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T/F: ACSR preferred over AAAC

Short answer

TRUE. ACSR has a steel core that provides higher tensile strength than AAAC, enabling higher working tension, smaller sag, and longer spans. This makes it the standard choice for most transmission lines.

State whether the following statement is TRUE or FALSE. Justify your answer with a brief explanation: ACSR is preferred choice than AAAC (All Aluminum alloyed conductor) for transmission line because of its high tensile strength.

TRUE (in general practice).

  • ACSR (Aluminium Conductor Steel Reinforced) has a galvanized steel core inside aluminium layers. The steel, especially in high-steel strandings such as 30/7, gives a higher ultimate tensile strength than an AAAC of the same conductance. The steel core also does not creep, so the sag stays stable over the years.
  • Higher strength allows higher working tension, so the sag is smaller for a given span. This allows longer spans, fewer or shorter towers, and a lower line cost. ACSR also performs better at long river or valley crossings and under ice and wind loads.
  • This is why ACSR is the standard choice for most transmission lines, including NEA lines in Nepal.

AAAC is still preferred in some cases:

PointACSRAAAC
Tensile strengthHigh (steel core)Moderate
CorrosionGalvanic risk at steel–Al interfaceVery good (homogeneous)
WeightHeavierLighter
Surface hardnessSofter outer AlHarder alloy, less damage
Best useLong spans, normal sitesCoastal or polluted areas, short spans, distribution

So ACSR is preferred mainly because of its high tensile strength. AAAC is chosen where corrosion resistance and lower weight matter more.

✓ Answer checked by Claude Opus 5.5 (high effort)

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