Bare Conductor vs Insulated Cable: Which Is Better for Overhead Lines?

By Jianyun Cable – Professional Manufacturer of Quality Electrical Cables

Overhead power lines remain one of the most cost-effective ways to distribute electricity over long distances. Two fundamentally different conductor technologies dominate this field: **bare conductors** (traditional ACSR, AAAC, AAC) and **insulated overhead cables** (commonly known as ABC – Aerial Bundled Cable). Choosing between them significantly affects safety, reliability, maintenance costs, and project economics. This 2025 comparison explains the differences, strengths, weaknesses, and ideal use cases for each type.

1. Introduction: Two Main Types of Overhead Conductors

For decades, bare conductors were the standard for overhead transmission and distribution lines. Since the 1980s–1990s, insulated bundled cables (ABC) have gained massive popularity — especially for low-voltage and medium-voltage distribution — dramatically improving safety and reliability in many regions. Neither type is universally “better”; the right choice depends on voltage level, environment, budget, safety requirements, and local regulations.

2. What Is a Bare Conductor?

Bare conductors have no outer insulation. The most common types are:

• ACSR (Aluminum Conductor Steel Reinforced) – aluminum strands around steel core
• AAAC (All Aluminum Alloy Conductor)
• AAC (All Aluminum Conductor)

They rely on physical separation and large clearances to prevent phase-to-phase or phase-to-ground faults.

3. What Is an Insulated Overhead Cable?

Insulated overhead cables (most commonly ABC – Aerial Bundled Cable) consist of multiple phase conductors individually insulated with XLPE or PE, twisted together around a neutral or messenger conductor (which may be bare or insulated). The insulation eliminates the need for wide spacing between conductors and provides protection against contact.

4. Bare Conductor vs Insulated Cable: Head-to-Head Comparison

5. Advantages & Disadvantages of Bare Conductors

Advantages:

• Lower material cost
• Excellent heat dissipation → higher current-carrying capacity
• Proven technology for high-voltage transmission lines
• Long spans possible with steel-reinforced designs

Disadvantages:

• High risk of contact faults, electrocution, and short circuits
• Frequent outages from vegetation, animals, weather
• Large right-of-way and tree clearance costs
• Higher theft and vandalism risk

6. Advantages & Disadvantages of Insulated Cables

Advantages:

• Greatly improved safety for public and line workers
• Very low outage rates in wooded, coastal, or polluted areas
• Smaller corridor needed – ideal for urban and suburban areas
• Lower long-term maintenance and vegetation management costs
• Reduced theft and improved reliability

Disadvantages:

• Higher initial cable cost
• Lower current-carrying capacity (insulation traps heat)
• Shorter span lengths compared to ACSR
• More complex termination and jointing

7. Where Each Type Is Most Commonly Used

• Bare Conductors — High-voltage transmission lines (>66 kV), long rural spans, areas with very low population density, extreme high-current applications
• Insulated Cables (ABC) — Low-voltage distribution (0.4/0.6 kV), suburban & rural service drops, medium-voltage lines (up to 36 kV) in vegetation-heavy, coastal, or high-theft regions, urban upgrading projects, temporary installations

8. Final Thoughts: Which Is Better?

There is no universal winner — it depends on the project:

• Choose bare conductors for high-voltage transmission, very long spans, or when maximizing current capacity is critical and safety clearances can be maintained.
• Choose insulated cables (ABC) for low- and medium-voltage distribution, areas with trees, buildings, high population density, frequent storms, or theft problems. In most modern distribution networks (especially 0.6/1 kV), ABC is now the preferred and often mandated solution due to superior safety, reliability, and total lifecycle cost.

For new overhead distribution projects or upgrading aging bare lines, insulated bundled cables (ABC) typically deliver the best balance of safety, reliability, and long-term economy in 2025.

Need high-quality bare conductors or state-of-the-art ABC cables for your overhead line project? Contact Henan Province Jianyun Cable Co., Ltd. — your professional partner for reliable overhead conductor solutions.