Analysis Of The Electrophysical And Thermophysical Properties Of Copper-Graphite Material For Arcing Contacts Of A High-Current Low-Voltage Circuit Breaker

Thermal wear of electric contacts significantly influences the operation period of medium- and high-current low-voltage circuit breakers. This wear also depends on the material properties of the breaker arcing contacts. The paper discusses the influence of composition of the material of arc-extinguishing contacts on the electrophysical and thermophysical properties of the circuit breaker. The paper presents the results of an experimental analysis of the thermal conductivity, heat capacity and electrical conductivity of a copper-based composite material with the addition of graphite obtained by plasma spraying in air. The obtained experimental data are compared with calculation results of material properties. A mathematical model of arc burning over a hemispherical surface of an electrode with a composite coating was developed based on the obtained experimental data.