This paper presents a method aiming to detect different inter-turn short circuit fault severity by analyzing zero-sequence voltage for a new five-phase fault-tolerant fractional-slot concentrated winding interior permanent magnet motor (FTFSCW-IPM). To eliminate the effect of common mode voltage (CMV) in single DC power supply application, fault severity analysis is conducted based on an open-end winding (OW) space vector. This new method is verified by simulation results in a five-phase FTFSCW-IPM OW system.