ASTM B228-11a(2021) PDF

Overview

ASTM B228-11a(2021) is the internationally recognized standard specification for concentric-lay-stranded copper-clad steel conductors. Published by ASTM, this standard covers requirements for bare concentric-lay-stranded conductors manufactured from round copper-clad steel wires intended for general use in electrical applications. It defines a range of grades based on strength, conductivity, and annealing processes, providing clear guidance on composition, construction, ordering, testing, and packaging. By adhering to the ASTM B228 standard, manufacturers and users ensure consistency, safety, and performance of copper-clad steel electrical conductors in a variety of applications.

Key Topics

• Conductor Grades: ASTM B228 classifies conductors into five grades:
  • Grade 40 HS (High Strength, 40% Conductivity, Hard Drawn)
  • Grade 30 HS (High Strength, 30% Conductivity, Hard Drawn)
  • Grade 30 EHS (Extra High Strength, 30% Conductivity, Hard Drawn)
  • Grade 40 DSA (40% Conductivity, Dead Soft Annealed)
  • Grade 30 DSA (30% Conductivity, Dead Soft Annealed)
• Construction Requirements: The standard prescribes the number of wires, wire diameters, and lay lengths for 3, 7, and 19-wire stranded configurations. All wires within a conductor must be of the same grade and quality to ensure uniformity in mechanical and electrical properties.
• Testing and Inspection: Physical and electrical properties of wires are to be tested before stranding. This includes tensile strength and elongation, with additional provisions for testing completed conductors if required.
• Joints and Splices: Joints are allowed within individual wires under strict criteria to maintain conductor integrity and rated strength. Methods include weld-annealed and compression-weld joints, each with specific protection requirements.
• Packaging and Marking: ASTM B228 details packaging sizes, protection requirements, and mandatory package markings to facilitate handling, shipping, and traceability.

Applications

Copper-clad steel concentric-lay-stranded conductors specified under ASTM B228 are widely used in:

• Power Distribution: Utilized as overhead ground wires and shield wires where both high strength and conductivity are crucial.
• Communications Infrastructure: Suitable for use in telephone lines and railway signaling where mechanical strength and resistance to corrosion are needed.
• General Electrical Uses: Ideal for situations requiring conductors that balance conductivity, durability, and cost-efficiency. Common in utility, industrial, and transportation sectors.
• Corrosive Environments: The copper coating provides enhanced resistance to corrosion compared to bare steel conductors, extending service life in exposed or harsh conditions.

Related Standards

Several other standards are referenced within ASTM B228 and are pivotal for manufacturing and testing copper-clad steel conductors:

• ASTM B227: Specification for Hard-Drawn Copper-Clad Steel Wire - provides requirements for wire used as input for stranded conductors.
• ASTM B910/B910M: Specification for Annealed Copper-Clad Steel Wire - governs softer, more ductile wire grades.
• ASTM B354: Terminology Relating to Uninsulated Metallic Electrical Conductors - defines key technical terms.
• ANSI C42: Definitions of Electrical Terms - offers industry-standard terminology.
• NIST Handbook 100: Copper Wire Tables - supplies reference data for calculations involving electrical and physical wire properties.

Adhering to ASTM B228-11a(2021) and related standards ensures electrical conductors meet rigorous demands for strength, conductivity, and reliability, supporting safe and effective performance in various electrical infrastructure projects.