Introduction

A busbar can be correctly sized for its electrical load and still develop excessive heat at its joints. This problem often occurs in electrical panels, power distribution systems, EV battery packs and energy storage installations.

The cause isn’t always the conductor itself. Contact resistance, joint design, surface condition and manufacturing accuracy can all affect connection performance.

For electrical engineers, procurement managers and equipment manufacturers, understanding these factors helps prevent overheating and improve connection reliability.

Adinath Enterprises manufactures customized copper and aluminum busbars according to customer drawings and technical requirements, helping businesses meet application-specific component needs.

What Causes an Overheating Busbar Joint?

Busbar joint overheating takes place when there is high resistance at the connection point. While the electrical current flows through the busbar joint, it generates the heat.

This can be illustrated with the help of the formula from Joule’s Law of Heating:

P = I²R

Where P is heat power, I is electric current, and R is resistance. Because it is currently squared value, even a little change in resistance results in huge heat generation at high currents.

1. High Contact Resistance

Contact resistance appears when two conducting surfaces come into contact. Although contacts appear to be smooth, they are not homogenous, and there is a lot of roughness and imperfections on the surface of metal contacting points, leading to electrical current flow through very small contacting points.

The reasons leading to the contact resistance include

• Low pressure of clamping.

• Oxidation and pollution.

• Insufficient torque.

• Misalignment.

• Small area of contact.

This is how all these factors lead to the overheating of the contacting points.

2. Improper Joint Design

For any busbar connection to obtain its adequateness, the area of contact, fastening mechanization, and distribution of pressure must be adequate.

Certain factors, such as wrong dimensions, incorrect hole locations, and no contact surface, can turn out very troublesome for a high contact resistance. Any connection may appear to be very strong but might not have good conductivity.

While joints are designed, there are aspects necessary for consideration, like busbar dimensions, hole position, overlaps, and type of material used.

3. Problems with Manufacturing and Dimensions

The achievement of a high-quality busbar joint depends on the quality and precision of the manufacturing process.

Burrs produced by punching, wrong hole positions, bad bends, and errors in dimensions prevent the elements from touching and pressing equally against each other.

Precision stamping, bending, drilling, and derubbing result in all busbars being within the technical standards.

Influence of Material and Surface Condition on Heating

Copper and aluminum are both well-known materials utilized in electrical busbars, but they have distinct properties. Comparing two busbars with the same geometrical cross-section gives copper not only a higher conductivity but also a relatively more important weight. However, since aluminum has a lower density than copper, it is often chosen in applications where weight matters, such as some technologies for lithium batteries.

Unfortunately, the use of either copper or aluminum alone may not lead to high-quality joints. The surface of aluminum gets oxidized when exposed to air, thus impeding electric contact. In the case of the copper busbar, the oxide layer is not the only problem, as the surface contamination may also increase the contact resistance.

Hence, for each specific application of the busbar, one should ensure that a particular type of surface treatment or coating is applied to achieve the required level of contact resistance and corrosion resistance.

Important Role of Thermal Expansion and Mechanical Stress

When the busbar operates, it heats up and cools down with the decreasing power used. This means that thermal expansion and contraction occur, which can result in breaking of the connection if the fastener construction is faulty.

Moreover, vibration creates additional mechanical stress in various systems of power producers, as well as in large-sized machines.

The first signs of the problem include

• Hot spots near the fasteners

• Color change or visible damage.

• Loosening or installing capability.

• The difference in temperature at two similar fasteners is too big.

In such cases, it is recommended to perform thermographical inspections, measure resistance, and check the installation.

Methods to Avoid Heating of Busbar Joint

The heat generation possibilities may be decreased by engineers and maintenance personnel at the busbar junction section of the system.

• The busbar junction should be designed according to the contact area needed, distance, and arrangement of fasteners.

• The contact surfaces should be properly cleaned according to procedure.

• The torque control should be achieved by the proper assembly method and the torque of the busbar junction.

• Measurements ensure that tolerances, elbows, and positions of holes are within limits.

• The final product should be inspected to verify its dimensions and quality of made holes, burr elimination, and surface finish.

