Acss, Aluminium Conductors Steel Supported (ASTM B 856)

ACSS, Aluminium Conductors Steel Supported (ASTM B 856)
Construction
ACSS, a non-homogenous conductor, is a concentric-lay stranded conductor made from round aluminum 1350-O wires and round, coated steel core wire(s). Steel wires are coated with Class A coating of zinc – 5% aluminum mischmetal alloy. Other Classes of coatings are also available for additional protection from corrosion. Standard, High, Extra and Ultra High Strength steel are also available.
Specifications
ACSS conductors are manufactured in accordance with the ASTM specification B856.
Features
ACSS conductors are preferred over ACSR conductors for specific transmission line applications:
With zinc – 5% aluminum mischmetal alloy coating on steel wires, ACSS conductors can be operated up to 250 ° C. ACSS conductors carry more current than ACSR conductors due to:
Minimum average conductivity of 63% IACS for 1350-O aluminum wires vs. An average conductivity of 61.2% for 1350-H19 aluminum wires in ACSR.
ACSS conductors can be operated up to 250 ° C vs. The maximum operating temperature for an ACSR conductor does not exceed 100 ° C.
ACSS conductors are prone to resist the effects of aeolian vibration due to very little or no mechanical load on the annealed aluminum wires.
Long term creep is not a factor when designing with ACSS conductors.
Applications
ACSS conductors are useful for:
Reconductoring lines: Increase ampacity with existing tensions and clearances.
New lines: Optimize structures due to low sag. Also, provide higher emergency loading capability.
Lines: Where aeolian vibration is an issue.