The work is dedicated to topical issues – to increase the power capacity of 110 - 330 kV overhead lines (OL) without OL significant reconstruct. Offered to the estimates examined a proposal to use the specified methodology for calculating the allowable load current after limiting the heating condition. Methodological nature: the allowable load current is determined under certain environmental meteorological conditions (air temperature, wind speed and direction, solar radiation), while maintaining levels of vertical distances between wire and ground or between the wire and the crossed object. Subject to the wind regimes, if necessary, increasing the vertical distances between the OL wire and ground or between the wire and the crossed object, can achieve significant allowable transferable capacity. Using the methodology, can accurately and rapidly determine the allowable load current of the overhead powerlines. Based on the methodology, the allowable current estimates of real overhead powerlines. The obtained data are presented in graphical form. Offered load current calculation algorithms give a theoretical justification for the possibility to increase the overhead powerline transferable power, by investing relatively small resources. Given a broad overview, this helps to orient transferable capacity potential of technical capabilities through a variety of conductor materials and a monitoring system the line state of operational control. Material recommended for energy and electrical specialties for students in-depth learning of electricity transmission, for use in student research. Material may be used in the design, to identify transferable capacity potential in certain overhead lines.