How Busbar Temperature Rise Affects Performance (And How to Control It)

Introduction 

A busbar that is discoloured or a panel that has had heating occur that you did not expect indicates that something is not right temperature rises in busbars are not minor concerns, as they can have an impact on the performance of your busbar, the efficiency of your busbar and your safety. Busbars in actual applications have been demonstrated to become inefficient, frequently trip and fail “prematurely” due to improper management of busbar temperature.

The most difficult part of the temperature problem is that it starts out small and “hidden” (e.g., the heat may be so small that you cannot feel it) but continues to grow exponentially. Therefore, let’s break down the temperature issue in simple terms, what things are causing the heating of your busbars, and how to control it.

Table of Contents

• What is Busbar Temperature Rise? 

• Why Temperature Rise Matters More Than You Think 

• Where This Problem Shows Up in Real Applications 

• Key Factors That Cause Busbar Heating 

• Effects of Excess Temperature on Performance 

• How to Control Busbar Temperature Rise 

• Copper vs Aluminium: Which Handles Heat Better? 

• Common Mistakes to Avoid 

• How to Choose the Right Busbar for Better Thermal Performance 

• Expert Tips from Industry Experience 

• FAQs

What is Busbar Temperature Rise? 

Busbar temperature rise is defined as the rise in the temperature of a busbar due to the ambient temperature, the electrical current flowing through the busbar, and the resistance between the busbar and the environment around it.

The busbar temperature rise is usually measured in degrees Celsius (°C) and is directly correlated to the amount of current the busbar carries.

Why Temperature Rise Matters More Than You Think? 

Many people think that, “a little bit of heat is always okay.” Yes, it is okay, but only if it is under acceptable limits.

When the temperature rises beyond the safe limits:

The 4 items above have been defined as:

• Conductivity decreases 

• Energy loss increases 

• Insulation deteriorates 

• Risk of failure increases dramatically

Because, in general, increased temperature = decreased efficiency + increased risk.

Where This Problem Shows Up in Real Applications? 

Tempering temperature rise issues typically occur most frequently in:

• Electrician panels (Low Voltage/Medium Voltage) 

• EV battery systems 

• Solar distribution boards 

• Industrially rated switchgear 

• Data centers and/or very high load environments 

Essentially, where the power flowing through the wire is very high and continuous in nature.

Key Factors That Cause Busbar Heating 

1. High Current Load

More current = more heat produced.

This phenomenon creates a natural electrical behavior.

2. Material Resistance

Copper = lower resistance

Aluminium = higher resistance.

Aluminium therefore will heat up much quicker than copper when subjected to the same load.

3. Improper Sizing

Undersized busbars are perhaps the largest contributor to overheating. 

4. Poor Ventilation

No airflow → heat gets trapped.

5. Loose Connections

Loosening of connections will produce rare but significant spikes in temperature due to increased contact resistance.

6. Surface Finishes and Coatings

An increase in surface oxidation will increase the contact resistance.

Properly applied plating will decrease heat produced.

Effects of Excess Temperature on Performance? 

Excessive heat that exceeds the specified limits has the following effects:

1. Increased Power Loss

Increased contact resistance results in an increase in I²R power losses.

2. Decreased Efficiency

More energy will be wasted as heat rather than converted to useable output. 

3. Damaged Insulation

Insulated materials deteriorate faster with heat. 

 4. Possibility of Failure

Severe temperature levels can cause:

• Melting

• Rogue circuits 

• Fires

5. Decreased Lifespan

When the component does not have an immediate failure, the long-term damage will accumulate. 

The top benefits of having control over temperature are: 

• Increased efficiency (electricity) 

• Longer lifetime of equipment 

• Lower maintenance costs 

• Improved safety and reliability 

• Maintained system performance when under load 

How To Control Your Busbar Temperature Rise?

Where people tend to look for practical information. 

1. Choose The Right Busbar Material 

Copper—-More conductive and less heat generated. 

Aluminum—More economical but must size properly for the application. 

2. Use Proper Busbar Sizing.  Never Size Busbars “Just Enough.”

Always provide a margin for additional load. 

3. Use Plated Busbars. 

Tin plated busbars or silver plated busbar will reduce resistance and oxidation. 

