to prove that the 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. c. There offered HT Stay Insulators are already fully Type Tested at Laboratories accredited by the National Accreditation Board of Testing and Calibration Laboratories (NABL) within five years prior to the date of opening of the tender. 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. MARKING: a. Each insulator shall be legibly and indelibly marked to show the following: i) Name of the Purchaser : NESCO Utility ii) Name or trade mark of the manufacturer iii) Year of manufacturer iv) ISI certificate, mark, if any b. Marking on porcelain shall be applied before firing. 10. Packing : All insulators shall be packed in crates or boxes suitable for rough handling. Packing shall be marked with the strength and voltage rating. Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 22

33KV STAY INSULATOR GURANTEED TECHNICAL PARTICULARS (To be submitted along with Bidder s offer) Sl. no. Description Unit 33KV Stay Insulator 1 Manufacturer s name 2 Address of manufacturer 3 Location of type testing 4 Applicable standard & Type 5 Type of insulator (Porcelain or toughened glass) 6 Dry impulse withstand voltage 7 Wet power frequency, 1 minute, withstand voltage 8 Dry, Critical Impulse Flashover Voltage 9 Dry, power frequency, Critical Flashover Voltage 10 Wet, power frequency, Critical Flashover Voltage 11 Power frequency Puncture Voltage 12 Safe Working Load 13 Minimum Failing Load 14 Creepage Distance 15 Protected Creepage Distance 16 Type and Grade of Materials : Insulator 17 Colour of Insulator 18 Weight of Insulator 19 Number of Insulators per Crate 20 Type of semi conducting Glaze 21 Minimum dia of Stay wire hole 22 Whether drawing showing dimensional details have been furnished along with Bid 23 Whether Type Test Certificate have been furnished 24 Other particulars (if any) Name & Signature of Bidder with seal Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 23

33 KV F Clamp/ Pole top Bracket (GI) : 33 KV line pole top bracket made out of 65 mm long 100x50x6 mm M.S channel welded with 65x65x6 mm M.S Angle & hot dip galvanize as per IS-2633/1972.(Latest Amendment), confirming to REC Construction Standard.M-4 & drawing. GUARANTEED TECHNICAL PARTICULARS FOR 11KV POLE TOP BRACKET Sl.No. Constructional Features Specified Bidders Offer 1. Material used 65x65x6 mm MS Angle & 100x50x6 mm MS Channel 2. Overall height 380 mm 3. Flange Width (one welded & 65 mm 4. Spacing between two flanges 100mm 5. Spacing of 2 nos of 18 mm holes for fixing on pole top 6. C/L Distance of 2nos of 25mm holes on top flanges of the bracket 100mm 40mm from edge of the flange 7. Galvanization Hot dip 8. ISS 2062,2633 9. Drawing enclosed Name & Signature of Bidder with seal Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 24

33 KV GI Pin : 33 KV GI Pin conforming to IS 2486 (part II)/74 and suitable for 33 KV Pin Insulator having stalk length of 300 mm & shank length 150 mm with minimum failing load of 10 KN & provision of double nuts & a spring washer. The threading shall good finish & with standard galvanization. GUARANTEED TECHNICAL PARTICULARS FOR 33KV G.I PIN Sl no. Description Specified Bidder s Offer 1 Manufacture Name & Address 2 Standard applicable specification IS 2486 3 Minimum failing load 10KN 4 Dimensions (mm) a) Length 450mm b) Shank length 150mm c) Stalk length 300mm 5 Type of Threads 6 Threads per inch 8-9 threads per inch 7 Type of galvanization of pin & nuts Hot Dip 8 Mass of Zinc (minimum) 690 gm/m2 9 Applicable specification IS 2633 10 No. of Nuts with each pin & its size To be submitted 11 No. of spring washer with each pin & its size by the bidder To be submitted by the bidder 12 Packing Details a) Type of packing Heasian Bag b) Weight of each pin approx.(with nut & washers) c) No. of pins in each packing (Kg) 15 Pcs 13 Tolerance in weight ±3% 14 I.S.I Certificate License number 16 Manufacture's Trade mark with each GI Pins 17 Drawing & Sample To be submitted by bidder Name & Signature of Bidder with seal Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 25

