For longer powerlines without branches, wires are transposed according to the transposing scheme. At closely branched grids and where several electric circuits share a route (in particular when the lines operate at different voltages) on the same pylons the outside unbalance of the line, which is caused by the other electric circuits, dominates. In these cases, one finds large deviations from the transposing schemes. For example, in some such transpositions, only two of the three conductors on the pylons change their place. Also, transpositions on pylons near power substations are used to get an optimal arrangement of the feeding system without crossing of conductors.