Overhead-line power conductors do not run parallel to the ground; they actually sag between adjacent towers, defining catenary curves. However, in the analysis of inductive coupling phenomena between power lines and neighboring circuits, the standard approach to deal with the sag effect is to assign a constant average height to power line conductors. The purpose of this research is to assess the accuracy of such an ordinary procedure. To do that, two different approaches are developed in order to more accurately account for the sag effect: a pure segmentation method, and a corrected segmentation method which takes into consideration the real curvature of the sagged conductors. The latter, and novel, approach is compared with the other options. Calculations presented in this work utilize magnetic vector potential as an analysis tool.