In the article the research of transition process aspects of the single-phase circuit on the earth (SPCE) in networks of 6-35 kV are considered. The oscillogram of transition process of SPCE, the analysis and calculation of numerical values of currents and voltage are provided. The specified empirical formula of calculation of current of SPCE is offered and recommendations whenever possible to use the relay protection and automatic equipment in parameters of transition process of SPCE are made. The results of analytical and experimental studies of SPCE received in the article can be used for operation of relay protection and automatic equipment of an electric network, in particular in the conditions of mountain territories.