ABSTRACT
This chapter describes the effects of arcing on electrical contacts. Arcing occurs as the contacts come together by the breakdown of the contact gap before they touch each other. This arcing period depends upon the circuit voltage and closing speed of the contact, but it is usually of very short duration. The consequences of the arc, however, affect all of our choices for the application of contact material. For the designer of switching devices in a circuit, one of the most important consequences of arcing is the effect the arc has on the erosion of the contact material. The increase in the power density in the arc spots will give rise to excessive heating of the spot with the consequence that jets of metal will be ejected from the spot regions. The electric arc allows a smooth transition of the circuit current to current zero.
