[en] Data obtained for electron-induced excitation transitions between levels with principal quantum numbers n=3 in Cl-like Fe X, S-like Fe XI, and Si-like Fe XIII ions by different theoretical methods were compared, and recommended data for electron collision strengths and effective collision strengths have been chosen. Simple analytical formulas with 7 free parameters were used to describe electron temperature dependence of effective collision strengths in a wide temperature range. The values of free parameters have been determined by fitting the recommended numerical data. The obtained results can be used for plasma kinetics calculations and for spectroscopic methods of plasma diagnostics. (author)