1. Round aluminum rods should be inspected for roundness, and for defects such as folded edges, misalignment, cracks, inclusions, kinks, and severe mechanical damage such as blemishes, pits, peeling, burrs, and corrosion spots.
2. Inspect the surface of round copper wire for smoothness, free from triangular cuts, burrs, cracks, folds, inclusions, severe blemishes, pitting, and corrosion spots caused by mechanical damage. It's worth noting the degree of oxidation; a golden yellow color is normal, light red indicates slight oxidation, and a deep red or blue surface indicates severe oxidation. Any wire with severe oxidation should be rejected. Aluminum wire is more prone to defects during manufacturing and should be strictly controlled when used for overhead power lines.
3. The conductors on the surface of the aluminum stranded wire should be tightly and neatly twisted, without any looseness, twists, jumps, bulges, or breaks. Furthermore, the welded joints of single wires should be rounded and require anti-corrosion treatment. The increased portion at the joint should generally not exceed twice the diameter tolerance. The distance between two welded joints of a single wire must also meet the standard: no less than 15 meters between two welded joints of the same single wire; and no less than 5 meters between two welded joints of different single wires on the same layer, and no less than 15 meters for the inner layer and the outer layer. Welding is not allowed when the copper core is a single copper wire.
