Temperature Rise Behavior of Ag/SnO2 Contact Materials for Contactor Applications

Abstract

Critical temperature rise can be a failure mechanism for contact materials in power applications. The use of contact materials with reduced silver content to be more cost effective and the smaller sizes of devices impact this failure mode. Furthermore this effect is enforced by reductions in the volume of contact material and lower contact forces, due to energy saving by less power consumption of the driving coil. This paper presents influences of metal oxide content to contact resistance and temperature rise by experiments in a break-only model switch and in contactor applications. Temperature rise tests according to IEC standards show the influences of contact force on temperature rise of contactors and the effect of different switching conditions/loads on temperature rise. Therefore results of AC-3 and AC-4 standard contactor lifetime tests have been compared. contact material; contactor; Ag/SnO2; temperature rise; contact resistance