PUBLICATION 440-1988

RURAL ELECTRIFICATION BOARD (REB)

PEOPLES REPUBLIC OF BANGLADESH

STANDARD FOR

SOFT ANNEALED STRANDED

IRON WIRE

 

 

 

1.     SCOPE

 

This standard establishes the physical and performance requirements of soft annealed stranded iron wire to be used as ground wires on the REB distribution system.

 

2.     GENERAL

 

Soft annealed stranded iron wire furnished to REB specifications shall conform to the physical and performance requirements of this specification. This wire shall consist of three strands concentrically twisted with a uniform pitch which is not less than 14 and does not exceed 20 times the nominal diameter of the wire.

 

3.     MATERIAL

 

The wire shall be made from iron obtained by either the open-hearth, basic–oxygen, or electric-furnace process, or from iron of such quality and purity that the wire strands shall have the properties described in ASTM A363-72. The wire shall be grade BB, and copper-bearing to meet the requirements of ASTM A111-66.

 

4.     GALVANIZING

 

The galvanizing coating on the iron ground wire strands shall be of zinc which complies with ASTM B6-77. The zinc coating weight shall be Class C.

 

5.     PHYSICAL CHARACTERISTICS

 

Iron wire used by REB shall have the physical characteristics presented below:

 

Nominal Wire Size (in.)	Number of Strands	Nominal Diameter of Coated Strands (in.)	Permitted Variation of Coated Strand Diameter (in.)	Class C Minimum Coating Weight oz/ft2	Weight of Wire (lb/1000 ft)	Maximum Resistance (ohm/1000 ft)
5/16	3	0.145	0.004	2.70	171	1.15

 

6.     FINISH

 

The surface of the iron wire shall be free from flaws and imperfections. The zinc coating shall be continuous and of uniform thickness.

 

7.     TESTS & INSPECTION

 

The breaking strength of the wire and the weight of the zinc coating shall be determined by the methods and procedures outlined in ASTM A111-66. The resistivity of the wire shall be determined by methods outlined in ASTM B193-78. The manufacturer shall conduct factory inspections and tests on the iron ground wire to certify that it does comply with the physical and performance requirements of this standard.  REB reserves the right to witness factory tests and inspection and shall request test reports. The manufacturer shall also conduct conductor reel tests and inspections and submit test reports before shipment to verify that the reels and  lagging comply with the requirements of this standard. REB shall also have the prerogative to inspect conductor reels at any time to insure compliance of this standard. Non-conforming reels and lagging are unacceptable.

 

8.     PACKING & SHIPPING

 

REB iron wire shall be shipped on non-returnable reels manufactured from "aluminum", "steel" or export quality preservative treated "Wood". All reels shall have preservative treated wood lagging. Wood reels and all lagging shall be constructed from new lumber which shall be square sawn, be of smooth surface, with no splits, warps, crooks, loose fibers, decay or insect infestation. The lumber used for wood reels and all lagging shall be preservative treated in accordance with "American wood preservers Associates standards" and as stipulated below:

 

Description              Requirements/Methods                                 AWPA Standards

 

Lumber:                     All softwood species                                           C1-82, C-2-83 and C16-82

 

Preservatives:            Acid Copper Chromate (ACC)                              P5-83, C1-82, C2-83

(any one)                   Ammoniacal Copper Arsenate (ACA)                    and C16-82         

                                 Chromated copper arsenate

                                 Type C (CCA-C)

 

Treatment:                 Pressure treatment after all                                 C1-82, C2-83 and C16-82

                                 carpentry works

 

Results of treatment: 

 

Penetration:                Minimum 0.4 inches from the                              C16-82

                                 surface of any face

 

Assay Zone:               0-0.6 inch. zone                                                 C16-82

 

Retention:                  0.62 pcf for ACC, 0.40 pcf for ACA                       C1-82, C2-83 and C16-82

                                 and CCA. Copper shall be calculated as CuO,

                                 Chromium as CrO3 and arsenic as AS2O5

 

Tests:                        1. Wet ash analysis for oxides                             A7-75, A2-85 section 2,5,6

                                 2. X-Ray                                                            A9-86

                                 3. Atomic Absorption                                          A7-75 and A11-83

 

A typical wooden reel and lagging are shown in Figures 1A and 1B and shall have the following dimensions:

                                           

Reel Designation	Dimensions, (Inches) cm
	Flange Diameter	Drum Diameter	Width		Arbor Hole Diameter
			Inside	Outside
NRX 22.12	(22) (55.88)	(12) (30.48)	(12) (30.48)	(15.5) (39.37)	(3) (7.62)

 

 

The nominal length and weight of REB iron wire shipped on NRX 22.12 reels is as follows:

 

REB Item No.	Weight (lb/mile) kg/km	Nominal Length (ft) m	Weight of Nominal Length (lb) kg
N-1	(903) 254	(1,800) 549	(308) 138

           

 

Each reel shall contain one length of iron wire. REB shall permit a variation in length of plus or minus five percent (±5%) of the nominal shipping length.

 

After the wire is wound on the reel, the top layer shall be covered by a sheet of poly-ethylene or similar plastic material. Paper liners and wrappings are prohibited.

 

The reel shall be prepared for shipping by:

 

1. Nailing one inch 2.54cm (1") lagging strips to the flanges using two (2) eight-penny (8d) nails at each end.
2. Binding the laggings circumferentially with at least four (4) 1.27cmx0.159cm (1/2"x1/16") galvanized steel straps (Figure 1B).
3. Metal tags shall be attached to the inside and outside of the reel containing the following information:
   1. Gross and net weights.
   2. Wire size, number of strands, type.
   3. Class of zinc coating.
   4. Actual length in meters.
   5. Catalog number.
   6. Manufacturers name and/or identification symbol.
   7. Shipping data.
   8. REB item number.

 

9.     OTHER STANDARDS

 

The physical and performance requirements of REB soft annealed stranded iron wire, based on other internationally recognized standards, are acceptable only if the requirements of such standards are equivalent to or exceed the requirements quoted in this document.

 

10.   BIBLIOGRAPHY OF REFERENCE STANDARDS [Latest Edition]

 

1.     ASTM A363-72: Standard Specification for Zinc–Coated (Galvanized) Steel Overhead Ground Wire Strand.

 

2.     ASTM A111-66: Standard Specification for Zinc–Coated (Galvanized) "Iron" Telephone and Telegraph Line Wire.

 

3.     ASTM B6-77: Standard Specification for Zinc (Slab Zinc).

 

4.     ASTM B193: Standard Test Method for Resistivity of Electrical Conductor Materials.

 

5.     AWPA C1: "Standards for Preservative Treatment by Pressure Process-All Timber Products".

 

6.     AWPA P5: "Standards for Water-Borne Preservatives".

 

7.     AWPA A2: "Standard Methods for Analysis of Water-Borne Preservatives and Fire Retardant Formulations".

 

8.     AWPA A7: "Wet Ashing Procedures for Preparing Wood for Chemical Analysis".

 

9.     AWPA A9: "Standard Method for Analysis of Treated Wood and Treating Solutions by Atomic Absorption Spectroscopy".

 

10.   AWPA A11: "Analysis of Treated Wood and Treating Solutions by Atomic Absorption Spectroscopy".

 

11.   AWPA C2: "Pressure Treatment By Pressure Process for Lumber, Timbers, Bridge Ties and Mine Ties".

 

12.   AWPA C16: "Preservative Treatment By Pressure Process for Wood Used on Farms".