Copper Busbar

What is a Copper Busbar?

A copper busbar is a conductive metal bar made of copper, used primarily for conducting electricity and distributing power within electrical systems. It serves as a central point for power distribution in switchboards, panel boards, substations, and other electrical apparatus. In short, it distributes electric power from incoming feeders to outgoing circuits and handles large amounts of current with low energy loss. It also minimises the need for multiple cables or wires.

Made of copper due to its excellent electrical conductivity and thermal performance. It is typically a flat, rectangular bars, but also available in round, square, or hollow shapes. The size varies based on current-carrying requirements; can range from small bars in control panels to large bars in power distribution systems.

To achieve the electrical conductivity needed for these applications the copper needs to have a purity of greater than 99.9% copper. The most common alloy used is ETP Cu or C11000.

Key features and properties of Copper Busbars

·         Superior Electrical Conductivity – Copper has the highest electrical conductivity of any non-precious metal (only silver is better). This allows smaller cross-sections of copper to carry the same current as larger aluminium bars, saving space.

·         Excellent Thermal Conductivity - Copper efficiently dissipates heat, which reduces the risk of overheating in high-current applications. Lower thermal resistance improves performance and safety in enclosed switchgear or panels.

·         Higher Mechanical Strength - Copper is stronger and less prone to deformation under mechanical stress or high temperatures. Better for tight clamping and mechanical connections — reduces loosening over time.

·         Better Corrosion Resistance - Especially when tinned or plated, copper resists corrosion in harsh environments. Unlike aluminium, copper's oxide layer is conductive, so it doesn’t interfere with electrical contact.

·         Reliable Long-Term Performance - Less prone to creep (slow deformation under pressure), a problem common with aluminium. More dimensionally stable in thermal cycling environments (less expansion/contraction).

·         Compact and Flexible Designs - Since copper carries more current per square millimetre, it enables more compact busbar layouts. Easier to install in tight or confined spaces, especially in urban or mobile power units.

·         Widely Accepted in Standards and Specifications - Copper busbars are often the default choice in critical applications like data centres, hospitals, aerospace, and defence due to their performance and reliability.

Why Copper is Preferred for Busbars

Copper is preferred for busbars in many applications due to a combination of electrical, mechanical, and long-term reliability advantages. Here's a breakdown of the key reasons:

• High conductivity: Low resistance and minimal power loss.
• Durability: Strong, corrosion-resistant, and long-lasting.
• Compact design: Takes up less space than multiple cables.
• Ease of maintenance: Accessible and easy to inspect or modify.

Common Applications of copper busbars

Main applications of copper busbars include:

1. Power Distribution Systems

• Switchgear and switchboards: Distribute power safely in industrial and commercial settings.
• Panel boards and load centres: Efficient internal power routing.
• Busduct systems: Distribute power across floors or buildings in large facilities.

2. Electrical Panels and Control Cabinets

Motor control centres (MCCs)

• Distribution boards
• Automation control panels

Why: Copper ensures low resistance, efficient power delivery, and safe operation.

3. Data Centres and Server Rooms

• • Power distribution units (PDUs):

  o    Distribute LV and MV power across power distribution infrastructure, and from power module to IT room

  o    Distribute LV alternate current power through the IT room, above the racks, supplying each IT rack with power

  o    Distribute LV direct current power in the rack

  o    Distribute LV direct current power in the server

  • Uninterruptible power supplies (UPS)
  • Blade server power infrastructure

  Why: High conductivity and compact design support dense, high-load environments.

  

  4. Industrial Equipment and Machinery

  • Large motors, drives, and generators
  • Welding equipment
  • Heavy-duty manufacturing and process automation

  Why: Withstands high current loads and mechanical stresses reliably.

  5. Power Generation & Renewable Energy

  • Solar power plants: Interconnect PV arrays, inverters, and switchgear.
  • Wind farms: Internal turbine wiring and grounding.
  • Hydro & thermal plants: High-capacity busbar trunks and grounding.

  Why: Reliable, corrosion-resistant conduction in outdoor or high-load environments.

  6. Electrical Substations & Utilities

  • High-voltage busbars for transformers, circuit breakers, and feeders.
  • Medium/low-voltage applications in transmission and distribution grids.

  Why: Excellent thermal and electrical performance under continuous load.

  

  7. Transportation and EV Infrastructure

  • Electric vehicles (EVs): Battery connections, inverters, and charging systems.
  • Railway systems: Power distribution in locomotives and metro systems.
  • Marine & aerospace: Compact, high-efficiency busbars for critical systems.

  Why: Space-saving, lightweight (in laminated or custom form), and highly reliable.

  8. Telecommunications and Broadcast Equipment

  • Power backup systems
  • Rack-mounted server and telecom gear

  Why: Consistent voltage levels and low interference in sensitive environments.

  9. Building and Facility Grounding

  • Equipotential bonding and lightning protection systems.
  • Building grounding grids for safety and EMI protection.

  Why: Corrosion resistance and mechanical durability for long-term performance.

  

  Copper Busbar Specifications & Sizing

  Standard Sizes Available

  Refer to Austral Wright Metals copper bar product range

  https://australwright.com.au/wp-content/uploads/2012/07/CopperFlat1.pdf

  Customisation and Fabrication Options

  Copper busbar is produced in other specialty forms for busbar applications. These include:

  ·         Tinned copper busbars: For improved corrosion resistance.

  ·         Flexible copper busbars: Made of laminated foils for vibration resistance and flexibility.

  ·         Insulated busbars: For compact, safe, touch-proof installation.

  

  Advantages of Copper Busbars

  Copper is most preferred for mission-critical applications requiring confined spaces or compact panel design, environments with fluctuating temperature or high humidity and installations requiring long lifespan and minimal maintenance.

  Cost-Effectiveness

  The cost-effectiveness of copper busbars depends on balancing initial investment with long-term performance and reliability. While copper is more expensive upfront, it often proves more economical over the system's lifetime due to its superior properties. Copper busbar is significantly more expensive per kg than aluminium (~2–3x higher), however for the same current capacity, copper requires less material due to higher conductivity, reducing size but not necessarily total cost.

  While copper busbars have a higher initial cost, they offer long-term savings through higher efficiency. lower maintenance and improved reliability.

  They’re especially cost-effective in systems where downtime, heat, or space constraints are expensive risks.

  Longevity

  Under normal operating conditions copper busbar can last 25~50 years. In indoor, controlled environments, copper busbars can last well beyond 50 years with minimal degradation. In harsh or corrosive environments, lifespans can still reach 20–30 years with proper insulation or tin-plating.

  Why Copper Busbars Last So Long? When it oxidises, it forms a thin, conductive oxide layer that doesn’t impede electrical performance.

  Tinned copper or epoxy-coated copper extends life in marine or chemical environments.

  In addition to its corrosion resistance, copper also resists creep and deformation under mechanical stress and thermal cycling. It holds tight electrical connections over time, reducing the chance of loosening or failure.

  Copper dissipates heat more efficiently than aluminium, reducing thermal fatigue and the risk of insulation breakdown.

  Best practices to maximise longevity:

  ·         Use tinned copper in corrosive environments

  ·         Apply heat shrink or epoxy coatings where needed

  ·         Ensure tight, torque-verified connections

  ·         Allow for thermal expansion gaps in high-current systems

  ·         Schedule periodic inspections (every 3–5 years in critical systems)

  

  Ordering Copper Busbars from Austral Wright Metals