Aluminum conductor steel-supported core


  • ASTM B 609: Standard Specification for Aluminum 1350 Round Wire, Annealed and Intermediate Tempers, for Electrical Purposes.
  • ASTM B 498: Standard Specification for Zinc-Coated (Galvanized) Steel Core Wire for Aluminum Conductors, Steel Reinforced (ACSR).
  • ASTM B 856: Standard Specification for Concentric-Lay-Stranded Aluminum Conductors, Coated Steel Supported (ACSS).


ACSS is a concentric-lay stranded composite conductor made up of a core of galvanized steel strands and one or more layers of annealed or soft 1350-O Aluminum. The steel core wire is Class A galvanized zinc-coated steel which, due to the annealed or soft temper Aluminum, carries most or all of the mechanical load of the conductor. Upon request, the steel core is available in High strength.



Aluminum conductor steel supported (ACSS) cable is used for overhead transmission lines. ACSS is designed to operate continuously at higher temperatures up to 2500C without loss of strength, which allows for a significant increase in current carrying capacity over ACSR. ACSS is self- damping, sags less than ACSR under emergency electrical loadings, and its final sags are not affected by the long term creep of aluminum. These advantages make ACSS useful in new line applications where structures can be optimized due to the reduced conductor sag or where high emergency loads may be required; or in lines where Aeolian vibration is a problem. Existing lines can be re-conductored using ACSS to allow for increased current using the existing clearances and tensions.