40mm dia GI Earthing Device: 1. Scope :- This specification provides for design, manufacturing, testing before dispatch, supply & delivery of Earthing Device (Heavy Duty) (for use in Sub-station earthing). 2. APPLICABLE STANDARDS :- The Earthing Device must be made out of 40 mm nominal Bore & 3.2 mm (Medium Gauge- No minus Tolerance allowed) wall thickness Hot Dip G.I. Pipe (as per IS ;- 1239,m Part-1, 1990 & REC construction Standard J-2), ISI marked of reputed Make & 2.5 mtrs length tapered finished smooth at one end for a length of 75 mm & Clamp at the other end. Staggered drills hole of 12 mm Dia of interval of 150mm shall be made before galvanization. The GI Earthing Clamp/ Strip (C- Clamp Type) is to be of 50mm width, 6mm thickness & flange length of 65 mm in each side. This should be suitable for termination of 4 nos of GI Flat earth electrodes. The Clamp/ Strip & Earthing pipe after fabrication will be hot dip galvanized confirming to IS: 2629/85 with latest amendments. The clamp shall have two holes in both sides suitable for 5/8 x 2 Bolt & provided with two GI bolts& Nuts in each side of 12mm dia 50mm long half threaded with spring washer as per IS: 3043/1982.The galvanization tests are to be conducted as per IS: 2633/72 & IS: 6745/72 & its latest amendments. Guaranteed Technical Particulars of Earthing Device (To be submitted along with Offer) Par 1. Location of Factory or Place of Manufacture 2. Maker s Name, Address & Country 3. Size of a b Pipe Earthing Strips 4. Length 5. Thickness of Pipe 6. Galvanization Process 7. Galvanization thickness a b For Earthing device For Connecting Flat 8. Galavanization tests to be conducted as per ISS 9. Any other Particulars ( like details of Clamp/ G.I. Bolts) 10. Details of Drawings submitted Bidder s Offer Name & Signature of Bidder with seal Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 26

20mm HT GI Stay Set : 16mm LT Stay Set: TECHNICAL SPECIFICATION OF LT AND HT STAY SET SCOPE:This specification covers design, manufacture, testing and dispatch of LT Stay Sets of 16 mm and HT stay sets 20 mm dia. GENERAL REQUIREMENTS 16 mm Dia Stay sets (Galvanized) LT Stay Set This stay sets (Line Guy set) will consist of the following components:- Anchor Rod with one washer and Nut Overall length of rod should be 1800 mm to be made out of 16 mm dia GI Rod, one end threaded up to 40 mm length with a pitch of 5 threads per cm and provided with one square GI washer of size 40X40x1.6mm and one GI hexagonal nut conforming to IS:1367:1967 & IS:1363:1967. Both washer and nut to suit threaded rod of 16 mm dia. The other end of the rod to be made into a round eye having an inner dia of 40mm with best quality welding. Anchor Plate Size 200 x 200 x6 mm To be made out of GI plate of 6 mm thickness. The anchor plate should have at its centre 18 mm dia hole. Turn Buckle & Eye Bolt with 2 Nuts To be made of 16 mm dia GI Rod having an overall length of 450mm, one end of the rod to be threaded up to 300 mm length with a pitch of 5 threads per cm and provided with two GI Hexagonal nuts of suitable size conforming tois:1363:1967 & IS:1367:1967. The other end of rod shall be rounded into a circular eye of 40mm inner dia with proper and good quality welding. Bow with Welded Angle To be made out of 16mm dia GI rod. The finished bow shall have an over all length of 995 mm and eight of 450 mm, the apex or top of the bow shall be bent at an angle of 10 R. The other end shall be welded with proper and good quality welding to a GI angle 180 mm long having a dimension of 50x50x6mm. The angle shall have 3 holes of 18 mm dia each. Thimble To be made on 1.5 mm thick GI sheet into a size of 75x22x40mm and shape as per standard shall be supplied. Average Weight of Finished 16mm Stay Sets shall be at least 7.702 KG (Minimum) (Excluding Nuts Thimbles and Washer) 8.445 Kg. (Maximum) Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 27

