In overhead power transmission and distribution systems, aluminum-based conductors are widely used because of their light weight, excellent conductivity, and cost efficiency. Among the most common types are AAC (All Aluminum Conductor) and AAAC (All Aluminum Alloy Conductor).
While they look similar, these two conductors have distinct characteristics that make them suitable for different applications.
1. Overview
| Type | Full Name | Material | Typical Use |
|---|---|---|---|
| AAC | All Aluminum Conductor | Pure aluminum (EC grade, 1350-H19) | Short-span, low-tension distribution lines |
| AAAC | All Aluminum Alloy Conductor | Aluminum alloy (typically 6201-T81) | Medium and long-span overhead transmission lines |
2. Construction
AAC (All Aluminum Conductor):
Constructed with strands of hard-drawn 1350 aluminum. The design maximizes electrical conductivity but offers limited mechanical strength.AAAC (All Aluminum Alloy Conductor):
Made of aluminum-magnesium-silicon alloy (6201) strands. This alloy provides higher tensile strength, better corrosion resistance, and slightly lower conductivity compared to AAC.
3. Key Differences
| Feature | AAC | AAAC |
|---|---|---|
| Material | EC-grade aluminum (1350-H19) | Aluminum alloy (6201-T81) |
| Conductivity | ~61% IACS (higher) | ~52–53% IACS |
| Tensile Strength | Lower | 30–50% higher |
| Corrosion Resistance | Moderate | Excellent, especially in coastal or industrial areas |
| Operating Temperature | Up to 75°C | Up to 90°C |
| Weight | Slightly lighter | Slightly heavier due to alloy |
| Sag at High Temperature | More pronounced | Less sag due to higher strength |
| Typical Use | Short-span distribution lines | Long-span transmission or coastal areas |
4. Performance Comparison
Mechanical Strength:
AAAC’s aluminum alloy composition provides greater tensile strength and allows longer spans with less sag.Electrical Conductivity:
AAC offers slightly better conductivity, making it efficient for short distances where mechanical load is low.Corrosion Resistance:
AAAC is more resistant to atmospheric corrosion, especially from salt or industrial pollution, making it ideal for coastal, humid, or polluted regions.Thermal Performance:
AAAC can withstand higher operating temperatures (up to 90°C), while AAC is typically limited to 75°C continuous operation.
5. Applications
AAC Conductors
Suitable for short-span, low-stress distribution networks.
Commonly used in urban areas where mechanical strength is less critical.
Easy to install and terminate due to soft, pure aluminum strands.
AAAC Conductors
Designed for medium- and long-span transmission lines.
Excellent choice for coastal or industrial environments with high corrosion risk.
Used where improved strength-to-weight ratio and higher temperature performance are required.
6. Summary Table
| Aspect | AAC | AAAC |
|---|---|---|
| Composition | Pure aluminum | Aluminum alloy (Al-Mg-Si) |
| Conductivity | Higher | Slightly lower |
| Strength | Lower | Higher |
| Corrosion Resistance | Moderate | Excellent |
| Temperature Rating | 75°C | 90°C |
| Best For | Urban, short spans | Long spans, coastal areas |
7. Conclusion
Both AAC and AAAC conductors serve critical roles in overhead power systems:
AAC offers high conductivity and cost efficiency for short-span, low-stress applications.
AAAC, on the other hand, provides greater mechanical strength, superior corrosion resistance, and better long-term reliability, especially in demanding outdoor environments.
When selecting between AAC and AAAC, engineers should consider span length, mechanical tension, environmental conditions, and budget requirements to ensure optimal system performance.
Contact TOT Wire & Cable
TOT Wire & Cable supplies a full range of overhead conductors, including AAC, AAAC, and ACSR, manufactured to international standards.
We offer competitive pricing, custom lengths, and fast delivery for domestic and export projects.
📩 Contact us today to get a quote or technical assistance for your overhead transmission line project.
