The model calculation of fault currents for the defined network circuit 0,4-35 kV with aspect to the performance characteristics of covered conductors is performed. Three-phase and two-phase fault currents with fault power capacities are defined. Performed calculation by using method in the case of traditional non-insulated conductors provided the possibility to carry out the comparable analysis of results indicated decreasing three-phase fault currents for the existing control points at 10-15%. Three-phase fault currents for the investigated circuit define the most severe switching conditions for circuit breakers. Obtained values are an order less in comparison with switching capability of modern circuit breakers for medium voltages. It confirms the switching capability parameters of the circuit breakers are higher that it needed according to the real circuit conditions. Besides, the costs of the network construction increase. In this case using load interrupter switches can be as an alternative variant but technical and economic efficiency should be proved in the frames of the project with aspects to the development plan of the network.