TransPowr® ACSS/TW Bare Overhead Conductor (US)

TransPowr® ACSS/TW is a trapezoidal aluminum conductor supported by a steel core, featuring a concentric lay of stranded wires. The aluminum strands are trapezoidal, allowing a more compact arrangement of the wires. 

Conductor designs that maintain the same circular mil cross-sectional area of aluminum as a conventional round conductor yield a TW conductor that is 10 to 15 percent smaller in overall diameter. In contrast, designs that match the overall diameter of a conventional round conductor result in a TW conductor containing 20 to 25 percent more aluminum cross-sectional area. 

ACSS/TW conductors are manufactured in accordance with the latest ASTM B857 standards. The steel strands serve as the central core of the conductor, around which are stranded two, three, or four layers of 1350-O aluminum wire (annealed). The steel core can consist of a concentrically stranded cable comprising 7, 19, or more wires. Several combinations of aluminum and steel strands and layers are available. The sizes and constructions listed in the following pages represent common examples used in overhead lines. 

Standard ACSS/TW designs feature a regular-strength Class A zinc-5% aluminum mischmetal alloy-coated steel core (/MA2).

Features and Benefits

TransPowr ACSS/TW conductors are similar to conventional ACSR/TW conductors but offer several important advantages. They can operate continuously at high temperatures up to 250°C without sustaining damage. ACSS conductors exhibit less sag than ACSR/TW under emergency electrical loadings, feature self-damping properties, and their final sags are not influenced by the long-term creep of aluminum. 

ACSS/TW conductors, which have an equivalent aluminum circular mil cross-sectional area, are smaller in overall diameter compared to conventional round-wire ACSR conductors. This reduced diameter minimizes the impact of ice and wind loading on the conductor. 

Furthermore, ACSS/TW conductors are designed to have an equivalent overall diameter, allowing for a larger cross-sectional area of aluminum within the conductor. This design not only reduces power loss during daily operations but also significantly increases the conductor's current-carrying capacity.

Applications

Trapezoidal aluminum conductors, steel-supported (ACSS/TW), are utilized for overhead transmission lines. They are particularly beneficial in reconductoring applications that require increased current while maintaining existing tensions and clearances. Additionally, they are advantageous for new line installations, where structures can be optimized by reducing sag, and for new lines that must accommodate high emergency loads. These conductors are also effective at mitigating aeolian vibration.

Options

• E3X® surface coating (/E3X)
• High-strength Class A zinc-5% aluminum mischmetal alloy-coated steel core (/MA3 to ASTM B803)
• Extra-high-strength Class A zinc-5% aluminum mischmetal alloy-coated steel core (/MA4 to ASTM B958)
• Ultra-high-strength Class A zinc-5% aluminum mischmetal alloy-coated steel core (/MA5 to ASTM B958)
• Aluminum-clad steel core (/AW)
• 250°C operating temperature rating utilizing either the zinc-5% aluminum mischmetal alloy-coated steel core wires or the aluminum-clad steel core wires
• Non-specular surface finish (/NS)