The modelling of transfer characteristics of low-voltage power distribution networks for Power Line Communications requires the knowledge of the electrical parameters of the cables comprising these networks. In this study, a method is developed for characterising the power line cable parameters. In complement to many existing approaches, the authors estimate the cable parameters from a limited set of measurements. Measurement results can take into account fabrication tolerances, bending of the cables etc., which help to obtain more accurate results. A multi-conductor powerline cable has multiple, coupled propagation modes with corresponding primary parameters. Based on multi-conductor transmission line theory, the authors propose a practical measurement approach to derive the parameters separately. A previous analysis was made for four-conductor powerline cable. Here, it will also be generalised for three-conductor cables. With the parameters, the transfer function of the same kind of cable can be obtained easily. The approach is validated by comparing the deduced transfer function of a power line cable with the directly measured one.