TECHNICAL SPECIFICATION FOR ACSR CONDUCTORS

1.00 This section of the specification covers manufacture, testing at manufacturers

works and supply of ACSR conductors indicated in the schedule of

requirement.

2.0 The basic technical and other. Particulars of the equipment and the various

components are specified in the following sections and tender schedule.

3.0 ACSR CONDUCTOR: The conductor shall comply in all respects with the

latest edition of ISS-398 (Part-II) 1976 with its latest amendment.

a) The aluminium strands shall be hard drawn from electrolytic aluminium rods

of EC grade having purity not less than 99.5% and a copper content not

exceeding 0.04%. They shall have the same properties and characteristics as

prescribed in IEC:889-1987. The Aluminium wires used in the manufacture of

the conductor shall be of the highest electrical quality and free from

scratches, die marks and other surface imperfections.

b) They shall be reinforced with a central core of galvanized steel wire drawn from

high carbon steel wire rods produced by either the acid or the basic open-hearth

process, or the electric furnace process, or the basic oxygen process and shall

conform to the following requirements as to the chemical composition as

prescribed in

IS 398 (Pt. II) – 1996:

Element % Composition

Carbon 0.50 to 0.85

Manganese 0.50 to 1.10

Phosphorous Not more than 0.035

Sulphur Not more than 0.045

Silicon 0.10 to 0.35

The steel wire shall not be subject to any heat treatment after being galvanized.

The zinc coating of steel wires shall be smooth and of uniform thickness. There

shall be no bare spots owing to adherence of scales or other causes.

4.0 JOINTS IN WIRES: Joints in the individual Aluminium, wires are permitted but

no two such joints shall be within 15 meters apart in the complete stranded

conductors. There should be no joints in the galvanized steel wire except

those made in the base rod or wire before final drawing forming the core of

steel reinforced Aluminium.

5.0 The resistance of the individual Aluminium wire shall be determined

separately before stranding by means of standard tests on sample wires. The

test samples shall be of sufficient length to give an accuracy of atleast one

part in a thousand.

6.0 The ACSR conductor size and standard lengths shall be as per IS 398 (Part-II)

1976 with its latest amendments and is indicated in the schedule of material

specification.

7.0 STANDARD SIZES OF WIRES: The Aluminium wire and galvanized steel wire

for the standard construction of conductors have diameter specified as shown

below,as per Tables 1&2 Section of IS 398 (Part-II).

TABLE-1: Aluminium Wire used in the construction of Aluminium Conductors Galvanized Steel Reinforced.

Diameter in mm Cross Sectional area of nominal dia wire

Mass Resistance at 200 C max/Km.

Breaking load Nominal

Minimum

Maximum

Before stranding

After stranding

2.59 2.56 2.62 5.269 mm2

14.24 Kg/Km

5.527 0.89 KN 0.85 KN

3.35 3.32 3.38 8.814 mm2

23.82 Kg/Km.

3.286 1.43 KN 1.36 KN

TABLE-2: Steel wire used in the construction of Aluminium conductors galvanized steel reinforced.

Diameter in mm Cross Sectional area of nominal dia wire

Mass Resistance at 200 C max/Km.

Breaking load Nominal

Minimum

Maximum

Before stranding

After stranding

2.59 2.54 2.64 5.269 mm2

41.09 Kgs/Km

- 6.92 KN 6.57 KN

3.35 3.28 3.42 8.814 mm2

68.75 Kgs/Km

- 11.58 KN 11.0 KN

8.0 LAY RATIO: Ratio of the axial length of a complete turn of the helix formed

by the individual wire in a standard conductor to the external diameter of the

helix.

The lay ratio shall be as shown below.

TABLE-3: Lay Ratios of Aluminium Conductor, Galvanized Steel Reinforced.

Number of Wires Ratio of Aluminium wire dia to

Steel wire dia

Lay ratio for steel core Lay ratio for Alumini-um outside layer

Aluminium Steel Minimum Maximum Minimum Maximum

6 1 1.00 - - 10 14

Note: For the purpose of calculation, the mean lay ratio shall be taken as the

arithmetic mean of the relevant minimum and maximum values given

in this table.

