Arc Thermal Recovery Speed in Different Gases and Gas Mixtures

One important requirement for circuit breakers when interrupting, short line fault currents is their ability to withstand the initial rise of the recovery voltage immediately after current zero. For gas flow breakers this capability is limited by the thermal recovery speed oI tne gas. The measured relative thermal recovery performance of various gases and their mixtures are reported. They differ by more than four orders of magnitude. Some of the gases have been selected because of their possible candidacy for application. Others because of the expeotid effect of their ditterent gas parameters on interruption performance. An attempt has been made to correlate specific mass dependent thermodynamic and kinetic parameters of the gases to their thermal interruption performance.