Technical guidelines for hard aluminum wire for overhead strands

[Chinese aluminum industry network] This specification is based on the "hard aluminum wire for overhead strands (GB/T17048-2009)" standard.

1 Scope This specification specifies the requirements, test methods, inspection rules, packaging, marking, storage and transportation of materials for the procurement of "hard aluminum wires for overhead stranded wires".

2 Reference standard GB/T3048.2-2007 Test methods for electrical properties of wire and cable - Part 2: Tests for resistivity of metallic materials (IEC 60498: 1974, MOD)

GB/T4909.3 Test methods for bare wires Part 3: Tensile tests GB/T4909.7 Test methods for bare wires Part 7: Winding tests 3 For calculation of hard aluminum lines For numerical calculations, use the following values for hard aluminum lines:

Resistivity at 20°C, Larger (nΩ·m) 28.264 (equivalent to 61.0% IACS)

Density at 20°C (kg/dm3) 2.703

Linear expansion coefficient (1/°C) 23310-6

Temperature coefficient of resistance at 20°C (1/°C) 0.00403

4 Requirements 4.1 Material The hard aluminum wire shall be made of aluminium of the required purity in order to achieve the mechanical and electrical properties specified in this standard. The content of aluminum should not be less than 99.5%.

4.2 Diameter and diameter tolerance The nominal diameter of the hard aluminum wire, in millimeters, accurate to two decimal places.

The difference between each measured value of the hard aluminum wire diameter and the nominal value shall not be greater than the corresponding value specified in Table 1.

Table 1 Diameter and diameter tolerance of hard aluminum wire nominal diameter d

Tolerance d≤3.00

±0.03

d>3.00

+1%d

In order to check whether the diameter of the hard aluminum wire meets the above requirements, the diameter should be measured twice in the same cross-section and perpendicular to each other.

4.3 Couplings Hard aluminum wire is permitted to be fitted before being drawn later. However, if all of the following conditions are met, the finished hard aluminum wire also allows a connector:

a) A looped hard aluminum wire weighs 500kg or more;

b) no more than one joint in the looped hard aluminum wire;

c) The number of turns of such a looped hard aluminum wire containing a joint does not exceed 10% of the total number of turns;

d) When required by the user, the manufacturer shall provide proof that the tensile strength of the joint is not less than 130 MPa.

The finished finished hard aluminum wire with one joint should be clearly marked.

5 inspection rules