9.0 TESTS & INSPECTION OF RAW MATERIAL AT SUPPLIER’S WORKS :

Within two weeks of receipt of each consignment of raw materials viz., steel,

Electrolytic Aluminium rods, etc., at the manufacturers works, the contractor

shall furnish to the purchaser in triplicate the raw material manufacturers

certificates.

10.0 The test certificates shall cover all tests on required number of samples as

stipulated in clause 12.1 of ISS. (Part-II) 1976 with latest amendments if any.

10.1 The manufacturer shall not commence manufacturing the conductor ordered

prior to purchaser’s approval of the test certificate for raw materials.

10.2 Similarly test certificates in triplicate for tests on the finished ACSR conductor

shall be submitted. The suppliers shall furnish along with RCs, the number of

pieces of conductor in each reel and the length of individual pieces.

10.3 All tests as detailed in clause 12 of ISS-398 (Part-II) 1976 with its latest

amendments shall be carried out on conductors covered by this specification

and shall be submitted by the contractor for purchasers approval within four

weeks of the acceptance of the letter of intent of the purchaser. No change in

the schedule of tests, unless desired by the purchaser shall be subsequently

made by the contractor or his sub-contractors of the manufacturers without

prior – consent of the purchaser.

10.4 The purchaser may at any time call for any tests that are laid down in the

specification as optional tests. The contractor shall arrange to carry out such

tests expeditiously and it his own cost. The certificates for such optional tests

shall be submitted to the purchaser for approval.

10.5 The contractor shall notify the purchaser, at least fifteen days in advance, the

time of manufacture so that inspection of materials during manufacture and

or witnessing of the tests can be arranged. If the purchaser waives inspection

he will advice the contractor accordingly. Inspection shall also include method

of packing and stacking of finished materials in the works.

11.0 Packing: Drawing of the reels/drums shall be enclosed with tenders. The

ACSR conductor reels shall be of dimensions approved by the purchaser and

made of seasoned wood sufficient strong and in sound condition to ensure

that the reels shall reach the site intact with lagging end free from damage

due to transport hazards by rail and over land. These reels shall conform to IS

1778/1961 with latest – amendments if any.

a) The standard length of the ACSR conductor shall be as per schedule of

materials specification. Longer lengths are acceptable. However, short

lengths not less than one Km. each are acceptable to the minimum extent

of 5% of the quantity ordered.

b) The contractor shall submit in duplicate detailed packing specification for

the conductors for the purchasers approval at least fifteen days prior to

commencement of dispatch. Finally approved specification shall be

furnished along with the dispatch documents.

REEL OR DRUM SHALL BEAR THE FOLLOWING INFORMATION

a) Reel or drum number

b) Size and description of contents

c) Length of each piece of conductor (on reels)

d) No. of pieces in each package/reel

e) Gross weight

f) Net weight

g) Purchase order No. & Date

h) Place and designation of consignee

The above details shall be legibly and indelibly marked.

SCHEDULE OF MATERIAL SPECIFICATION FOR WEASEL AND RABBIT

ACSR CONDUCTORS:

Code Name of

Conductor

Nominal Aluminium

area

Dia of wires in mm Appx. Calculat

ed breaking load in KN

Appx. Over all dia (mm)

Standard length in

Mtrs.

App.Mass Kg./Km.

Aluminium Steel

Weasel 30 Sq.mm. 6/2.59 1/2.59 11.12 7.77 2000 127.7

Rabbit 50 Sq.mm. 6/3.35 1/3.35 18.25 10.05 1400 213.6

12.0 Quantity tolerance ± 5% tolerance shall be allowed on the ordered quantity

on each category of ACSR separately.

