Wear of electrical contacts

Abstract Both electrical and mechanical wear contribute to the loss of contact material. Electrical wear due to arcing phenomena depends on the form of the contacts, a.c.- or d.c.-switching, contact speed, and contact pressure. Mechanical wear due to friction depends on the nature of the material, the form of the contacts, their relative movement, and the pressure between them. Decrease of contact wear, either by eliminating one of the causes of wear or by redesigning the contact mechanism, is of extreme importance in increasing the reliability of contacts.