Even if intrinsically a five-phase machine can work with one opened phase, thermal constraints (temperatures in windings and Permanent Magnets) impose to decrease the mean torque in faulty operation mode. In order to elaborate optimum control which ensures safety and maximum torque, it is necessary to estimate in real-time the temperatures induced by the currents imposed in the remaining healthy windings of the machine. For a five-phase prototype, a multi-nodal thermal modelling which can take into account irregular losses and flow distribution has been developed. It is based on Electromagnetic FEM results for the losses and CFD calculation analysis. Results are presented in normal and faulty operation modes.