20 mm Dia Stays Sets for 33 Kv,11 KV Lines (Galvanized) HT Stay Set The Stay Set (Line Guy Set) will consist of the following components: Anchor Rod with one Washer and Nut Overall length of Rod should be 1800mm to be made out of 20 mm dia GI rod one end threaded up to 40 mm length with a pitch of threads per cm. And provided with one square G.I Washer of Size 50x50x1.6mm and one GI Hexagonal nut conforming to IS: 1363:1967 & IS:1367:1967. Both washer and nut to suit the threaded rod of 20mm. The other end of the rod to be made into a round eye having an inner dia of 40mm with best quality of welding. Dimensional and other details are indicated and submitted by bidders for owner s approval before start of manufacturing. Anchor Plate Size 300 x 300 x 8 mm To be made out of G.S. Plate of 8 mm thickness. The anchor plate to have at its centre 22mm dia hole. Turn Buckle, Eye Bolt with 2 Nuts. To be made of 20 mm dia G.I Rod having an overall length of 450 mm. One end of the rod to be threaded up to 300 mm length with a pitch of 4 threads per cm. The 20 mm dia bolt so made shall be provided with two G.I Hexagonal nuts of suitable size conforming to IS: 1363:1967 & IS: 1367:1967.The other end of the rod shall be rounded into a circular eye of 40mm inner dia with proper and good quality of welding. Welding details are to be indicated by the bidder separately for approval. Bow with Welded Channel: To be made out of 16mm dia G.I Rod. The finished bow shall have and overall length of 995 mm ad height of 450 mm. The apex or top of the bow shall be bent at an angle of 10R. he other end shall be welded with proper and good quality welding to a G.I Channel 200 mm long having a dimension of 100x50x4.7 mm. The Channel shall have 2 holes of 18 mm dia and 22 dia hole at its centre as per drawing No.3 enclosed herewith. Thimble 2 Nos. To be made of 1.5 mm thick G.Isheet into a size of 75x22x40mm and shape as per standard. Galvanizing The complete assembly shall be hot dip galvanized. Welding The minimum strength of welding provided on various components of 16mm and 20 mm dia stay sets shall be 3100 kg & 4900 kg respectively. Minimum 6mm filet weld or its equivalent weld area should be deposited in all positions of the job i.e. at any point of the weld length. The welding shall be conforming to relevant IS: 823/1964 or its latest amendment. Threading The threads on the Anchor Rods, Eye Bolts and Nuts shall be as per specification IS;4218:1967 (ISO Metric Screw Threads). The Nuts shall be conforming to the requirements of IS: 1367:1967 and have dimension as per IS 1363:1967. The mechanical property requirement of fasteners Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 28

shall confirm to the properly clause 4.6 each for anchor rods and Eye bolt and property clause 4 for nuts as per IS: 1367:1967.Average weight of finished 20 mm Stays Set: 14.523 Kg.(Min) (Excluding Nuts Thimble & Washer) :15.569 Kg.(Max.) TESTS The contractor shall be required to conduct testing of materials at Govt./Recognized testing laboratory during pre-dispatch inspection for Tensile Load of 3100 Kg/4900Kg. applied for one minute on the welding and maintained for one minute for 16 mm and 20mm dia stay sets respectively. IDENTIFICATION MARK All stay sets should carry the identification mark of the Purchaser (NESCO) applicable. This should be engraved on the body of stay rods to ensure proper identification of the materials. The nuts should be of a size compatible with threaded portion of rods and there should be not play or slippage of nuts. Welding wherever required should be perfect and should not give way after erection. TOLERANCES The tolerances for various components of the stay sets are indicated below subject to the condition that the average weight of finished stay sets of 16mm dia excluding nuts, thimbles and washers shall not be less than the weight specified above. GURANTEED TECHNICAL PARTICULARS (To be submitted along with Offer) Sl No. Item Description Specified Parameters Bidder s Offer Section Fabrication Material Tolerances Tolerances 1 Anchor Plate 6mm thick +2.5%- 5% 8mm thick +2.5%-5% 200x200mm+1% 300x300mm+1% GI Plate 6 mm thick GI Plate 8 mm thick LT Stay Set HT Stay Set 2 Anchor Rod 16mm dia +5%-3% Length 1800mm+0.5% Rounded Eye 40 mm inside dia + 3% Threading 40mm+11%-5% GI Round 16mm dia GI Round 16mm dia LT Stay Set 20mm dia +3%- 2% Length 1800mm+0.5% Round Eye 40mm inside dia +3%. GI Round 20mm dai GI Round 20mm dia HT Stay Set Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 29

