The absence of the disruptive instabilities, increasing of the confinement time with the ECRH heating and the steady-state operation make stellarator concept as a competitive candidate for future fusion reactors as the tokamak. Impurity accumulation in the core though is one of the stellarator drawbacks because it dilutes the plasma and increases the radiation losses contributing to the plasma collapse. Neoclassical theory predicts a non-ambipolar transport of different species electrons and ions in stellarators due to magnetic field ripples that are produced by the three-dimensional coils structure. Non-ambipolar transport creates, depending on the collisionality of each species, inward (outward) an ambipolar radial electric field for ion (electron) root regimes. Ion root regime has been predicted for the future stellarator reactor scenarios, which imply very likely impurity accumulation. However, outward transport has been observed during an improved confinement regime so-called HDH mode at W7-AS (K. McCormick 2002) and the impurity hole at LHD (K. Ida 2009) but without without satisfactory theoritical explanation. Historically, neoclassical treatment considers only the radial component of the electric field, which is a good approximation for the bulk species, but not for the higher charge species like impurity. Recent approaches have considered the tangential component due to the variation of the electrostatic potential within a flux surface which is more important for high charge impurity (see