Product designers, technicians, and engineers are trained to accept manufacturer specifications when selecting electromechanical relays and contactors.  None of these specifications, however, indicate the serious impact of electrical contact arcing on the life expectancy of the relay or the contactor.  This is especially true in high-power (e.g., over 2 Amp) applications. 
Electrical current contact arcing may have a deleterious effect on electrical contact surfaces, such as relays and certain switches.  Arcing may degrade and ultimately destroy the contact surface over time and may result in premature component failure, lower quality performance, and relatively frequent preventative maintenance needs.  Additionally, arcing in relays, switches, and the like may result in the generation of electromagnetic interference (EMI) emissions.  Electrical current contact arcing may occur both in alternating current (AC) power and in direct current (DC) power across the fields of consumer, commercial, industrial, automotive, and military applications.  Because of its prevalence, there have literally been hundreds of specific means developed to address the issue of electrical current contact arcing.