Bolts for Electrical Connections

Electrical connections are often made up of materials that have various coefficients of thermal expansion. Additionally, the joint materials also carry more current than the bolts, causing the joint to heat up more than the bolts. The resultant differential thermal expansion (DTE) results in an increase in bolt load, which can cause the joint components to yield. During each thermal cycle, bolt load may be reduced.

Electrical connections can also loosen over time due to vibration or embedment relaxation, which is caused by microscopic high points on both threads and mating surfaces. As the bolt load is reduced, electrical joint resistance increases or causes heat or hot spots, which can result in even higher resistance and ultimately, catastrophic failure. 

Bolts for electrical connections provide the ideal solutions for these electrical application challenges. Solon Belleville spring washers provide the properties you need to apply a flexible preload and maintain the safety of people and equipment.

Belleville Springs Maintain Bolt Preload

Solon Belleville Springs can solve a variety of electrical application challenges. They provide an effective solution for DTE by maintaining bolt preload. After yield and relaxation of the joint components, a Belleville spring maintains consistent load on the joint, preventing hot spots.
 
If connections aren’t bolted properly, they can cause catastrophic failure and arc flash, a type of electrical explosion. Properly used Solon Belleville springs can reduce the loss of a preload by 5x or more, and greatly reduce the chance of failure.

Other Advantages of Washers for Electrical Connections

Solon Disc Springs (SDS), like Belleville spring washers, have a number of beneficial properties compared to other types of springs. As long as they are installed properly, they provide:
  • Support for very large loads
  • Versatility, with an endless number of disc spring combinations
  • Long service life
  • No impermissible relaxation
  • Preferred by the National Electrical Contractors Association (NECA)
  • Reduced downtime
 


Applications for Bolted Connections

  • Electrical connections where the components of the connection are made of dissimilar (AL7CU or AL9CU) or similar materials
  • Aluminum bus or copper bus
  • Aluminum terminal lug
  • Substations / utilities

Belleville Spring Washers from Solon Manufacturing Meet NECA Standard

The National Electrical Contractors Association standard 3.4.1 specifies the use of a steel bolt with a Belleville conical spring washer. This allows for the differing rates of thermal expansion of the materials. Solon’s Belleville Springs & Washers are the ideal bolted connection for utility and subcontractors who service the industry. 

To ensure the safety of people and equipment, it’s important to install all Belleville spring washers according to manufacturer recommendations to ensure the proper torque. When bolted correctly, Solon Belleville Springs & Washers are reliable and reduce equipment downtime.

Learn more about the Use of Belleville Washers in Electrical Applications

Solon Manufacturing Co. provides high quality engineered solutions for a variety of industries. Belleville springs & washers for electrical connections are the ideal solution for utility workers, distributors, and subcontractors working with electrical connections.

To learn more about our washers for electrical connections, view our resources:
 Contact us or request a quote for Belleville springs & washres for the electrical industry.