In order to investigate the He-3-n-p system as a three-body problem, we have formulated He-3-n and H-3-p effective potentials using both a microscopic treatment and a phenomenological approach. In the microscopic treatment, potentials are generated by means of the resonating group method (RGM) based on the Minnesota nucleon-nucleon potential. These potentials are converted into separable form by means of the Microscopic Pauli Correct (MPC) method. The MPC potentials are properly formulated to avoid Pauli forbidden states. The phenomenological potentials are obtained by modifying parameters of the EST approximation to the Paris nucleon-nucleon potential, such that they fit the low-energy He-3-n, H-3-p, and He-3-p phase shifts, Therefore, they describe the He-3-n differential cross section,the polarization observables, and the energy levels of He-4. The He-3-n-p Faddeev equations are solved numerically. We reproduce correctly the ground state and the first excited state of Li-5. Furthermore, the Paris-type potential is used to investigate the He-3(d,p)He-4 reaction at a deuteron bombarding energy of 270 Mev, where the system is treated as a three-body problem. Results for the polarized and unpolarized differential cross sections demonstrate convergence of the Born series.