Condensed species in products of the reaction of SF₆ with Cu up to 4000 K

This paper is concerned with condensed species in the equilibrium composition of a system of products of the reaction of sulphur hexafluoride with copper. It is assumed that SF₆ is an insulation medium in the circuit breaker and reacts with the Cu contained in the circuit breaker contacts or in other parts of the circuit breaker. The system of products of the reaction of SF₆ with Cu is assumed to be in local thermodynamic equilibrium for temperatures ranging from ambient temperature to 4000 K, with the pressure in the system being within an interval from 0.1 MPa to 2 MPa. The occurrence of condensed species and their phase transformations significantly affect the composition and thus also the system properties in a range of temperatures at which arc ignition or arc extinction take place. Data on the condensed species considered are analysed and the effects of the phase rule and the selected theoretical model on the occurrence of condensed species in the equilibrium composition are examined. (paper)