What types of copper busbars are there?

There are many forms of copper busbars, each suitable for different applications:

Flat (rectangular) bus bar:

Description: The most common type has a rectangular cross-section.

Advantages: Due to the large surface area relative to volume, excellent heat dissipation performance, easy stacking for higher current capacity, and easy punching for connection.

Application: Widely used in switchgear, distribution boards, transformers and general power distribution.

Circular bus:

Description: Not as common as flat surfaces, but used for specific applications.

Advantages: Current is evenly distributed along the circumference, making it easier to route in some narrow spaces.

Applications: Sometimes used in high-voltage applications or specific busway designs.

Custom shaped (profiled/extruded) bus bar:

Description: Busbars with special cross-sectional areas are specially designed for specific purposes and are usually extruded. For example, L-shapes, U-shapes, Z-shapes or complex profiles for integrated components.

Advantages: Optimize for specific current paths, space constraints, or integration with other components, potentially reducing assembly time and materials.

Applications: Electric vehicle battery pack, dedicated power supply module, compact electronic equipment.

Laminated (sandwich) bus bar:

Description: Multiple layers of thin copper conductors are separated by dielectric (insulating) materials and laminated together.

Advantages: High capacitance, low inductance (reduced noise and voltage spikes), excellent heat dissipation performance, compact design, and improved current distribution.

Applications: Power electronics, inverters, converters, electric vehicle motor controllers, high-frequency applications, precise power transmission and data centers where noise suppression is critical.

Flexible bus bar:

Description: Made of multiple layers of thin copper foil or braided copper wire, it can be bent and twisted. It is usually insulated with PVC or silicone.

Advantages: Excellent flexibility to connect misaligned components, absorb vibration, reduce pressure at connection points and fit into tight spaces.

Applications: Battery connections, switchgear connections (vibration or thermal expansion needs to be considered), railway applications, wind turbines, anywhere there is movement or vibration.

Insulated bus (bus system):

Description: Copper busbars are pre-insulated with PVC, epoxy resin, heat shrink tubing and other materials, or integrated into insulating housings (bus ducts).

Advantages: Improved safety (preventing accidental contact), reduced risk of short circuits, compact design, easier installation.

Applications: Any area that is critical to safety and space optimization, such as industrial plants, high-rise buildings and data centers.

What are the precautions for installation and connection of copper busbars?

Correct installation and connection are crucial for the safe and reliable operation of copper busbars. Key preventive measures include:

Surface preparation:

Cleanliness: Ensure that contact surfaces are clean and free of dirt, grease, oxides and burrs. Use a wire brush or abrasive pad to clean before connecting.

Remove oxides: For uncoated copper, gently grind the surface to remove any oxide layers, revealing fresh, bright copper.

Conductive paste (optional but recommended): For high-current connections, coating a thin layer of non-oxidizing conductive joint compound can further improve conductivity and prevent oxidation.

Connection method:

Bolted connection: The most common method. Use high-quality bolts, nuts and washers (flat washers, spring/lock washers) made of compatible materials (e.g., steel, stainless steel, appropriate plating).

Welding/Brazing: Provides a permanent connection with very low resistance, but requires specialized equipment and skills.

Clamping: Less common for mains power connections, but used in certain applications.

Tightening torque:

Key: Use a calibrated torque wrench to tighten the bolts to the torque value specified by the manufacturer.

Reason: Insufficient tightening can cause excessive contact resistance, overheating, and possible arcing. Excessive tightening can cause deformation of the bus bars, stretching of bolts or damage to washers, and can also lead to poor contacts or mechanical failure.

Re-tighten: Certain connections, especially those in high-vibration or high-temperature environments, may require regular retightening (retightening) after initial operation due to material creep.

Insulation treatment:

Appropriate insulation: Ensure that all exposed live parts are adequately insulated to prevent accidental contact, short circuits and flashover. This may include:

Heat shrink tube: Apply to joints and bus sections.

Busbar cover/sheath: prefabricated plastic cover.

Epoxy coating/powder coating: Insulation for factory applications.

Air clearances and creepage distances: Maintain specified distances between live parts and from the ground.

Avoid contact with dissimilar metals (electrochemical corrosion):

Risk: When two different metals come into electrical contact in the presence of an electrolyte such as moisture, electrochemical corrosion may occur, accelerating the degradation of the more reactive metal.

Solution:

Board surface: Use tin-plated or silver-plated copper busbars, especially when connected to aluminum parts (although direct contact between copper and aluminum should still be avoided whenever possible).

Use transition plates/washers: If direct contact cannot be avoided, use a bimetal connector specifically designed to reduce electrochemical corrosion (e.g., copper aluminum bimetal washers or plates).

Humidity control: Ensure that the environment is dry.

Thermal expansion and contraction:

Reserved space: The design of bus ducts should consider the effects of thermal expansion and contraction, especially over long distances or environments with large temperature fluctuations. Failure to do so may cause mechanical stress, deformation, or connection and support damage.

Expansion joint: For long busbar operation, use flexible connectors or special expansion joints.

Support and support:

Adequate support: Install the bus bars on appropriate insulators and supports to prevent sagging and maintain appropriate clearance.

Short-circuit withstand capacity: Supports and supports are designed to withstand the high electromagnetic forces generated during short circuit faults.

Shock absorption:

In high-vibration environments, use flexible busbars or shock-absorbing brackets to prevent loose connections or fatigue failure.

Air clearances and creepage distances:

Observe the specified air gaps (the shortest distance between live parts through air) and creepage distances (the shortest distance between live parts along the insulating surface) to prevent flashover.

GRL provides OEM copper busbars that can be customized in various size

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