Permanent Magnet (PM) synchronous machines are becoming increasingly popular for a wide range of applications. This is mainly due to the significant advantages they provide in terms of power density and efficiency. One of the key challenges of using PM machines is fault-tolerance issue as the machine cannot be simply de-excited. This becomes even more important in safety-critical applications. The most severe and probable type of fault is the turn-to-turn fault. This paper provides a thorough analysis of turn-to-turn faults in surface PM machines with multilayer fractional-slot concentrated windings. Different winding arrangements, and different slot/pole combinations are analyzed.