3 Turn Buckle Bow 16mm dia +5%-3% Threading 40mm+11%-5% Length 995mm+1% 16mm dia Length180mm+1% 50x50x6mm GI Round 16mm dia. GI Angle LT Stay Set 4 Eye Bolt Rod 20mm dia +3%- 2% 16mm dia +5%-3% 20mm dia +3% - 2% Channel length 200mm + 1% 100x50x4.7m m Length 450mm + 1% Threading 300mm+1% Round Eye 40mm inside dia +3% Length450mm +1% Threading 300mm+1% Round Eye 40mm inside dia +3% G I Channel GI Round 16 mm dia GI Round 20mm dia. HT Stay Set LT Stay Set HT Stay Set 5 Galvanisation thickness a Anchor Plate b Anchor Rod c TurnBuckle Bow d Eye Bolt Rod All galvanization shall be carried out in accordance with IS: 2629. The weight of Zinc deposited shall be in accordance with IS: 2629 and shall not less than 0.61 kg/m² with a minimum thickness of 86 microns for items of thickness more than 5 mm, 0.46kg/m²(64 microns) for items of thickness between 2 mm & 5 mm& 0.33kg/m²(47 microns) for items less than 2 mm thickness. 6 Thimble 2 nos. to be made of 1.5 mm thick G.S Sheet into a size 75x22x40 mm & shape as per standard. 7 One G.S Hexagonal Nut confirming to IS:1363 & 1367 with one square washer of size 50x50x6 mm (G.S) along with Anchor Rod. 8 Two G.S Hexagonal Nuts of suitable size along with Eye Bolt Rod. Name & Signature of the bidder with seal Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 30

7/8 GI Stay Wire : 7/12 GI Stay Wire : TECHNICAL SPECIFICATIONS 7/8 SWG and 7/12 SWG STAY WIRE) 1. Application Standards Except when they conflict with the specific requirements of this specification, the G.I Stay Stranded Wires shall comply with the specific requirements of IS: 2141-1979. IS: 4826-1979 & IS: 6594-1974 or the latest versions thereof. 2. Application and Sizes a) The G.I. stranded wires covered in this Specification are intended for use on the overhead power line poles, distribution transformer structures etc. b) The G.I stranded wires shall be of 7/8 SWG( 7/4.0 mm for 33KV lines) and 7/12 SWG (7/2.5 mm for LT lines) standard sizes. 3. Materials The wires shall be drawn from steel made by the open hearth basic oxygen or electric furnace process and of such quality that when drawn to the size of wire specified and coated with zinc, the finished strand and the individual wires shall be of uniform quality and have the properties and characteristics as specified in this specification. The wires shall not contain sulphur and phosphorus exceeding 0.060% each. 3.1 Tensile Grade The wires shall be of tensile grade 4, having minimum tensile strength of 700 N/mm² conforming to 1S:2141. 3.2 General Requirements a) The outer wire of strands shall have a right-hand lay. b) The lay length of wire strands shall be 12 to 19 times the strand diameter. 3.3 Minimum Breaking Load & Galvanising The minimum breaking load of the wires before and after stranding shall be as follows: Min. breaking load of the No. of Wires & Const. Wire Dia (mm) Single wire before stranding (KN) Min. breaking load of the standard wire (KN) 7 (6/1) 2.5 3.44 21.40 7 (6/1) 3.15 5.46 34.00 7 (6/1) 4.0 8.80 54.90 Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 31

Minimum weight of zinc coating before stranding Minimum weight of zinc coating before stranding 490 gm/mm2 490 gm/mm2 490 gm/mm2 475 gm/mm2 475 gm/mm2 475 gm/mm2 4. Construction a) The galvanized stay wire shall be of 7-wire construction. The wires shall be so stranded together that when an evenly distributed pull is applied at the ends of completed strand, each wire shall take an equal share of the pull. b) Joints are permitted in the individual wires during stranding but such joints shall not be less than 15 metres apart in the finished strands. c) The wire shall be circular and free from scale, irregularities, imperfection, flaws, splits and other defects. 5. Tolerances A tolerance of (+) 2.5% on the diameter of wires before stranding shall be permitted. 6. Sampling Criteria The sampling criteria shall be in accordance with IS :2141. 7. Tests on Wires before Manufacture i) The wires shall be subjected to the following tests in accordance with IS :2141. a) Ductility Test b) Tolerance on Wire Diameter ii) Tests on Completed Strand The completed strand shall be tested for the following tests in accordance with IS:2141. a) Tensile and Elongation Test: The percentage elongation of the stranded wire shall not be less than 6%. b) Chemical analysis c) Galvanizing Test The Zinc Coating shall conform to "Heavy Coating" as laid down in 1S:4826 8. Marking Each coil shall carry a metallic tag, securely attached to the inner part of the coil bearing the following information: a) Manufacturers name or trade mark b) Lot number and coil number c) Size d) Construction e) Tensile Designation f) Lay g) Coating h) Length i) Mass Tech. Specification of TN No. NESCO Utility/MR Materials/18/26.11.16 Page 32