Aluminum busbars are critical in electrical substations. They act as main conductors that carry large amounts of current between components like transformers, breakers, and switches. Today, more engineers are choosing aluminum over copper. The decision is based on lower weight, better material costs, and strong electrical performance.
To work properly, aluminum must be bent with care. Inaccurate bends can cause poor alignment, weak joints, or faults in the system. This makes proper tooling, tolerances, and material selection a key part of the process.
Why Aluminum Busbars? Advantages Over Copper
Aluminum has become a practical alternative to copper, especially in large-scale power systems where weight and cost matter.
Lower Weight
Aluminum weighs roughly 70% less than copper when comparing equal volumes (HLC, 2024). That makes it easier to transport and install, and it reduces stress on support structures.
Better Costs
Aluminum has a lower price per kilogram and requires less energy during refining. It is also easier to recycle, which reduces overall production costs.
Safe Expansion
Aluminum expands more than copper under heat, which can introduce movement at joints. Designs must account for this to prevent loosening or stress over time.
Corrosion Resistance
Aluminum forms a natural oxide layer that protects the surface. Anodizing or coating the material further improves its durability in outdoor and high-voltage environments.
Welding Options
Shops can use TIG or MIG welding on aluminum. Friction-stir welding is gaining attention for some aluminum profiles, but most substation busbars still rely on MIG or TIG welds, especially for solid bars.
Bending Requirements in Substation Applications
Busbars used in substations must be formed with accuracy. If bends are off by even a few millimeters, it can cause problems with phase clearance or mounting.
Common Busbar Sizes
Most aluminum busbars fall within a size range of 50 mm × 10 mm to 120 mm × 20 mm (IEEE Power & Energy Society, 2008). These bars offer a strong balance between conductivity and rigidity.
Bend Radius Rules
According to IEEE 605 guidelines, the inner bend radius must match or exceed the width of the bar. This prevents cracks or thinning in the bend zone.
Precision Tolerances
Shops often work within a ±0.5 mm tolerance to make sure each phase aligns correctly (ALLEGRO, 2021). Holding this level of accuracy requires the use of CNC bending equipment.
Bending Techniques
Each shape is formed using the method that best matches the bend type:
- CNC rotary bending handles smooth arcs with consistent curves.
- Press brake forming produces clean 90° bends.
- Roll bending shapes long S-curves that reduce stress in the metal.
Design and Safety Considerations
Proper design and bending are important for more than just appearance. They affect safety, thermal performance, and how long the system holds up under load.
Clearance and Creepage
Bend locations must maintain enough distance between phases to prevent arcing. Tight spacing or sharp turns can reduce air gaps and increase electrical risk.
Heat Flow
Poorly designed bends can trap heat. That extra heat increases resistance and shortens the life of the conductor. Even spacing and consistent material thickness help avoid this.
Fit for Insulation
Each bent section must match the size and shape of the insulation. When busbars are too wide or uneven, sleeves and wraps may not cover them properly.
Mounting and Load
Flat and even bends are important for proper mounting. If the bar is warped or twisted, it can shift the load onto fasteners or misalign bolt holes.
Case Example: Substation Retrofit in Southeast Asia
In one Southeast Asian retrofit, a utility replaced old copper busbars that had become too heavy and corroded. The project team selected CNC-bent aluminum to complete the upgrade.
What They Did
Technicians used 3D scanning to measure the full layout of the electrical panels. Based on that scan, they created aluminum busbars from 6061-T6 and bent each one to match the existing structure.
What They Gained
Switching to aluminum reduced the total weight by 45% (Voltaira, 2025). Installation time was faster, and the added space between phases improved airflow. This helped keep temperatures lower under load.
Conclusion: Where Conductivity Meets Craftsmanship
Aluminum busbars are a smart choice for modern substations. They weigh less, cost less, and perform well when formed correctly. The quality of each bend directly affects system performance. Poor forming can cause fitment issues, uneven heating, or stress on terminals.
When bending is done with care, the final result is a clean, aligned assembly that’s easy to install and safe to operate. CNC tools, tested alloys, and proper design rules make this possible across all types of high-voltage projects.
This shift from copper to aluminum isn’t just about replacing material. It requires a clear approach to shaping, mounting, and assembly. When those steps are done right, aluminum busbars provide long-term results that meet both electrical and mechanical needs.
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