An Overview of Thermoweld Connections in Grounding Applications

When designing electrical protection systems, the most fundamental principle should be that all connections remain secure throughout the entire service life of the facility. If connections weaken, grounding, equipotential bonding, and lightning protection systems become vulnerable to failures. With Yılkomer thermoweld equipment solutions, we invite you to use our products for the strongest possible connections.

In this article, you can discover what the thermoweld connection system—also known as exothermic welding or CADWELD—is, when it should be used, and how it compares to mechanical grounding connections.

What Is a Thermoweld Connection?

A thermoweld grounding connection is a process used to join similar metals such as copper-to-steel or copper-to-copper. An exothermic reaction is used to create a molecular bond between the two parts. The connection takes place in a purpose-designed graphite mold, also referred to as a thermoweld mold. The weld is formed by igniting thermoweld powder (metal powder) used to heat the metal. Simply put, the exothermic process involves a chemical reaction that releases heat and does not require an external heat source. Ignition of the powder is sufficient at this stage, after which the exothermic reaction occurs with the generated heat.

What Is the Heat-Generating Exothermic Welding Chemical Reaction?

3Cu2O +2Al → 6Cu + Al2O3 + HEAT
Copper Oxide + Aluminum → Copper + Aluminum Oxide (Slag) + HEAT

Approximate Reaction Temperature – 2500°C

When applied correctly, after cooling, the thermoweld connection is homogeneous, meaning a true weld is achieved and the elements are fully fused. The connection is permanent, irreversible, and does not require any additional hardware to hold it in place.

Let’s Compare Thermoweld and Mechanical Connections!

In general, thermoweld connections are superior to mechanical connections for grounding due to the permanent bond formed between two materials. Their use is especially critical with electrical connections to ensure a reliable bond.

Advantages of Exothermic Welded Connections

• Low grounding resistance is maintained for a long time.
• Resistant to corrosion; does not degrade in the presence of moisture.
• Connection lifespan exceeds the lifespan of the conductors.
• No risk of loosening due to molecular bonding.
• High resistance to repeated fault currents.
• Provides the lowest possible ground transition resistance.
• Very safe to use with proper training.

Disadvantages of Mechanical Connections

• They cause uneven current flow.
• They carry a risk of corrosion.
• Additional measures such as corrosion tape are required to extend connection life.

An Additional Note for Lightning Protection Connections!

Additionally, in lightning protection connections, mechanical connections with corrosion tape may be used against the risk of breakage of thermoweld connections. In grounding systems, however, thermoweld connections are the ideal solution.

How Is Thermoweld Applied?

System Components

• Thermoweld Mold
• Thermoweld Powder
• Igniter / Lighter
• Thermoweld Tongs
• Cleaning tools: brush, scraper
• Additional elements such as washers and paste

Thermoweld Application Instructions

• Place the thermoweld powder into the mold.
• Set the control unit to the ignition position.
• Press the ignition button on the control unit and wait.
• Open the mold lid and remove the powder container.

Once you learn the application, making the connection will take only a few minutes. Thermoweld applications are especially important for rail systems, industrial facility grounding, data centers, and power plants.

As Yılkomer, all thermoweld equipment is included in our product range. Additionally, if you wish, you can receive application support from our expert team.

Remember ‘Yılkomer Protects Your Values’