2.1 Details of conductor :

2.1.1 The contractor shall conform to IS : 398 (part – V) – 1982 except where other wise specified herein.

2.7.6 The details of the conductor are tabulated below :

Drake Lynx Coyote Rabbita) Stranding & wire diameter

26/4.442 mm Al + 7.3.454 mm steel

.. 30/7.29 mm + 7/7.29 mm steel

26/2.54 mm Al + 7/1.91 mm steel

6/3.35 mm All + 1/3.3.5 mm steel

b) Sectional area of Aluminum

402.9 mm sq. 183.4 mm sq. 131.7 mm sq. 52.9

c) Total sectional area

468.4 mm sq. - - -

d) Overall diameter

28.13 mm 19.53 15.89 10.0…

e) Approximate weight

1622 kg/km 844 kg/km 521 214

f) Calculated DC resistance at 20 deg. C

0.0715 ohm/km

0.1610 ohm/km

0.2246 ohm/km

0.5524 ohm/km

g) Minimum UTS

141.75 KN - - -

2.8 WORKMANSHIP

3.1.2 The finished conductor shall be smooth, compact from uniform and free from all imperfections including spills, die marks, scratches, abrasions, scuff marks, kinks (protrusion of wires), dents, press marks, cut marks, wire cross over, over riding, looseness (wire being dislocated by finger/hand pressure and/or unusual bangle noise on tapping), material inclusions, while rust powder formation or black spots (on account of erection with trapped rain water etc.,) dirt, grit etc.,

3.1.3 All the aluminum and steel strands shall be smooth, uniform and free from all innerfections such as spills and splits, die marks, scratches abrasions and kinks after drawing.

3.1.4 The steel strands shall be hot dip galvanized and shall have a minimum zinc coating of 260 gm/sq. mm after stranding of the uncoated wire surface. The zinc coating shall be smooth, continuous and of uniform thickness, free from imperfection and shall with stand minimum three dips after stranding in standard prerce test. The finished stands and the individual wire shall be of uniform quality and have the same property and the characteristics as prescribed in ASTM designation : B498-74 and relevant IS.

3.1.5 The steel strands shall be preformed and post formed in order to prevent the spreading of the strands in the event of cutting of composite core wire. Care shall be taken to avoid damage to galvanization during performing and post forming operation.

3.2 Joints in wires

3.2.2 Aluminum wires No joints shall be permitted in the individual wire in the outermost layer of a finished conductor. However joints in the 12 wire and 18 wire inner layers of the conductor shall be allowed but these joints shall be made by cold pressure but twelding shall and be such that no such joints are within 15 Mtr. of each other in the complete stranded conductor.

3.2.3 Steel wire There shall be no joints of any kind in the finished wire entering into the manufacture of the strand. There shall also be no strand splices in any length of the completed stranded steel core of the conductor.

3.3 Tolerance The manufacturing tolerance tot eh extent of the following limits only shall be permitted in the diameter of individual aluminum and steel strands and lay-ratio of the conductor :

3 Diameter of Aluminum and steel strands :Standard Maximum Minimum

Aluminum 3.53 mm 3.55 mm 3,51 mmSteel 3.53 mm 3.50 mm 3.46 mm

4 Lay ratio of conductor : Maximum Minimum

Steel 7 wire layer 18 16

Aluminum 12 wire layer 14 1218 wire layer 13 1126 wire layer 12 10

3.4 Materials

3.4.2 Aluminum The aluminum strands shall be hard drawn from electrolytic aluminum rods having purity not less than 99.5% and a copper content not exceeding 0.01%

3.4.3 Steel The steel wire strands shall be drawn from high carbon steel wire rods and shall conform to the following chemical composition :

Element : % compositionCarbon : 0.50 to 0.85 Manganese : 0.50 to 1.10Phosphorous : not more than 0.035Sulphur : not more than 0.045Silicon : 0.10 to 0.35

3.4.4 Zinc :The zinc used for galvanizing shall be electrolytic high grades zinc of 99.95% purity. It shall conform to and satisfy all the requirements of IS 209 -1979.

3.5 Standard length :

3.5.2 The conductor shall be supplied in standard length of 1500 – 1800 meters as required. No joint shall be allowed within a single span of stringing.

