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| FAQs: Alumoweld & Copperweld |
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Below are the FAQs submitted by customers regarding the Alumoweld & Copperweld product line.
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Steel is sacrificial to copper. What happens when I cut the wire? Won’t this expose the steel? Will this allow the conductor to corrode?
–To answer, you first have to have some basic knowledge of how corrosion occurs between dissimilar metals. You must have an anode (steel), a cathode (copper), and an electrolyte (moisture). Because of the bond between the thick copper cladding and the steel core, no moisture can migrate into the interface between the cathodic material and the anodic material. This precludes corrosion from propagating further into the wire. Based on analysis of old buried wire samples, corrosion will only advance into the cut end a maximum distance of twice the diameter of the wire. At this depth a rust barrier is formed and effectively seals out the moisture. Without the electrolyte the corrosive action ceases. Also, when Copperweld is cut, the copper cladding cold flows to partially cover the cut end. This reduces the area of exposure of the steel.
We use a 4/0 19 strand copper wire in our substation. I would like to use Copperweld, but it looks like the fusing capacity is slightly lower than copper in the same size. Which product do I use?
–Copperweld’s fusing capacity may be slightly lower than copper in some size comparisons, but the diameter is usually larger. The larger diameter is important, in the fact that it provides more surface area for contact with the earth. This allows for quick dissipation of fault currents into the earth. Copperweld is much stronger than copper, and better suited to take the physical demands in a buried ground grid. The Copperweld alternates to 19 strand 4/0 copper are - 19 #9 DSA 40%, or 19 #8 DSA 30%. (Based on equivalent fusing capacity. See ED 1896)
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