4. Improve Ventilation. 

• Use appropriate panel designs, 

• Allow for a good air flow, 

• Add additional cooling, if necessary. 

5. Verify All Connections Are Tight. 

All connections should be re-torqued periodically. 

6. Use Insulated/Sleeved Busbars. 

Insulated/sleeved busbars distribute heat better and increase safety. 

7. Thermal Analysis (Advanced Methods). 

For serious systems, it may be necessary to conduct thermal imaging and/or load tests. 

Copper vs Aluminum, Which One Handles Heat Better? 

Let us keep this simple:

Factor	Copper	Aluminium
Conductivity	High	Medium
Heat Generation	Low	Higher
Cost	Expensive	Affordable
Weight	Heavy	Light

Real world takeaway:

Copper is your material of choice when you consider both space and performance. If you have a limited budget, Aluminium is an option for you, but be very careful with how it is designed. 

Challenges/Limitations:

Despite the best design practice, busbar designers face challenges and limitations from:

1. Space constraints in busbars.

2. Limitation on budget.

3. Different load conditions on busbars.

4. Environmental conditions i.e. humidity, heat.

Because of the above, there is no one size fits all in busbar design. 

Common Mistakes to Avoid 

There are many different mistakes I see people make when designing their busbars:

1. Only considering the monetary cost of the busbar.

2. Only considering or ignoring the temperature calculation of the busbar.

3. Using undersized aluminium busbars.

4. Failing to account for proper busbar plating.

5. Not checking the joint tightness.

6. Poor busbar ventilation design.

These small mistakes can lead to problems later on! 

How to Choose the Right Busbar for Better Thermal Performance? 

Selecting busbars isn’t just about the specification but also how you intend to use them.

Busbars can be selected based on:

1. Current load requirements

2. Ambient temperature conditions

3. Copper versus Aluminum

4. Tin vs. Silver surface plating

5. Insulation requirements

6. Space constraints

7. Potential future expansion of the load

Questions you should ask your supplier include before buying busbar from them:

1. What are your expectations for temp rise at full load (when it is fully loaded)?

2. Is the temp rise you are giving me based on a calculation or a test?

3. Can the busbars be customized?

4. What kind of coatings do you offer?

A good supplier will do more than selling you the product they will guide you down the right path like Adinath Enterprises do.

Expert Tips from Industry Experience 

• Always build for the gradual load and not the periodic load 

• Be sure to provide enough space for future growth 

• Use thermal imaging when doing maintenance work 

• Don’t reduce your standard when it comes to joint integrity 

• Temperature control is very important to Evs and batteries 

In fact, the majority of failures are not due to material issues rather they tend to be because of lack of planning. 

FAQ Section

1. How hot can busbars be?

Busbars generally should not go beyond 30 – 50 degrees Celsius from ambient temperature, depending on the applicable codes, standards, or material requirements. 

2. Why is heat generated in a busbar more by aluminum than copper?

Aluminum generates more heat than copper because its electrical resistance is greater than that of copper. 

3. Can overheating cause permanent damage to a busbar?

Yes, overheating of a busbar could result in insulation failure, oxidation, and degradation over time. 

4. How can I reduce the temperature of a busbar in a panel?

Increasing airflow, ensuring correct size of busbars, utilizing plating on the busbars, and ensuring well-tightened connections are methods for reducing the busbar’s temperature. 

5. Is plating necessary?

Yes, plating is absolutely necessary when you are dealing with a humid environment. Plating prevents oxidation and enhances conductivity. 

6. How often should I inspect the busbars?

The inspection frequency for busbars should ideally be between 6 and 12 months. However, this may vary by application or the load carried..

Summary

The raises in the busbar’s temperature can never go ignored. The operation, efficiency, and reliability of the equipment are greatly affected by the temperature rise, and most problems found are after they occur (after installation), which has the potential to be an expensive cost to fix.

Fortunately, most of this can be avoided.

By selecting the appropriate materials, selecting the appropriate size for the busbar, and designing your busbar appropriately in advance, you should be able to avoid 90% of the heat issues prior to their occurrence.

If you are working with a project for which the reliability and performance of the equipment’s function is important, it is advisable to identify your project and work with a reliable busbar manufacturer who can provide you the right material and design for the project requirements.