Copper Busbar Prototyping

A Comprehensive Guide to Designing, Fabricating, and Testing Copper Busbars 

Busbar Introduction 

Copper busbars are essential components in electrical distribution systems, providing a reliable and efficient way to transfer power. They are widely used in industrial, commercial, and residential applications due to their excellent conductivity, durability, and ease of installation. Prototyping copper busbars is a crucial step in the development process, allowing engineers to test and refine their designs before full-scale production and distribution. 

Understanding copper busbars  

What is a copper busbar? 

A copper busbar is a strip or bar of copper that conducts electricity within a switchboard, a distribution board, a substation, or any other electrical equipment. Busbars are used to connect low to high voltage equipment at electrical switchyards, and low voltage equipment in battery banks and distribution boards. 

What advantages? 

MSS copper busbars offer several advantages over other types of conductors: 

• High Conductivity: Copper, and especially ETP CW004A has a high electrical conductivity, which means it can carry more current than other materials of the same cross-sectional area. 
• Availability: Copper ETP being a standard material for electrical parts fabrication, is widely available from manufacturers direct or stockist. The size of your products will define whether a cross section is specific or standard. 
• Durability: Copper is highly durable and resistant to corrosion, ensuring a long service life for busbars made from it. 
• Thermal Conductivity: Copper's excellent thermal conductivity helps dissipate heat generated during high current flow, reducing the risk of overheating. 
• Mechanical Strength: Copper busbars have good mechanical strength, making them suitable for use in environments with mechanical stress or vibration. 
• Ease of Fabrication: Copper is easy to work with, allowing for precise and complex busbar designs to be fabricated efficiently. 

The prototyping process 

Prototyping copper busbars involves several stages, including design, fabrication, and testing. Each stage is critical to ensuring that the final product meets the required specifications and performs reliably in its intended application. 

Design 

The design phase of copper busbar prototyping involves creating detailed drawings and specifications for the busbar. This includes determining the size, shape, and layout of the busbar, as well as selecting the appropriate materials and finishes. At MSS International, we support our customers going through the different stages, defining specifications and identifying constraints. 

Key considerations for an efficient busbar design 

• Current Carrying Capacity: The busbar must be designed to carry the required current without excessive voltage drop or overheating. This involves selecting the appropriate cross-sectional area and material for the busbar. 
• Voltage Rating: The voltage rating of the busbar must be sufficient to withstand the maximum operating voltage of the system. MSS’ Quality Team can support voltage testing during simulation phases as well as sampling phases.  
• Thermal Management: Proper thermal management is essential to prevent overheating and ensure reliable operation. This includes considering the thermal conductivity of the material and incorporating cooling mechanisms if necessary. 
• Mechanical Strength: The busbar must be mechanically robust to withstand mechanical stresses and vibrations. This involves selecting a material with suitable mechanical properties and designing the busbar to distribute these stresses evenly. 
• Environmental Factors: The busbar must be designed to withstand the environmental conditions it will be exposed to, such as temperature, humidity, and corrosive atmospheres. In such case, insulation methods and plating finishes are considered to bypass those constraints.  

Design tools and software 

Modern design tools and software can greatly enhance the design process for copper busbars. These tools allow MSS’ engineers to create detailed 3D models of the busbar, perform simulations to predict its performance, and adjust as needed. The MSS Team works on the latest version of designing software, matching with its customer systems too: 

• Computer-Aided Design (CAD) Software: CAD software allows MSS to create precise 2D and 3D drawings of the busbar, including all relevant dimensions and customer base technical specifications. 
• Finite Element Analysis (FEA) Software: FEA software enables engineers to simulate the mechanical and thermal performance of the busbar, identifying potential issues and optimizing the design. 
• Electrical Simulation Software: Electrical simulation software can be used to model the electrical performance of the busbar, including current distribution, voltage drop, and heat generation. 
• Thermal Simulation Software: Thermal simulation software allows engineers to predict the thermal behaviour of the busbar, including temperature distribution and heat dissipation. G Corner, due to its involvement in critical plant systems for refining and green hydrogen, has a strong ability to perform all simulation, ensuring the highest safety in the design, the production and the commissioning of any electrical systems.  

Fabrication 

The fabrication phase involves manufacturing the copper busbar according to the design specifications. This includes cutting, bending, drilling, possible fastener fitting, and finishing the busbar to achieve the desired shape and dimensions. 

Material selection 

Selecting the right material is critical to the performance and durability of the copper busbar. The most commonly used material is high-conductivity copper, such as Electrolytic Tough Pitch (ETP) copper. Other materials, such as oxygen-free copper and high-strength copper alloys, may be used for specific applications, keeping in mind niche material are always more expensive. 

