The Study of Dynamic Welding of Electrical Contacts in Relay Applications

摘要

As the demand for using smaller relays to switch higher load power application increases, dynamic welding of contacts has become a major cause for relay failure. This paper describes the influence of several major factors that affect dynamic welding. These factors include contact material, contact over-travel, arcing, thermal stress relaxation and contact bond. Some factors have both the positive and negative influence on dynamic welding. For example, high metal oxide content in contact material can increase the anti-welding property of the contacts. It also increases the contact resistance which can cause high temperature rise and thermal stress relaxation of the copper spring material which can increase contact welding. All of these factors can interact and it is important to understand these interactions to be able to improve relay performance.