Due to their many advantages, Permanent Magnet Synchronous Motors (PMSMs) are increasingly used not only in industrial drive systems, but also in electric and hybrid vehicle drives, aviation and other applications. Unfortunately, PMSMs are not free from damage that occurs during their operation. It is assumed that about 40% of the damage that occurs is rolling bearing damage. This article focuses on the use of Kohonen neural network (KNN) for rolling bearing damage detection in a PMSM drive system. The symptoms from the Fast Fourier Transform (FFT) and Envelope Analysis (ENV) of the mechanical vibration acceleration signal were analysed. The signal envelope was obtained by applying the Hilbert transform (HT). Two neural network functions are discussed: a detector and a classifier. The detector detected the damage and the classifier determined the type of damage to the rolling bearing (undamaged bearing, damaged rolling element, outer or inner race). The effectiveness of the analysed networks from the point of view of the applied signal processing method, map size, type of neighborhood radius, distance function and the influence of input data normalization are presented. The results are presented in the form of a confusion matrix, 2D and 3D maps of active neurons.