This paper addresses the problem of various parameter influences on the optimal selection of locations remote controlled disconnectors in the medium voltage ( MV ) air networks. Primarily addresses to the reduction of the duration of interruption due to failure of components of the electricity distribution network. In the introductory chapter problem is presented and the legislation that determines a different approach to ensure delivery of quality electricity to customers. The second chapter describes the organization and responsibilities of the electricity distribution networks management, whose employees in organizational units are responsible for the optimal management of networks and the delivery of quality electricity. To grasp the scope of the problem it needs to be familiar with the size and structure of the Croatian distribution network, and a more detailed look at the segment Elektra Križ, one of 21 distribution areas, is responsible. Disconnection devices and their locations are the network component that is the subject of this paper. Their designs, types, purpose and location of installation are described in chapter four. To become more familiar with the issue of determining the location of the disconnectors in the distribution network it should be familiar with the SCADA system by which we monitor and manage network components and the importance of automation in medium voltage network to supply high quality electricity to customers. Quality of electricity among other things depends on the number and duration of interruptions that can be divided into planned interruptions and failures. Dividing the duration of interruption in parts, we can get to the elements that affect each part of the interruption duration, indirectly or directly. Unsupplied electrical energy is an indicator of reliability of supply, assigning a cost not deliver energy output parameter that can be economically evaluated and penalize inefficient suppliers. Energy is the product of force and time, in this paper we will consider their impact on the quantity of undelivered electricity from the point of a It. Is necessary to correctly determine the substation load model 10 (20) / 0.4 kV which are generally not under remote control and do not know the load at the time of interruption of electricity supply To determine the optimal location we use known developed mathematical algorithms, but their results depend on the exact parameters that describe the network model. This problem is dealt with in the next three chapters. At the end there are concluding observations on the approach in defining the parameters that affect the optimal choice of disconnector location in the power grid.