Electrical contact temperature change after short-circuit current

Theoretical analysis is preformed concerning temperature rise of electrical contacts exposed to short-circuit current. This temperature is calculated for three different contact materials: AgNi, AgCdO and AgSnO₂, used in low voltage electromagnetic relays. An assumption is made that the heat process is adiabatic. Amount of heat is calculated based on let-through energy (Joules heat) of miniature circuit breaker and on real electrical contact resistance. A simplified model of electrical contact heating is proposed.