Cutting and shaping 

The first step in the fabrication process is cutting the copper bars to the required length. This can be done using various cutting methods at MSS International, including: 

• Shearing: A shear machine cuts the copper bars to length using a straight cutting action. This method is fast and efficient but may produce sharp edges, which is a must avoid for electrical application. 
• Sawing: A saw machine uses a blade to cut the copper bars. This method produces cleaner cuts but may be slower than shearing. 
• Laser Cutting: A laser cutting machine uses a high-powered laser to cut the copper bars. This method provides precise and clean cuts but can be more expensive. MSS uses in-house oxygen laser capability, cutting to extreme strict tolerance, should this be at our India or Poland manufacturing complexes. Our automatic system will load, produce, and extract the finished busbar. An integrated maintenance system has been implemented and conducts autonomous adjustment to always maintain the strict tolerances. A human presence is always needed to secure the whole infrastructure and visually check the extracted flat patterns. 

Once the copper bars are cut to length, they are shaped into the desired configuration using bending and forming techniques. At MSS we operate two different processes: 

• Bending: The copper bars are bent into the required shape using a manual or automatic press brake. The bending process must be carefully controlled to avoid cracking or deforming the copper. 
• Forming: The copper bars are formed into complex shapes using specialized forming equipment. This may include stamping, punching, and embossing techniques. We use dedicated general tools to form, avoiding expensive tool costs to our customers. 

Drilling and machining 

After the copper bars are cut and shaped, holes and other features are added using drilling and machining techniques: 

• Drilling: Holes are drilled into the copper bars using a drill press or other drilling equipment. The size and location of the holes must be precise to ensure proper assembly and performance. MSS will use in-house manufactured gauges to place the busbars into the correct position. Fasteners can be fitted according to our customer needs following this operation.  
• Milling: Milling machines are used to create slots, grooves, and other features in the copper bars. This process requires careful control to achieve the desired dimensions and surface finish. 
• Tapping: Tapping machines are used to create threaded holes in the copper bars for screws and bolts. This process must be done accurately to ensure proper assembly and fastening to requirement. 

Finishing 

The final step in the fabrication process is finishing the copper busbar to provide the desired surface properties and appearance: 

• Deburring: Removing any rough edges or burrs from the cut and drilled surfaces to ensure smooth and safe handling. This operation remains mandatory for prototype and serial production. 
• Polishing: Polishing the copper surface to achieve a smooth and shiny finish. This may be done using mechanical polishing equipment or chemical polishing methods; however such process it not mandatory. A shiny finish can be naturally kept at MSS as the whole team handling busbars work using thin fabric gloves to avoid fingerprint and other acid contamination. 
• Coating: Applying a protective coating to the copper surface to prevent corrosion and enhance durability. Common coatings include tin plating, nickel, silver plating, as well as epoxy/non-PVC coatings done through spraying or dipping methods. In general MSS applies spray coating for electrical insulation up to 45kV/mm, having an operating temperature of around 125°C. 

Testing 

Once the copper busbar prototype is fabricated, it must undergo rigorous testing to ensure it meets the required specifications and performs reliably in its intended application. The testing process is an important phase to technically validate the part, this process has also a direct impact to final product validation. This includes electrical, mechanical, and environmental testing. 

Electrical testing 

Electrical testing is conducted internally at MSS International to verify the busbar's electrical performance, including its current carrying capacity, voltage drop, and heat generation. The MSS Quality Team conduct non-destructive test method directly in MSS’ own laboratory: 

• Current carrying capacity: Testing the busbar's ability to carry the required current without excessive voltage drop or overheating. This involves measuring the voltage drop and temperature rise at different current levels. 
• Voltage drop: Measuring the voltage drop across the busbar to ensure it is within acceptable limits. This involves applying a known current and measuring the resulting voltage drop. 
• Heat generation: Testing the busbar's ability to dissipate the heat points generated during current flow. This involves measuring the temperature rise at different current levels and verifying that it is within acceptable limits. 

All results are recorded, templated and communicate to our customers for validation purpose.  

Mechanical testing 

Mechanical testing is conducted to verify the busbar's mechanical strength and durability:  

• Tensile strength: Testing the busbar's tensile strength by applying a pulling force until it breaks. This provides information about the material's strength and ductility. 
• Flexural testing: Testing the busbar's ability to withstand bending forces by applying a bending load until it deforms or breaks. This provides information about the material's flexibility and toughness. Should the breaking point be not achieved, the MSS Team will review the damage level made during the test phase and communicate accordingly 
• Torque testing: Fitted fasteners are tested for the in and out. Usually tested to 15Nm for standard application, MSS uses and tests much larger products for larger applications.  

Conclusion 

Prototyping copper busbars is a critical step in the development process, allowing engineers to test and refine their designs before full-scale production. By following a systematic approach to design, fabrication, and testing, MSS international ensures that produced copper busbars meet your required specifications and perform reliably in your intended applications. 

MSS then develop the right process and right tooling to manufacture serial production busbars at our manufacturing located either in India or Poland. For more information, contact our team today!