To study the interaction between the electrode and the electrical are in a
SF6 self-blast circuit breaker, a coupling between experimental and theoret
ical approaches is proposed. The experimental approach allows physical vari
ables such as the temperature just below the contact surface and the total
metallic vapour mass in the electrical are to be measured. The theoretical
study is based on a hydrodynamic model for electrical are modelling, which
takes into account Joule heating, radiation and real-gas effects. The arc/e
lectrode interaction model is built on an energy balance at the boundary be
tween the gas flow (the are) and the electrode (cathode or anode). The vali
dation is obtained through comparisons between measured and calculated resu
lts.