• The efficiency of the process should be evaluated by measuring temperature growth and any resistance problems that may occur.

Construction of a junction requires adherence to electrical, mechanical, and manufacturing properties for optimum efficiency.

The significance of manufacturing custom busbars

In most cases, typical busbars are not suitable for any type of electric system. Thanks to the possibility of custom manufacturing, it is possible to choose the size, type of holes, bending angles, and connection types of the busbar.

Custom busbars made of either aluminum or copper can be manufactured by Adinath Enterprises. The busbars manufactured can serve the following:

• Electric equipment and energy distribution devices.

• The batteries of electric vehicles and lithium batteries.

• Energy storage systems.

• Batteries of household inverters.

• Switching components and conversion devices.

Measured manufacturing processes are cutting, punching, bending, drilling, and applying the necessary finishing. Quality control is a manufacturing process to ensure that the produced components have been manufactured according to requirements.

For prismatic lithium battery applications, Adinath Enterprises provides laser-welding type aluminum busbars.

Thanks to high-quality operation, it is possible to correct the designs of assemblies, but there are many types of defects, such as defects in joint design, defects introduced during installation, and defects during testing.

Most common mistakes causing overheating

• The busbar size should not be the only factor to be taken into account: A satisfactory size doesn’t guarantee that contact resistance is low.

• Neglecting dimensional tolerances: Any inaccuracies in hole position or bends can lead to misalignment.

• Ignoring the rules of surface treatment: The material should be the right one and also be treated accordingly.

• Applying incorrect torque: Either too little or too much torque should not be applied.

• Ignoring verification: Every important connection should be checked to meet design requirements and temperature rise criteria.

How to Choose a Copper Busbar Manufacturer in India

When searching for a suitable copper busbar manufacturer in India, considering just the price and thickness of the product will not be enough. You should consider the following aspects:

1. Manufactured against drawings: Is the supplier capable of meeting your size, hole, and bend requirements?

2. Material characteristics: Are the specifications for types and electrical characters of copper provided?

3. Manufacturing process: Are punching, bending, drilling, and deburring carried out according to required processes?

4. Quality checks: Are the important dimensions and products inspected before dispatch?

5. Surface treatment: Is the supplier capable of undertaking plating or any other process?

6. Production consistency: Is the supplier able to adhere to specifications in prototype and production orders?

Adinath Enterprises, founded in 1994, is an ISO 9001:2015 certified company that manufactures customized copper and aluminum busbars based on client specifications.

Frequently Asked Questions

1. What causes busbar connections to heat up, despite their correct dimensions?

This issue can manifest itself due to guarding failure, contact contamination, and excessive or insufficient clamping force.

2. Is plating of busbar-associated connections enough to avoid overheating?

Just plating would not solve the problem. While proper plating improves contact efficiency and the prevention of corrosion, the joint design, surface quality, and assembling quality also play major roles.

3. Can loose screws cause busbar overheating?

Yes, associate components may have elevated resistance if they are not clamped correctly. However, applying excessive tightening torque may damage them; thus, the recommended torque should be used.

4. How is it possible to detect an overheated busbar connection?

The abnormal heating and possible failures can be detected through infrared thermography, resistance measurements, and visual checks.

5. Is copper superior to aluminum in joints?

Copper has a lower resistivity than aluminum for equal cross-section; however, aluminum is lighter than copper. The best response to this question will depend on the current, dimensions, temperature limits, and joint configuration.

6. Does Adinath Enterprises make customized copper busbars?

Yes, Adinath Enterprises makes customized copper or aluminum busbars according to customers’ drawings.

Selecting the Appropriate Busbar to Ensure Dependable Connections

Overheating of busbar joints may occur due to resistance in contact, geometry of joints, contamination on the surface, mounting issues, or faults in manufacturing. Working on these components simultaneously allows effective enhancement of the reliability of connections as well as reduction of possible maintenance issues.

If you need specific copper or aluminum busbars, Adinath Enterprises can provide you with custom solutions according to your needs via drawings and dimensional control processes. Just send us your engineering drawings so that we can discuss the optimal solution for you.