Alumoweld Aluminum-Clad Steel Overhead Ground Wire

ASTM B-415 Hard-Drawn Aluminum-Clad Steel Wire
ASTM B-416 Concentric-Lay-Stranded Aluminum-Clad Steel Conductors

The reliable, uninterrupted transmission of electrical power is vital to the electric utility industry. Transmission lines carrying large blocks of power must be permanently protected against damage from lightning. Alumoweld overhead ground wires provide the best means of obtaining this protection. They combine conductivity, , and high strength–all of the properties necessary for such assurance.

The thick aluminum cladding on each wire offers optimum protection against atmospheric corrosion while providing the conductivity important in proper operation of protective relays. The high conductivity of Alumoweld strand also reduces the temperature rise of the static wire under fault current conditions.

Application
Overhead ground wire, shield wire protecting transmission lines against lightning damage.

Construction
Alumo-clad steel wire and strand wire is used by power utilities as well as formed wire and optical ground wire manufacturers. Alumo-clad steel wire outlasts other options by as much as 200% in corrosive environments, significantly lowering maintenance and replacement costs. When compared to solid aluminum wire, aluminum clad steel wire offers tremendous savings.

Alumo-clad steel wire overhead ground wire has excellent corrosion resistance. Its strength and conductivity remain unchanged in any atmosphere where aluminum is satisfactory, especially those known to be corrosive from industrial or atmospheric conditions.

This assurance against corrosion is obtained through the application of a thick covering of pure aluminum which provides a substantial barrier of protective metal. The minimum cladding thickness of Alumo-clad steel wire is 10% of the radius of the wire. the cladding has a continuous, strong metallic bond to the steel core that will not crack or flake.

Alumo-clad steel wire also provides strength greater than or equal to other overhead ground wires. For commonly used wire sizes, the tensile strength of the individual wire can approach 200,000 pounds per square inch. When used in a strand for overhead ground wire, this high strength permits greater span lengths, less sag and heavier loads under storm loading conditions.

Directly related to strength and sag performance is the lighter weight of aluminum clad steel wire. Due to its thick cladding of aluminum, Alumo-clad steel wire is 15% lighter that a steel strand of equivalent size. This lighter weight, combined with high strength, permits aluminum clad steel wire to be installed to the same sags as steel with correspondingly lower tensions and tower stresses on the towers or supporting structures.

Excellent Conductivity
Due to a thick aluminum cladding, Alumoweld overhead ground wire provides one-third the conductivity of an aluminum conductor of equal size, and several times the conductivity of steel. Each Alumoweld product is tested for resistivity, a practice not generally used for steel. This insures known electrical properties in Alumoweld overhead ground wires.

These properties are maintained throughout the life of the line, as contrasted to the properties of steel wires with other protective coatings which can deteriorate over time. Such deterioration further reduces the already low conductivity of steel overhead ground wires.

Effect of Short Circuit on Overhead Ground Wire
Assuming complete absorption of heat by the ground wire

20 degree C, D.C. Resistant:
7 No. 8 AWG Alumoweld, .446 ohms/1,000 feet
3/8-inch steel, 1.140 ohms/1,000 feet

Temperature Coefficient of Resistance:
7 No. 8 AWG Alumoweld, .0036/degree C
3/8-inch steel, .0035/degree C aluminum clad steel wire

Per Industry Standards:

ASTM B-415 Hard-Drawn Aluminum-Clad Steel Wire
ASTM B-416 Concentric-Lay-Stranded Aluminum-Clad Steel Conductors

The reliable, uninterrupted transmission of electrical power is vital to the electric utility industry. Transmission lines carrying large blocks of power must be permanently protected against damage from lightning or the occasional fault. AFL Alumoweld overhead ground wires, also referred to as shield wires, provide the best means of obtaining this protection. They combine conductivity, corrosion resistance, and high strength–all of the properties necessary for such assurance.

Light Weight

Directly related to strength and sag performance is the lighter weight of Alumoweld strand. Due to its thick cladding of aluminum, Alumoweld is 15 percent lighter than a steel strand of equivalent size. This lighter weight, combined with high strength, permits Alumoweld strand to be strung to the same sags as steel with correspondingly lower tensions and lower stresses on the towers or supporting structures.

Sag Data

Alumoweld overhead ground wires may be sagged to provide the proper mechanical safety and lightning protection for any power conductor.

Features:

• Superior corrosion resistance compared with traditional galvanized steel ground wires
• Lower in weight than similarly sized traditional galvanized steel products
• Permanent bond between the aluminum coating and steel core for lifetime performance
• More conductive than traditional galvanized steel options
• Equivalent Alumoweld options exist for the most common galvanized cables
• Available in custom drum lengths to suit your plan/profile requirements
• No special installation training or equipment required