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Its high strength, good conductivity, excellent corrosion resistance, and compatibility with solid aluminum wire make Alumoweld highly desirable as a reinforcing material for ACSR conductors (ACSR/AW). When substituted for existing reinforcing materials, it extends the life of the strength members to meet that of the more conductive members; while increasing electrical capacity and conductivity. Alumoweld is available to all ACSR manufacturers for use as the core strength member.
An Improved Conductor
A major improvement is built into any ACSR conductor when an Alumoweld core is used. The resulting conductor (ACSR/AW) has better corrosion resistance, lighter weight, and lower power losses than ACSR constructed with galvanized or aluminized steel core. These benefits have led many utilities to select ACSR/AW for both distribution and transmission lines.
Better Corrosion Resistance
When Alumoweld core is used in place of galvanized or aluminized steel, the permanent strength of the conductor is assured. Continuous exposure of combinations of Alumoweld and Alloy 1350 aluminum wires at test sites located in industrial, semi-industrial, and marine atmospheres has shown that they are completely compatible and that their resistance to corrosion is virtually identical.
Accelerated laboratory tests, in which various types of corrosive conditions were simulated, also confirm that Alumoweld has a service life comparable to that of high-purity Alloy 1350 aluminum wires of the same diameter.
Because of the compatibility and coordinated corrosion resistance of Alumoweld and aluminum wires, ACSR/AW can be used safely in corrosive areas where ordinary ACSR may have a shortened service life.
Alumoweld core wires completely eliminate any possibility of a galvanic corrosive action taking place within the conductor. This type of corrosion will occur in some environments when galvanized steel and aluminum wires are in contact with each other.
The high purity of the protective cladding on Alumoweld also makes it far superior to aluminized steel. Further, its uniform cladding is four to five times as thick as the coating on aluminized wire.
Greased cores, with their added weight, inherent construction difficulties, and tendency to collect dirt and contaminants, are no longer needed in corrosive areas when ACSR/AW with Alumoweld core is used.
Mechanical Advantages
Depending on the stranding configuration and conductor size, ACSR/AW weighs three- to six-percent less than its ACSR counterpart. This feature is converted into savings in line design and construction costs.
In most cases, the strength-to-weight ratio of ACSR/AW conductors will surpass galvanized or aluminized cores. In fact, standard ACSR conductors having "B" and "C" galvanized or aluminized cores have strength-to-weight ratios which are considerably lower than those of ACSR/AW.
In addition to the above mechanical consideration, the excellent, time-tested fatigue resistance of ACSR/AW has been demonstrated in installations in both marine and industrial environments.
Uses Standard Fittings
The design and dimensions of ACSR/AW are identical to those of ordinary ACSR. You simply substitute Alumoweld on a size-for-size basis for galvanized or aluminized steel wires. Consequently, standard fittings used for ordinary ACSR perform equally well on ACSR/AW.
Alumoweld Adds Value
Alumoweld's high tensile strength and thick pure aluminum cladding add value to your ACSR. The cladding is so thick that approximately 25 percent of the cross section of an Alumoweld wire is aluminum. This amount of additional aluminum added to the conductor increases its conductivity and ampacity; and significantly improves protection against corrosive attack. Alumoweld has one-third the conductivity of an equal-sized Alloy 1350 (EC grade) aluminum wire. The result is a conductor with lower power losses.
Improved Efficiency
The lower A.C. resistance of ACSR/AW provides savings to the user in two ways: lower demand costs and lower operating costs. This reduced resistance is related to conductor configuration and to the increased cross-sectional area of aluminum resulting from the substitution of Alumoweld for ordinary galvanized or aluminized core wire.
Two complementary factors operate in ACSR/AW to achieve lower A.C. resistance. First, the thick cladding contributes an extra cross-sectional area of pure aluminum to facilitate current flow. This also raises the ampacity. The second way Alumoweld core wire reduces A.C. resistance is the lowering of magnetic losses. While it has the same diameter as galvanized or aluminum wire, Alumoweld has significantly less steel in its composition than in ordinary galvanized wire, thus lowering magnetic losses.
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| Figure 1 |
A.C. Resistance vs. Current
No. 1/0-6/1 Conductors
Raven vs. Raven/AW
Figure 1 reveals test data that compares the behavior of typical 6/1 ACSR with the behavior of ACSR/AW under increasing load. The difference in A.C. resistance increases sharply with loads; and the magnitude of this difference is attributable to the amount of magnetic induction in each of the respective core wires.
For multi-layer conductors, the magnetic effect is somewhat less. However, it has been conclusively demonstrated that higher conductivity Alumoweld core wire results in lower A.C. resistance at every load.
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| Figure 2 |
Resistance vs. Current
Multi-layer Conductors in Free Air
Drake vs. Drake/AW
26/7, 795,000 cmil Drake vs. Drake/AW
54/7, 1-33,000 cmil Curlew vs. Curlew/AW
To determine the importance of lower A.C. resistance for a given conductor, Alumoweld has published a methodology for conductor evaluation (Publication No. 182) that considers both fixed and operating costs.
Lower Voltage Drop
Because of its lower resistance and reactance values, the voltage drop of an ACSR/AW conductor can be significantly lower than that of an ordinary ACSR conductor; which could defer installation of regulating equipment or eliminate the necessity to re-conductor a line.
Emergency Overloads/High Temperature Operations
In cases of emergency electrical overloads, the high strength of Alumoweld core wire provides the best chance of operating without damage to, or significant loss of, strength in the conductor. Unlike AAC, AAAC, or ACAR conductors, ACSR/AW has a high-strength Alumoweld core which enables it to withstand higher temperatures and still maintain sags at an acceptable level.
Furthermore, because aluminum's melting point is considerably higher than that of zinc, Alumoweld strand will operate at much higher temperatures than galvanized strand without experiencing deterioration of its protective cladding.
Increased Ampacity
By virtue of the thick aluminum cladding on the core wires, ACSR/AW conductor has more ampacity than an ACSR conductor of equal size. Tests indicate that at equal maximum operating temperatures, an ACSR/AW conductor can carry up to five percent more current than an ACSR conductor.
Properties of Alumoweld Core Wire Compared With Steel
(Comparision based on .1217" diameter wire)
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