Effective Shape of Electrical Contacts to Shorten Duration of Break Arcs Generated between Contacts with Airflow Ejection Structure

In a 100VDC/10A resistive circuit, break arcs are generated between electrical contacts. Silver electrical contacts with airflow ejection structure are separated at a constant speed. The duration and motion of the break arcs are investigated for different contact shapes. Three types of contact shapes are used. Contact diameters and airflow hole diameters are changed. Following results are shown. An effective shape of the contacts was found to shorten the arc duration. The arc duration was shortened by decreasing the diameter of the contacts and increasing the diameter of airflow hole for the airflow ejection. The results are discussed in terms of the motion characteristics of the cathode spots on the cathode surface and the shapes of the break arcs.