Concentric-Lay-Stranded Aluminum Conductors, Aluminum-Alloy Reinforced (ACAR, 1350/6201)

B524/B524M-99: Standard Specification for Concentric-Lay-Stranded Aluminum Conductors, Aluminum-Alloy Reinforced (ACAR, 1350/6201)

For electrical engineers and designers tasked with specifying materials for overhead power transmission, understanding the performance characteristics of conductors is paramount. ASTM B524/B524M-99 provides an authoritative framework for selecting and utilizing Concentric-Lay-Stranded Aluminum Conductors, Aluminum-Alloy Reinforced (ACAR), ensuring reliability and efficiency in critical infrastructure.

What is B524/B524M-99?

ASTM B524/B524M-99 is a comprehensive industry standard that defines the requirements for ACAR conductors. Originating from ASTM's commitment to material excellence, this specification outlines the material properties, construction, and performance criteria for these specialized stranded aluminum conductors, which are engineered for robust overhead electrical applications. Its primary purpose is to establish a common baseline for quality and interoperability among manufacturers and users.

Scope & Purpose

This standard governs the design, manufacturing, and testing of concentric-lay-stranded conductors utilizing aluminum 1350-H19 outer wires and aluminum-alloy 6201-T81 core wires. It specifies permissible wire types, stranding configurations, and key performance metrics such as electrical resistance and physical dimensions. The standard explicitly covers conductors intended for use as overhead electrical conductors and does not extend to conductors for underground or other specialized applications.

Who Must Comply?

• • Primary audience: Electrical Engineers, Materials Engineers, Product Designers, Quality Control Inspectors, and Procurement Specialists involved in power transmission and distribution projects.
• • Industries affected: Electrical Utilities, Power Generation and Transmission, Cable Manufacturing, and Electrical Systems Construction.
• • Compliance nature: Voluntary, but widely adopted as a best practice and often mandated by project specifications and utility standards.
• • Enforcement: Compliance is typically verified through material testing, product certification, and quality assurance audits by project owners, independent testing agencies, or regulatory bodies overseeing critical infrastructure.

Key Requirements Overview

The standard requires that the individual aluminum wires (1350-H19) and aluminum-alloy wires (6201-T81) used in the conductor construction meet their respective ASTM material specifications. Professionals must ensure that the concentric stranding arrangement adheres to the configurations detailed within the standard, specifying the number and arrangement of wires. Key provisions include the establishment of permissible joint types and locations within the conductor wires, ensuring electrical continuity and mechanical integrity. Furthermore, the standard outlines requirements for conductor marking, packaging, and the testing necessary to verify conformance to specified electrical and physical properties.

Related Standards & References

ASTM B524/B524M-99 is intrinsically linked with several other ASTM standards for a complete understanding of ACAR conductor requirements. ASTM B230/B230M (Specification for Aluminum 1350-H19 Wire for Electrical Purposes) and ASTM B398/B398M (Specification for Aluminum-Alloy 6201-T81 Wire for Electrical Purposes) are essential, as they define the properties of the constituent wires. Additionally, **ASTM