3.6 Tests :

3.6.2 The following type acceptance & routine tests and tests during manufacturing shall be carried out On the conductor.

3.6.3 Type testsThe following type tests shall be conducted on samples of connection. The testing charges for the type test shall be charged separately in the prescribed schedule of the Bid.

UTS test on stranded Conductor The no of sample shall be mutually agreed between contractor and owner b)DC resistance test on standard conductor As per Annexure – A.

3.6.4 Acceptance Tests

a) Visual check, for joints ) scratches etc., and length of ) As per Annexure - Aconductor )

b) Dimension checks on steel )

and Aluminum strands )

c) Check for lay ratios of )various layers ) -do-

d) Galvanizing test on steel )strands )

e) Torsion and Elongation )test on steel strands )

f) Breaking load test on steel )and aluminum )

g) Wrap test on steel ) IS : 398 (part V) 1982 aluminum strands ) clause 12.5.2, 12.7 &

12.8

h) DC resistance test )aluminum strands )

i) UTS test on welded joints )of aluminum strands ) As per Annexure – A.

NOTE : All the above tests except test mentioned at (i) shall be carried out on Aluminum and steel strands after stranding only.

3.6.5 Routine Tests :

a) Check to ensure that the joints are as per specification.

b) Check that there are no cuts, fins etc., on the strands.

c) All acceptance test as mentioned in clause 2.7.3 above to be carried on each coil.

2.7.5 Tests during manufacture

a) Chemical analysis of zinc )used for galvanizing )

b) Chemical analysis of )aluminum used for making ) As per Annexure – A.Aluminum strands. )

c) Chemical analysis of steel )& used for making steel strands )

i. Sample batch for type testing

The contractor shall offer material fro selection of sample For type testing. Only after getting quality assurance plans from owners quality assurance dept The samples shall be manufactured strictly in accordance with the quality assurance plan approved by owner.

TECHNICAL DATA SHEET FOR ACSR CONDUCTOR

Name of the Supplier  1 Code Word  

2

Maker’s Name, Address & Country  a)     Aluminium rods  b)     Stele wire/rods  c)      Complete Conductor  

3Stranding and Wire Diameter (mm)  a)     Aluminium  b)     Steel  

4 Nominal Aluminium area in Sq.mm.  

5Sectional Area of Aluminium Strands in Sq.m.m.

 

6 Total Sectional area in Sq.mm.  

7

Cross sectional area of nominal diameter wire in Sq.mm.

 

a) Aluminium wire  b) Steel Wire  

8 Overall diameter of conductor in mm.

 

9 Breaking load of conductor in Kg.  

10Minimum breaking load in Kg. for  a) Aluminium wire  b) Steel Wire  

11

Zinc coating of steel wire  a)     Uniformity of coating No. and duration of dips (Process test with stood I min. X Nos.)

 

b)     Minimum weight of coating (grm./Sq.mm.)

 

12

Mass in Kg. per Km.  a) Aluminium wire  b) Steel Wire  c) Conductor  

13

Resistance in Ohms per Km. at 20 Deg.C.

 

a)     Continuous maximum current rating of conductor (Amps) in still air or 45 Deg.C ambient temperature.

 

b)     Temperature rise for the above current Deg. C.

 

14 Purity of Aluminium Rods  

15Maximum working tension for complete conductor Kg.

 

16

Modulus of Elasticity (Kg/mm2)  

a) Aluminium  b) Steel  c) Conductor  

17Co-efficient of linear expansion per degree

 

a) Aluminium  

b) Steel  c) Conductor  

18 Standard length of each piece in Km.  19 Tolerance, if any on standard length  20 No. of standard lengths in one reel  

21Approximate dimensions of the reel in Cms.

 

22Mass of the conductor in one reel in Kg.

 

23Gross mass of the reel including mass of the conductor.

 

24 Mass of the reel in Kg.  

25Standard according to which the conductor will be manufactured and tested.

 

26Date of commencement of production of conductor.

 

27Other Particulars  

Signature of Vendor with Seal, Name and Address